78 resultados para ALLELIC RICHNESS
Resumo:
九寨沟湖泊湿地在维持九寨沟的生态平衡中起着重要的作用,在旅游产业的发展下,湿地生态系统及生物多样性面临着较大的威胁。尽管九寨沟湿地具有重要的生态价值,但目前对其研究尚比较薄弱。湿地植物群落和植物地理研究可以为湿地资源的可持续利用和监测保护提供科学依据。作者从2004年8月到2007年11月对九寨沟湿地的植物物种组成、地理分布、优势植物群落的结构、生长动态、湿地土壤种子库进行了调查研究。主要结果如下: 1. 九寨沟湿地物种组成、地理分布特点及湿地植物群落特点 九寨沟湿地共有苔藓植物8科13属16种,维管植物为48科107属199种。九寨沟湿地植物的地理成份较为丰富,维管植物在科级水平上有7种地理分布型(变型),在属级水平上有13种地理分布型(变型), 在种级水平上共有29种地理分布型(变型)。九寨沟湿地植物以温带成份和我国特有成份为主,同时兼有热带、亚热带成份和环极—高山成份。九寨沟湿地植物的分布表现出明显的垂直地带性和水平地带性。湿地植物群落可划分21个群落类型,不同植物群落类型的物种多样性及物种组成存在较大的差异。九寨沟湿地植物的物种多样性和群落多样性以及较高的生产力特征,是维持其湿地生态景观多样性和稳定性的基础。 2. 土壤、水环境、海拔等对湿地植物的分布及生物多样性的影响 九寨沟湿地土壤、水等环境因子存在较大的差异。帕米尔苔草和宽叶香蒲等群落的凋落物较多,土壤有机碳、土壤总磷较高,可能是九寨沟湿地的重要土壤碳库。 九寨沟湿地植物沿水环境梯度的分布规律表现为:沉水植物(轮藻—篦齿眼子菜,水苦荬,杉叶藻)——挺水植物(水木贼,芦苇,宽叶香蒲)——湿生草本(苔草、节节草、披散木贼)——湿生灌木(柳灌丛,小檗灌丛)等。海拔也影响湿地植物的物种组成。 水深对物种多样性有影响,水深与物种丰富度负相关。随着水深的增加,水木贼、芦苇、杉叶藻、宽叶香蒲等群落的物种多样性下降;在长期淹水和季节性淹水的地方,水木贼群落物种多样性存在显著差异。土壤总氮与水木贼群落物种丰富度正相关。 3. 土壤营养元素、水环境对植物生长的影响 水深影响湿地植物生物量的分配。芦苇无性系分株在47 cm水深的环境中单株平均生物量最大;在干滩地中(地面水深0 cm),叶生物量百分比最大,而茎生物量百分比最小,茎的生物量百分比和生长速率随水深的增加而增加;在较干的滩地生境中,开花率、花序的生物量百分比明显大于水较深的生境。 水深与水木贼地上生物量负相关,但水木贼地上生物量在长期淹水和季节性淹水的地方没有显著的差异。在水浅的地方,杉叶藻、水木贼、芦苇等植物群落中,其他伴生物种的生物量占样方总生物量的百分比较大。 土壤有机碳、土壤总氮、土壤总磷等对湿地植物生物量的影响比较大:宽叶香蒲地上生物量与土壤总磷正相关;水木贼地上生物量与土壤总氮正相关;杉叶藻地上生物量与土壤有机碳正相关。 水深、土壤营养成分对湿地植物高度、密度等有影响。水木贼的平均高度在季节性淹水的地方比长期淹水的地方低,平均密度在长期淹水的地方比季节性淹水的地方低;除了5月份,其他观察月份水木贼的密度都与水深负相关,同时与土壤有机碳正相关。另外,芦苇密度与土壤有机碳含量正相关,宽叶香蒲密度与水深负相关,帕米尔苔草高度与土壤有机碳负相关。 4. 优势植物群落的动态变化 在优势植物群落中,优势种的高度、密度、盖度、生物量等在群落中占绝对优势。除五花海,水木贼群落的物种组成、高度、生物量在两年间没有显著的变化。芦苇群落的物种丰富度在近两年有所增加。 湿地植物生长表现为明显的季节动态,生长的峰值大多在7月-8月。优势植物群落的物候与水文周期有关。湿地植物群落的物种组成和密度,可以作为对湿地监测和保护的生物指示。 5. 九寨沟湿地土壤种子库特征及其在湿地生物多样性恢复中的作用 水深和现存植被物种丰富度可以解释湿地土壤种子库的变化。水深可以解释表层物种丰富度45%的变化。现存植被物种丰富度可以分别解释10 cm土层、2-5 cm土层及5-10 cm土层土壤种子库45%、48%和25%的变化。 湿地土壤种子库的密度为0-15945粒m-2, 种子库中共发现23个物种。现存植被优势物种和种子库优势物种不同。各层土壤种子库密度和物种丰富度并不存在显著的差异,但第二层土壤种子库密度最大。海拔、现存植被优势种盖度、土壤总磷、土壤总氮、土壤有机碳对湿地土壤种子库的密度和垂直结构没有影响。土壤种子库物种丰富度小于地上植被物种丰富度。湿地土壤种子库与地上植被的相关性不大。在浅水区域,湿地土壤种子库在湿地植被恢复中有一定作用。但在深水区域,保护现存植被更重要。 The lakeshore wetlands are valuable ecological units of the Jiuzhaigou lakes. Pressure for travel industry development pose a continuing and severe threat to the biodiversity-support function of the wetland system. Despite the ecological importance of wetlands in Jiuzhaigou, they are so far poorly studied. Both general plant communties and biogeographical studies are needed in order to attain basis for sustainable use the wetland resources and adequate protection of these areas. The present study was undertaken to examine aquatic plants distribution and the species compositon, structure and growth dynamics of their communities with variations of environmental factors along altitudes, water depth and soil properities gradients in Jiuzhaigou. Analysis of field survey data collected during August 2004 and November 2007 in lakeshore wetlands in Jiuzhaigou National Nature Reserve, Sichuan, China. The results were as following: (i) Species composition and biogeography in wetland vegetation 8 families, 13 genus, 16 species of moss and 48 families, 107 genus and 199 species of vascular plants in Jiuzhaigou wetlands were found. The floristic compositions were abundunt. Ten geographical distribution types at family level, 13 geographical distributions types at generic level and 29 geographical distribution types at specific level in vascular plants were found. Most species in Jiuzhaigou wetlands are temperate elements and Chinese endemic elements, with a few of tropical and subtropical and some circumarctic elements. And the plant distributions show clear vertical and horizontal patterns. There were 21 major wetland plant community types. Species composition and species richness in different plant communities are different. The species diversity and plant community diversity and their high biomass are the basis for the diversity and stability of wetland landscapes in Jiuzhaigou. (ii) Water depth, soil nutrients and altitudes influence on the species diversity and plant distribution. Total phosphorous and organic cabon in soil were higher in C. pamiernensis and T. latifolia communities, where are important cabon reservoirs in Jiuzhaigou wetlands. Along gradients of water depth, among populations of the dominant plant species present: submerged macrophytes (Chara vulgaris, Potagemonton pectinatus, Veronica anagalis-aquatica,Hippuris vulgaris), emergent macrophytes (Equisetum fluviatile, Phragamites australis, Typha latifolia), helophytes (Carex pamirensis )and shrubs (Salix sp., Berberis sp. ). Altitudes influence on the assemblage of plant communities. Water depth negatively correlated with species richness. Specie richness showed differences between permanently flooded sites and seasonally flooded sites in E. fluvatile communities. And total nitrogen in soil was negatively correlated with species richness in E. fluviatile communities. Altitudes show no significant influence on species richness, but in fact, through our analyses, they do have influence on the assemblage of wetland plants. (iii) Water depth, soil nutrients influence on the plant growth Water depth influences the biomass allocation in Phragmities australis. The average aboveground biomass of a single ramet (4.2 g) was the largest in the habitat with water level 47 cm above the soil surface. At the habitat with water level under soil surface 15 cm (-15 cm), the leaf biomass percentage (of the total ramet biomass) was the largest (46.1%), and the height and percentage of ramose ramets ( with branches on stem )(of the total ramets in a plot) were found obviously different. The deeper in water, the larger the biomass percentage and growth rate of stems were. The flowering rate and biomass of panicles were greater in shallow water than those in deep water. Water depth negatively correlated with aboveground biomass of E. fluviatile. However, above-ground biomass of E. fluviatile showed no significant difference between permanently flooded sites and seasonally flooded sites. But in shallow water, more biomasses of accompanying species were found in dominant plant communities such as H. vulgaris communities, E. fluviatile communities and P. australis communities. Water depth, soil nutrients influence on shoot density and shoot length of wetland plants. The shoot density of E. fluviatile was correlated to water depth in all growth months. Annual average density was significantly lower at permanently flooded sites than at seasonally flooded sites. But the annual average shoot length was significantly lower at seasonally flooded sites than at permanently flooded sites. (iv) Growth dynamics of dominant communities in Jiuzhaigou wetland The shoot length and shoot density, coverage and biomass of domiant species were dominated in plant communities. The species composition increased in P. australis communities in recent two years. The species richness in E. fluviatile communities showed no difference between 2005 and 2007. The above-ground biomass and shoot density in Five-flower Lake from July 2005 to July 2007 were significantly different, while in other sites, the differences were not significant. Shoot height, shoot density and above-ground biomass showed significant seasonal changes in all sites. Growth dynamics correlated with the cycle of water levels in lakes. Most plants growth parameters peaked at July or August. The biomass of T. latifolia peaked in August. But the shoot length of T. latifolia in deeper water peaked in July. The shoot length of E. fluviatile increased significantly from May to August except in seasonally flooded sites in Arrow-bamboo Lake. The species composition of communities and shoot density can be used as bioindicators in Jiuzhaigou wetland. (v) Soil seed bank in Jiuzhaigou wetland and its role in vegetation restoration Seed density in all soil layer samples was negatively correlated to water depth. Water depth can explain 45% variance of species richness in surface layer in sediment. Species richness in extant vegetation can explain 45%, 48%, 25% variance of species richness in total 10 cm and in 2-5 cm and 5-10 cm layer sediment respectively. Mean seed densities in wetlands ranged from 0 to 15945 m–2. A total of 23 species germinated in seed bank. The dominant species in seed bank and extant vegetation showed great difference. The total number of species and seedlings that germinated in different layers was not significantly different. But the second layer had the greatest seed density. In shallow water, seed bank can contribute to vegetation restoration, while in deeper water, protection of extant vegetation may be a better strategy.
