大别山不同龄级映山红种群遗传多样性的SSR分析

[目的]利用SSR标记比较大别山黄狮寨不同年龄级映山红(Rhododendron simsii Planch.)种群的遗传多样性及遗传结构,探究映山红不同世代间遗传多样性的变化规律,为大别山野生映山红资源的合理利用和高效保护提供科学依据。[方法]按照基径大小和丛枝多少将大别山黄狮寨典型映山红种群划分为老树、成树、小树、幼苗4个年龄级,筛选出12对多态性强的SSR引物用于PCR扩增,扩增产物经6%变性聚丙烯酰胺凝胶电泳检测并银染。构建"0/1"矩阵,利用POPGENE 32. 0软件分析种群遗传多样性。基于Nei's遗传距离,采用软件MEGA5. 0进行UPGMA聚类。[结果]不同龄级的映山红遗传多样性差别较大,幼苗和老树种群多样性最差,小树种群多样性最丰富。12个微卫星标记观测等位基因数为3～9个,平均5. 08;有效等位基因数为2. 254 9 6. 129 7,平均3. 460 5;观察杂合度HO和期望杂合度HE分别为0. 676 4～0. 881 2和0. 607 7～0. 690 7。Shannon信息指数(I)以小树群体最高,成树次之,幼苗最低。近交系数Fis为-0. 638 3～0. 174 4,平均为-0. 294 6;总近交系数Fit为-0. 615 1～0. 270 6,平均为-0. 162 1,表明各龄级种群内主要繁殖方式为杂交。分子方差分析(AMOVA)表明89. 76%的遗传变异存在于年龄级内,仅10. 24%存在于年龄级间。基因流水平高,仅1个位点Nm 1。遗传一致度最高的为小树和成树种群。[结论]大别山黄狮寨映山红种群遗传多样性丰富,种群间中度分化,遗传变异主要存在于年龄级内。     

黄藤遗传多样性的RAPD分析

利用RAPD标记从DNA水平对收集的4个天然黄藤种群进行遗传多样性分析。15条引物扩增得到154条片段,整个种的多态性位点比率为75.97%,Ne i’s指数为0.258 4,Shannon信息指数为0.388 8。黄藤种的遗传多样性为0.257 8,种群间的Ne i遗传分化系数为0.141 2,各种群间的遗传变异非常小。4个种群间的遗传相似性分析结果显示:毛感乡和尖峰岭种群间的遗传相似度最高,吊罗山和坝王岭种群间的遗传相似度最低。AMOVA分析结果表明:种群间基因分化系数为0.026 2,大部分遗传变异(97.38%)来源于群体内。研究结果揭示:收集的天然黄藤种群具有较高的遗传多样性,有良好的保存和利用价值,尖峰岭种群可以作为重点保护。     

珙桐天然种群遗传多样性的ISSR标记分析

利用ISSR分子标记分析来自11个天然珙桐种群的遗传多样性。从100条引物中筛选出5条引物能扩增出稳定、清晰且具多态性的条带,共扩增出77个条带。其中74个为多态,多态条带百分率(PPB)为96.10%;各种群PPB值为37.66%～63.64%,平均为54.07%。种内Shannon多样性指数(HSP)为0.4849,种群内Shannon多样性指数(HPOP)为0.1886～0.3274,平均为0.2774。这表明珙桐在物种和种群水平上均维持较高的遗传多样性。分子方差分析显示,种群间与种群内遗传变异分别占总遗传变异的46.22%,53.78%,种群间呈高度遗传分化。种群间遗传距离与对应的地理距离呈显著正相关(r=0.546,P<0.01)。UPGMA法聚类分析将11个珙桐种群分为3组。研究结果为珙桐遗传资源保护策略制定提供有价值的种群遗传学信息。     

地涌金莲野生与栽培种群遗传多样性RAPD分析

利用RAPD分子标记技术对采自滇川两省的12个地涌金莲野生和栽培种群进行遗传多样性分析.选择10条随机引物在12个种群中共扩增出88条带,其中多态性带85条,整个种的多态性位点百分比PPB为96.59%,遗传多样性指数H为0.289 0以及Shannon信息指数I为0.441 6.种群间的遗传分化系数Gst为0.568 2,即43.18%的遗传变异来自于种群内,56.82%的遗传变异来自于种群间,种群间的遗传分化水平略高于种群内.种群间遗传一致度变化范围为在0.66～0.95之间.聚类结果显示:野生种群之间遗传距离较近,与地理分布基本相一致;栽培种群遗传距离较远,与地理分布不一致.     

