我国盾叶薯蓣居群遗传结构分析

利用随机扩增多态DNA(RAPD)标记,分析研究了中国11个盾叶薯蓣居群82个个体的遗传多样性与遗传结构,15个寡聚核苷酸引物扩增共得到108条带,其中96条为多态带,占88．89％。Shannon多样性指数(I)为0．3093,居群水平的变异从0．1564到0．3098,物种水平的Nei基因多样度(h)为0．2499,居群水平的变化范围为0．1607到0．2137。遗传变异分析表明,物种水平的基因分化系数Gst为0．3415,居群间的基因流Nm为0．9641,居群间遗传交换小。分子方差分析(AMOVA)表明,居群内变异为68．96％,地区间变异为19．45％,居群问变异为11．58％。聚类结果以长江为界,将盾叶薯蓣分为南北两个大类群。研究结果对盾叶薯蓣种质的迁地保护有重要意义。     

利用rp132-trnL分析阿尔金山自然保护区真藓居群遗传多样性

本研究对分布在中国新疆维吾尔自治区阿尔金山自然保护区的6个真藓(Bryum argenteum)居群的遗传结构及遗传多样性进行比较。通过对32条叶绿体DNA的rpl32-trnL序列的核苷酸序列变异的分析,发现了14种单倍型,存在201个可变位点;分子变异分析显示有51.02%的遗传变异发生在居群间水平,居群内部的遗传变异为48.98%,真藓居群间的遗传分化程度较高略大于居群内的遗传分化。居群遗传变异的分化系数为0.510 2,基因流值为0.48,显示各居群间的基因流低。单倍型多态性水平为(0.780 2±0.076 0),核苷酸多态性水平为(0.058 59±0.020 09),表明真藓居群遗传多样性丰富。对所有变异位点进行的Taijma's检验的结果是Taijma's D值为-1.567 05 (p0.10),显示所有变异符合中性进化假说。     

武陵山区蛇足石杉遗传多样性的AFLP分析

采用AFLP分子标记对武陵山区蛇足石杉(Huperzia serrata)4个居群进行遗传多样性的研究,结果表明:(1)7对引物组合共扩增出条带615条,其中549条为多态性条带;在物种水平上,多态性条带百分率PPB=89.27%,有效等位基因数Ne=1.257,Nei’s基因多样度指数H=0.178,Shannon多样性信息指数Isp=0.298;在居群水平上,PPB=71.42%,Ne=1.235,H=0.154,Shannon多样性信息指数Ipop=0.251;遗传多样性在居群间有明显的差别,其中坪坝营(PBY)居群最高(PPB=81.95%),而铁峰山(TFS)居群最低(PPB=64.55%)。(2)居群间的遗传分化较低,基于Nei’s基因多样性分析结果显示,居群间遗传分化系数GST=0.159;Shannon’s居群分化系数[(Isp-Ipop)/Isp]为0.16;WINAMOVA分析显示,武陵山区蛇足石杉的遗传变异主要存在于居群内,居群内的遗传变异分量为65.057,占总变异的75.77%,而居群间的遗传变异分量为20.804,占总变异的24.23%;居群内存在极显著的遗传分化(ΦST=0.242,P0.001)。(3)由遗传分化系数(GST)估计,武陵山区蛇足石杉居群间的基因流Nm=2.647,表明蛇足石杉属于异交种。(4)两两居群间的Nei’s遗传一致度(IN)范围为0.031 0~0.969 4;Mantel检测结果显示,居群间的遗传距离与地理距离之间不存在显著的正相关关系(r=0.269,P=0.887)。研究认为,遗传多样性与遗传结构主要决定于居群历史,较少干扰而稳定的居群偏向克隆生殖,遗传多样性较低,而新建居群的遗传多样性则较高;克隆生长、生态位选择、异交,以及有效的孢子风媒传播等可能是其维持较高遗传多样性水平的因素,而过度采挖等人类活动和生境片断化是导致蛇足石杉濒危的主要因素。     