Resumo:
西南地区在我国的经济发展和生态环境建设中占重要地位,但也是我国生态环境最脆弱的地区之一,生态系统退化,生态功能减弱,严重制约着西南林业的可持续经营与发展。本项目采用DNA 分子标记SSR 研究不同生境条件下粗枝云杉群体的遗传变异及其时空分布格局,考察遗传变异与复杂的山地生态环境间的潜在联系,系统地揭示粗枝云杉天然群体与环境系统相互作用的生态适应与分子进化机制。粗枝云杉适应性强,生长迅速,在植树造林和工业用材方面占有重要地位,研究成果可为中国西南部亚高山天然林的可持续经营及退化生态系统的恢复与重建提供理论依据和科学指导。主要研究结果如下: 1. SSR 位点变异丰富,等位基因频率的分布格局多样。7 个SSR 标记全是多态位点,每位点的等位基因数变化范围为13~24,平均为19.9 个。SSR 位点的等位基因片段长度范围变化较大。73.1%的等位基因变异遵循逐步突变模型(SSM)而发生1 个重复基元的变化,22.3%和4.6%的变异分别按两阶段突变模型(TMP)发生1 个重复基元以上的变化和在SSR 位点侧翼区发生1 个碱基变化的插入-删除事件。 2. 粗枝云杉拥有中等偏高水平的遗传多样性和相对大的群体间遗传分化。通过分析代表10 个群体的250 个个体在7 个SSR位点的变化,调查了源自中国西南山区的粗枝云杉的微卫星变异。相当高的遗传多样性和强烈的群体分化发生在粗枝云杉中, 其群体平均Nei's 期望杂合度为0.707 , 群体间遗传距离为0.121~0.224(FST)和0.100~0.537(RST)。然而,群体间遗传距离与地理距离之间无相关性,从而排除了简单的距离分离模式并暗示迁移不是影响粗枝云杉遗传变异格局的主要因素。事实上,使用私有等位基因估算的基因流数量非常低,仅等于0.753。等位基因置换检验(Allele permutation tests)揭示逐步突变及遗传漂变都对群体间分化有贡献。另外,在多数位点检测到显著的群体间遗传差异,这个结果说明自然选择,假设通过环境压力,是引起粗枝云杉微地理分化的主要因素之一。根据SSR基因型,250 个粗枝云杉个体的70%被正确地归类入其各自的来源群体,结果表明微卫星(SSR)对区分来自中国不同生态地理位点的粗枝云杉基因型是有效的。 3. 在SSR、RAPD 和AFLP 位点,显著的群体间遗传结构被发现的,但三种标记间遗传分化程度和群体遗传关系有差异。利用来自10 个群体的247 个个体,我们报告了关于样本粗枝云杉群体间遗传关系的总体看法。根据各自对评价遗传关系的信息能力和适用性,SSR、RAPD 和AFLP 标记被选用,三种技术非常有效地区别这些基因型。使用的SSR、RAPD 和AFLP 标记分别估计平均Dice 相似性系数。Mantel 检验产生显著但相对低的共表型适合度(RAPD = 0.63£AFLP = 0.60和SSR = 0.75)。比较三种标记系统,RAPD 和AFLP 共表型指数相对高地相关(r =0.59),而RAPD 和SSR 及SSR 和AFLP 之间的相关系数分别是0.53 和0.35。所有系统树,包括不同标记资料结合获得的系统树,反映了多数群体依据它们的地理条件而成某种特定关系。结果暗示单个或结合标记系统能用来深入洞察粗枝云杉遗传研究,并且不同标记系统合并资料能提供更可靠的信息。 Southwestern region plays an important role in economic developmentand ecological construction in China. Yet, it is also one of the weak regionsof ecological environment in China with degraded ecosystem and imperfectfunction, which restricts the sustaining management and development ofsouthwestern forestry. The genetic variation and spatial distribution patternof P. asperata populations originating from different habitats wereinvestigated using SSR molecular markers in this study. The correlationsbetween genetic variation and ecological and environmental conditionswere detected, and the interaction between P. asperata populations andenvironmental system and the mechanism of ecological adaption -molecular evolution were revealed. Given the significant ecological andeconomic roles of the fast-growing and wide-adaptive species in reforestation and production of pulp wood and timber, the study couldprovide a strong theoretical evidence and scientific direction for thesustaining management of subalpine natural forest, and the afforestationand rehabilitation of degraded ecosystem. The results are as follows: 1. The genetic variation at SSR loci was abundant and the distributionof allelic frequencies was uneven. All seven loci were polymorphic, and thenumber of alleles per locus varied from 13 to 24 with a mean valueequaling 19.9. The allele sizes at SSR loci were found to vary widely.73.1% of allelic variation followed stepwise mutation model (SSM) whichresults increase or decrease by one repeat type, and 22.3% and 4.6% wereresulted from two-phase mutation model (TMP) with allele size varying bymore than one repeat type and from insertion-deletion events in theflanking regions at SSR loci with a single basepair changing, respectively. 2. P. asperata possessed a moderate to high level of genetic diversityand considerable genetic differentiation. Microsatellite variation of P.asperata. originating from the mountains of southwestern China wasinvestigated by analyzing variation at seven SSR loci in 250 individualsrepresenting ten populations. A fair degree of genetic diversity and strongpopulation subdivision occurred with the mean gene diversity (H) of 0.707,and genetic distances among populations varying between 0.121 and 0.224(FST) and between 0.100 and 0.537 (RST). However, inter-populationgenetic distances showed no correlation with geographic distances between the population sites. This ruled out a simple isolation by distance modeland suggested that migration does not have a great impact. In fact, theamount of gene flow, detected using private alleles, was very low, equalingonly 0.753. Allele permutation tests revealed that stepwise-like mutations,coupled with genetic drift, could contribute to population differentiation.Moreover, significant genetic differences between populations weredetected at most loci. The results indicate that natural selection, presumablythrough environmental stress, may be one of the main factors causingmicro-geographical differentiation in the genetic structure of P. asperata.Based on SSR genotypes, 70% of the 250 individuals were correctlyclassified into their sites of origin. This suggests that microsatellites (SSRs) are effective in distinguishing genotypes of P. asperata originating fromdiverse eco-geographical sites in China. 3. Using a set of 247 individuals from ten P. asperata populations wereport an overview on the genetic relationship among the sampled P.asperata populations. RAPD, AFLP and SSR were used in terms of theirinformativeness and applicability for evaluate relationship and all threetechniques discriminated the genotypes very effectively. Mean Dicesimilarities coefficient were estimated using RAPD, AFLP and SSR,respectively. The Mantel test resulted in a significant but relatively low fit(RAPD = 0.63, AFLP = 0.60 and SSR = 0.75) of cophenetic values.Comparing the three marker systems to each other, RAPD and AFLP cophenetic indices were highly correlated (r = 0.59), while correlationcoefficient between RAPD and SSR was r = 0.53 and between SSR andAFLP was r = 0.35. For all markers a relatively high similarity indendrogram topologies was obtained although some differences wereobserved. All the dendrograms, including that obtained by the combineduse of all the marker data, reflect some relationships for most of thepopulations according to their geographic conditions. The results indicatethat single or combined marker system could be used to insight into geneticstudy in P. asperata and the combined data of different marker systems canprovide more reliable information.
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对白水河自然保护区进行了生物多样性和植物区系调查,根据获得的生物多样性数据和标本的鉴定结果分析,得到结果和推论如下:1.白水河自然保护区生物多样性的垂直分布格局1.1 植物群落α 多样性随海拔梯度的变化乔木种的丰富度及多样性随海拔上升表现出明显的线性下降趋势。而灌木和草本物种丰富度及多样性随海拔上升表现出抛物线式的下降趋势。乔木种从海拔1400m 的15 种至林线时下降为2 种;灌木和草本植物分别从35 和38 种至山顶时下降为5 种和20 种。乔木物种随海拔升高出现明显的物种替代现象,表明海拔梯度包含了多种环境因子的梯度效应,影响着植物群落的分布与结构及物种多样性。1.2 植物群落β 多样性随海拔梯度的变化海拔2200 m 左右是一个明显的生境转折点。海拔2200 米以下相邻群落的相似性( CJ ) 明显大于海拔2200 m 以上的群落,说明海拔2200 m 以下的群落间共有种多,生境差异较小;而海拔2200 以上的群落则相反,相似性较低。低海拔区由于人为干扰较大,所以群落具有较高的物种丰富度,相邻群落之间的物种替换总量(Cody 指数) 较大。海拔2800 米到海拔3200 米之间因杜鹃群落的影响,物种替换总量(Cody 指数) 略有升高。研究β 多样性沿海拔梯度的变化必须考虑到物种丰富度和群落类型的影响,用不同指数从不同角度能更好地理解β 多样性沿环境梯度的变化。2.白水河自然保护区植物区系性质及起源白水河自然保护区自产种子植物计138 科421 属990 种。本文在科、属的水平上对该保护区植物区系特性进行了较深入的统计和分析。统计表明,温带和热带分布型均占有相当比重,但温带分布型稍占优势;热带、亚热带和温带的科、属多,中国特有属也有相当比例,它们是保护区具有特征意义的类群,其中许多属为古老和残遗成分。结论认为白水河保护区植物区系起源古老,较完好的保存了北极-第三纪古植物群。We have collected the specimens and gotten the biodiversity datas of BaiShuihe Nature Reserve in Peng Zhou,analysed the datas,the results as follows:1. Diversity of the plant community along altitudinal gradient1.1 α diversity of the plant communities along altitudinal gradientFrom 1400m to 3900m at Baishuihe Nature Reserve, 52 plots were investigatedwith an interval 100m in altitude; α diversity and β diversity of plant communitiesand their variety along altitudinal gradient were studied. The results showed that indifferent successional layers of trees, richness and diversity decreased linearly withthe increase of altitude. But shrub and herb layers don’t decrease linearly with theincrease of altitude. Tree species decreased from 15 species at 1400m so only 2species at timberline. Shrub and herb species decreased from 35 and 38 species at2000m to 5 and 20 species at 3800m respectively. Tree species are replacedobviously with the increase of altitude; It shows that altitude includes manyenvironmental facts, which infect the distribution, structure and diversity of plant population.1.2 The variety of βdiversity along altitudinal gradient.The entironment changed obviously near 2200m according to our research. Forsimilarity(CJ) between neighboring plots above 2200m is larger than wich below it.It shows that below 2200m,the neighboring plots has more same species,and thehabitats of neighboring plots has more similarity. Above 2200 is the other way round.The plant communites have higher species richness and species turnoverlargestly between neighboring plots because of the disturbance from humanity at lowaltitude. Between 2800m and 3200m species turnover not so obviously because ofmore Rhododendron live there.We should think over species and the types of plant communities effect thevariety of β diversity along altitude gradient. Use more biodiversity indexs and fromseveral aspects to understand the variety of β diversity along altitudinal gradient.2.Origin and characteristic features of Bai Shuihe Nature Reserve990 species of wild seed plants (belonging to 421 generas in 138 families) inthe floristic region of Bai Shuihe Nature Reserve were reported here. The statisticsand comparatively intensive analysis at generic and familiar levelss. Based on thestatistics,the results show that both temperate and tropical distribution types areacounted for considerable proportion of the total,but formal is a little moreimportant than the later. The North Temperate and E.Asia-N.America disjunctedpatterns are more concentrated in this area. These may be considered as thecharacteristic features of Bai Shuihe Nature Reserve flora, while many of them arearchaic and relic elements. According to above data,the floristic region of BaiShuihe Nature Reserve may be considered as a typical region in Chinese flora. Also,the flora of Bai Shuihe Nature Reserve are originated since ancient time as a wellconserved Arctic-Tertiar flora.
