992 resultados para PINUS RADIATA
Resumo:
花粉是种子植物受精过程中雄性生殖细胞的载体,在有性生殖过程中起着非常重要的作用。花粉与柱头、花柱、子房等都有相互作用,起识别作用的是细胞壁蛋白,而花粉粒的壁有明显的两层:内壁和外壁。裸子植物花粉与被子植物相比具有萌发时间长、生长缓慢、授粉-受精时间长等特点。花粉的内壁与外壁在花粉萌发和生长过程中的功能仍然缺乏研究,但是迄今为止现有的分子生物学技术在获得裸子植物花粉壁突变体方面并没有发挥作用。本研究以裸子植物白皮松(Pinus bungeana)和青杄(Picea wilsonii)花粉为材料建立裸子植物花粉脱壁的体系,包 括脱外壁花粉和花粉原生质体的制备,即将花粉的两层壁逐层剥离,并在此基础上进行了细胞学研究。 本文首先建立了裸子植物脱外壁花粉的分离技术。实验表明低浓度的酶组合短暂酶解后,辅以机械研磨,可以释放出大量的脱外壁花粉。其中在这两种裸子植物中的处理稍有不同,白皮松的脱外壁花粉在含12%蔗糖,0.5%纤维素酶和0.3%离析酶的溶液,pH 5.8 ,孵育半小时,辅以一定力度机械研磨的方法获得,而青杄脱外壁花粉的条件是0.8%纤维素酶和0.5%离析酶、12%蔗糖的溶液,其它条件类似。 其次我们成功建立了一种快速、有效、可重复的分离白皮松和青杄花粉原生质体的系统,分离频率可高达70%。对白皮松而言,最好的分离条件是2% 纤维素酶、1.5%离析酶、15%蔗糖、pH 5.8,黑暗、24℃条件下轻微振荡、酶解6 小时。3%纤维素酶和2%离析酶组合比较适宜青杄花粉原生质体的分离,同时需要较低浓度的蔗糖溶液(12%)。青杄花粉原生质体要远大于白皮松花粉原生质体,前者直径为80µm,后者为40µm。强烈的FDA 荧光显示很好的活性。在制备的过程中,酶的浓度、酶的配比、酶解时间、渗透压调节剂、起始材料对分离率都有影响。 运用免疫荧光标记技术显示,脱外壁花粉的表面存在纤维素、果胶质、阿拉伯半乳聚糖蛋白(AGPs)和凝集素结合位点,其中纤维素在整个表面都有分布,但在萌发孔附近的荧光最强;白皮松脱外壁花粉表面有胼胝质的存在,主要位于靠近气囊的部位,而青杄脱外壁花粉表面未能检测到胼胝质;酸性果胶质在白皮松脱外壁花粉靠近萌发孔处的荧光稍弱于其它部位,而在青杄脱外壁花粉的表面近极端的荧光要强于远极端;白皮松脱外壁花粉表面有酯化果胶的沉积,而青杄脱外壁花粉表面缺失酯化果胶;白皮松和青杄两种植物脱外壁花粉表面均有阿拉伯半乳糖的分布,而白皮松脱外壁花粉的荧光要远强于青杄;白皮松和青杄脱外壁花粉表面有伴刀豆凝集素(Conconavalin agglutinin, Con A )和大豆凝集素(soybean agglutinin, SBA )结合位点的分布,而缺失麦胚凝集素(wheat germ agglutinin, WGA)结合位点。另外,傅立叶红外光谱(FTIR) 分析结果也同样支持上述结论。
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华山松(Pinus armandi)是我国西部高海拔温凉山区的主要树种,自然分布大约在北纬23° 30'-36°30',东经88°50'-113°30'之间,横跨13个省(区)包括两个季风区,六个气候带。由于水平空间区域广阔,分布区中间地带又为川藏高原的高山峡谷区,群体疏散,基因的迁移和交流困难,致使南北群体出现深刻的遗传分化,并在形态上、生理上充分表达出来。研究结果表明: 1)华山松树高生长出现明显的地理渐变模式,在同一适宜的立地条件下,15年生的南方群体的树高会超出北方种源的2-3倍。针叶长度也同样具有明显的南北差异,南方群体较长。 2)地理因子相关分析表明纬度因子是主导因子,根据种源的地理坐标,利用中科院植物所植被数量生态学开放室有关数据库和生态信息系统(EIS)进行有关气候数据统计分析表明大多数环境气候因子主要是由纬度决定的。在环境因子当中,年平均温度和极端最低气温,在华山松地理变异过程中起主要作用。利用聚类分析方法,可把华山松大致分为南北两个地理型,正好与气候因子聚类而成的两个环境类型相对应,反映着两个自然地理区的自然生态因子的综合区别。 3)利用已有的幼林生长数据和我们在华山松进入杆材期(15年生)的树高调查结果,作相关分析,发现二者相关关系显著。因此,利用早期树高作生长预测在林木选育上是可行的。 4)根据六个种源测定结果,发现南方温暖湿润气候条件下华山松种子较大,种壳较薄,而北方种源种子相对较小,种皮要厚一些。 5)虽然种群之间中性盐及碱性溶液提取的种子蛋白含量差异明显,但没有地理变异趋势。分析多肽组成,中性盐溶种子蛋白也没有地理特征。但碱性溶液提取的种子蛋白多肽组成却有明显地域性。