浙江中部七子花种群结构与空间分布格局的研究

为揭示七子花的种群特征,在浙江中部3个七子花主要分布地设置500 m2样方10个,应用相邻格子法对七子花的种群结构和空间格局进行了研究.结果表明,七子花种群结构呈纺锤型,幼苗极少,大树也不多,种群主要集中在幼树、小树和中树阶段,显示出衰退的变化趋势,不同样地的七子花种群结构特征有所差异;由于生境条件的不同,不同样地表现出复杂的分布格局,其中生境条件较差的种群集群程度较高,在人为干扰后,集群程度有减弱的趋势,而某些生境条件较好种群的集群强度较弱,甚至呈随机分布;不同发育阶段种群空间分布格局有差异,总体上有集群分布向随机分布、聚集度高向聚集度低变化的趋势;不同区组大小的七子花种群分布格局不同,不同样地之间差异不明显.     

广西火桐自然种群和迁地保护种群的遗传多样性比较

采用ISSR标记方法,对广西火桐Erythropsis kwangsiensis 10个自然种群和1个迁地保护种群的遗传多样性和遗传结构进行了分析和比较。结果表明:用10个引物从广西火桐总DNA中共扩增出60条带,其中多态性条带51条。自然种群中以维新种群的遗传多样性最高,而三叠岭瀑布种群最低。自然种群的总遗传变异Ht为0.281 5,种群内遗传变异HS为0.076 4,种群间遗传变异为0.205 1,基因流为0.183 2。迁地保护种群的HEt和HES均为0.118 8。自然种群间存在一定程度的遗传分化(Gst=0.731 9),种群间变异占主导地位。合并后的自然种群的多态性条带百分率(RPPB)、Nei’s多样性指数(H)和Shannon信息指数(I)均高于迁地保护种群,分别为85.00%和31.67%、0.284 1和0.118 8、0.428 5和0.175 7。研究结果表明:广西火桐迁地保护种群的遗传多样性较低,未能涵盖整个种群。建议从多个自然种群中收集种子,尽可能多的采集样本,分区育苗种植,以增加遗传多样性水平。     

武夷山不同海拔光皮桦种群遗传多样性及其与生态因子的相关性

运用RAPD技术,对现存于武夷山国家级自然保护区内4个不同海拔光皮桦天然种群共91个基因株的遗传多样性进行分析.18个10碱基随机引物共扩增出199条清晰的条带,种群平均多态位点百分比(PPL)为60.05%,Nei's基因多样性指数(h)为0.224 2,Shannon信息指数(I)为0.318 1;不同种群遗传变异水平随海拔差异呈规律性变化,表现为沿海拔升高而呈由高到低的分布;在物种水平上光皮桦具有较高的遗传多样性(PPL=87.44%,h=0.344 2,I=0.489 9),种群间的遗传分化系数Gst=0.348 6.利用AMOVA软件对遗传变异的等级剖分结果表明,种群问有显著的遗传分化,约1/3的遗传变异存在种群间,种群内占2/3.Pearson相关分析表明,光皮桦种群内遗传多样性与海拔、气候因子(年均温和年降水)、土壤养分(全氮、碳氮比、有机质含量)之间存在极显著或显著的相关关系.Mantel检验结果显示,光皮桦种群间遗传距离与海拔差距、土壤养分因子的分异相关显著.以上结果表明不同海拔区域的生态因子、低基因流等对光皮桦种群间的遗传分化影响较大.     

不同盐度梯度下一年蓬的遗传多样性和遗传分化

利用RAPD技术对3个不同盐度梯度下入侵杂草一年蓬的遗传多样性和遗传分化进行了研究。结果表明,12个随机引物在90株个体中共检测到187个可重复位点,其中多态位点158个,总多态位点百分率为84.49%,3个种群平均多态位点百分率为70.77%。采用Shannon信息指数计算的3个种群总的遗传多样性为0.4522,平均为0.4027;采用Nei指数计算的3个种群总的基因多样性为0.3042,平均为0.2746。3个种群的多态位点百分率、Shannon信息指数、Nei指数大小顺序均为P2>P1>P3。AMOVA分子变异显示,88.54%变异来源于种群内,11.46%变异来源于种群间。一年蓬高的遗传多样性与低的遗传分化与其生物学特性有关,是其广泛入侵的重要原因。     