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横断山地区是一个十分自然的植物区系地区,在中国植物区系分区中是作为泛北极植物区中国-喜马拉雅亚区中的一个地区,其种子植物区系具有丰富的科、属、种,地理成分复杂,特有现象和替代现象明显。该地区作为植物区系和生物多样性的研究热点地区,长期以来极受中外植物学家关注。横断山脉东缘是中国-喜马拉雅和中国-日本植物区系的交汇过渡区域,北部的岷江流域以及南部的金沙江流域,孕育了该区丰富的物种资源和植被资源。而岷江干热河谷和金沙江干热河谷的相似性和相关性,更为该区的植物区系和生物多样性南北的对比研究提供了有利的条件。 本研究选择的九顶山西坡和龙肘山分别位于横断山区北部和南部,九顶山属岷江流域而龙肘山属金沙江流域。本研究结合植物区系研究和生物多样性研究,对该区的植物资源进行调查。通过样带调查和样线踏查结合,大量详实的野外样方调查和标本采集,进行传统的区系研究和生物多样性研究。研究该区物种多样性的海拔梯度格局及其潜在的影响影子,并利用新的区系评估质量方法对九顶山西坡的植物区系质量进行定量的研究,以期能更为深刻的理解该区的植物资源,为该区的资源保护和利用提供合理可行的建议。主要研究结论如下: 1)九顶山西坡植物区系的性质和特点 经鉴定和统计,九顶山西坡共有1707 种维管植物,分属617 属和140 科,其中种子植物1616 种,分属572 属117 科。就科的分布区成分构成而言,该区系的热带成分与温带成分相当,热带成分略占优势,表明九顶山西坡的植物区系与热带植物区系有较强的联系。但是,在九顶山西坡属的分布区类型所占的比例上,温带成分远远超过了热带成分,本区的种子植物分布表现出明显的温带性质。且温带分布类型的许多物种组成了九顶山西坡植被的建群种和优势种,是本区系最重要的成分,充分体现了本区系的温带性质。 2)九顶山西坡不同植被带的生物多样性海拔梯度格局 基于对土门-断头崖、茶山-九顶山、雁门沟-光光山三条垂直植被样带的调查,我们发现九顶山西坡的生物多样性沿海拔梯度的变化呈现出一定的规律性,不同样带之间有一定差异。就三条样带的物种组成相似性来看,虽然土门-断头崖样带属于涪江水系,而茶山-九顶山样带和雁门沟-光光山样带属于岷江水系,但不同水系对该区物种组成的影响并不明显。三条样带中,草本层物种丰富度均远远大于灌木层和乔木层,而以乔木层物种丰富度最低;α-多样性指数随着海拔梯度的变化在土门-断头崖样带中呈现单一下降趋势,在茶山-九顶山样带表现为双峰模型,而在雁门沟-光光山样带则表现为不显著波动变化;均匀度指数在土门-断头崖样带呈现出单一下降的趋势,在雁门沟-光光山样带表现为凹形曲线,而在茶山-九顶山样带却无明显的变化规律。β-多样性指数在土门-断头崖样带和茶山-九顶山样带呈现出明显的波动状态,植被类型替代现象明显;而在雁门沟-光光山样带却并未有十分显著的转折点,因其水平植被带受到干扰,同海拔替代现象不显著。 3)九顶山西坡维管植物丰富度的海拔梯度格局 我们考察了九顶山西坡和两条垂直样带(土门-断头崖和雁门沟-光光山样带)的不同分类等级(包括科、属、种)和不同生活型物种(乔木、灌木、禾草、蕨类和其它草本)的丰富度沿着海拔梯度的分布。结果发现,物种的丰富度海拔梯度格局具有不同的模式,单一下降和中间膨胀格局依然是其主流。不同生活型的物种具有不同的丰富度格局,但是对于环境需求相似的类型具有较相似的丰富度格局。不同的丰富度格局可能由多因素导致,包括:气候,海拔跨度,面积,人为干扰等等。 4)九顶山西坡区系质量评估 我们尝试使用传统的区系质量评估方法对九顶山西坡的区系质量进行评估,并尝试使用一种新的区系质量评估体系对该区的区系进行评价。在九顶山西坡随着海拔梯度的上升,平均保守性系数在各条植被带中均呈现出逐渐上升的趋势。区系质量指数随着海拔的升高都表现为双峰模型,在植被交错区区系质量指数相对较高,而在海拔的两极,区系质量指数都很低。大部分地区使用新方法计算所得的加权平均保守性系数和区系质量指数都比传统方法计算的平均保收性系数和区系质量指数要高,说明在九顶山西坡的三条样带中,大部分地区都是那些保守性系数较高的物种占据优势,同时也表明九顶山西坡具有很高质量的区系和自然植被。 5)龙肘山种子植物区系的性质和特点 龙肘山种子植物区系的物种较为丰富,共有154 科,544 属,1156 种。科的优势十分明显,单种属和寡种属数量众多,说明本区系植物成分较为复杂、起源古老、物种多样性指数较高。地理成分复杂,分布类型多样,其中热带成分在总数量上高于温带成分,但是许多温带成分的属是该区植被的重要建群类群和优势类群,表现出明显的亚热带性质。 6)龙肘山生物多样性的现状和特点 在海拔梯度上,龙肘山地区无论是科、属、种的数量,还是不同等级分类单元之间的数量比,均呈现先升后降的趋势,并在中海拔地区达到峰值。物种多样性指数从总体上来说变化幅度不大,略有先升后降的趋势,在中海拔梯度物种多样性最高。乔、灌、草三层的多样性指数表现出乔木层<灌木层<草本层的特征;乔木层均匀度的变化很大,而灌木层和草本层均匀度的变化较小;灌木层均匀度的波动又强于草本层。β-多样性指数呈现单峰模式,中海拔地区最高。就龙肘山东、西坡物种多样性相比较而言,两者虽然在数值上交替上升,但是却体现出了较为一致的趋势,但西坡因受到干热河谷气候的影响,其平均气温要高于东坡,导致了东坡植物群落和物种的分布比西坡要低。在区系成分构成上,低山区的相同海拔段,西坡的热带亚热带成分所占的比例要比东坡高,这是因为西坡的平均气温比东坡稍高,导致了热带、亚热带物种分布更多。而随着海拔的上升,东、西两坡的气候、土壤等条件趋于一致,其植物区系成分的构成格局也趋于一致。 The Hengduan Mountain region is a very natural floristic region; it belongs toChina-Himalaya sub-region of Holarctic region in floristic subarea of China. The flora in this areais rich in family, genus and species; has a very complex composition of geographical elements;especially with high richness of endemic species and obvious substitution phenomenon. Thisregion as a hot-spot area of floristic and biodiversity, has fascinated biologists in the world for along time. The eastern range of Hengduan Mountain is the transition zone of China – Himalayaforest sub-region and China-Japan forest sub-region in floristic. The water systems are quitedifferent, Minjiang River in the north and Jishajiang River in the south grow quit different but alsoabundant plant species and vegetation resources. The similarity and correlativity of Minjiang River dry valleys and Jinshajiang River dry valleys have provided advantageous condition tocontrast flora and biodiversity between north and south. In the present study, the Jiuding Mountainlies in the north of Hengduan Mountain and belongs to Minjiang River, and the LongzhouMountain lies in the south of Hengduan Mountain and belongs to Jinshajiang River. In our study, we combined the methods of floristic research and biodiversity investigation toexplore the resources of plant species and vegetations; sampled with transects along the altitudinalgradients and also with transverse straps with similar elevation; collected the vascular plant specimen with sampling plots of ecology. We explored the plant species richness patterns alongaltitudinal gradients and discussed the underlying factors aroused these patterns; and used a novelmethod to assess the quality of Jiuding Mountain’s flora. All for a deeper comprehension of the plant recourses of this region; and provided feasible and reasonable suggestion for the protectionof resources. The results were as follows: 1 The characteristic of the flora of the west slope of Jiuding Mountain We had collected 1707 species of vascular plants belonging to 617 genera in 140 families inthe west slope of Jiuding Mountain,in which included 1616 seed plant species belonging to 572genera and 117 families. As for the composition of the areal types of the Families of seed plants,tropic components and temperate components are well-balanced, and percentage of tropicscomponents is higher than that of temperate ones for a litter bit. This shows the flora in the westslope of Jiuding Mountain has strong relationship with the tropic flora. But for the composition ofthe areal types of genera, temperate components have far exceeded the tropics ones, indicated thewhole flora with a conspicuous temperate character. Temperate components possess maximumproportion in the west slope of Jiuding Mountain, and many of them belong to constructivespecies and dominant species in the vegetation, are most important components in JiudingMountain’s Flora, also have embodied the temperate character of this area sufficiently. 2 Biodiversity patterns along altitudinal gradients in different vegetation transects in the westslope of Jiuding Mountain Based on the investigation of three vegetation transects (including Tumen-Duantouya transect,Chashan-Jiudingshan transect and Yanmengou-Guangguangshan Transect) in the west slope ofJiuding Mountain, we found the change of biodiversity along the altitude gradients displayedcertain regularity, but have differences among different transects. The three transects belong todifferent water systems; the Tumen-Duantouya transect belongs to Fujiang River, and the othertwo belong to Minjiang River. From the similarity of species compositions of different transects,we found different water system didn’t show obvious impact on the species composition. In all thethree transects, the species richness of herb layer was remarkably higher than shrub and tree layer,and the species richness of tree layer was the lowest one. With the increasing of the altitude, theline of α-diversity was monotonically decreasing curve in Tumen-Duantouya transect, andbimodal curve in Chashan-Jiudingshan transect, but in Yanmengou-Guangguangshan transectshowed a wave-like curve although not very obvious. Species evenness showed monotonicallydecreasing trends in Tumen-Duantouya transect, and very low at mid-altitude in Yanmengou-Guangguangshan transect, but in Chashan-Jiudingshan transect changed irregularly. Changes inβ-diversity corresponded with the transition of vegetation in the Tumen-Duantouya transect andChashan-Jiudingshan transect, and the curve of β-diversity along altitude had obvious turningpoint; but in Yanmengou-Guangguangshan transect had no obvious turning point, and thesubstitution phenomenon was not obvious, transverse vegetation straps distributed interlaced. 3 Richness patterns of vascular plant species along altitude in the west slope of Jiuding Mountain Direct gradient analysis and regression methods were used to describe the species richnesspatterns along the altitudinal for Mt. Jiuding, as well as separately for Tumen-Duantouya Transectand Yanmengou-Guangguangshan Transect. Altitudinal gradient of diversity of units at differenttaxonomic level (including Family, Genus and Species) and at different life form (including tree,shrub, pteridophyte, grass and other herb) were tested to find differences among the richnesspattern. We found altitudinal richness also shows different patterns, and both monotonicallydecreasing pattern and hump-shaped pattern can be founded in vascular species richness. Speciesin different life forms show different altitudinal patterns, but those species with similarrequirements to environmental conditions show similar richness patterns along altitudinalgradients. Different richness patterns can be aroused by different climate, different altitudinal span,area factor, anthropogenic factor and so on. 4 Floristic quality assessments in the west slope of Jiuding Mountain We used both the conventional method broadly adopted in the USA and the new one toassess the floristic quality in the west slope of Jiuding Mountain. The Mean Coefficient ofConservatism (MC) had the trend of increment along the altitudinal gradients. The FloristicQuality Index (FQI) was a bimodal curve with increasing of elevation; FQI got maximum valuesin the transition zones of different vegetations in the middle altitude, and had very low values atthe two end of elevation. In most areas of the west slope of the Jiuding Mountain, the resultscalculated using the new methods were higher than those using the conventional method. Thisindicated the dominant species of the communities had very high coefficients of conservatism inmost areas of Jiuding Mountain, and the communities are relatively kept pristine and the habitats very integrative. 5 The characteristic of the flora of Longzhou Mountain The flora of Longzhou Mountain has very abundant in species composition; there are about1156 species of seed plants belonging to 544 genera in 154 families. In which, twelve families with more than 20 species include totally 232 genera and 532 species, and form the majority of itsflora. The origin of its flora is old, monospecific genera and oligotypic genera amounts to 510 innumber, which constitute 93.75% of total number of genera. The geographical components arevarious in Longzhou Mountain, the majority of flora are temperate and pantropic ones. The tropiccomponents overtopped temperate components on genera quantity, but many temperatecomponents belong to constructive species and dominant species in the vegetation, and the wholeflora shows an obvious subtropical character. 6 Current situation and characteristic of biodiversity in Longzhou Mountain With the increasing of altitude, the number of species, genus, family and the ratios ofdifferent taxonomic levels all displayed a trend of descending after rising first, and peaked atmiddle height area. The change of α-diversity was not very acutely, with the trend of descendingafter rising first in some degree, the middle height area had highest α-diversity. As studying thetree layer, shrub layer and herb layer respectively, the Shannon-Wiener index was in followingorder: tree layer < shrub layer < herb layer; the change of evenness was more complicatedly thanthat of diversity, the tree layer changed acutely, but the shrub layer and herb layer fluctuatedsmoothly. Changes in β-diversity also showed the trend of descending after rising first. TheJaccard index and Cody index all peaked at the middle height forest area. As for the comparison ofplant diversity and evenness between the west and east slope, the numerical values ascendedalternatively, but the trend of changing was similar. The distribution of similar plant communitiesand species in east slope were lower than the west slope for the influence of Jinsha River DryValley. As for the composition of different floristic components, in lower altitude area of westslope, the tropic and sub-tropic plants had higher ratio than east slope’s and even could be equal tothe temperate plants. With the increasing of elevation, the floristic composition become morelikely between the east and west slope and temperate plants dominated the flora.
