926 resultados para Philodemus, ca. 110-ca. 40 B.C.
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Twelve commonly occurring coenocytic and siphonaceous species of marine benthic algae, i.e., Bryopsis pennatta Lamouroux, Caulerpa chemnitzia (Esper) Lamouroux, Ca. faridii Nizamuddin, Ca. manorensis Nizamuddin, Ca. racemosa (Forsskal) J. Agardh, Ca. taxifolia. (Vahl) C. Agardh, Chaetomorpha antennina (Bory de Saint-Vincent) Kutzing, Cladophora uncinella Harvey, Codium decorticatum (Woodward) Howe, Co. flabellatum Nizamuddin, Co. iyengarii Borgesen, and Valoniopsis pachynema (Martens) Borgesen, belonging to four different orders of the class Bryopsidophyceae, division Chlorophyta, were collected from the intertidal region of different coastal areas near Karachi (Pakistan) and investigated taxonomically. Codium decorticatum is a new report from this region and Co. decorticatum, Co. flabellatum and Co. iyengarii are described for the first time from the coast of Pakistan.
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This study examines the kinetics of carbonation by CO2 at temperatures of ca. 750 °C of a synthetic sorbent composed of 15 wt% mayenite (Ca12Al14O33) and CaO, designated HA-85-850, and draws comparisons with the carbonation of a calcined limestone. In-situ XRD has verified the inertness of mayenite, which neither interacts with the active CaO nor does it significantly alter the CaO carbonation–calcination equilibrium. An overlapping grain model was developed to predict the rate and extent of carbonation of HA-85-850 and limestone. In the model, the initial microstructure of the sorbent was defined by a discretised grain size distribution, assuming spherical grains. The initial input to the model – the size distribution of grains – was a fitted parameter, which was in good agreement with measurements made with mercury porosimetry and by the analysis of SEM images of sectioned particles. It was found that the randomly overlapping spherical grain assumption offered great simplicity to the model, despite its approximation to the actual porous structure within a particle. The model was able to predict the performance of the materials well and, particularly, was able to account for changes in rate and extent of reaction as the structure evolved after various numbers of cycles of calcination and carbonation.
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比较了云南高黎贡山地区的贡山独龙江和腾冲大蒿坪白颌大角蟾(Megophryslateralis)两个地理种群的核型、C-带和Ag-NORs结果表明,两个地理种群在核型和带型上都有差异两个地理种群的核型均为2n=26,NF=52染色体形态差异不明显,而次缢痕的位置完全不同,贡山独龙江标本的次缢痕位于No.2的长臂上近着丝点处,腾冲标本的次缢痕位于No.5的短臂上近着丝点的部位在腾冲标本中发现一雄性个体中有一条额外的染色体,可能是B染色体两地标本的C-带差异不太显著,贡山独龙江标本的C-带相对较为显著.贡山独龙江标本的Ag-NORs位于No.2长臂近着丝点处,与次缢痕的部位对应,两条同源染色体上大小有显著差异.腾冲标本的Ag-NORs位于No.5短臂上近着丝点处,与次缢痕的部位对应依据核型和带型的比较,对白颌大角蟾的分类和进化问题进行了讨论。
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银额果蝇昆明群体有丝分裂中期核型中存在B染色体, 出现频率为69.1%在已 研究过的来自各个地区的银额果蝇中, 昆明群体的B染色体频率最高。B染色体 数目为1—6条。该群体内单雌系间的B染色体数目不同, 个体间和细胞间的B染色 体数目也不同。在核型中, B染色体最小, 形态稳定, 点状, C-带和G-带呈阳性 。 图版1图2表1参12
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Physical model experiments on compensation grouting in sands were performed in two different setups (Cambridge and Delft). The effect of water-cement (w/c) ratio, bentonite content (b.c.) and injection rate on compensation efficiency was investigated. Results show a considerable drop in compensation efficiency resulted from reducing the soil density. Injection in dense sand (R.D. = 93%) resulted in efficiencies between 40-90%, whereas injection in medium-dense sand (R.D. = 60-75%) yielded in reduced efficiencies between 10-40%. When the w/c ratio increased from 0.5 to 1.5 for a given density (R.D. = 93%) and the b.c. of 4%, the compensation efficiency value decreased. Typical efficiencies were between 60% and 40-50% for w/c ratios of 0.5 and 1.5, respectively. The values of compensation and grout efficiencies were almost equal, suggesting that pressure filtration happens mainly during injection. Increasing the b.c. improved the compensation efficiency. When a higher b.c. of 12% to 14% was used, typical compensation efficiencies in dense sand were 78 and 90% for w/c ratios of 1.5 and 1.8 respectively. © 2012 Taylor & Francis Group.
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鲤科是鱼类最大的科,在中国淡水鱼类组成中鲤科鱼类的成分占一半以上.鲤科鱼类的演化过程代表了东亚淡水鱼类的整体演化过程.为探讨东亚鲤科鱼类系统发育关系,共分析了包括18种新测序列在内的54种鲤科鱼类细胞色素b基因的全序列.分析的物种涵盖了鲤科鱼类的12个亚科并对问题较多的(鱼丹)亚科(Danioninae)和雅罗鱼亚科(Leuciscinae)进行了广泛的采样.系统发育树的建立使用了多种方法,包括邻接法、最大简约法和最大似然法.亚口鱼科(Catostomidae)的胭脂鱼(Myxocyprinus asia
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Psychological factors play a major role in exacerbating chronic pain. Effective self-management of pain is often hindered by inaccurate beliefs about the nature of pain which lead to a high degree of emotional reactivity. Probabilistic models of perception state that greater confidence (certainty) in beliefs increases their influence on perception and behavior. In this study, we treat confidence as a metacognitive process dissociable from the content of belief. We hypothesized that confidence is associated with anticipatory activation of areas of the pain matrix involved with top-down modulation of pain. Healthy volunteers rated their beliefs about the emotional distress that experimental pain would cause, and separately rated their level of confidence in this belief. Confidence predicted the influence of anticipation cues on experienced pain. We measured brain activity during anticipation of pain using high-density EEG and used electromagnetic tomography to determine neural substrates of this effect. Confidence correlated with activity in right anterior insula, posterior midcingulate and inferior parietal cortices during the anticipation of pain. Activity in the right anterior insula predicted a greater influence of anticipation cues on pain perception, whereas activity in right inferior parietal cortex predicted a decreased influence of anticipatory cues. The results support probabilistic models of pain perception and suggest that confidence in beliefs is an important determinant of expectancy effects on pain perception.