濒危小灌木长叶红砂种群的遗传多样性

采用RAPD和ISSR2种分子标记对濒危小灌木长叶红砂5个种群的遗传多样性进行检测。18个RAPD引物和14个ISSR引物分别扩增出118和114个位点,多态位点比率(P)分别为88.98%和89.47%。在物种水平上,RAPD标记的结果为:Shannon’s信息多样性指数(I)为0.4656,Nei’s指数(H)为0.3303;ISSR检测的结果:I=0.4688,H=0.3083。2种分子标记均表明濒危小灌木长叶红砂具有较高的遗传多样性水平。Nei基因多样性指数表明,大部分遗传变异存在于种群内。RAPD分析发现86.22%的遗传变异发生在种群内;ISSR分析发现89.29%的遗传变异发生在种群内。种群间遗传变异低的主要原因是种群间存在较强的基因流(Nm)分别为3.0097和4.1787)。长叶红砂较高的遗传多样性水平与物种特性和对高胁迫环境的长期适应有关,濒危植物并不一定表现为遗传变异水平的降低。     

雌性榧树4个居群遗传多样的SRAP分析

为给榧树的育种提供理论依据,以浙江淳安朱塔、太湖源,安徽樵山、小荣4个雌性天然榧树居群86个样品为研究材料,根据优化的SRAP-PCR反应体系和扩增条件,用26对引物扩增出了404个位点,其中多态位点330个,占81.68%,平均多态信息含量值为0.294 3。POPGENE分析结果表明,居群总的Nei’s基因多样性指数为0.294 9,Shannon信息指数为0.454 5,居群间的基因流为4.090 9,雌性榧树总的遗传多样性水平较高。居群间的基因分化系数为0.108 9,遗传变异主要存在居群内,且4个居群间的遗传距离与地理距离相关不显著。     

天然蒙古栎群体遗传多样性的RAPD分析

蒙古栎 (ＱｕｅｒｃｕｓｍｏｎｇｏｌｉｃａＦｉｓｃｈ)为壳斗科、栎属植物 ,主要分布区包括中国的华北、东北、内蒙古东部 ,朝鲜半岛 ,俄罗斯远东和蒙古的连续分布区及日本桦太、北海道的间断分布区 (吴晓春 ,1 993)。蒙古栎是我国东北的典型植被类型———红松阔叶林的主要伴生树种之一 ,同时在红松林被干扰破坏后是形成次生阔叶林面积较大的主要树种 ,也是分布区超过北纬 45°的唯一栎属植物。近年来 ,蒙古栎的分布区和群体数量呈扩张趋势 ,其原因除人为干扰外 ,可能涉及气候变化、物种特性、种内遗传多样性、种间互作等等。对蒙古栎群体…     

Genetic diversity of natural Hepatacodium miconioides populations in Zhejiang Province

Hepatacodium miconioides is the Class II protected plant species in China. This paper studies the genetic diversity and differentiation of its nine natural populations in Zhejiang Province by using random amplified polymorphic DNA (RAPD) technique. Twelve random primers were selected in the amplification, and 164 repetitive loci were produced. The percentage of polymorphic loci in each H. miconioides population ranged from 14.60% to 27.44%, with an average of 20.73%. Among the test populations, Kuochangshan had the highest percentage of polymorphic loci, Simingshan took the second place, and Guanyinping had the lowest percentage. As estimated by Shannon index, the genetic diversity within H. miconioides populations accounted for 27.28% of the total genetic diversity, while that among H. miconioides populations accounted for 72.72%. The genetic differentiation among H. miconioides populations as estimated by Nei index was 0.715,7. This figure was generally consistent with that estimated by Shannon index, i.e., the genetic differentiation among populations was relatively high, but that within populations was relatively low. The gene flow among H. miconioides populations was relatively low (0.198,7), and the genetic similarity ranged from 0.655,7 to 0.811,9, with an average of 0.730,6. The highest genetic distance among populations was 0.422,9, while the lowest was 0.208,3. All the results showed that there was a distinct genetic differentiation among H. miconioides populations. The genetic distance matrix of nine test populations was calculated using this method, and the clustering analysis was made using the unweighted pair group method with arithmetic mean (UPGMA). The cluster analysis suggested that the nine populations of H. miconioides in Zhejiang Province could be divided into two groups, the eastern Zhejiang group and the western Zhejiang group. __________ Translated from Chinese Journal of Applied Ecology, 2005, 16(5): 795–800 [译自: 应用生态学报, 2005, 16(5): 795–800]     