其中36KD多肽仅出现在北方种群中,南方种群则没发现有同样多肽。 6)西藏种源表现出了一种独特的生物学特性,其种子较大有南方种源特征,但种皮厚又带有北方种源的特点,除此之外,它的碱性溶液提取的种子蛋白中含有36KD多肽,因此它可能是南北两个类群中的中间类型。 7)用活体针叶作测材料时,没能检测出光谱特性的地理变异。但改用分离的叶绿体作试验材料,发现南方种群的光能吸收4阶导数光谱在680nm处的峰值较大,670nm峰值较小,而北方种群中出现了670nm峰值较大的类群,推测北方种群反应中心活力有下降趋势。另外,低温荧光发射光谱及低温荧光激发光谱也有明显的地域分化,表明体内色素状态有一定的地理变异。 8)时绿素a荧光诱导动力学测定表明,南方种群可变荧光(Fv/Fo)与光能转换效率(Fv/Fm)较高,北方种群则相对要小一些,与四阶导数吸收光谱测定结果吻合.利用饱和脉冲重复激发技术,发现光化学荧光淬灭(Qp)和非光化学荧光淬灭(Qn)在北方种群中较大,南方种群较小,其中,Qn变化非常明显,而Qp变化较小. 综合研究结果,除树高生长.针叶和种子形态外,36KD碱溶性种子蛋白多肽680nm处4阶导数吸收光谱峰值大小,可变荧光强度(Fv/Fo)光能转换效率(Fv/Fm)以及非化学荧光淬灭系数都带有明显的地理特征,与华山松生长和适应能力紧密相关,可作为生理指标应用于生态地理型的区分或华山松的早期选择。
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Premise of the study: Microsatellite markers were developed for Pinus koraiensis to characterize its genetic diversity and understand its population structure. Methods and Results: Using the Fast Isolation by AFLP of Sequences COntaining (FIASCO) Repeats protocol, 20 primer sets were developed in Chinese populations of P. koraiensis. Three of the markers showed polymorphism with two alleles per locus when assessed in a sample of two populations of P. koraiensis from the Changbai Mountain in the Jilin Province of China. Five and three loci were successfully amplified in P. taiwanensis and P. massoniana, respectively. The amplification size of these loci matches those in P. koraiensis. Conclusions: These markers may be useful for further investigation of population genetics of P. koraiensis.
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为了揭示黄土高原地区人工油松林自然化发育过程中的植物叶片与土壤养分库和碳库的变化规律,采用典型样地法,以子午岭林区天然油松群落为参照,选择了不同立地条件的人工油松林,分别对其土壤的氮库、碳库及植物叶片养分库和碳库进行了分析。结果表明,该区油松针叶C、N、P的含量平均值分别为(499.5±63.75)mg/g、(8.53±0.50)mg/g和(0.94±0.64)mg/g,叶片C含量大小依次为阳坡天然林>阴坡天然林>阴坡人工林>阳坡人工林,阳坡人工林叶片N、P含量显著高于阳坡天然林。不同立地条件下油松林叶片C/N、C/P差异显著,叶片N、P和N/P均达到极显著水平,但是叶片C含量差异不显著。油松叶片C含量与N、P含量均呈极显著负相关,N和P之间的呈显著正相关。不同立地的油松林除40~60cm土层土壤C、N含量无显著差异外,0~20cm和20~40cm两个土层的人工林土壤C、N含量显著高于天然林,同时阳坡人工林土壤C、N含量显著高于阴坡人工林。0~20cm、20~40cm两个土层土壤C含量与N含量均呈极显著正相关,与植物N、P均呈显著正相关。子午岭林区阳坡的人工油松林不仅叶片养分含量较高,而且林地土壤是该区土壤的...