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日益增强的旅游活动干扰已成为九寨沟世界自然遗产的有效保护与持续管理不可回避的问题,也已成为当前区域生态保护与经济发展的焦点问题之一。评估乡土植物种的基本特征、质量、种子休眠程度以及萌发能力;筛选适宜的植被恢复乡土物种并选择有效植被恢复技术措施是开展植被恢复试验的重要前提和保障。本文以九寨沟世界自然遗产为例,通过对景区乡土植物种子基本特征的测定以及采用乡土物种作为植被恢复技术试验与恢复技术筛选的试验物种,在景区旅游干扰区的三种生境类型:原始针叶林、混交林和边坡,根据不同的影响因素设计试验,从而探索适宜的恢复措施和植被恢复物种。初步结论如下: 1. 本文研究的28种乡土植物中,17种测定的物种活力较高(>72%),均具有作为恢复物种的潜力。但28种种子中75%的发芽率为0%。大部分种子存在一定程度的休眠,包括甘肃山楂、称花藤、疏花槭、陇东海棠、球花荚迷、巴东小檗、蔷薇、宝兴栒子、光泽栒子、光枝柳叶忍冬、甘青铁线莲、毛果铁线莲、宽叶旌节花、糙叶五加和独活。因而种子存在深度休眠是乡土物种自然更新和植被恢复的主要障碍,需要根据种子的形态生理特征,寻求打破乡土植物种子休眠的有效方法,提高种子发芽率。 2.低温层积只显著提高了蔷薇、毛果铁线莲、宽叶旌节花和假升麻3种种子的发芽率,也相对较早地提高了陇东海棠、鲜黄小檗和独活的萌发。对于其它物种的种子,低温层积没能有效打破休眠提高发芽率。综合分析结果表明九寨沟28种林下或林缘乡土植物中窄叶鲜卑花、毛果铁线莲、宽叶旌节花、假升麻、陇东海棠、鲜黄小檗和独活等12种可直播或通过低温层积处理后直播用于旅游干扰退化地段的植被恢复中,而其它的种类尚需进一步寻求打破休眠的措施以提高种子发芽能力。 3.在原始林生境下,七筋菇、巴东小檗、耳叶风毛菊、长叶毛花忍冬及独活5种乡土植物种子的出苗能力不高,因此目前急需提出有关提高种子出苗的方法措施。在相同的处理条件下,不同物种出苗数存在着较大的差异,相比而言,巴东小檗、耳叶风毛菊和长叶毛花忍冬种子出苗与幼苗存活较高,对于其环境适应能力较强,因此它们更适宜采用播种的方式应用于九寨沟原始林践踏地段地表的植被恢复实践;而七筋菇和独活在室内和自然气候条件下萌发都很困难,在植被恢复过程中,可考虑采用其它播种方式。而在边坡和混交林生境试验结果表明,供试物种无萌发和出苗现象,这可能跟外界环境条件、干扰和种子命运有关。 4. 本研究中腐殖质、松土和苔藓覆盖处理措施均未能提高物种出苗,且对样方内植被结构以及物种丰富度也无显著影响,其中的影响因素也是多方面的,因此还需进一步研究探索。但腐殖质对幼苗存活能力方面有一定的积极作用。 The increasing tourism disturbance is an unavoidable issue to effective conservation and sustaind tourist management of Jiuzhaigou Nature Reserve. It has become one of the focal problems of regional ecological protect and economic development. Assessing the traits, quality, seed dormancy and germination of native seed and choosing the suitable species and ways for vegetation restoration were the important precondition and guarantee before vegetation restoration. In this paper, as an example to Jiuzhaigou world nature heritage, through the estimation to the basic characteristics of native seeds and the use of native species for the test of vegetation restoration and the choosing of vegetation restoration techniques, in three different habitats being disturbed, including the primitive forest, mixed forest and side slope. According to different factors, designing experiments in order to explore the appropriate measures and species of vegetation restoration . Our results are as follows: 1. There are 77% seeds of the 28 species with high viability(>72%), which had the potential possibility of being restoration species. The germination of 75% of the seed was 0%.Most of the seed was dormant, So dormancy of seed was the barrier for natural regeneration and vegetation restoration, Further research is needed on investigating the other more effective methods to release seed dormancy of these native species in the future. 2. Cold stratification did not release seed dormancy of most species. In our study, there are only 3 species including Clematis peterae var. trichocarpa, Stachyurus chinensis and Aruncus sylvester (P<0.05) with germination percentage increased by cold stratification. By comprehensive analysis, the result shows: In 28 undergrowth native seeds, Sibiraea angustata, Clematis peterae var. trichocarpa, Stachyurus chinensis, Aruncus Sylvester, Malus kansuensis, Berberis diaphana,and Heracleum hemsleyanum could be used to vegetation restoration by sowing directly or sowing after cold stratification in degenerate gland being disturbed by turism, and othes seed of 28 were needed to search other methods to release seed dormancy for advancing the ability of germination. 3.In the habitat of primitive forest, the ability of emergence of the native species Clintonia udensis, Berberis henryana, Saussurea neofranchetii, Lonicera trichosantha var.xerocalyx and Heracleum hemsleyanum was low, so it is urgently needed to search about the methods of advancing emergence. In the sametreatment, the number of emergence of different species was very different. Relatively speaking, the emergence and seedling survival of the species Berberis henryana, Saussurea neofranchetii and Lonicera trichosantha var.xerocalyx was higher, and the adaptability of the species was better, so they were more suitable for vegetation restoration on trampling-induced degraded patches of primitive forest in Jiuzhaigou; But the germination of Clintonia udensis and Heracleum hemsleyanum was both difficult in laboratory and natural conditions, so it could be considered to apply other sowing methods. However, the result showed that: applied species didn’t germinate or emergent in the habitat of side slope and mixed forest, which could be related to external environment conditions, interference and the fate of the seed. 4.In this study, humus, scatification and bryophyte cover measures didn’t advance the emergence of the species or the structure of vegetation and richness in plot significantly, the impact factors of which were many, therefore further research is needed . However, humus had a certain positive effect on the ability of seedling survival.
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黄龙世界自然遗产地岷江冷杉林(Abies faxoniana)生境类型多样,群落结构复杂,群落植物种类组成多样性丰富。揭示不同生境的生物多样性及其差异是认识生物多样性格局、形成及维持机制的前提和进行多样性保育的基础。本文采用样方法对黄龙钙化滩生境、阴坡非钙化生境及半阳坡非钙化生境的岷江冷杉原始林植物群落结构及植物多样性进行了研究。结果表明: 黄龙岷江冷杉林具有明显的复层异龄结构,垂直结构明显,乔木、灌木、草本、苔藓层次分明。共发现高等植物386 种,其中维管植物46 科103 属163 种,苔藓植38 科83 属物223 种。各层片结构及物种组成如下: (1)钙化滩生境、阴坡非钙化生境、半阳坡非钙化生境分别发现乔木18 种、13种、8 种。乔木层均可分为两个亚层,第一亚层优势种均为岷江冷杉,第二亚层主要为岷江冷杉异龄树或其它大高位芽物种。钙化滩生境第一亚层除优势种岷江冷杉外混生有巴山冷杉(Abies fargesii)、粗枝云杉(Picea asperata)以及阔叶树种白桦(Betula platyphylla)等,第二亚层主要为岷江冷杉异龄树;阴坡非钙化生境第一亚层除优势种岷江冷杉外间有巴山冷杉和白桦,第二亚层物种主要为川滇长尾槭(Acer caudatum var. prattii);半阳坡非钙化生境第一亚层除优势种岷江冷杉外混生有巴山冷杉,第二亚层主要为岷江冷杉异龄树。依乔木层优势种的差异,钙化滩生境及半阳坡非钙化生境为岷江冷杉纯林,阴坡非钙化生境为岷江冷杉-川滇长尾槭混交林。不同生境乔木层郁闭度、乔木密度、树高结构、直径结构均存在差异。 (2)钙化滩生境发现灌木41 种,平均盖度为18.49±1.72(%),平均高度为52.12±4.45(cm),优势种为直穗小檗(Berberis dasystachya);阴坡非钙化生境发现灌木30 种,平均盖度为29.33±2.56 (%),平均高度为119.55±8.01 (cm),优势种为箭竹 (Fargesia spathacea) 、唐古特忍冬(Lonicera tangutica) 和袋花忍冬(Lonicera saccata);半阳坡非钙化生境发现灌木29 种,平均盖度为31.35±1.93 (%),平均高度为107.55±4.24 (cm),优势种为箭竹(Fargesia spathacea)。不同生境灌木层结构和物种组成多样性差异显著,钙化滩生境的灌木盖度、高度总体上较非钙化的坡地生境低, 钙化滩生境灌木以小型叶的落叶灌木为主,沟两侧非钙化的坡地生境上则发育了丰富箭竹。 (3)钙化滩生境发现草本46 种,平均盖度为7.18±0.79 (%),平均高度为5.04±0.26(cm),以山酢浆草(Oxalis griffithii)为优势种;阴坡非钙化生境发现草本物种71 种,平均盖度达29.04±2.31(%),平均高度为9.08±0.52(cm),以钝叶楼梯草(Elatostema obtusum)、山酢浆草为优势种;半阳坡非钙化生境草本物种50 种,平均盖度为以8.79±0.82(%),平均高度为7.67±0.43 (cm),以扇叶铁线蕨(Adiantum flabellulatum)、双花堇菜(Viola biflora)、华中蛾眉蕨(Lunathyrium shennongense)、山酢浆草为优势种。阴坡非钙化生境草本层片发育良好,多样性最为丰富,盖度和物种丰富度均显著高于钙化滩生境和半阳坡非钙化生境。 (4)钙化滩生境发现苔藓物种140 种,平均盖度达84.25±1.30 (%),以仰叶星塔藓(Hylocomiastrum umbratum) 等大型藓类为优势种;阴坡非钙化生境发现苔藓物种115 种,平均盖度为79.29±1.64 (%),以刺叶提灯藓(Mnium spinosum)、大羽藓(Thuidium cymbifolium)、毛尖燕尾藓(Bryhnia trichomitra)等个体较小的物种为优势种;半阳坡非钙化生境发现苔藓物种91 种,平均盖度为60.64±1.93 (%),也以刺叶提灯藓为优势种。 (5)钙化滩生境、阴坡非钙化生境、半阳坡非钙化生境的物种数分别为234 种、221 种、175 种。乔木层的Shannon-Wiener 指数分别为0.75 ±0.12、1.87±0.12、1.78±0.07(灌木层,0.44±0.08、1.71± 0.15、2.49±0.06;草本层,0.33±0.13、1.31±0.15 、2.15±0.08; 苔藓层1.30±0.11、2.08±0.04、1.73±0.11,);Pielou 均匀度指数分别为0.45±0.05、0.29±0.06、0.28±0.08(灌木层,0.75±0.03、0.68±0.05、0.52±0.06;草本层,0.68±0.02、0.77±0.02、0.74±0.02;苔藓层,0.40±0.03、0.63±0.02、0.52±0.03);Simpson's 优势度指数分别为0.63±0.06、0.78±0.04、0.83±0.07(灌木层,0.21±0.03、0.28±0.05、0.45±0.06;草本层,0.25±0.02、0.12±0.01、0.17±0.01;苔藓层,0.45±0.04、0.18±0.01、0.31±0.04)。三种生境间乔木层、草本层的Sorenson 群落相似性系数较低, 灌木层、苔藓层的的Sorenson 群落相似性系数较高。 综上所述,黄龙岷江冷杉林的群落结构、植物多样性在三种生境间存在差异性,这将意味着我们在进行黄龙世界自然遗产地的森林经营管理时要较多地关注岷江冷山林群落在不同生境中的差异性。 