硬核资源遗传多样性的AFLP分析（英文）

为了解云南省硬核[Scleropyrum wallichianum (Wight et Arn.) Arn.]的遗传多样性,采用AFLP标记分析了7个居群84份种质材料的遗传变异。结果表明,从64对引物组合中挑选出多态性较好的引物8对,共扩增出1 728条带,其中多态性条带1 388条,多态性百分率为80.14%。硬核在物种水平的多样性指数分别为Na=1.416, Ne=1.179, H=0.137, I=0.225,在居群水平上分别为H=0.111,I=0.175;在遗传相似性系数为0.52时,这些种质材料可分为3组,其中易武居群具有丰富的遗传变异,大部分的遗传变异存在于居群内,而在0.05置信区间内居群间遗传变异仅为11.5%;居群间的遗传距离和地理距离无显著相关性(r=0.0323, P=0.5820)。因此,硬核资源可采用就地和迁地保护策略,以增加其遗传多样性。     

中国卵叶海桑遗传多样性的ISSR研究

卵叶海桑 (Sonneratiaovata)是海桑科濒危红树植物 ,在我国仅分布于海南文昌清澜自然保护区内。采用简单序列重复区间扩增 (ISSR)分子标记技术对该天然居群和东寨港红树林自然保护区引种的人工居群共 3个居群 3 9个个体进行了遗传变异分析。 1 1个引物共扩增出 1 85条带 ,其中 1 2 7条具多态性 ,多态位点百分率为 68.65 %。在居群水平上相对较低 ,多态位点百分率 3 6.76%～ 5 4.5 9% ,平均值为 47.2 1 %。Nei的基因多样性、Shannon信息指数在物种水平上分别为 0 .1 41 1和 0 .2 2 92 ;在居群水平上平均值分别为 0 .1 2 0 9和0 .1 91 0。Nei的遗传分化系数Gst表明 :87.5 8%遗传变异分布在居群内 ,1 2 .42 %的遗传变异分布在居群间。居群间的遗传一致度达 0 .970 7。东寨港迁地保护的人工居群有效地保护了卵叶海桑的遗传多样性。     

兰花蕉的遗传多样性研究

采用简单重复序列区间(ISSR,Inter-Simple Sequence Repeat)分子标记技术,对采自广东省的濒危植物兰花蕉(Orchidantha chinensisT.L.Wu)的7个居群137个个体进行遗传变异分析。用10个ISSR引物共扩增出清晰谱带101条,其中58条具有多态性,总多态位点百分率为57.43%。居群水平相对较低,多态位点百分率在6.93%-35.64%之间,平均为18.24%。经POPGENE1.31数据处理,结果表明:在物种水平上Nei基因多样性为0.1254±0.1686;Shannon信息指数为0.2000±0.2429;Nei基因分化系数为0.5481,表明54.81%的遗传变异分布在居群间,45.19%的遗传变异分布在居群内。物种居群间的遗传一致度在0.8855-0.9511之间。我们认为红花潭是其最适合生境,建议在此建立自然保护区;鉴于兰花蕉居群间出现了一定程度的分化,为最大限度地保护兰花蕉的遗传多样性,建议在自然居群间进行相互移栽,以提高群体间的基因交流。     