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Expectations about the magnitude of impending pain exert a substantial effect on subsequent perception. However, the neural mechanisms that underlie the predictive processes that modulate pain are poorly understood. In a combined behavioral and high-density electrophysiological study we measured anticipatory neural responses to heat stimuli to determine how predictions of pain intensity, and certainty about those predictions, modulate brain activity and subjective pain ratings. Prior to receiving randomized laser heat stimuli at different intensities (low, medium or high) subjects (n=15) viewed cues that either accurately informed them of forthcoming intensity (certain expectation) or not (uncertain expectation). Pain ratings were biased towards prior expectations of either high or low intensity. Anticipatory neural responses increased with expectations of painful vs. non-painful heat intensity, suggesting the presence of neural responses that represent predicted heat stimulus intensity. These anticipatory responses also correlated with the amplitude of the Laser-Evoked Potential (LEP) response to painful stimuli when the intensity was predictable. Source analysis (LORETA) revealed that uncertainty about expected heat intensity involves an anticipatory cortical network commonly associated with attention (left dorsolateral prefrontal, posterior cingulate and bilateral inferior parietal cortices). Relative certainty, however, involves cortical areas previously associated with semantic and prospective memory (left inferior frontal and inferior temporal cortex, and right anterior prefrontal cortex). This suggests that biasing of pain reports and LEPs by expectation involves temporally precise activity in specific cortical networks.
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稀土掺杂的长余辉发光玻璃是一种新型的发光材料,其应用范围可以从传统的弱光照明领域延伸到信息存储领域。我们在探找新型的长余辉发光玻璃体系的过程中,总结了一些设计长余辉玻璃材料的方法,研究了稀土离子在玻璃基质中的发光行为和斓系离子与材料中缺陷的作用。我们在论文中首次报道了稀土掺杂的碱土硼硅酸盐玻璃的长余辉发光和光激励长余辉发光现象。试激活的碱土硼硅酸盐玻璃(Ro-BZO3-5102:TbZo3,R=Mg,cas几B。)在254 nm紫外光辐照30 min以后,余辉时间长达6-10个小时。将激发后的玻璃避光保存24小时至余辉消失后,再使用低能量的366 nm的紫外光檄发样品,玻璃会重新发射长余辉,即产生光激励长余辉发光;而未预先经254 nm紫外光辐照的玻璃没有光激励长余辉现象发生。在这一体系中,光激励长余辉的衰减与首次激发的长余辉的衰减具有不同的衰减规律,辅以吸收光谱和热释光谱的表征,我们对其发光的机理进行了探讨。我们还研究了三价稀土离子在碱土硼硅酸盐玻璃中的发光性质,以及共掺稀土和其他金属离子对试激活的碱土硼硅酸盐玻璃荧光和长余辉发光的影响。此外1本论文还首次报道了Du3+,Tm+和Zr4+等离子在玻璃中的长余辉发光现象。
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毛壳霉属(Chaetomium)和曲霉属(Aspergillus)真菌产生多种具有生物活性的化合物。为系统阐明两属微生物的次生代谢物,对三种毛壳霉、两种曲霉真菌分别进行固态发酵,以色谱和波谱技术研究发酵物中的成分,分离鉴定了51个化合物,其中23个为新化合物,测试了部分化合物对肿瘤细胞的活性。 1、从螺卷毛壳霉(C. cochloides)固态发酵物中分离鉴定了11个化合物,3个新化合物为螺卷毛壳霉素A~C(1~3)。化合物1、3及dethio-tetra (methylthio) chetomin(4)对Bre-04、Lu-04和N-04细胞株生长抑制的GI50值为0.05~7.0 μg/mL。 2、从印度毛壳霉(C. indicum)固态发酵物中鉴定的三个异喹啉生物碱印度毛壳霉素A~C(12~14)代表两类骨架新颖的异喹啉生物碱。 3、从巴西毛壳霉(C. brasiliense)固态发酵物中鉴定了11个化合物,其中Mollicellins I~J(15~16)、2-Hydroxymethyl-6-methylmethyleugenin(19)为新化合物。化合物16和Mollicellin H(18)对Bre-04、Lu-04、N-04细胞株生长抑制的GI50值在2.5~8.6 μg/mL。 4、从土曲霉(A. terreus)固态发酵物中鉴定了18个化合物。5个为新化合物为Terretonin A~D(24~27)和Asterrelenin(28),24~27为二倍半萜化合物,28为吲哚生物碱。 5、从杂色曲霉(A. versicolor)固态发酵物中鉴定了16个化合物。9个新的化合物Brevianamides K~N (40~43)、Averins A~C (44~46)和Glyanphenines A~B (47~48)代表三种类型的生物碱。 6、综述了1997-2007年间新的二倍半萜的研究进展。 The fungi of the genera Chaetomium and Aspergillus produce various secondary metabolites with biological activities. In order to systematically study the secondary metabolites, the solid-state fermented rice culture of three species of Chaetomium and two of Aspergillus were chemically studied. By the means of chromatograhy and spectroscopy, 55 compounds were isolated and identified, among of them 23 were new ones. The biological activities of some compounds were investigated. 1. From the fungus C. cochliodes, three new epipolythiodioxopiperazines, chaetocochins A-C (1-3) were isolated, together with 8 known ones (4-11). Compounds 1, 3 and 4 showed growth inhibitory effects against cancer cell lines Bre-04, Lu-04 and N-04 with GI50 values from 0.05 to 7.0 μg/mL. 2. Three novel isoquinolines Chaetoindicins A-C (12-14) were isolated and identified from the fungus C. indicum. Chaetoindicin A, Chaetoindicins B-C represented two classes of novel carbon skeletons. 3. Three new compounds, Mollicellins I-J (15-16), and 2-hydroxymethyl-6-methylmethyleugenin (19), were isolated from C. brasiliense. Compound 16 and Mollicellin H (18) showed growth inhibitory effects against cancer cell lines Bre-04, Lu-04 and N-04 with GI50 values from 2.5 to 8.6 μg/mL. 4. Eighteen compounds were isolated from the fungus A. terreus. Terretonin A-D(24 - 27)and Asterrelenin(28) are new compounds belonging to sesterterpoids and indole-ralated alkaloid, respectively. 5. From the fungus A. versicolor, sixteen secondary metabolites, including nine new ones, Brevianamides K-N (40-43), Averins A-C (44-46), and Glyanphenines A-B (47-48), were isolated and identified. Brevianamides K-N (40-43), Averins A-C (44-46), and Glyanphenines A-B (47-48) represented three classes of alkaloids. 6. New sesterterpenes and their bioactivities reported from 1997 to 2007 were summarized.