There were multiplex habitat types, complicated community structure and abundant species composition in the Huanglong World Natural Heritage Site. Uncovering the differences of biodiversity among different habitats was a precondition to understand the distribution, formation and sustaining mechanism of the biodiversity, and the foundation of biodiversity conservation. In the present study, using plenty of quadrants, we investigated the community structure and the biodiversity of the primitive Abies faxoniana forest in different habitats (travertine bottomland, semi-sunny-slope non-calcified habitat and shady-slope non-calcified habitat) in the Huanglong World Natural Heritage Site. The main results are as follows: All the primitive Abies faxoniana forests in the three habitats were uneven-aged with obvious vertical structure including tree layer, shrub layer, herb layer and bryophyte layer. A total of 386 higher plants including 163 vascular plant species (103 generic, 46 families) and 223 bryophyte species (83 generic, 38 families) were investigated. The structure and species composition of each layer are as follows: (1) There were 18, 13 and 8 tree species in travertine bottomland, shady-slope non-calcified habitat and semi-sunny-slope non-calcified habitat, respectively. The tree layers in all habitats can be divided into two clear sub-layers. The upper tree layers were dominated by Abies faxoniana, and the lower tree layers were dominated by uneven-aged Abies faxoniana or other phanerophytes species. There were Abies fargesii , Picea asperata and Betula platyphylla besides the dominated species (Abies faxoniana) in the upper tree layer in travertine bottomland, and the lower tree layers were dominated by uneven-aged Abies faxoniana; There were Abies fargesii and Betula platyphylla besides the dominated species (Abies faxoniana) in the upper tree layer in shady-slope non-calcified habitat, and the lower tree layers were dominated by Acer caudatum var. prattii; There was Abies fargesii besides the dominated species (Abies faxoniana) in the upper tree layer semi-sunny-slope non-calcified habitat, and the lower tree layers were dominated by uneven-aged Abies faxoniana. According to composition percentage of dominate species in tree layer, both the forest in travertine bottomland and in semi-sunny-slope non-calcified habitat could be ranked as pure forest, and the forest in shady-slope non-calcified habitat could be ranked as mingled forest. There were significant differences in crown density, plant density, height structure and diameter structure among the three habitats. (2) A total of 41 shrub species (average coverage 18.49±1.72%; average height 52.12±4.45 ㎝)were found in travertine bottomland, and the dominate species was Berberis dasystachya; A total of 30 shrub species (average coverage 29.33±2.56 %;average height 119.55±8.01 ㎝)were found in shady-slope non-calcified habitat, and the dominate species was Fargesia spathacea, Lonicera tangutica and Lonicera saccata. A total of 29 shrub species (average coverage 31.35±1.93%; average height 107.55±4.24 ㎝) were found in semi-sunny-slope non-calcified habitat, and the dominate species was Fargesia spathacea. There were significant differences in structure and species diversity of the shrub layers among the three habitats. The coverage and height of shrub had lower value in travertine bottomland than in two non-calcified habitats. Moreover, travertine bottomland was dominated by deciduous shrub species with microphyll and non-calcified habitats developed abundant Fargesia spathacea species. (3) A total of 46 herb species (average coverage 7.18±0.79%;average height 5.04±0.26 ㎝)were found in travertine bottomland, and the dominate species was Oxalis griffithii; A total of 71 herb species (average coverage 29.04±2.31%;average height 9.08±0.52 ㎝)were found in shady-slope non-calcified habitat, and the dominate species was Elatostema obtusum and Oxalis griffithii. A total of 50 herb species (average coverage 8.79±0.82%;average height 7.67±0.43 ㎝) were found in semi-sunny-slope non-calcified habitat, and the dominate species was Adiantum flabellulatum, Viola biflora, Lunathyrium shennongense and Oxalis griffithii. Herb layers developed well in shady-slope non-calcified habitat and had the higher species richness and coverage than travertine bottomland and semi-sunny-slope non-calcified habitat. (4) A total of 140 bryophyte species (average coverage 84.25±1.30%)were found in travertine bottomland, and the dominate species was big bryophyte species such as Hylocomiastrum umbratum and so on; A total of 115 bryophyte species (average coverage 79.29±1.64%)were found in shady-slope non-calcified habitat, and the dominate species was small bryophyte species such as Mnium spinosum, Thuidium cymbifolium, Bryhnia trichomitra and so on. A total of 91 bryophyte species (average coverage 60.64±1.93%) were found in semi-sunny-slope non-calcified habitat, and the dominate species was Mnium spinosum. (5) There were 234, 221 and 175 plant species in travertine bottomland, shady-slope non-calcified habitat and semi-sunny-slope non-calcified habitat, respectively. Shannon-Wiener index of the tree layer was 0.75 ±0.12, 1.87±0.12 and 1.78±0.07 (the shrub layer, 0.44±0.08, 1.71± 0.15 and 2.49±0.06; the herb layer, 0.33±0.13, 1.31±0.15 and 2.15±0.08; the bryophyte layer, 1.30±0.11, 2.08±0.04 and 1.73±0.11.) for the three habitats, respectively; Pielou index of the tree layer was 0.45±0.05, 0.29±0.06 and 0.28±0.08 (the shrub layer, 0.75±0.03, 0.68±0.05 and 0.52±0.06; the herb layer, 0.68±0.02, 0.77±0.02 and 0.74±0.02; the bryophyte layer, 0.40±0.03, 0.63±0.02 and 0.52±0.03.) for the three habitats, respectively. Simpson's index of the tree layer was 0.63±0.06, 0.78±0.04 and 0.83±0.07 (the shrub layer, 0.21±0.03、0.28±0.05、0.45±0.06; the herb layer, 0.25±0.02, 0.12±0.01 and 0.17±0.01; the bryophyte layer, 0.45±0.04, 0.18±0.01 and 0.31±0.04.) for the three habitats, respectively. There were low Sorenson index both in the tree layer and in the herb layer among the three habitats, whereas, high Sorenson index occurred both in the shrub layer and in the bryophyte layer. To sum up, there were differences both in community structure and plant diversity among the three different habitats, which means that we should pay more attention to habitats heterogeneities of the primitive Abies faxoniana forest when we take action to manage the forest in the Huanglong World Natural Heritage Site.
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大熊猫(Ailuropoda melanoleuca)是我国特有的濒危野生动物之一,迁地保护已经成为大熊猫物种保护的一个重要方面。当前大熊猫圈养种群数量增长很快,但是其“多雄配一雌”的交配(配种方式),以及生产过程中记录遗失等原因,造成圈养种群普遍存在亲子关系不清、谱系混乱等问题。为了加强遗传管理,有必要进行亲子关系鉴定、完善谱系;还需要检测种群的基因多样性水平,并在此基础上提出相应的遗传管理建议。 本研究应用9个具有高度多态性的大熊猫微卫星标记,对来自成都大熊猫繁育研究基地2006和2007年度出生的17只大熊猫幼崽及其全部候选父母共37个样品做了基因型分析;然后应用最大似然法,判断幼崽的父-子关系。同时,还对来自卧龙大熊猫保护研究中心的31只大熊猫个体也做了基因分型。将两个种群的数据进行比较:1)等位基因多样性和杂合度水平;2)通过F统计法,分析两个种群的遗传分化水平;3)通过遗传距离法,对所有个体进行聚类分析。 研究结果表明: 1)在母子关系不清的情况下,9个微卫星标记联合的父亲鉴定排除概率E为0.940090;而在母子关系确实的条件下,E= 0.993933。由于本研究中所有后代的母亲都是清楚的,因此这9个微卫星位点能够有效用于圈养大熊猫的亲子鉴定。似然法分析也表明,本研究所获得的亲子鉴定结果置信度在95%以上。 2)2005年种源交换后,成都大熊猫的等位基因多样性和杂合度水平都略高于卧龙种群(但没有达到显著水平),两个种群间的遗传分化水平也有所降低。但是,与卧龙相比,成都种群面临较大的近交压力。 基于以上研究结果,我们建议:进一步加强种源交换和基因交流,把两个种群当作一个遗传单元(MU)来进行管理。 Giant panda (Ailuropoda melanoleuca) is one of the endangerd wildlife endemic to China, and the ex-situ breeding become more and more important for the conservation of this speices. Although the captive population is expanding rapidly, the uncertainty occurs because the paternities of cubs are not clear due to the breeding pattern of “multiple male to single female,”as well as the records lost, resulting in errors in the studbook. For this reason, the paternity of the cubs and the genetic diversity of the captive giant pandas should be tested carefully to get information for the genetic management in the future. 9 polymorphism microsatellite markers were used to do paternity assignment for the 17 cubs born in 2006 and 2007 from Chengdu Research Base for Giant Panda Breeding (CGB) based on the maximum-likelihood methods. A total of 37 individuals were sampled, including all the candidate dams and sires. These samples were also used for comparing with 31 individuals sampling from Wolong China Research and Conservation Center for the Giant Panda (WCG). The comparing indexes were: 1) Allelic diversity and heterozygosity; 2) Genetic differentiation based on F-statistic; 3) Cluster analysis based on genetic distance. The results show that: 1) If the mother is unkown, the combined exclusion probability using these 9 loci is 0.940090. If the mother is known then the exclusion probability is 0.993933. Since the dam-offspring relationship is known in captive populations, the results could resolve unknown paternities in the study. And the confidence level of the results is 95% based on the likelihood methods. 2) The allelic diversity and the heterozygosity of CGB were higher than WCG (n ot significant), and the genetic differentiation was reduced a little since the genetic exchange between two populations in 2005. However, the population of CGB will be threatening by inbreeding seriously than that of WCG. From above, we suggest to reiforce the genetic exchange and geneflow between CGB and WCG, and these two populations should be regarded as one genetic management unit (MU).