陕西唐棣遗传多样性和遗传分化的AFLP分析

采用扩增片段长度多态性分子标记技术对陕西省分布的6个野生唐棣居群的96个个体进行了遗传多样性分析, 以明确野生唐棣资源的亲缘关系,为唐棣资源的保护、良种选育和开发利用提供理论依据。结果显示：(1)从64对引物组合中筛选出8对扩增条带清晰、多态性高的引物组合,共扩增出277条清晰条带,其中多态性条带116条,多态性位点百分率为42.86%。(2)UPGMA聚类、主坐标分析(PCoA)和遗传结构分析结果相似,将6个陕西野生唐棣居群分成2大支,秦岭南北居群间遗传分化明显,且群体间存在一定基因流。(3)分子方差分析(AMOVA)结果显示遗传变异主要存在于居群内(63%),居群间遗传变异为37%。Mantel检验表明陕西唐棣居群地理距离与遗传距离之间无明显相关性(r = 0.192,P = 0.220)。研究表明,AFLP分子标记可以准确、有效地用于唐棣遗传多样性分析;唐棣遗传变异主要来源于居群内,居群间的基因交流有限;陕西野生唐棣遗传多样性水平较低,但部分居群的遗传多样性较高。该研究结果可为野生唐棣资源的保护、良种选育和开发利用提供理论依据。     

不同天然居群小蓬竹的遗传多样性

从分子水平探讨不同居群小蓬竹的遗传多样性以及与环境因子的相关性,揭示其濒危原因,为小蓬竹的保护和后续开发利用提供理论支撑,助力实施极危物种最佳保护策略。运用RAPD标记技术和POPGENE32对16个小蓬竹天然居群进行遗传多样性研究和遗传变异分析。结果表明,8个RAPD随机引物共扩增出105条清晰、重复性高的条带,其中多态性条带有98条,分子量300~2000bp;物种水平多态性位点百分率PPL=93.33%,有效等位基因数Ne=1.4942,Nei’s基因多样性H=0.3005,Shannon多样性指数I=0.4586;落湾(ZY1)居群的遗传多样性水平最高(PPL=60.95%,H=0.2329,I=0.3451),[JP3]桃坡(PT1)居群的最低(PPL=44.76%,H=0.1700,[JP]I=0.2523);16个天然居群的遗传分化系数Gst=0.3231,基因流Nm=1.0478,基于Shannon’s多样性指数的分化系数[(HSP-HPOP)/HSP]为0.3429。小蓬竹居群内存在丰富的遗传多样性,各个天然居群间具有一定的遗传分化但分化水平并不高,主要的遗传变异存在于居群内部。     

云南南部野生大叶千斤拔资源遗传多样性的ISSR分析

应用ISSR分子标记技术,对云南南部7个地区的野生大叶千斤拔( Flemingia macrophylla)居群进行了遗传多样性分析。结果表明：云南野生大叶千斤拔具有较高的遗传多样性。在物种水平上,平均每个位点的多态位点百分率(PPL)为94.85％,有效等位基因数(Ne)为1.4627,Nei’s基因多样性指数(He)为0.2815, Shannon’s多样性信息指数(Ho)为0.4337;在居群水平上,PPL ＝43.44％,Ne ＝1.2981,He ＝0.1704,Ho ＝0.2499。基于Nei’ s遗传多样性分析可得出,居群间的遗传分化系数( Gst)为0.3975,表明居群内的遗传变异为60.25％,居群间的遗传变异为39.75％,这说明居群间的遗传分化要低于居群内的遗传分化。根据遗传多样性分析和聚类结果,应在大叶千金拔遗传多样性较高的勐腊易武( MY)、丘北( QB)和宁洱( NE)地区,设立保护点对其进行就地保护。     

濒危植物毛柄小勾儿茶片断化居群的遗传多样性

采用扩增片段长度多态性(AFLP)标记对我国特有的濒危植物毛柄小勾儿茶(Berchemiella wilsonii var. pubipetiolata)现存于浙江和安徽的4个片断化居群中的89株个体进行了遗传多样性和遗传结构的研究。结果表明,与其它木本濒危植物相比,毛柄小勾儿茶具有与它们相当的遗传多样性,8对选择扩增引物共扩增出122条清晰的条带,居群的平均多态位点百分率为P_p=26.4%,其中马家河居群最高(29.5%)而湍口居群最低(23.8%),居群的平均基因多样度为H_ep=0.162 8(0.140 5~0.172 4);而在物种水平上的遗传多样性为P_s=36.9%, H_es=0.202 4。居群间的遗传分化系数F_ST=0.193 9,表明居群间有显著的遗传分化,进一步利用AMOVA软件对遗传变异进行等级剖分发现:24.88%的遗传变异存在于地理宗间(浙江地理宗和安徽地理宗),14.71%的遗传变异存在于居群间,60.42%存在于居群内。该研究结果表明,由于人为干扰引起的生境片断化和居群减小导致了毛柄小勾儿茶居群的遗传多样性丧失和遗传分化,并对毛柄小勾儿茶的生存造成潜在威胁。该文还就保育策略进行了讨论。     