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从新几内亚核桃木的树皮中分离得到的吲哚类喹诺里西定生物碱10-Desbromoarborescidine A,因发现其具有阻滞钙离子通道的活性而倍受关注。10-Desbromoarborescidine A由A、B、C、D四个环组成,只有一个手性中心,是吲哚生物碱中结构较简单的一种,常作为此类生物碱全合成方法的模型化合物。但迄今为止,能高效而简便的实现手性10-Desbromoarborescidine A不对称全合成方法线路不多,大多数以不对称诱导的方式建立其手性中心,手性催化的方式仅有一例金属催化。从逆合成分析可知,Desbromoarborescidine A的全合成可以通过亚胺不对称催化还原进行关键的手性中心构建,而本课题组在之前的研究中通过手性有机小分子催化剂的发展,已将三氯硅烷氢转移还原亚胺发展成了一类简便实用、高效、高对映选择性并具有优良底物适应范围的不对称催化反应,我们希望以这一反应作为关键手段,发展一条Desbromoarborescidine A及其类似物不对称合成新路线。 根据我们设计的新路线,首先成功合成了其关键中间体,然后我们进行了关键的不对称催化尝试。用本实验室已有的高性能有机小分子催化剂虽得到了较好的对应选择性,但是产率很低。同时,为了验证整条线路的可行性,我们也用消旋的中间体进行拉通线路的尝试。但不幸的是,在脱除保护基时遇到了很大困难。尝试换不同的保护基,或改变脱保护基的顺序,都未能成功合成目标产物。究其原因可能是由于吲哚的特殊性造成的,吲哚类亚胺与常规的芳香亚胺有较大的差异,其NH基团无论保护还是不保护,对与其2位相联接的C=N双键均有很大的影响,导致其不对称催化还原难以进行。另外,由于所设计的还原产物含有处在吲哚苄位的胺基,稳定性较差,造成保护基脱除困难。 烯胺C-亚磺酰化反应是本课题组最近发现的一个新反应,之前未见文献报道。本研究对该反应进行了反应条件优化和底物扩展,发现带Cbz,Ac,COt-Bu,CO2Et,Bz等保护基的一系列环状和非环状烯胺在亚磺酸钠、DMAc和MeSiCl3的共同作用下能高效高产率生成β-胺基烯基亚砜类新化合物,为合成多官能团化的烯基亚砜新化合物提供了一条简便实用的途径。 The main constituent of Dracontomelum mangiferum B1, indoloquinolizidine alkaloid 10-Desbromoarborescidine A, has drawn great attention due to its calcium channel blocking activity. Its molecular structure is relatively simple compared with the other alkaloids of the same type, which has only one chiral center, albeit with four cycles A, B, C, and D. This compound is often used as a model target for exploring different strategies for the total synthesis of indole alkaloids. Nevertheless, so far there still lack practical and highly efficient methods for the asymmetric total synthesis of 10-Desbromoarborescidine A. Most of the current available methods rely on stoichiometric asymmetric synthesis for the construction of the chiral center. There is only one example reporting utilization of asymmetric catalysis, but with transition metal complex as the catalyst. Our retrosynthetic analysis shows that catalytic asymmetric reduction of imine could be used as the key step for the construction of the chiral center of Desbromoarborescidine A. Since in the previous studies our group has developed the asymmetric reduction of imines by trichlorosilane into a practical and highly efficient and enantioselective method using newly designed chiral organocatalysts, we hope to apply this method to develop a novel synthetic route for the total synthesis of Desbromoarborescidine A and its analogues in this study. According to the newly designed synthetic route, we first accomplished the synthesis of the key intermediates which was then examined for the critical asymmetric catalysis. The asymmetric reduction using the highly efficient organocatalysts, developed in our lab afforded high ee but poor yield. We tried different reaction conditions to improve the yield, but failed to get any good results. Simultaneously, to vertify the feasibility of the synthetic route we designed, we also tired to go through the route toward the racemic synthesis of Desbromoarborescidine A. But unfortunately, protection and deprotection proved to be big hurdles. All the different protection groups and different sequences of protection and deprotection we tried failed to get us through the designed synthetic sequence and furnish the final product. Most likely, the indole part is the culprit behind the failures.The NH group of the indole, no matter protected or not, may impact the catalytic asymmetric reduction of C-N double bond connected with 2-C. Additionally, the reduction product we designed contains an amino group in the β-position of the indole, which may cause problems due to its instability. C-sulfenylation of enamines is a novel reaction discovered recently by our group, which has not been seen before in the literature. In this study, optimization of the reaction conditions and exploration of the substrate scope were further undertaken for this reaction, which reveal that a series of enamines with N-Cbz, Ac, COt-Bu, CO2Et protection groups could all undergo smooth C-sulfinylations with the comined use of sodium benzene sulphinate, DAMc and MeSiCl3, efficiently furnishing the β-amino vinylsulfoxide products in high yield, affording a practical and highly efficient methods for synthesis of functional vinylsulfoxides.