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本研究对自育小麦白粉病抗源“07鉴126”和条锈病抗源CD1437、CD0534-5进行抗性遗传分析和微卫星引物的筛选,建立了与PmCD1和YrCD抗病基因连锁的SSR分子标记,主要研究结果如下: 1.小麦白粉抗源“07鉴126”抗白粉病基因的鉴定和分子标记的建立 品系“07鉴126”对我国目前白粉菌强优势生理小种E09、E11和其它多种小种表现免疫或高度抵抗。Pm-sus是07鉴126的自然突变感病株。利用“07鉴126”和Pm-sus的F2抗病性分离群体进行抗条锈病性遗传分析和分子标记定位,结果表明,“07鉴126”的白粉抗性为显性单基因控制的全生育期抗性,暂命名为PmCD1;并筛选到了与PmCD1共分离的显性SSR分子标记Xbarc183。系谱分析和分子标记分析表明PmCD1来源于荆州黑麦。抗谱分析表明PmCD1不同于已知的黑麦抗白粉基因,是一个新的抗白粉病基因。Xbarc183这一分子标记的建立为PmCD1的分子标记辅助选择和抗病基因累加提供了方便。 2.小麦条锈抗源CD1437抗条锈病基因的鉴定和分子标记的建立 利用对优势条锈菌小种条中32免疫的小麦品系CD1437及其自然突变感病株Yr-sus杂交构建F2、F3抗病性分离群体。抗条锈病性遗传分析结果显示,1437的抗条锈性为显性单基因控制的全生育期抗性,该基因暂命名为YrCD。SSR分析发现,位于1B染色体上的7个SSR标记Xcfd65、Xgwm11、Xgwm18、Xbarc187、Xwmc406、 Xwmc419、Xwmc216依次分布在YrCD的一侧,与YrCD的遗传距离在1.7 cM至9.2 cM。YrCD和YrCH42的等位性分析显示二者可能为等位基因。YrCD和Yr24、Yr26的抗谱相似。系谱分析和分子标记分析表明贵农20是YrCD的供体。本研究推测YrCD、Yr24、Yr26和YrCH42可能是等位基因,并推测Yr-sus是缺失突变体。 3. 小麦条锈抗源CD0534-5抗条锈病基因的鉴定 利用对条中32免疫的小麦抗条锈病品系CD0534-5及其感病重组自交系CD0534-4建立F2抗病性分离群体。抗条锈病性遗传分析表明,CD0534-5的条锈抗性由两对独立的显性主效基因控制。用BSK法分析,发现其中一对基因与SSR分子标记Xgwm11、Xgwm18、Xwmc128、Xwmc419连锁,该基因是来源于贵农20的YrCD。另一抗性基因来源贵农19,是极有利用价值的未知抗性基因。 This study focused on the investigation and identification of a novel powdery mildew resistant gene PmCD1 in wheat lines 07jian126 and stripe rust resistant gene YrCD in wheat lines CD1482 and CD0534-5, and screened SSR markers tightly linked to them. The main results were as follows: 1.Identification and SSR markers screening of a novel powdery mildew PmCD1 in wheat line 07jian126. Using a Pm resistant wheat line 07jian126 and its Pm susceptible mutant, a F2 population was constructed. Pedigree and genetic analyses indicated that the Pm resistance in 07jian126 was tranderred from rye (Secale cereale L.) cv. Jinzhou and was controlled by a single dominant gene. Differential test using 21 Bgt isolates revealed that the Pm resistant gene in 07jian126 is novel and was temporarily designated as PmCD1. A dominant SSR marker Xbarc183/130 bp was found co-segregated with PmCD1 in the F2 population. The diagnostic band of Xbarc183/130 bp co-segregating with PmCD1 could be used as an ideal marker in marker-assisted-selection during wheat breeding program. 2. Identification and SSR markers mapping of yellow rust resistant gene YrCD in wheat line CD1437. Wheat line CD1437 was highly resistant to predominant Chinese stripe rust race CYR32 at both seedling and adult stages. A F2 population was developed from the cross of CD1437 and its Yr susceptible mutant Yr-sus. Genetic analysis indicated line CD1437 contains a single dominant gene, temporarily designated YrCD. Seven SSR markers on the chromosome 1BS including Xcfd65, Xgwm11, Xgwm18, Xbarc187, wmc406, Xwmc419and Xwmc216 were close linked to YrCD with a genetic dsitance 1.7 cM to 9.2 cM. YrCD came from wheat cultivar Guinong 20. Allelic test of CD1437 and Chinese cultivar Chuanmai 42 indicated that YrCD and YrCH42 were allelic. Reaction patterns of YrCD and Yr24, Yr26 to 21 PST isolates were the same. These results suggested that YrCD and Yr24, Yr26, YrCH42 might be allelic. 3.Detection and identification of yellow rust resistance genes in wheat line CD0534-5 Wheat line CD0534-5 was highly resistant to predominant Chinese stripe rust race CYR32, while its recombinant inbred line CD0534-4 was susceptible. Genetic analysis with a F2 population developed from the cross of CD0534-5 and CD0534-4 indicated line CD0534-5 contains two independent dominant genes. Four SSR markers on the chromosome 1BS including Xgwm11, Xgwm18, Xwmc128, Xwmc419 were found to linked with one gene in CD0534-5. According the locations of makers and pedigree, this gene in CD0534-5 was YrCD, from cultivar Guinong 20. Another resistant gene was from cultivar Guinong 19, different with those genes on 1B such as Yr10, Yr15, Yr5 etc, was a valuable resistant gene in wheat breeding.
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同源四倍体水稻(2N=4X=48,AAAA)是由二倍体水稻(2N=2X=24,AA)通过秋水仙素诱导染色体加倍后得到的新品系,具有优良的抗病性以及较高的蛋白质含量。因此,在四倍体水平上挖掘水稻的增产潜力成为水稻育种的新手段。同源四倍体水稻具有很强的遗传可塑性和很弱的遗传保守性,利用其作为水稻远缘杂交的桥梁,从野生物种中不断地引进有益的基因,这将有助于杂交水稻的多代利用和固定水稻的杂种优势。但是迄今为止,还没有关于同源四倍体水稻遗传多样性,遗传背景的报道。目前世界关于同源四倍体水稻的研究主要集中在中国,主要研究方向为培育、筛选结实正常的亲本材料,配置和筛选结实率正常或接近正常的组合。经过几十年研究,虽然在材料构建,细胞学研究等方面取得了较大进展,但同样由于结实率低的瓶颈问题未解决,而使多倍体水稻育种未能取得实质性进展。而近年来一些关于同源四倍体水稻低结实率机理的细胞学研究也由于缺乏统计学数据而缺乏说明性。本文用SSR标记,对选取的36个结实率正常同源四倍体水稻三系亲本和14个来源二倍体亲本,分析他们的遗传差异和群体遗传结构。本文还利用我们培育的高、低结实率的同源四倍体水稻恢复系、优良保持系和杂种F1及二倍体对照为材料,进行系统深入的细胞遗传学研究,进一步探讨同源四倍体水稻有性传递后代的发育过程,探索分裂期染色体行为特征与遗传性状稳定性的关系,为进一步选育多倍体水稻品种并将其应用于生产提供理论依据。同源四倍体水稻突变株D4063-1直链淀粉含量比来源二倍体明恢63下降一半,即其直链淀粉含量为5.23%,为研究其直链淀粉含量下降的原因,本文还根据普通水稻Wx基因设计引物,扩增测序获得了D4063-1Wx基因的全序列,与已报道Wx基因进行比对分析,并根据D4063-1和籼稻、粳稻的序列差异并根据D4063-1在该片段上的特征序列位点设计了用于识别D4063-1的寡核苷酸片段,为快速、准确的鉴别低直链淀粉的D4063-1创造了条件。 SSR标记具有基因组分布广泛、数量丰富、多态性高、容易检测、共显性、结果稳定可靠、实验重现性好、操作简单、经济、易于高通量分析等许多优点,被认为是用于遗传多样性、品种鉴定、物种的系统发育、亲缘关系及起源等研究的非常有效的分子标记。本研究选取了中国科学院成都生物所培育的同源四倍体和二倍体水稻亲本,并用36个微卫星标记进行了遗传差异和种群遗传结构分析。在50个品系中,我们观察到较高水平的多态性,每基因等位基因数(Ae)分布于2至6之间(平均值3.028),多态性信息含量(PIC)分布于0.04至0.76之间(平均值0.366);期望杂合度(He)分布于0.04至0.76之间(平均值0.370),Shannon指数(I)分布于0.098至1.613之间(平均值0.649)。同源四倍体品系的等位基因数,期望杂合性和Shannon指数都比二倍体品系高。在供试50个品系中,较多材料均发现Rare基因,根据SSR多态性指数我们构建了同源四倍体和二倍体水稻的核心指纹库。F-统计值表明遗传差异主要存在于同源四倍体品系中(Fst=0.066)。聚类分析结果表明50个品系可以分为4个组。I组包括所有的同源四倍体和二倍体籼稻保持系,以及一个同源四倍体籼稻雄性不育系及其来源二倍体。II组仅包括IR来源的品系。III组比II组和IV组更复杂,包括同源四倍体和二倍体籼稻恢复系品系。IV组包括同源四倍体和二倍体粳稻品系。此外,由于等位基因及配子的遗传差异,同源四倍体与二倍体品系中存在单位点和双位点的遗传差异。分析结果表明,二倍体和四倍体水稻基因库的不同,其中遗传变异可以区分四倍体与二倍体水稻。同源四倍体水稻具有长期而独立的遗传性,我们能够选育并得到与二倍体亲本相比有特殊优良农艺性状的品系。 本研究以高结实率的同源四倍体水稻恢复系DTP-4、D明恢63及优良保持系D46B为材料进行农艺性状及细胞遗传学比较研究。DTP-4、D明恢63及保持系D46B的的染色体组成均为2N=4X=48,花粉母细胞具有较为理想的减数分裂行为,配对染色体的比率在99%以上,这与理论染色体组构成相符。DTP-4和D明恢63PMC减数分裂各个时期单价体和三价体的比例都非常低,而在MI, PMC观察到较多的二价体和四价体且四价体多以环状形式出现,其最大频率的染色体构型分别为12II 6IV和10II 7IV。恢复系DTP-4和D明恢63在MI四价体频率分别为2.00/PMC和2.26/PMC,而保持系D46B在MI四价体频率为6.00/PMC,极显著地高于恢复系品系,表明保持系D46B具有更好的染色体配对性质;AI保持系D46B的染色体滞后频率为10.62%,远低于恢复系材料DTP-4和D明恢63的19.44%和23.14%,接近二倍体对照明恢63的7.30%水平;TI保持系D46B具有比恢复系更低频率的微核数。而在TII,D46B的正常四分小孢子比率不但高于恢复系品系甚至高于二倍体对照。对高低结实率的同源四倍体水稻恢复系和杂种F1代的花粉育性,结实率和细胞遗传学行为进行了比较研究。DTP-4, D明恢63, D46A´DTP-4和D46A´D明恢63的花粉育性和结实率比D什香和D46A´D什香显著提高。减数分裂分析的结果表明,DTP-4,D明恢63,D什香,D46A´DTP-4,D46A´D明恢63和D46A´D什香其减数分裂染色体构型分别为:0.05I +19.96 II (9.89棒状+10.07环状) +0.01III + 2.20 IV, 0.11I +19.17 II (8.90 棒状+10.37 环状) +0.09III + 2.26 IV + 0.01 VI, 1.33I +9.46 II (4.50 棒状+4.96 环状) +0.44III + 6.02 IV + 0.09VI + 0.09 VIII, 0.02I +14.36 II (6.44 棒状+7.91 环状) +0.01III + 4.80IV + 0.01VIII, 0.06 I +17.67 II (11.01 棒状+6.67 环状) +0.06 III + 3.10 IV + 0.01 VI and 1.11 I +11.31 II (5.80 棒状+5.51 环状) +0.41 III + 5.63 IV+0.03VI+0.03VIII。在同源四倍体水稻恢复系和杂种F1代材料中,最常见的染色体构型为16II +4IV和12II +6IV。在减数分裂过程中,结实率较高的材料染色体异常现象较少而结实率较低的材料染色体异常现象较严重。在杂种F1代中,二价体的比例要低于其相应的恢复系亲本,同样的,单价体,三价体和多价体的比例相比其恢复系亲本也偏低。然而,在减数分裂MI,杂种F1代中四价体的比例要显著高于其恢复系亲本。在中期I,每细胞单价体的比例和花粉育性呈现出极高的负相关(-0.996),当单价体数目升高时,花粉育性下降。其次是每细胞三价体的比例(-0.987),之后则是每细胞多价体的比例与花粉育性的负相关(-0.948)。但是统计分析表明,二价体和四价体的比例对花粉育性和结实率没有显著影响。这一结果表明出了花粉育性和细胞减数分裂行为的相关性,同源四倍体的减数分裂行为为筛选高结实率的同源四倍体种系提供了理论依据。 突变体是遗传学研究的基本材料。利用突变体克隆水稻基因,并进而研究基因的生物学功能是水稻功能基因组学的重要研究内容。本课题组在多年的四倍体水稻育种研究中已获得多个低直链淀粉含量突变体,其中一些突变体在直链淀粉含量下降的同时,胚乳外观也发生了显著改变,呈半透明或不透明。同源四倍体水稻突变株D4063-1直链淀粉含量比来源二倍体明恢63下降一半,即其直链淀粉含量为5.23%。为研究其直链淀粉含量下降的原因,我们根据普通水稻Wx基因设计引物,扩增测序获得了D4063-1Wx基因的全序列,与已报道Wx基因进行比对分析;同源四倍体水稻D4063-1Wx基因最显著变化为在外显子序列中发生了碱基缺失,导致移码突变,在第9外显子终止密码子提前出现。D4063-1Wx基因碱基位点的变化还导致了其序列上的酶切位点的变化,对常用限制性内切酶位点分析分析结果表明同源四倍体水稻相对于籼稻和粳稻多了2个sph1酶切位点,相对于粳稻减少了6个Acc1,增加了4个Xba1,1个Xho1,1个Pst1和1个Sal1酶切位点。聚类分析表明D4063-1Wx基因序列与籼稻亲源关系较近,由此推测D4063-1Wx基因来源于籼稻的Wxa基因型。另外,根据D4063-1Wx基因的碱基差异,我们推测D4063-1Wx基因外显子碱基变化导致的RNA加工障碍是其直链淀粉降低的主要原因,并可能与其米饭较软等品质相关。本文还根据D4063-1和籼稻、粳稻的序列差异并根据D4063-1在该片段上的特征序列位点设计了用于识别D4063-1的寡核苷酸片段,并作为PCR反应的引物命名为AUT4063-1,将该引物与我们设计的扩增普通籼稻、粳稻的Wx基因引物F5配合使用建立了识别D4063-1的显性和共显性两种检测方式的分子标记,为快速、准确的鉴别低直链淀粉的D4063-1创造了条件。 研究同源四倍体水稻基因组的遗传差异,探索同源四倍体水稻的遗传规律,研究分裂期染色体行为特征与遗传性状稳定性的关系,旨在揭示四倍体水稻中同源染色体配对能力的遗传差异,为进一步选育多倍体水稻品种并将其应用于生产提供理论依据。 