利用AFLP分子标记探讨蜡梅种质资源的遗传多样性

利用AFLP分子标记技术,对中国蜡梅种质资源7个野生种群的遗传多样性进行了研究。利用筛选出的3对引物,共扩增出253条谱带,其中218条多态带,多态位点占86.17% ;种群间的基因分化系数为0.2906,说明蜡梅基因多样性主要存在于种群内;种群总的Nei s基因多样性指数为0.2933,Shannon信息多态性指数为0.4487,蜡梅总的遗传多样性水平较高。蜡梅不同种群遗传多样性水平差异较大,种群多态位点百分率在65.44% ～87.16%之间,Nei s基因多样性指数为0.1653 ～0.4012,Shannon信息多态性指数为0.3132 ～0.5603。神农架种群(SN)和保康种群(BK)的遗传多样性水平较高。用NTSYS2.01版软件对样品进行UPGMA聚类分析,结果7个种群并没有按地理距离进行聚类。最后提出要对各蜡梅野生群体采取相应的迁地和就地保护措施。     

用AFLP技术分析四川核桃资源的遗传多样性

 利用AFLP分子标记技术, 运用EcoRⅠ/MseⅠ双酶切组合, 选用多态性高、分辨力强的4对选择性扩增引物组合E32/M48、E33/M61、E35/M61、E33/M62分别对四川省3个野生核桃(Juglans regia)种群和1个野生铁核桃(J. sigillata)种群共46个样品进行遗传多样性分析、居群遗传结构分析及种属关系探讨。结果表明: 1)共扩增出244个遗传位点, 其中146个多态位点, 多态率为59.84%; 核桃群体组和铁核桃群体的多态性百分率分别为55.33%和52.05%, 两个物种遗传多态性水平相当; 核桃群体组所检出的位点平均有效等位基因数Ae、Nei’s基因多样度H、平均Shannon信息指数I分别为1.322 9、0.190 8和0.286 3, 而铁核桃群体分别为1.339 9、0.196 1和0.289 8, 铁核桃群体遗传多样性水平略高于核桃群体。2)群体间特异带及群体间共有带占总扩增带数的15.16%, 其中铁核桃群体特异谱带最多, 群体特异谱带揭示了群体间的遗传差异及相似性。3) Shannon信息指数(I)、Nei’s基因多样性指数(H)和分子方差分析(AMOVA)表明核桃遗传多样性在群体间和群体内的分布分别为14.36%和85.64%、12.6%和87.4%、11.07%和88.93%, 表明群体内的遗传多样性大于群体间的遗传多样性; 核桃群体组与铁核桃群体的变异主要存在于群体组内, 组间的遗传变异仅占总变异的9.35%, 两者间的遗传分化系数Gst为0.093 5, 与AMOVA分析结果一致。4) 4个群体的Nei’s遗传距离在0.038 2～0.069 2之间, 遗传一致度在0.933 2～0.962 5之间, 表现出较高的遗传相似性; 运用Nei’s遗传一致度对供试种群进行了UPGMA聚类, 结果表明核桃的3个群体优先聚类, 大渡河流域群体与甘南地区群体聚类最近。AFLP所检测出的结果既是核桃与铁核桃生物学特性的反映, 又是其各自生态学特性的反映, 该研究结果对核桃种质资源的保护和育种提供一定的理论依据。     