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大气臭氧的损耗导致了地球表面具有生物学效应的紫外线-B(UV-B)辐射增强。同时,大气成分变化中除了UV-B辐射增强外,氮沉降是一个新近出现而又令人担忧的环境问题,其来源和分布正在迅速扩展到全球范围,并不断向陆地和水生生态系统沉降。本试验在四川省境内的中国科学院茂县生态站内进行,以云山、冷杉、色木槭和红椋子幼苗为模式植物,从生长形态、光合作用、抗氧化能力和矿质营养等方面研究了青藏高原东缘4种树苗对全球变化-增强UV-B辐射和氮供应(氮沉降)的响应。该试验为室外盆栽试验,包括四个处理:(1)大气UV-B辐射+无额外的氮供应(C);(2)大气UV-B辐射+额外的氮供应(N);(3)增强UV-B辐射+无额外的氮供应(UV-B);(4)增强UV-B辐射+额外的氮供应(UV-B+N)。其目的:一方面有助于丰富我国对全球变化及区域响应研究的全面认识,进一步完善在全球气候变化条件下臭氧层削减和氮沉降对陆地生态系统影响的内容;另一方面,在一定程度上有助于我们更好的理解在全球变化下森林更新的早期过程。具体结果如下: 增强的UV-B辐射在生长形态、光合、抗氧化能力、活性氧和矿质营养方面对4种幼苗都有显著的影响。UV-B辐射增强对幼苗的影响不仅与物种有关,而且,还与氮营养水平相关。总体表现为,高的UV-B辐射导致了色木槭和红椋子幼苗叶片的皱缩和卷曲,并降低了色木槭幼苗的叶片数和叶重,在额外的氮供应下,云杉、冷杉和红椋子的叶重也显著地降低了;色木槭和红椋子幼苗叶片的解剖结构受到了增强的UV-B辐射的影响,增强的UV-B辐射显著地降低了色木槭叶片的栅栏组织厚度,提高了红椋子叶片的厚度;增强的UV-B辐射显著地降低了4种幼苗的单株总生物量、植物地下部分的生长、总叶绿素含量 [Chl (a + b)]、净光合速率和最大量子产量(Fv/Fm),提高了4种幼苗叶片的膜脂过氧化(MDA含量),改变了植物体不同器官中的矿质元素含量;增强的UV-B辐射提高了冷杉、色木槭和红椋子叶片中的过氧化氢含量(H2O2)、超氧负离子(O2-)生成速率,在额外的氮供应下,云杉叶片中的活性氧含量也显著地提高了;在无额外的氮供应条件下,增强的UV-B辐射显著地提高了4种幼苗叶片中的UV-B吸收物质、脯氨酸含量和抗氧化酶的活性(SOD、POD、CAT、GR和APX)。在额外的氮供应条件下,UV-B辐射的增强却显著地降低了冷杉叶片中脯氨酸含量和红椋子叶片中UV-B吸收物质含量,但是,在4种幼苗叶片中,5种抗氧化酶的活性对UV-B辐射的增强没有明显的规律性,增强的UV-B辐射显著地提高了云杉叶片中的POD、SOD和GR的活性,提高了冷杉叶片中的POD和GR活性,提高了色木槭叶片中的POD、SOD和CAT活性和红椋子幼苗叶片中的POD和SOD活性。从这些结果可知,植物在遭受高的UV-B辐射导致的过氧化胁迫时,植物体内形成了一定的保护机制,但是,这种保护不能抵抗高的UV-B辐射对植物的伤害。 额外的氮供应在生长形态、光合、抗氧化能力、活性氧和矿质营养方面对4种幼苗都有一定的影响,不同幼苗对额外的氮供应响应不同,并且受到UV-B辐射水平的影响。在当地现有的UV-B辐射水平下,额外的氮供应显著地提高了幼苗的单株总生物量、植物地下部分的生长、Chl (a + b)、净光合速率(红椋子除外)、UV-B吸收物质(冷杉除外)、脯氨酸含量(红椋子除外)和部分抗氧化酶的活性,降低了H2O2的含量、O2-的生成速率和MDA含量(红椋子除外),改变了植物体内部分矿质元素含量,显著地提高了云杉和冷杉叶片中的Fv/Fm。这些指标总体表明,在当地现有大气UV-B辐射水平下,额外的氮供应对植物的生长和发育是有利的。在增强的UV-B辐射水平下,4种幼苗的生长形态和光合大部分指标都没有受到额外氮供应的影响,额外的氮供应提高了红椋子幼苗的单株总生物量和Chl (a + b)含量,提高了冷杉和色木槭叶片中的活性氧含量和MDA含量,却降低了红椋子叶片中的活性氧含量;额外的氮供应也提高了云杉、色木槭和红椋子叶片中UV-B吸收物质和脯氨酸含量,降低了冷杉叶片中UV-B吸收物质和脯氨酸含量;在抗氧化酶活性方面,额外的氮供应降低了云杉、冷杉叶片中5种抗氧化酶的活性和红椋子叶片中POD和GR的活性,提高了色木槭叶片中的POD和SOD的活性;4种幼苗植物体内的矿质元素含量对额外的氮供应没有显著的规律性。从这些结果可知,在高的UV-B辐射下,额外的氮供应提高了云杉、冷杉和色木槭幼苗对高的UV-B辐射的敏感性,然而,额外的氮供应却促进了红椋子幼苗的生长,原因可能是,在高的UV-B辐射下,额外的氮供应增加了红椋子叶片的厚度、叶重和叶片数,降低了叶片中活性氧含量的结果。表明在高的UV-B辐射水平下,额外的氮供应降低了红椋子幼苗对高的UV-B辐射的敏感性。 在全球变化的趋势下,UV-B辐射增强和氮沉降可能同时存在,我们的研究表明,与大气UV-B辐射+无额外的氮供应处理相比,增强UV-B辐射+额外的氮供应处理显著地降低了幼苗的单株总生物量(红椋子除外)、Chl (a + b)、净光合速率、Fv/Fm(冷杉除外)和MDA含量(红椋子除外),提高了活性氧含量 (云杉除外)、UV-B紫外吸收物质含量(冷杉除外)、脯氨酸含量和部分抗氧化酶的活性,改变了植物体不同器官中的矿质元素含量。结果表明,在当地现有条件下,全球变化(UV-B辐射增强和氮沉降)对云杉、冷杉和色木槭幼苗的生长是不利,尽管植物体内一些抗氧化性指标提高了,然而,却对红椋子幼苗的单株总生物量的累积没有显著的影响。 The depletion of the ozone led to the increase of ultraviolet-B (UV-B) with biological effects in the earth’s surface. At the same time, except for enhanced UV-B radiation, nitrogen deposition was an anxious environmental problem at present, rapidly expanding to the global scope and continuously depositing to land and aquatic ecosystem. The experiment was conducted in Maoxian Ecological Station of Chinese Academy of Sciences, Sichuan province, China. Picea asperata, Abies faxoniana, Acer mono Maxim and Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings were selected as model plants to assess the effects of enhanced UV-B radiation and supplemental nitrogen supply on growth, morphological, photosynthesis, antioxidant and mineral nutrient traits of 4 species seedlings in east Qinghai-Tibetan Plateau. The experiment was potted outdoor, including 4 treatments: (1) ambient UV-B without supplemental nitrogen (control, C); (2) ambient UV-B with supplemental nitrogen (N); (3) enhanced UV-B without supplemental nitrogen (UV-B); (4) enhanced UV-B with supplemental nitrogen (UV-B+N). One hand, it was helpful for enriching our country to comprehensive understanding of the researches in the global change and the region response, further perfecting the effects of the depleted ozone layer and nitrogen deposition on land ecosystem under the global change; the other hand, it was favorable for us to better understanding of the early process of forest renews under the global change. The results were as follows: Enhanced UV-B radiation had significant effects on 4 species seedlings in growth, morphological, photosynthesis, antioxidant and mineral nutrient traits of 4 species seedlings. The effects of enhanced UV-B on plants were not only related with species, but also related with nitrogen nutrient level. Generally, the increase of UV-B radiation led to the shrinkage and curl of leaves in Acer mono Maxim and Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings, and reduced the number of leaf and leaf weight of Acer mono Maxim seedlings, under supplemental nitrogen supply, leaf weight of Picea asperata, Abies faxoniana and Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings significantly also reduced; the anatomical features of leaf in Acer mono Maxim and Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings affected by enhanced UV-B radiation, the increase of UV-B radiation markedly reduced the palisade tissue thickness of Acer mono Maxim leaf and enhanced the leaf thickness of Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings; the enhanced UV-B radiation significantly reduced total biomass per plant of 4 species seedlings, the growth of the underground parts, Chl (a + b), net photosynthetic rate and maximum potential quantum yield of photosynthesis (Fv/Fm), and increased the degree of lipid peroxidation (MDA content) and changed the content of mineral elements in different parts of plants; the enhanced UV-B radiation also increased the rate of superoxide radical (O2-) production and hydrogen peroxide (H2O2) content in leaves of Abies faxoniana, Acer mono