Autotetraploid rice (2N=4X=48, AAAA) is a new germplasm developed from diploid rice (2N=2X=24, AA) through chromosomes doubling with colchicines and is an excellent resource for desirable resistance genes to the pathogens and high protein content. Therefore, heterosis utilization on polyploidy is becoming a new strategy in rice breeding. At present, the main research on autotetraploid rice centralizes in China. Breeding effort has been made to improve autotetraploid rice genetically, however, the progresses are limited due to higher degree of divergence between hybrid sterility and polygenic nature. But to date, almost nothing is reported about the genetic diversity, original and genetic background of autotetraploid rice. Despite several reports on cytological analysis of the mechanisms of low seed set in autotetraploid rice still the results are inconclusive due to lack the statistical evaluation. Therefore, the study on the mechanisms of low seed set in autotetraploid is a priority for rice breeding. Microsatellites or simple sequence repeats (SSRs) are the widely used marker for estimating genetic diversity in many species, including wild, weedy, and cultivated rice. In our research, genetic diversity and population genetic structure of autotetraploid and diploid populations collected from Chengdu Institute of Biology, Chinese Academy of Sciences were studied based on 36 microsatellite loci. For the total of 50 varieties, a moderate to high level of genetic diversity was observed at population levels with the number of alleles per locus (Ae) ranging from 2 to 6 (mean 3.028) and PIC ranging from 0.04 to 0.76 (mean 0.366). The expected heterozygosity (He) varied from 0.04 to 0.76 with the mean of 0.370 and Shannon’s index (I) ranging from 0.098 to 1.613 (mean 0.649). The autotetraploid populations showed a slightly higher level of effective alleles, the expected heterozygosity and Shannon’s index than that of diploid populations. Rare alleles were observed at most of the SSR loci in one or more of the 50 accessions and core fingerprint database of the autotetraploid and diploid rice was constructed. The F-statistics showed that genetic variability mainly existed among autotetraploid populations rather than among diploid populations (Fst=0.066). Cluster analysis of the 50 accessions showed four major groups. Group I contained all of the autotetraploid and diploid indica maintainer lines and a autotetraploid and its original diploid indica male sterile lines. Groups II contained only original of IR accessions. Group III was more diverse than either group II or IV and comprised of both autotetraploid and diploid indica restoring lines. Group IV included japonica cluster of the autotetraploid and diploid rices. Furthermore, genetic differences at the single-locus and two-locus levels, as well as components due to allelic and gametic differentiation, were revealed between autotetraploid and diploid varieties. This analysis indicated that the gene pools of diploid and autotetraploid rice are somewhat dissimilar, which made a variation that distinguishes autotetraploid from diploid rices. Using this variation, we can breed new autotetraploid varieties with some new important agricultural characters but the diploid rice has not. Cytogenetic characteristics in restorer lines DTP-4, DMinghui63 and maintainer line D46B of autotetraploid rices were studied. DTP-4, DMinghui63 and D46B showed the advantage of high seed set and biological yield. The meiotic chromosome behavior was slightly irregular in DTP-4, DMinghui63 and D46B. We observed less univalent, trivalent and multivalent at MI, but more bivalent and quadrivalent were observed. The most frequent chromosome configurations were 12II 6IVand 10II 7IV in restorer and maintainer lines, respectively. The quadrivalent frequency of DTP-4 and Dminghui63 at metaphase(MI) was respectively 2.00/PMC and 2.26/PMC. However that frequency of D46B was 6.00/PMC, which was greatly significantly higher than DTP-4 and Dminghui63. That indicates the maintainer D46B has better chromosome pairing capability in metaphase (MI). The frequency of lagging chromosomes of the maintainer D46B at anaphaseI (AI) was 10.62%, which was significantly lower than that of DTP-4(19.44%) and Dminghui63(23.14%) and nearly reaching the level of diploid CK(7.30%). In telophaseI (TI) maintainer D46B showed lower frequency of microkernel at TI and lower frequency of abnormal spores at telophaseII(TII). We also studied pollen fertility, seed set and cytogenetic characteristics of restorer lines and F1 hybrids of autotetraploid rice. DTP-4, DMinghui63, D46A´DTP-4 and D46A´DMinghui63 showed significantly higher pollen fertility and seed set than DShixiang and D46A´DShixiang. Pairing configurations in PMC of DTP-4, DMinghui63, DShixiang, D46A´DTP-4, D46A´DMinghui63 and D46A´DShixiang were 0.05 I+19.96 II (9.89 rod+10.07 ring)+0.01 III+2.20 IV, 0.11 I+19.17 II (8.90 rod+10.37 ring)+0.09 III+2.26 IV+0.01 VI, 1.33 I+9.46 II (4.50 rod+4.96 ring)+0.44 III+6.02 IV+0.09 VI+0.09 VIII, 0.02 I+14.36 II (6.44 rod+7.91 ring)+0.01 III+4.80 IV+0.01V III, 0.06 I+17.67 II (11.01 rod+6.67 ring)+0.06 III+3.10 IV+0.01 VI and 1.11 I+11.31 II (5.80 rod+5.51 ring)+0.41 III+5.63 IV+0.03 VI+0.03 VIII, respectively. Configuration 16 II+4 IV and 12 II+6 IV occurred in the highest frequency among the autotetraploid restorers and hybrids. Meiotic chromosome behaviors were less abnormal in the tetraploids with high seed set than those with low seed set. The hybrids had fewer frequencies of bivalents, univalents, trivalents and multivalents than the restorers, but higher frequency of quatrivalents than the restorers at MI. The frequency of univalents at M1 had the most impact on pollen fertility and seed set, i.e., pollen fertility decreased with the increase of univalents. The secondary impact factors were trivalents and multivalents, and bivalents and quatrivalents had no effect on pollen fertility and seed set. The correlative relationship between pollen fertility and cytogenetic behaviors could be utilized to improve seed set in autotetraploidy breeding. The amylose content of autotetraploid indica mutant Rice D4063-1 dropped by half than diploid Minghui 63, that is, its amylose content of 5.23%.The whole sequence of Waxy gene of D4063-1 is amplified and sequenced. And the discrepancy of bases is found comparing to the reported Waxy gene. The Waxy gene of autotetraploid Rice D4063-1 had a base deletion in exon sequence, which resulted frameshift mutation in exon 9 and termination codon occur early. The mutation of Wx also led to the change of some common restriction endonuclease sites. Results showed compared to indica and japonica, D4063-1 had two adding sph1 sites. Compared to japonica, D4063-1 had six decreasing Acc1, a adding Xho1, Pst1 and Sal1 restriction sites. Phylogeny analysis shows that the DNA sequence of Waxy gene of D4063-1 is closer to Indica, and we suppose that the Waxy gene of D4063-1 is origin from genotype Wxa. In addition, according to the base differences of Wx in D4063-1, we deduce that RNA processing obstacle led by base change of intron is the main cause to low the amylose content, and related to phenotype of its soft rice. Based on analysis of fragments of D4063-1, indica and japonica and according to the special point of the three species, primers as markers-AUT4063-I were designed for distinguishing the D4063-1 from other rice. Combining with primer pair F5, dominant and codominant ways were established for discriminating them., rapid and correct identification of D4063-1 from other rice could be done. The genetic analysis is important to ensure the original of autotetraploid rice, for maintaining the “distinctiveness” of autotetraploid varieties, and to differentiate between the various genetic background of autotetraploid rice. The autotetraploid breeding will benefit from detailed analysis of genetic diversity in the germplasm collections. Further investigation on mechanisms of meiotic stability should benefit polyploid breeding. These findings demonstrated opportunity to improve meiotic abnormalities as well as grain fertilities in autotetraploid rice.