Resumo:
土壤可溶性有机物质(Dissolved organic matter,DOM)作为土壤有机质的活性组分,在陆地生态系统物质循环中扮演非常重要的角色。土壤DOM的主要成分可溶性有机碳(Dissolved organic carbon,DOC)和氮(Dissolved organic nitrogen,DON)参与C、N循环过程。为深入揭示全球C、N循环过程机制,在未开展DOC和DON的地区进行相关研究是有必要的。森林土壤(包括枯枝落叶层)DOC、DON动态及调控机理的研究是目前国际上森林生态系统C、N循环研究热点之一。本研究立足于暖温带岷江上游茂县地区人工林植被,对土壤DOC和DON的库容量,季节动态及其与其它养分之间的关系进行了系统研究,旨在了解DOC和DON在该区生态系统中的重要作用,并探讨作为DOM主要来源的叶凋落物对DOC和DON的动态影响,研究有助于更加详细地了解该区生态系统C和N循环过程。本论文主要研究结论如下: 1研究了岷江上游地区两大主要土壤类型(棕壤和褐土)不同植物群落下土壤的DOC和DON含量及特征,结果表明:DOC和DON在两种土壤类型中均有库容量存在,DOC在0-10cm和10-20cm土层的含量幅度分别111.96~159.95 mg kg-1和69.02~100.84 mg kg-1。DON在0-10cm和10-20cm土层的含量幅度分别11.88~23.08 mg kg-1和4.70~10.77 mg kg-1。游离氨基酸在0-10cm和10-20cm土层的含量幅度分别0.84~1.66 mg kg-1和0.39~0.73 mg kg-1。DOC、DON与土壤中的一些养分因子表现出了显著的相关关系,共同反映了土壤的状况和质量,在该区开展DOC和DON的系统研究是有必要的。 2 对油松与连香树林地土壤DOC、DON以及其它化学指标的季节动态进行了研究,结果表明:油松与连香树林地土壤DOC和DON的季节动态变化表现了类似的规律,DOC和DON的含量均以秋季最高。DOC和DON的季节动态变化主要受凋落物生物因素的影响,但其微生物活力的生物因素以及降雨、温度等非生物因素也是控制土壤DOC和DON含量的重要因素。土壤DON在土壤中的行为不同于矿质氮,其季节动态不同于NO3--N和NH4+-N的季节动态,在研究N循环过程中,应考虑DON的变化情况。 3 对油松与连香树林地分解层和表层土壤(0-10cm)氨基酸周转动态进行了研究,结果表明:油松林地和连香树林地均以分解层的氨基酸含量高于矿质表层土壤的含量。每个取样时期,油松林地内各层次的氨基酸含量高于连香树林地内相应层次的含量。两林地各层次无机氮含量均超过了氨基酸的含量,并且室内培养30天后无机N的含量仍然高于氨基酸的含量,所以可以认为该区立地条件下无论是在有机分解层还是矿质土层植物吸收利用的氮素仍是以无机N为主。 4 松林下松针凋落物易于累积,这与松针凋落物分解缓慢有关,从而导致松林内养分周转缓慢。通过用不同性质凋落物和灌丛地土壤构建微生态系统,比较油松、辐射松、连香树、灌丛虎榛子凋落物分解对C、N循环过程的影响,结果显示油松和辐射松针叶凋落物比连香树、虎榛子凋落物分解更慢,减缓了养分循环过程。然而将针叶凋落物与阔叶凋落物混合后,油松和辐射松针叶凋落物的分解加快,C、N元素的循环过程也加速。此结果表明在松林内维持具有高质量凋落物的灌丛植被或在松林内栽植一些阔叶树种如连香树对维持和增进松树人工林的土壤肥力有重大的作用。室内培养的结果还显示添加凋落物后土壤DOC和DON的含量显著增加,表明凋落物是土壤DOM的直接来源。然而不同物种凋落物处理下土壤DOC和DON的含量有所不同,并随时间发生改变。混合凋落物处理下土壤DOC和DON的含量均高于松针凋落物单独处理下土壤DOC和DON的含量。DON是一个主要的水溶性N库,随时间的变化趋势与无机N的变化趋势不同,在土壤N循环过程中起到了中间N库的作用。 As a labile fraction of soil organic matter, dissolved organic matter (DOM) plays a very important role in material cycling of terrestrial ecosystem. The turnover of DOM is now being considered as main components in nutrient cycling. DOM mainly includes dissolved organic carbon (DOC), -nitrogen (DON), -phosphorous (DOP) and –sulfur (DOS). Among these constituents, DOC and DON directly participate in C and N cycling. It is essential to study DOC and DON dynamics and their controlling factors in the areas where no related study has ever been carried out. Study about them can provide data supports on understanding the mechanism of the global C and N cycling. DOC and DON dynamics and their controlling factors have been focused on in the research of C and N cycling of forest ecosystems. Based on forest plantations of Maoxian, Minjiang River in warm temperate zone, soil DOC and DON pool size, their seasonal dynamics, and the correlation between DOC, DON and other nutrients were studied in order to understand the importance of DOC and DON in the study area. Soil DOC and DON dynamics induced by leaf litter decomposition were also studied. The study contributed to comprehensively understanding C and N cycling processes and providing baseline data for including DOC and DON into the indices system of evaluating nutrient conditions. The results were as follows: 1 Several different plant communities under brown soil and Cinnamon soil were chosen as sampling plots. The contents and features of soil DOC and DON were evaluated. The results showed that DOC and DON were present under the two soil types. DOC contents in the top soil (0-10 cm) and the subsoil (10-20 cm) respectively varied from 111.96 mg kg-1to 159.95 mg kg-1, and 69.02 mg kg-1 to 100.84 mg kg-1. DON contents in the top soil (0-10 cm) and the subsoil (10-20 cm) respectively varied from 11.88 mg kg-1to 23.08 mg kg-1, and 4.70 mg