Maxim, Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings, under supplemental nitrogen supply, the reactive oxygen species in leaves of Picea asperata seedlings also significantly increased by enhanced UV-B radiation; under without supplemental nitrogen supply, enhanced UV-B radiation evidently induced an increase in UV-B absorbing compounds, proline content and the activities of antioxidant enzymes (SOD, POD, CAT, GR and APX) of leaves in 4 species seedlings. Under supplemental nitrogen supply, enhanced UV-B radiation induced a decrease in proline content of leaves in Abies faxoniana seedlings and UV-B absorbing compounds of leaves in Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings, but, there were no obvious rules in the activities of five antioxidant enzymes of 4 species seedling leaves to enhanced UV-B radiation, enhanced UV-B radiation significantly increased the activities of POD, SOD and GR in Picea asperata leaves, the activities of POD and GR in Abies faxoniana leaves and the activities of POD, SOD and CAT in Acer mono Maxim leaves. The results indicated that some protective mechanism was formed when plants were exposed to enhanced UV-B radiation, but the protection could not counteract the harm of high UV-B radiation on plants. Supplemental nitrogen supply had some effects on 4 species seedlings in growth, morphological, photosynthesis, antioxidant and mineral nutrient traits. The response of 4 species seedlings was different to supplemental nitrogen supply, and was affected by UV-B levels. Under local ambient UV-B radiation, supplemental nitrogen supply significantly increased the total biomass per plant, the growth of underground parts, Chl (a + b), net photosynthetic rate (except for Acer mono Maxim seedlings), UV-B absorbing compounds (except for Abies faxoniana seedlings), proline content (except for Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings) and the activities of some antioxidant enzymes, and reduced H2O2 content, the rate of O2- production and MDA content (except for Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings) and changed the content of mineral elemental in different parts; supplemental nitrogen supply also evidently increased Fv/Fm in Picea asperata and Abies faxoniana seedlings. These results indicated that supplemental nitrogen supply was favorable for the growth of plants under local ambient UV-B radiation. Under enhanced UV-B radiation, mostly parameters in growth and morphology of 4 species seedlings were not affected by supplemental nitrogen supply. Supplemental nitrogen supply increased the total biomass per plant and Chl (a + b) of Swida hemsleyi (Schneid. et Wanger.) Sojak seedling, increased the reactive oxygen species and MDA content in Abies faxoniana and Acer mono Maxim leaves, and reduced the reactive oxygen species in Swida hemsleyi (Schneid. et Wanger.) Sojak leaves; supplemental nitrogen supply also increased UV-B absorbing compounds and proline content in Picea asperata, Acer mono Maxim and Swida hemsleyi (Schneid. et Wanger.) Sojak leaves, decreased UV-B absorbing compounds and proline content in Abies faxoniana leaves; in the activities of antioxidant enzymes, supplemental nitrogen supply significantly reduced the activities of antioxidant enzymes in Picea asperata and Abies faxoniana leaves and the activities of POD and GR in Swida hemsleyi (Schneid. et Wanger.) Sojak leaves, and increased the activities of POD and SOD in Acer mono Maxim leaves; the content of mineral elements in 4 species seedlings was no significantly rule to supplemental nitrogen supply. We knew from the results, under enhanced UV-B radiation, supplemental nitrogen supply made Picea asperata, Acer faxoniana and Acer mono Maxim seedlings more sensitivity to enhanced UV-B radiation, however, accelerated the growth of Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings. The reason was probably that supplemental nitrogen supply increased the leaf thickness, leaf weight and leaf number, reduced the reactive oxygen content of leaf in Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings grown under high UV-B radiation. This showed that supplemental nitrogen supply reduced the sensitivity of Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings to high UV-B radiation. Under the tendency of the global change, enhanced UV-B radiation and nitrogen deposition may probably coexist. The results showed, compared with the treatment of ambient UV-B radiation without supplemental nitrogen supply, the treatment of enhanced UV-B radiation with supplemental nitrogen supply significantly reduced the total biomass per plants (except for Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings), Chl (a + b), net photosynthetic rate, Fv/Fm and MDA content (except for Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings), and increased reactive oxygen content (except for Picea asperata seedlings), UV-B absorbing compounds (except for Abies faxoniana seedlings), proline content and part antioxidant enzymes, and changed the content of mineral elements of different parts. The results indicated that the global change (enhanced UV-B and nitrogen deposition) were not favorable for the growth of plants under local ambient UV-B radiation and nitrogen nutrient level,, though increased some antioxidant indexes, however, the treatment of enhanced UV-B with supplement nitrogen supply did not significantly affect on the biomass accumulation of Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings.