AFLP Analysis of Genetic Diversity of the Endangered Species Sinopodophyllum hexandrum in the Tibetan Region of Sichuan Province,China

Amplified fragment length polymorphism (AFLP) markers were used to estimate the genetic diversity of seven wild populations of Sinopodophyllum hexandrum (Royle) Ying from the Tibetan region of Sichuan Province, China. Six primer combinations generated a total of 428 discernible DNA fragments, of which 111 were polymorphic. The percentage of polymorphic bands (PPB) was 25.93 at the species level, and PPB within population ranged from 4.91 to 12.38%. Genetic diversity (H _E) within populations varied from 0.01 to 0.04, averaging 0.05 at the species level. As revealed by the results of AMOVA analysis, 58.8% of the genetic differentiation occurred between populations, and 41.2% within populations. The genetic differentiation was, perhaps, due to the limited gene flow (N _m=0.43) of the species. The correlation coefficient (r) between genetic and geographical distance using Mantel's test for all populations was 0.698 (P=0.014). The UPGMA cluster analysis revealed a similar result in that the genetic distances among the populations show, to a certain extent, a spatial pattern corresponding to their geographic locations. On the basis of the genetic and ecological information, we propose some appropriate strategies for conserving the endangered S. hexandrum in this region.     

黄独遗传多样性研究

采用ISSR标记技术研究了我国14个黄独样品的遗传多样性.从55条简单重复序列引物中筛选出9条多态性引物,共扩增出70条带,其中67条多态性带,多态性比率为95.71%,平均每条引物扩增出7.8条带.黄独原变种内Nei s基因多样性(h)为0.294 9,有效等位基因数(Ne)为1.491 1,Shannon多样性指数(I)为0.444 8.种水平h为0.326 3,Ne为1.552 9,I为0.488 3.基因分化系数(Gst)为0.782 1,基因流(Nm)为0.139 3.聚类分析表明来自海南省和台湾省的样品与我国内陆的样品较早分离.据此可将来自我国内陆的样品分为5组.ISSR聚类分析基本上支持依据形态特征对黄独变种的划分.同时实验结果也表明,云南可能是黄独在我国的分化中心.     

AFLP analysis of genetic diversity of the endangered species Sinopodophyllum hexandrum in the Tibetan region of Sichuan Province, China

Amplified fragment length polymorphism (AFLP) markers were used to estimate the genetic diversity of seven wild populations of Sinopodophyllum hexandrum (Royle) Ying from the Tibetan region of Sichuan Province, China. Six primer combinations generated a total of 428 discernible DNA fragments, of which 111 were polymorphic. The percentage of polymorphic bands (PPB) was 25.93 at the species level, and PPB within population ranged from 4.91 to 12.38%. Genetic diversity (H(E)) within populations varied from 0.01 to 0.04, averaging 0.05 at the species level. As revealed by the results of AMOVA analysis, 58.8% of the genetic differentiation occurred between populations, and 41.2% within populations. The genetic differentiation was, perhaps, due to the limited gene flow (Nm = 0.43) of the species. The correlation coefficient (r) between genetic and geographical distance using Mantel's test for all populations was 0.698 (P = 0.014). The UPGMA cluster analysis revealed a similar result in that the genetic distances among the populations show, to a certain extent, a spatial pattern corresponding to their geographic locations. On the basis of the genetic and ecological information, we propose some appropriate strategies for conserving the endangered S. hexandrum in this region.     