天山樱桃野生居群遗传多样性SSR分析

为给天山樱桃种质资源的保护和开发利用提供参考,应用SSR标记技术对新疆天山樱桃4个居群44份种质的遗传多样性进行分析。结果表明:筛选的14对SSR引物共检测到191个位点,包含148个多态性位点。Nei’s基因多样性指数和Shannon信息指数分别为0.239 8和0.367 6,各居群遗传分化系数为0.193 5,基因流为2.084 3。天山樱桃遗传分化水平较低,各居群间基因交流频繁,遗传变异主要存在于居群内。由基于遗传距离的聚类结果可知,裕民县与大西沟居群遗传关系最近,与特克斯居群遗传距离较远,4个天山樱桃居群中大西沟居群遗传多样性最高。     

大花黄牡丹遗传多样性的SRAP分析

应用SRAP标记对西藏特有植物大花黄牡丹的遗传多样性进行研究。用16对引物从5个自然居群79个单株中共检测到396个有效位点,其中多态性位点357个。在物种水平上,多态位点百分率(Ppl)为90.15%,Shannon表型多样性指数(Ηsp)平均为0.2521;居群水平上的Ppl为31.82%,Shannon表型多样性指数(Ho)为0.0694～0.3428,平均值(Ηpop)为0.1307。上述遗传参数表明,大花黄牡丹具有丰富的物种遗传多样性,5个居群中自然居群C的遗传多样性最高(Ppl=82.32%,Ho=0.3428)。据AMOVA分析结果,总的变异中有41.58%的变异存在于居群间,58.42%的变异存在于居群内,居群分化较显著(ΦST=0.4158,P<0.001),由POPGENE1.32得到的居群间遗传分化系数GST(0.4309)和Shannon表型多样性指数计算的居群间遗传多样性所占比例(0.4816)也表明了类似的遗传结构。Mantel检测表明地理距离和Nei’s遗传距离间相关不显著(P>0.05)。利用NTSYSPC(2.1)软件构建大花黄牡丹5个居群79个个体的UPGMA聚类图,遗传相似系数变幅在0.47～0.99,大多数居群内的个体表现出较为密切的亲缘关系(如居群B,D,E),但也有一些居群的个体未聚在一起(如居群C)。依据大花黄牡丹居群遗传变异特点,初步探讨其保护和利用策略。     

Genetic diversity of Lithocarpus harlandii populations in three forest communities with different succession stages

By using random amplified polymorphic DNA (RAPD) technique, this paper studied the genetic diversity and genetic differentiation of Lithocarpus harlandii populations in three forest communities (coniferous forest, coniferous and broad-leaved mixed forest, and evergreen broad-leaved forest) with different succession stages in Tiantai Mountain in Zhejiang Province. The results showed that a total of 173 repetitive loci were produced in 60 individuals of L. harlandii by 12 random primers, among which, 152 loci were polymorphic, and the total percentage of polymorphic loci was 87.86%. The average percentage of polymorphic loci of the populations was 65.32%, and their total genetic diversity estimated by Shannon information index was 0.4529, with an average of 0.3458, while that judged from Nei’s index was 0.3004, with an average of 0.2320. The percentage of polymorphic loci, Shannon information index, and Nei’s index of the populations were in the sequence of coniferous forest community > coniferous and broad-leaved mixed forest community > evergreen broad-leaved forest community. Analysis of molecular variance (AMOVA) showed that 72.85% of genetic variance was found within the populations, and 27.15% of genetic variance resided among the populations. The coefficient of gene diferentiation was 0.2277, and the gene flow was 1.6949. The genetic structure of L. harlandii was influenced not only by the biological characteristics of this species, but also by the microenvironment of different communities. The mean of genetic identity among three populations of L. harlandii was 0.8662, and the mean of their genetic distance was 0.1442. The genetic similarity between coniferous and broad-leaved mixed forest community and evergreen broad-leaved forest community was the highest, while that between evergreen broad-leaved forest community and coniferous forest community was the lowest. The unweighted pair group method with arithmeticmean (UPGMA) cluster analysis based on Nei’s genetic distance showed that conierous and broad-leaved mixed forest community first gathered with evergreen broad-leaved forest community, and then with coniferous forest community. __________ Translated from Chinese Journal of Ecology, 2007, 26(4): 509–514 [译自: 生态学杂志]     

Genetic structure of Tunisian natural carob tree (Ceratonia siliqua L.) populations inferred from RAPD markers

? Seven RAPD markers were used to assess the genetic diversity and structure of ten Tunisian natural Ceratonia siliqua L. populations from different geographic and bioclimatic zones.