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近十年,植物群体遗传学的研究飞速发展,然而与海拔相关的植物群体遗传结构和遗传变异研究却相对较少。到目前为止,还不清楚遗传变异与海拔之间是否有一个通用的格局。在山区,各种生态因子,如温度、降水、降雪、紫外线辐射强度以及土壤成分都随海拔梯度急剧变化,造成了即使在一个小的空间区域,植被类型变化显著,这种高山环境的异质性和复杂性为我们研究植物群体遗传结构和分化提供了方便。沙棘(Hippophea)属于胡颓子科(Elaeagnaceae)为多年生落叶灌木或乔木,雌雄异株,天然种群分布极为广泛。中国沙棘(H. rhamnoides subsp. sinensis)是沙棘属植物中分布较广的一个亚种,种内形态变异非常丰富,加之其具有独特的繁育系统和广泛的生态地理分布,是研究沙棘属植物遗传变异和系统分化的理想材料。本文从1,800 m 到3,400 m 分5 个海拔梯度进行取样,用RAPD 和cpSSR 分子标记研究了卧龙自然保护区中国沙棘天然群体的遗传结构和遗传变异。5 个取样群体依次标记为A、B、C、D 和E,它们分别代表分布在海拔1,800,2,200,2,600,3,000 和3,400 m 的5 个天然群体。RAPD实验用11 条寡核苷酸引物,扩增得到151 个重复性好的位点,其中143 个多态位点,多态率达94.7%。在5 个沙棘群体中,总遗传多样性值(HT)为0.289,B群体内的遗传多样性值为0.315,这完全符合沙棘这种多年生、远交的木本植物具有高遗传变异的特性。5 个群体内遗传多样性随海拔升高呈低-高-低变异趋势,在2,200 m海拔处的B群体遗传多样性达最大值0.315,3,400 m海拔处的E群体则表现最小仅0.098。5 个群体间的遗传分化值GST=0.406,也即是说有40.6%的遗传变异存在于群体间,1,800 m海拔处的A群体与其它群体的明显分离是造成群体间遗传分化大的原因。UPGMA聚类图和PCoA散点图进一步确证了5 个群体间的关系和所有个体间的关系。最后,经过Mantel检测,遗传距离与海拔表现了明显的相关性(r = 0.646, P = 0.011)。cpSSR 实验中,经过对24 对cpSSR 通用引物筛选,11 对引物能扩增出特异性条带,只有2 对引物(ccmp2 和ARCP4)呈现多态性。4 个等位基因共组合出4 种单倍型,单倍型Ⅰ出现在A 群体的所有个体和B 群体的8 个个体中,C、D、E 三个群体均不含有,而单倍型Ⅱ出现在C、D、E 三个群体的所有个体及B 群体的18 个个体中,A 群体不含有。另外两种单倍型Ⅲ和Ⅳ为稀有类型,仅B 群体中的4 个个体拥有。这种单倍型分布模式和TFPGA 群体聚类图揭示了,C、D、E 群体可能来源于同一祖先种,而A 群体却是由另一祖先种发展起来的,B 群体则兼具了这两种起源种的信息,这可能是因为在历史上的某一时期,在中国沙棘群体高山分化的过程中,B 群体处某个或者某些个体发生了基因突变,具备了适应高海拔环境的能力,产生了高海拔沙棘群体的祖先种。 In recent ten years, studies about population genetics of plants developed rapidly,whereas their genetic structure and genetic variation along altitudinal gradients have beenstudied relatively little. So far, it is uncleared whether there is a common pattern betweengenetic variation and altitudinal gradients. In the mountain environments, importantecological factors, e.g., temperature, rainfall, snowfall, ultraviolet radiation and soil substratesetc., change rapidly with altitudes, which cause the vegetation distribution varying typically,even on a small spatial scale. The mountain environments, which are heterogeneous andcomplex, facilitate and offer a good opportunity to characterize population genetic structureand population differentiation.The species of the genus Hippophae L. (Elaeagnaceae) are perennial deciduous shrubs ortrees, which are dioecious, wind-pollinated pioneer plants. The natural genus has a widedistribution extending from Northern Europe through Central Europe and Central Asia toChina. According to the latest taxonomy, the genus Hippophae is divided into six species and12 subspecies. The subspecies H. rhamnoides ssp. sinensis shows significant morphologicalvariations, large geographic range and dominantly outcrossing mating system. Thesecharacteristics of the subspecies are favourable to elucidate genetic variation and systemevolution. To estimate genetic variation and genetic structure of H. rhamnoides ssp. sinensisat different altitudes, we surveyed five natural populations in the Wolong Natural Reserve at altitudes ranging from 1,800 to 3,400 m above sea level (a.s.l.) using random amplifiedpolymorphic DNA markers (RAPDs) and cpSSR molecular methods. The five populations A,B, C, D, and E correspond to the altitudes 1,800, 2,200, 2,600, 3,000 and 3,400 m,respectively.Based on 11 decamer primers, a total of 151 reproducible DNA loci were yielded, ofwhich 143 were polymorphic and the percentage of polymorphic loci equaled 94.7%. Amongthe five populations investigated, the total gene diversity (HT) and gene diversity within population B equaled 0.289 and 0.315, respectively, which are modest for a subspecies of H.rhamnoides, which is an outcrossing, long-lived, woody plant. The amount of geneticvariation within populations varied from 0.098 within population E (3,400 m a.s.l.) to 0.315within population B (2,200 m a.s.l.). The coefficient of gene differentiation (GST) amongpopulations equaled 0.406 and revealed that 40.6% of the genetic variance existed amongpopulations and 59.4% within populations. The population A (1,800 m a.s.l.) differed greatlyfrom the other four populations, which contributes to high genetic differentiation. A UPGMAcluster analysis and principal coordinate analyses based on Nei's genetic distances furthercorroborated the relationships among the five populations and all the sampling individuals,respectively. Mantel tests detected a significant correlation between genetic distances andaltitudinal gradients (r = 0.646, P = 0.011).Eleven of the original 24 cpSSR primer pairs tested produced good PCR products, onlytwo (ccmp2 and ARCP4) of which were polymorphic. Four total length variants (alleles) werecombined resulting in 4 haplotypes. The haplotype was present in all individuals of Ⅰpopulation A and 8 individuals of populations B, the other three populations (C, D and Epopulations) did not share. The haplotype was present in all individuals of populations C, D Ⅱand E and 18 individuals of populations B, population A did not share. The other twohaplotypes and were rare haplotypes, which were only shared in 4 individuals of Ⅲ Ⅳpopulation B. The distribution of haplotypes and TFPGA population clustering map showedthat the populations C, D and E might be origined from one ancestor seed and population Amight be from another, whereas population B owned information of the two ancestor seeds. Itwas because that gene mutation within some individual or seed in the location of population Bwas likely to happen in the history of H. rhamnoides, which was the original ancestor of thehigh-altitude populations.