拟环纹豹蛛不同地理种群遗传多样性的AFLP标记研究

为查明拟环纹豹蛛Pardosa pseudoannulata不同地理种群的遗传多样性机制,应用AFLP技术对6个拟环纹豹蛛地理种群的遗传多样性进行了研究分析。8对引物组合扩增出1 038个AFLP条带,其中多态性条带占86.622%,全部个体显示了各自独特的AFLP图谱。AFLP标记的遗传多样性分析结果表明： 拟环纹豹蛛无论在物种水平(P=86.62%,H=0.2622,I=0.3101),还是在种群水平（P=73.0%,H=0.2155,I=0.2554）都表现出较高的遗传多样性。其中湖南长沙雷锋镇种群内遗传变异最大,云南高黎贡山福贡种群内遗传变异最小,华南北部（湖南、湖北、江西）地区拟环纹豹蛛遗传多样性明显高于华南南部（云南、海南）种群。据种群变异来源分析,有35.77%的遗传变异来自种群间,64.23%的变异来源于种群内（N_m=0.898）,不同地理种群显示出一定的遗传分化。分析认为海拔是影响拟环纹豹蛛遗传分化的重要因素,这为进一步明确我国稻田狼蛛优势种群在农药胁迫下的遗传适应性机制提供了实验依据。     

广西地不容种质资源的ISSR分析

采用简单序列重复区间扩增(ISSR)分子标记技术对广西地不容3个野生居群和1个引种居群共92个个体进行了遗传多样性研究。10个引物共扩增出61条带,其中60条具多态性,多态性位点百分率为98.36%。4个居群多态性百分率在73.77%～86.89%。Nei’s基因多样性指数(H)为0.3379,Shannon信息多样性指数(Ⅰ)为0.5055。3个野生居群Nei’s遗传分化系数(Gst)表明:83.87%遗传变异分布在居群内,16.13%的遗传变异分布在居群间。引种居群与3个野生居群间的遗传一致度达0.8846。引种居群有效地保护了广西地不容的遗传多样性。     

Genetic diversity and biogeography of the traditional Chinese medicine, Gardenia jasminoides, based on AFLP markers

Gardenia jasminoides Ellis is used in traditional Chinese medicine (TCM) in China. Levels of genetic variation and patterns of population structure within and among eight wild or cultivated populations of G. jasminoides Ellis in China were investigated using amplified fragment length polymorphism (AFLP) markers. Of the 11 primers screened, four produced highly reproducible AFLP bands. Using these primers, 244 discernible DNA fragments were generated with 165 bands (67.6%), were polymorphic, indicating considerable genetic variation at the species level. In contrast, there were relatively low levels of polymorphism at the population level with the percentage of polymorphic bands (PPB) ranging from 36.89% to 59.43%. Genetic diversity within populations ranged from 0.2086 to 0.3108, averaging 0.2392 at the species level. A high level of genetic differentiation among populations was detected based on Nei's genetic diversity analysis (76.59%), Shannon's index analysis (64.8%) and AMOVA analysis (72.75%). No significant statistical differences (analysis of molecular variance [AMOVA], p = 0.0639) in AFLP variation were found between regions. However, the variance among populations and within populations differed significantly (p < 0.001). An indirect estimate of historical levels of gene flow (N_m = 1.7448) was consistent with the high mean genetic identity (mean I = 0.9263) found among populations. There is an association between geographic and genetic distances between populations. Presently gene change exists between populations.     

Genetic diversity and differentiation in Dalbergia sissoo (Fabaceae) as revealed by RAPD

Dalbergia sissoo, a wind-dispersed tropical tree, is one of the most preferred timber tree species of South Asia. Genetic diversity and differentiation among natural populations of D. sissoo were examined for the first time. We found a relatively high level of genetic diversity in D. sissoo, both at the species level (percentage of polymorphic bands = 89.11%; H = 0.2730; I = 0.4180) and the population level (percentage of polymorphic bands = 68.7%; H = 0.239; I = 0.358), along with a relatively low degree of differentiation among populations (GST = 0.1311; AMOVA = 14.69%). Strong gene flow among populations was estimated, N(m) = 3.3125. The Mantel test suggested that genetic distances between populations were weakly correlated with geographic distances (R = 0.3702, P = 0.1236). The high level of genetic diversity, low degree of differentiation, strong gene flow, and weak correlation between genetic and geographic distances can be explained by its biological character and wide-spread planting. This information will be useful for the introduction, conservation and further studies of D. sissoo and related species.