kg-1 to 10.77 mg kg-1. Free amino acid contents in the top soil (0-10 cm) and the subsoil (10-20 cm) respectively varied from 0.84 mg kg-1to 1.66 mg kg-1, and 0.39 mg kg-1 to 0.73 mg kg-1. Significant correlations were found between DOC, DON and some nutrient indices, which together reflected soil condition and quality. It was hence essential to study DOC and DON in the study area. 2 Seasonal dynamics of DOC, DON, inorganic N, microbial biomass C and N were studied under Pinus tabulaeformis and Cercidiphyllum japonicum plantation. The results indicated that seasonal dynamics of soil DOC and DON under the two plantations performed similar change pattern, with the highest values in autumn. The seasonal dynamics of soil DOC and DON were mainly influenced by the litterfall. However, biotic factors such as soil microbial activities and abiotic factors such as precipitation and temperature also controlled the dynamics of soil DOC and DON. The seasonal dynamic of DON was different from that of NO3--N and NH4+-N, which showed that the behavioral differences between DON and inorganic nitrogen. And hence, it was proposed to include DON into soil N cycling in the study area. 3 Amino acid dynamics in Oa and topsoil (0-10 cm) under P. tabulaeformis and C. japonicum plantation were studied. The results showed that amino acid content in Oa was significantly higher than that in mineral soil. At each sampling time, significantly higher amino acid contents were found in P. tabulaeformis plantation than in C. japonicum plantation. The content of inorganic nitrogen was much higher than the content of amino acid in each sampling layer at each sampling time. After a 30-days laboratory incubation the content of amino acid was still lower than the content of inorganic nitrogen. The results implicated that the form of N absorbed by plants in these study sites were mainly inorganic nitrogen. 4 Usually needle litter is more resistant to decomposition, which leads to needle litter accumulation in pure coniferous stands and slows down the rate of nutrient circulation. By constructing microcosms with local shrubland soil and containing the four single-species (P. tabulaeformis, P. radiata, C. japonicum, Ostryopsis davidiana) litters, the decomposition rates and related C and N dynamics of needle litters and broadleaved litters during the early stage were compared. The results showed that the decomposition rates of pine needles were lower than those of broadleaved litters, which descended C and N cycling processes. However, the presence of C. japonicum or O. davidiana litter into pine needles increased the decomposition rates of pine needles and also dramatically promoted C and N cycling processes. It should be appropriate for plantation managers to consider C. japonicum as an ameliorative species or remain O. davidiana in pine plantations to improve soil conditions and help maintain soil fertility. The laboratory incubation still showed that DOC and DON contents in all litter-amended treatments were significantly higher than no litter-amended treatment, which proved that litter could be a direct source of DOM in soils. Different species litters induced different soil DOC and DON contents, which correspondingly changed over time. DOC and DON contents in mixed litter treatments were higher than those in pine needle litter treatments. As a major soluble N pool, DON developed a different changing pattern over time compared with inorganic N and played a role of interim N pool in soil N cycling.
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