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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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青稞,是我国藏区居民对裸大麦的称谓,它不仅是藏民的主要食粮、燃料和牲畜饲料,而且也是啤酒、医药和保健品生产的原料;青稞不仅为藏区人民的健康和经济发展做出了很大的贡献,而且对人类健康和社会经济的可持续发展都有重要的意义。青藏高原是我国及世界上青稞分布和种植面积最大的地区,资源极其丰富。虽然从经典遗传直到分子标记对我国大麦遗传多样性都有研究,但研究手段、数量仍然不够深入,对我国大麦资源遗传多样性研究的信息非常有限,不能很好地满足大麦遗传研究和育种应用的需要,尤其是对西藏栽培大麦的遗传多样性的研究还只是刚刚开始,关于栽培青稞多态性的研究报道很少。本研究采用SSR标记和蛋白质电泳两类技术,从SSR标记位点、单体醇溶蛋白、B组醇溶蛋白和淀粉粒结合蛋白(SGP)等四个方面对我国青藏高原栽培青稞的遗传多样性进行了综合评价。 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。本研究采用SSR标记分析了64份青藏高原栽培青稞的遗传多样性,同时评估SSR标记在我国大麦育种和品种鉴定中的应用潜力。选择了30个已知作图位点SSR标记,其中25个标记与重要性状的控制位点连锁紧密。选择的30个SSR标记,5个未得到很好的扩增产物,3个无多态性。22个多态性SSR标记位点中,每位点检测出等位基因2~15个,共检测出等位基因132个,平均每位点6.0 个。各多态位点检测出基因型为2~11种,位点HVM33的基因型最多。各多态位点的多态信息指数为0.16~0.91, 平均为0.65。根据PIC值选择了13个SSR标记用于我国青藏高原栽培青稞基因型鉴定,这些标记的PIC值为0.6以上。结合PIC值和基因型差异,选择了8个多态信息含量高的SSR标记,构建了高效指纹图谱,此图谱能把64份材料完全区分。 贮藏蛋白电泳分析是研究相关编码蛋白基因多态性的非常有效的方法。大麦单体蛋白与小麦醇溶蛋白相对应,具有丰富的多态性,可用于大麦遗传多样性、品种鉴定和群体进化等研究。本研究通过A-PAGE电泳技术研究了84份青藏高原栽培青稞的单体醇溶蛋白多态性。大麦单体醇溶蛋白图谱与小麦醇溶蛋白电泳图谱类似,所分离的蛋白清晰地分为ω-,γ-,β-和α-四个部分。青藏高原栽培青稞单体醇溶蛋白具有丰富的多态性,84份青稞材料中存在43条不同的蛋白带,75种组合带谱;其中67种为单一材料所独有,另8种则分别包含了2-3份材料。每份材料中拥有醇溶蛋白带为6-16条,含有6-10条单体醇溶蛋白带材料较多。西藏和四川材料群体单体醇溶蛋白多态性不同,具有区域特异性。西藏材料中发现了40条不同蛋白带,3条特异带,46 种蛋白组合;四川材料中出现了40种不同蛋白带,26种条带组合, 3条特异带。基于单体蛋白多态性的聚类与材料的来源有一定的相关性。A-PAGE单体蛋白具有丰富的多态性,可作为遗传研究和品种鉴定的标记。 大麦醇溶蛋白(hordein)是大麦籽粒的主要贮藏蛋白,与大麦的营养品质和加工品质密切相关,而且具有丰富的多态性,广泛用于品种鉴定、种质筛选、遗传多样性和亲缘关系研究。B组醇溶蛋白是主要的醇溶蛋白组份,约占总醇溶蛋白的80%,而且具有丰富的多态性。本研究采用SDS-PAGE分析了72份青藏高原栽培青稞B组醇溶蛋白的遗传多样性。青藏高原栽培青稞B组醇溶蛋白具有丰富的多态性,72份青稞材料中存在15种蛋白带,30种组合带谱,其中15种为单一材料所独有,另15种则分别包含了2-10份材料。每份材料中B组醇溶蛋白条带数为4-8条,含5、6条的材料较常见。不同来源的群体材料间B组醇溶蛋白组成存在差异,西藏青稞含有26种蛋白组合带谱,其中有19种特异带谱;四川群体中共发现11种蛋白组合带型,其中有4种特有带谱。两群体中都存在稀有条带。聚类分析将材料分成三组,材料聚类与材料来源地没有明显的相关性。 淀粉粒蛋白(Starch granule proteins, SGPs)是一类与淀粉粒结合的微量蛋白,一些淀粉粒蛋白具有淀粉生化合成中主要的酶蛋白功能,其变异会影响淀粉含量和特性,从而影响淀粉的应用。关于我国大麦淀粉粒组成研究还未见报道。本实验首次开创了我国大麦淀粉粒结合蛋白的研究工作。采用SDS-PAGE电泳技术研究了青藏高原栽培青稞的SGP组成,并分析了不同SGP组合间淀粉含量的差异,初步探索了所分离的SGP蛋白与淀粉合成的关系。66份青稞材料中分离了10种主要的SGP,其表观分子量为40-100KD,低于60KD的SGP带有7条,共有16种组合带谱;各SGP蛋白和组合带谱出现的频率存在差异,青藏高原青稞的SGP组成存在多态性。西藏青稞和四川青稞的SGP组成有很大差异,SGP组成具有地域差异性,西藏青稞含有12种蛋白组合带谱,其中有9种特异带谱;四川群体中共发现7种蛋白组合带型,其中有4种特有带谱;两群体中仅有3种共同的蛋白组合带谱。SGP蛋白特性将66份青稞分为三组, 即Ⅰ、Ⅱ、Ⅲ,材料聚类与材料来源具有一定的相关性。不同组合带谱材料间淀粉含量差异显著性检验结果显示,不同带谱间材料的总淀粉含量、直链淀粉含量和支链淀粉含量有差异,带谱2(SGP1+3+7+9+10)和8(SGP1+2+4+6+8)的总淀粉含量及支链淀粉含量显著大于组合带谱3(SGP1+3+7+10)的总淀粉含量。组合带谱7(SGP1+2+6+8)的直链淀粉含量显著低于带谱11(SGP1+5+8)的直链淀粉。带谱SGP2、3、4、5、6、7、8、9、10可能参与淀粉合成,SGP9可能与高支链淀粉的合成相关。 SSR标记位点、单体醇溶蛋白、B组醇溶蛋白、淀粉结合蛋白等四个方面的研究结果表明青藏高原SSR标记多态性、单体醇溶蛋白多态性、B组醇溶蛋白多态性和SGP多态性都非常丰富,与青藏高原是栽培青稞的多样性分布中心的观点一致。 青藏高原栽培青稞的SSR标记、单体醇溶蛋白、B组醇溶蛋白和SGP多态性表现出很大差异。SSR标记覆盖了整个基因组,多态性非常高。单体蛋白、B组醇溶蛋白、SGP蛋白是育种中非常关注的性状,他们只是代表基因组中的某一区域或位点,多态性相对较低。但单体蛋白多态性很高,84份材料中检测出43条不同蛋白带,75种不同的组合带谱。SSR标记技术和单体蛋白技术都是遗传多样性研究的有力工具,但单体蛋白技术不仅多态性高,而且经济、操作简便,是种质鉴定的理想方法。 对不同标记的多态性材料数据进行聚类,聚类图能为我们提供各材料间的遗传相似信息,为材料选择提供参考。但材料聚类与材料来源的地理区域的相关性表现不一致。SSR聚类和B组醇溶蛋白聚类与材料的来源地无相关性,而单体醇溶蛋白和SGP聚类与材料来源地有一定相关性,即西藏群体和四川群体分别有集中类群,这可能是人为选择的附加效应。 不同来源的群体材料的遗传多样性不同,具有区域特异稀有基因,加强不同地区间资源的交换和配合使用,有利于增加群体遗传多样性和新品种培育。 青藏高原栽培青稞的麦芽浸提性状、淀粉性状、病虫及裸粒等重要农艺性状控制位点存在丰富的变异,遗传基础宽广,可能蕴藏着多种不同的等位基因,是研究重要性状遗传特性、基因资源挖掘和遗传育种的宝贵资源库。 Hulless barley, due to its favorable attributes such as high feed value, good human nutrition,rich dietary fiber and ease processing, attracts people,s attention . Hulless barley plays a very important role in Tibetan life, used as essential food crop, main animal feed and important fuel. In addition to tsampa (roasted barley flour), a main food for Tibetan, hulless barley is also made into cake, soup, porridge, recent naked barley liquor and cornmeal. Qinghai-Tibet Plateau is one of a few areas which plant naked barley widely in the world and also has a long growing history. Genetic diversity of the cultivated hulless barley in this region , however, has not been documented. The study of genetic diversity existing within this population is of particular interest in germplasm identification, preservation, and new cultivar development. This study analyzed the genetic diversity of the cultivated naked barley from Qinghai-Tibet plateau through the study of SSR marker loci and monomeric prolamins, B-horden and starch granule proteins. SSRs are present abundantly in genomes of higher organisms and have become a popular marker system in plant studies. SSRs offer a number of advantages, such as the high level of polymorphisms, locus specificity, co-dominance, reproducibility, ease of use through PCRand random distribution throughout the genome. In barley, several hundred SSRs have been developed and genetically mapped and can therefore be selected from specific genomic regions. The genetic diversity of 64 cultivated naked barley from Tibet and Sichuan was studied with 30 SSRs of known map location.Among the selected SSR markers, PCR products of 5 SSR markers were not obtained and 3 SSR marker loci were monomeric. A total of 132 alleles were identified at 22 polyomeric SSR loci. The number of alleles per locus ranged from 2 to 15, with an average of 6.0. The polymorphism information content values for the SSRs ranged from 0.08 to 0.94, with an average of 0.65. 