? The species maintain a high diversity within population as estimated by the percentage of polymorphic loci and Shannon’s index (P% = 76.31, $\bar H'_{pop} = 0.569$ ). The range of variation between populations was large. Populations from the upper semi-arid bioclimates, with more continuous distribution area showed the highest level of variation.

? A high genetic differentiation among populations (Φ_ST = 0.250 and $\bar G_{ST} = 0.347$ ), as a result of population isolation was revealed. Nevertheless, the genetic structure is in accordance with bioclimate indicating that ecological factors also should influence differentiation. Populations from the sub-humid, upper semi-arid and mean semi-arid zones clustered together and were distinct from those of the lower semi-arid ones.

? Conservation strategy should be made according to the level of polymorphism within population and bioclimate.

     

岛屿地理隔离对山茶种群遗传结构的影响

利用简单重复序列间扩增(ISSR)分子标记对分布于我国浙江和山东的8个山茶种群共240个个体进行了遗传结构分析。结果表明:筛选出的20条引物扩增得到210条清晰条带,其中184条为多态性条带,多态位点百分率(PPB)为87.62%。经POPGENE1.32软件分析,山茶种群平均多态位点百分率(PPB)为68.99%,Nei’s基因多样性指数(HE)为0.256 9,Shannon信息指数(H)为0.377 9,种群遗传多样性较高。基因分化系数Gst=0.182 9,表明遗传变异主要存在于种群内个体间。地理距离与遗传距离具有显著相关性(r=0.856 7,P<0.05),岛屿地理隔离对山茶种群的遗传分化具有重要影响。UPGMA聚类表明:浙江5个山茶种群间的遗传相似度较高,山东青岛的植物园种群和五四广场种群可能移植自长门岩岛。我国野生山茶资源受人为破坏严重,建议在加强现有岛屿自然种群就地保护力度的同时,建立山茶种质资源库,促进基因交流。     

湘鄂西地区珙桐天然群体遗传结构的研究

以珙桐叶为材料,对湘西和鄂西两天然珙桐群体的60个样品进行RAPD分析.结果表明,9个随机多态引物,获得24个多态标记位点,平均每个引物产生2.67个多态位点;湘西和鄂西两群体之间的遗传多样性差异不明显,Shannon指数分别为0.427 4和0.448 1;种内平均遗传多样性为0.326 9,群体内平均遗传多样性为0.297 6,群体间的遗传多样性为0.029 3,基因分化系数为0.089 6,基因流为5.079 2.两个天然珙桐群体的遗传相似性非常高,达到0.923 3,遗传距离为0.079 8;湘西群体的多态百分位率略高于鄂西.这表明,湘西和鄂西两群体间存在着非常频繁的基因流.     

基于SRAP标记的土沉香遗传多样性分析

【目的】在我国野生土沉香被大量被采伐,种质资源越来越少,甚至面临消失的情况下,为了利用与保护野生土沉香提供理论依据,采用SRAP分子标记对其种源遗传多样性进行分析。【方法】基于我国11个土沉香种源群体和越南2个土沉香种源群体的SRAP结果,应用POPGEN32软件对遗传多样性参数进行计算。【结果】各群体Nei's基因多样度指数的变化范围为0.1715~0.5394,Shannon多样性指数的变化范围为0.2491~0.4837,多态位点百分比的变化范围为42.03%~76.81%。运用GenAlex 6.4软件对土沉香13个群体进行分子方差分析(Analysis of molecular variance,AMOVA),结果显示有30%的遗传变异来自土沉香群体间,70%的遗传变异来自土沉香群体内。【结论】13个土沉香种源有中度的遗传多样性和遗传分化,野生土沉香种质资源正日渐稀少,应该加强资源的保护与利用。