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高等植物种子胚乳贮藏蛋白是种子发芽时的主要氮源,也是人类和动物食用植物蛋白的主要来源。大麦种子胚乳贮藏蛋白主要是醇溶蛋白(hordeins),占大麦胚乳总蛋白的50–60%。根据大麦醇溶蛋白的大小和组成特点,大麦醇溶蛋白被划分为三种类型:富硫蛋白亚类(B,γ-hordeins)、贫硫蛋白亚类(C-hordeins)以及高分子量蛋白亚类(D-hordeins)。B组和C组醇溶蛋白是大麦胚乳的两类主要贮藏蛋白,它们分别占大麦总醇溶蛋白成分的70–80%和10–12%。遗传分析表明,大麦B、C、D和γ-组醇溶蛋白分别是由位于大麦第五染色体1H(5)上的Hor2、Hor1、Hor3和Hor5位点编码。Hor2位点编码大量分子量相同但组成不同的B组醇溶蛋白(B-hordein)。B-hordein的种类、数量和分布是影响大麦酿造、食用及饲养品质的重要因素之一。为深入了解B-hordein基因家族的结构和染色体组织,探明Hor2位点基因表达的发育调控机制,最终达到改良禾谷类作物籽粒品质的目的,本研究以青藏高原青稞为材料,采用同源克隆法,分别克隆B-hordein基因和启动子,通过原核生物表达验证B-hordein基因功能,并利用实时定量PCR探索B-hordein基因表达时空关系,取得如下研究结果: 1. 以具有特殊B组醇溶蛋白亚基组成的9份青藏高原青稞为材料,根据GenBank中三个B-hordein基因序列(GenBank No. X03103, X53690和X53691)设计一对引物,通过PCR扩增,获得23个B-hordein基因克隆并对其进行了序列分析。核苷酸序列分析表明,所有克隆均包含完整的开放阅读框。有11个克隆都存在一个框内终止密码子,推测这11个克隆可能是假基因。推测的氨基酸序列分析表明,所有大麦B-hordein具有相似的蛋白质基本结构,均包括一个高度保守的信号肽、中间重复区以及C-端结构域。不同大麦种重复区内重复基元的数目有较大差异。青稞材料Z07–2和Z26的B-hordeins仅具有12个重复基元结构,更接近于野生大麦。这些重复基元数目的差异导致了重复区序列长度和结构的变异。这种现象极可能是由于醇溶谷蛋白基因在进化过程中染色体的不平衡交换或复制滑动所造成的。对所克隆基因和禾本科代表性醇溶谷蛋白基因进行聚类分析,结果表明所有来自栽培大麦的B-hordeins聚类成一个亚家族,来自野生大麦的B-hordeins以及普通小麦的LMW-GS聚类成另外一个亚家族,表明这两个亚家族的成员存在显著差异。此外,我们发现B-hordein基因推测的C-末端序列具有一些有规律的特征:即具有相同C-末端序列的B-hordein基因在系统发生树中聚类为同一个亚组(除BXQ053,BZ09-1,BZ26-5分别单独聚为一类外)。这个特征将有助于我们对所有B组醇溶蛋白基因家族成员进行分类,避免了在SDS-PAGE电泳图谱上仅依靠大小分类的局限性。 2. 根据上述克隆的青稞B-hordein基因的5’端序列设计三条基因特异的反向引物,以青稞Z09和Z26的基因组DNA为模板,采用SON-PCR和TAIL-PCR技术分离克隆出8个B-hordein基因的上游调控序列(命名为Z09P和Z26P)。序列分析表明,推测的TATA box位于–80 bp,CAAT–like box位于–140 bp处。此外,Z09P和Z26P中有六个序列在–300 bp处均存在一个由高度保守的EM基序和类GCN4基序构成的胚乳盒(Endosperm Box,EB),在约–560 bp处存在一个胚乳盒类似结构。而Z09P-2和Z26P-3不存在保守的胚乳盒或其类似结构,预示着这两个启动子所调控的基因表达可能受不同类型反式作用因子的调节,推测该启动子对基因的表达调控具有多样性。 3. 将B-hordein基因的开放阅读框定向克隆到表达载体pET-30a中,将其导入大肠杆菌表达菌株BL21中进行外源基因的诱导表达以验证所克隆基因的功能。结果表明仅含重组子pET-BZ07-2和pET-BZ26-5的BL21细菌有目的表达蛋白产生。在诱导3 h时的蛋白表达量最高;3 mM IPTG诱导的蛋白表达量要高于1 mM IPTG诱导的表达量。这为分离纯化B-hordein蛋白以及进一步研究其对大麦籽粒品质的影响奠定基础。 4. 根据从青稞Z09和Z26中分离克隆的B-hordein基因序列设计一对基因特异的引物,同时,选择大麦α-微管蛋白基因(GenBank no. U40042)为看家基因并设计特异引物,利用实时荧光定量PCR检测了青稞籽粒4个胚乳发育时间段的B-hordein基因表达,荧光定量结果显示:两份材料中B-hordein基因的表达量均随发育过程的进行而逐渐升高。Z09中B-hordein基因在开花后7天开始转录,而Z26开花4天后就有低水平B-hordein的表达,这表明Z26中B-hordein基因可能比Z09表达的较早或者Z09中B-hordein基因表达水平较低以致于不能被检测到。此外,在4个不同的胚乳发育时期中,Z26中B-hordein基因的表达量均高于Z09材料。在开花12天到18天的过程中,Z09和Z26中B-hordein基因的表达水平有一个急剧性的升高。这说明在不同胚乳发育时期,Hor2位点的B-hordein等位基因变异体存在mRNA的差异表达。 Seed endosperm storage proteins in higher plants are the main resources of nitrogen for germinating and plant proteins for human and animals. Barley prolamins (also called hordeins) are the major storage proteins in the endosperm and account for 50–60% of total proteins. Hordeins are classically divided into three groups: sulphur-rich (B, γ-hordeins), sulphur-poor (C-hordeins) and high molecular weight (HMW, D-hordeins) hordeins based on the size and composition. B-hordeins and C-hordeins are two major groups and each respectively account for about 70-80% and 10-12% of the total hordein fraction in barley endosperm. Genetic analysis showed that B-, C-, C-, γ-hordeins are encoded by Hor2, Hor1, Hor3 and Hor5 locus on the chromosome 1H (5). Hor2 locus is rich in alleles that encode numerous heterogeneous B-hordein polypeptides. It is reported that B-hordein species, quantity and distribution are significant factors affecting malting, food and feed quality of barley. To understand comprehensively the structure and organization of B-hordein gene family in hull-less barley and explore the developmental control mechanisms of Hor2 locus gene expression and eventually to better exploitation in crop grain quality improvement, we isolated and cloned B-hordein genes and promotors of hull-less barley from Qinghai-Tibet Plateau by PCR, and testified their expression founction in bacteria expression system and explore their spatial and temporal expression pattern by quantitative real time PCR. Our results are as followed, 1. Twenty-three copies of B-hordein gene were cloned from nine hull-less barley cultivars of Qinghai-Tibet Plateau with special B-hordein subunits and molecularly characterized by PCR, based on three B-hordein genes published previously (GenBank No. X03103, X53690 and X53691). DNA sequences analyses confirmed that the six clones all contained a full-length coding region of the barley B-hordein genes. Eleven clones all contain an in-frame stop codon and they are probably pseudogenes. The analysis of deduced amino acid sequences of the genes shows that they have similar structures including signal peptide domain, central repetitive domain, and C-terminal domain. The number of the repeats was largerly variable and resulted in polypeptides in different sizes or structures among the genes. Twelve such repeated motifs were found in Z07–2 and Z26, and they are close to those of the wild barleys, and it is most probably caused by unequal crossing-over and/or slippage during replication as suggested for the evolution of other prolamins. The relatedness of prolamin genes of barley and wheat was assessed in the phylogenetic tree based on their polypeptides comparison. Our phylogenetic analysis suggested that the predicted B-hordeins of cultivated barley formed a subfamily, while the B-hordeins of wild barleys and the two most similar sequences of LMW-GS of T. aestivum formed another subfamily. This result indicated that the members of the two subfamilys have a distinctive difference. In addition, we found the B-hordeins with identical C-terminal end sequences were clustered into a same subgroup (except BXQ053,BZ09-1 and BZ26-5 as a sole group, respectively), so we believe that B-hordein gene subfamilies possibly can be classified on the basis of the conserved C-terminal end sequences of predicted polypeptide and without the limit of SDS-PAGE protein banding patterns. 2. The specific primers were designed according to the published sequences of barley B-hordein genes from Z09 and Z26. Using total DNA isolated from them as the templates, eight clones (designated Z09Pand Z26P) of upstream sequences of the known B-hordein genes was obtained by TAIL-PCR and SON-PCR. Sequences analysis shows that the putative TATA box was present at position –80 bp and CAAT-like box at position –140 bp. Besides, a putative Endosperm Box including an Endosperm Motif (EM) and a GCN4-Like Motif was found at position –300 bp in six clones, and another Endosperm-like box was found at positon –560 bp. While the Endosperm Box or Endosperm-like box was not found in Z09P-2 and Z26P-3. This may indicate that gene expression drived by the two promtors was probably controlled by different trans-acting factors and the genetic control mechanism of corresponding gene expression may be diverse. 3. The B-hordein genic region coding for the mature peptide was cloned into expression vector pET-30a and transformed into bacterial strain BL21 for identifying gene expression fountion. Protein SDS–PAGE analysis showed that only the transformed lysate with the pET-BZ07-2 and pET-BZ26-5 constructs produced proteins related to B-group hordeins of barley, and the mounts of proteins induced by 3 mM IPTG and 3 h were higher than other conditions. This established a base for isolating and putifying B-hordein and further exploring their effects on barley grain quality. 4. The gene-specific primers of B-hordein genes from Z09 and Z26 were used for the quantification of B-hordein gene expression. The α-tubulin gene from Hordeum vulgare subsp. vulgare (GenBank accession number U40042) was used as a control gene. The result shows the transcription of the B-hordein genes in Z09 was found 7 days after flowering, while the transcription of the B-hordein genes in Z26 was found 4 days after flowering, but at a very low level, and it suggested that the B-hordein genes in Z26 probably expressed earlier than those in Z09, or the B-hordein genes in Z09 expressed at so a lower level than Z26 that it can not detected. In addition, B-hordein genes in Z26 accession showed higher expression levels than those in Z09 in four developing stages. Furthermore, a progressive increase in the expression levels of the B-hordein genes between 12 and 18 days after anthesis was observed in both Z09 and Z26. It implies that the B-hordein allelic variants encoded by Hor2 locus exist the differential expression in mRNA levels of during barley endosperm development.
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土壤种子库与地上植被的耦合研究对于探索有效的植被恢复方法具有重要意义。通过野外调查和室内试验研究了黄土丘陵沟壑区退耕地土壤种子库与地上植被的关系。结果表明,地上植被的物种数(54种)多于土壤种子库中的物种数(28种),菊科、禾本科和豆科都是它们物种组成的主要植物;土壤种子库和地上植被的丰富度指数、多样性指数、生态优势度与退耕年限的相关性未达到显著水平,只有均匀度指数和退耕年限呈显著正相关关系;土壤种子库和地上植被的相似性比较小,相似性系数(CC)变化范围为0.143~0.414,平均为0.261。黄土丘陵沟壑区退耕地土壤种子库的物种数、丰富度指数和多样性指数均小于地上植被,这从一定程度上说明了该研究区土壤种子库在植被恢复中的潜力还比较小,植被恢复还需要适度的人为干预与调控。
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对黄土丘陵区退耕地植被特征的时空变异性进行了研究。结果表明,不同植被类型区植被特征之间差异不是很显著,仅延安与安塞在物种丰富度之间和安塞与吴旗在物种多样性之间存在较显著的差异(0.01
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The study on the relationship between plant species diversity and soil factors in the bird island of Qinghai Lake indicated that this island was a low diversity district,its Shannon-Wienner index and species richness decreased with the increasing soil available K,water soluble salt concentration and pH,and there were significant linear and quadratic correlations between them.Stepwise linear regressions showed that soil available K and water soluble salt were the key factors to estimate Shannon-Wienner index and species richness in this island,respectively,and no correlation was found between species evenness and soil factors.
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Qianyanzhou(QYZ) Ecological Station established in 1983 with an area of 204 hm~2 is affiliated to the Chinese Ecosystem Research Network.Before 1982,herbs had been dominant,sparsely dotted with shrubs.After 20-year restoration of the vegetation,the vegetation showed significant changes in both forest coverage and species diversity.Forest coverage had increased to 93.3% in 1999 from 0.4% in 1982.The vegetation could be broadly classified into two groups: artificial forest,accounting for the most percent,and natural secondary forest.These two groups could be subdivided into 12 types.Based on the 2003 field work,The authors studied plant community composition and vertical structure.The results were as follows: 1) On the study plots were there about 150 species,of which 100,49,and 47 grew in arbor layer and shrub layer and herb layer,respectively.Of 12 community types,the amount of species in shrub layer was larger than that of other two layers.As to the species richness in the different community types,Liquidambar formosana community showed the highest and Imperata cylindrical var.major community the least.The amount of species in arbor layer of artificial forest was smaller than those of natural Pinus massoniana forest,but no difference in understory.2) Loropetalum chinense,Quercus fabric and Vaccinium bracteatum were dominant shrub species with a wide distribution.Three ferns Woodwardia japonica、Dryopteris atrata and Dicrannepteris dichotoma were dominant herb species.Lianas were sparse,but Milletlia reticulata were found in all forest types.3) Up to now some natural regeneration species,such as Eurya muricata、Quercus fabri、Vaccinium bracteatum、Rhus chinensis、Adinandra bockiana,had grown in the arbor layer of artificial forests.Some herb species,such as Arundinella setosa、Miscanthus floridulus、Isachne globosa、Scirpus triqueter,which were dominant ones in the herb layer before the restoration of vegetation,disappeared now.4) The vertical structure of natural Pinus massoniana community and Liquidambar formosana community showed more complex comparing with artificial forests.For the artificial forests,the conifer and broad-leaves mixed forest had a more complex structure.In both natural Pinus(massoniana) community and Liquidambar formosana community,it was dominated by individuals with height of 3~4 m,while 10~12 m in the artificial forests.
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应用传统及PCRDGGE方法(denaturinggradientgelelectrophoresis),分别对不同浓度乙草胺、甲胺磷胁迫下黑土中可培养真菌CFU(colonyformingunits)、种群丰富度(richness)及种群结构动态变化规律进行了研究.结果表明,在实验室微域条件下,乙草胺对黑土可培养真菌CFU的影响随处理浓度的增加而抑制作用增强,表现出由低浓度(50mg·kg-1)时的刺激生长到高浓度(250mg·kg-1)时的长期抑制效应;250mg·kg-1甲胺磷在8周处理过程中对土壤可培养真菌生长具有显著的刺激效应,使可培养真菌CFU比对照增加10倍,但50和150mg·kg-1甲胺磷处理对土壤可培养真菌CFU无显著影响.种群丰富度系数分析结果表明,高、中浓度乙草胺处理可使土壤可培养真菌种群丰富度不可逆地降低.土壤真菌rDNA特异PCRDGGE聚类分析结果表明,不同浓度乙草胺、甲胺磷处理均不同程度地对土壤可培养真菌的种群组成和结构造成影响,其中甲胺磷尤为显著.