13 SSR markers with the PIC value >0.6 have been selected for discrimination of Qinghai-Tibet naked barley genotypews. A finger Print map was developed through 7 SSR markers with the high PIC value. It could be used as an efficient tool for gene discovery and identification of gernplasm. Hordeins, the main storage proteins of the barley seed, are composed of momomeric and polymeric prolamins and divided into -A, B, C and D groups in order of decreasing electrophoretic mobility. Hordeins show high inter-genotypic variation and have been extensively used as markers for cultivar identification and analyzing the genetic diversity. This study analyzed the genetic diversity of B-hordein in 72 naked barley from Qinqhai-Tibet Plateau. Extensive diversity was observed. A total of 15 different bands and 30 distinct patterns were found. Jaccard's coefficient of similarity was calculated, and the accessions were divided into three main groups by cluster analysis using UPGMA. Differentiation among the populations from different collecting regions based on the polymorphism of B-hordein was investigated. Monomeric prolamins show high inter-genotypic variation and have been used as molecular markers for cultivar identification, analyzing the genetic diversity in collections and investigating the evolution processes and structure of populations However, the cultivated hulless accessions from Qinghai-Tibet Pateau in China have never been examined with respect to monomeric prolamins. This study analyzed the genetic diversity of monomeric prolamins (protein fraction corresponding to wheat gliadins) using the Acid -PAGE technique in eighty-four cultivated hulless barley from Qinqhai-Tibet Plateau in China. Extensive diversity was observed. A total of 43 different bands were found, of which 21 different bands were in the region of ω group, 8 in the region of γ, 8 in the region of β, and 6 in the region of α group. Among the 86 accessions, 75 distinct patterns were identified. The number of bands ranged from 6 to 16, depending on the variety. Jaccard’s coefficient of similarity was calculated, and the lines were grouped by cluster analysis using UPGMA. A dendrogram was obtained from the analysis of the groups and five main clusters were identified. No relationship between the distribution in the dendrogram and growth habits and origins of the cultivars could be detected. Starch is the major constituent of the cereal endosperm, comprising approximately 65% of the dry weight of the mature wheat grain. The starch formed in all organs of plants is packaged into starch granules, which vary widely between species and cultivars in size and shape. Wheat endosperm starch granules contain about corresponding to the main biosynthase of starch. This report firstly dealed with intraspecific variation of the major SGPs in cultivated naked barley from Qinghai-Tibet plateau. A total of 10 major SGPs were observed in the range of 40KD-100KD and 16 types of patterns were found. Based on the variation of SGPs, accessions studied were classified into 3 groups. A geographical cline of electrophoregram was observed. In addition, significance test of the difference of starch content among groups and types of patterns were done, and the results indicated those SGPs could be related to the content of starch. Diagram obtained through cluster analysis exhibited a structuration of diversity and genetic relationship among cultivated hulless accessions. In breeding program, parents with genetically distant relationship for hybridization will increase genetic diversity of progenies. In conclusion, cultivated naked barley from Qinghai-Tibet Plateau in China presents a high variability with respect to monomeric prolamins,SSR markers , B- hordeins and SGPs. The result of this study supports Qinghai-Tibet Plateau is the center of cultivated hulless barley and the cultivated naked barley is considered to be a gene pool with large diversity and could be applied to breeding for cereal.