乐昌含笑种群遗传多样性的研究

基于随机扩增多态DNA(RAPD)方法分析了珍稀木兰科植物乐昌含笑6个种群的遗传多样性及分化程度。19条随机引物扩增出111个可分析位点,多态位点百分比为81．98％,经POPGENE分析发现,乐昌含笑的Nei’s基因多样度(Hc)为0．3255,Shannon表型指数(I)为0．4751,与其它植物比较具有较高水平的遗传多样性。6个乐昌含笑群体间基因分化系数(Gst)值为0．2226。群体内的遗传变异大于群体问的遗传变异。按照遗传距离将乐昌含笑6个群体划分为两类：第1类有广西三江、湖南宜章、湖南双牌和湖南资兴的群体,第2类包括江西官山和湖南醴陵的群体;研究表明：第2类种群的遗传多样性指数高于第1类种群的遗传多样性指数。     

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。     

白皮松天然群体遗传多样性的等位酶分析

采用8种等位酶对白皮松4个天然群体的遗传多样性和遗传分化进行了研究.在4个群体中共检测到10个基因位点,15个等位基因,其中6个位点为多态位点;群体总体水平多态位点比率P=60%,平均有效基因数A=1.92,平均期望杂合度He=0.106,种群平均遗传距离为0.006 8.南漳白皮松群落平均等位基因数A=1.9,平均有...     

美国白蛾种群的遗传多样性与遗传分化

采用微卫星技术对入侵中国的5个美国白蛾种群进行遗传多样性和遗传分化及影响因素的研究.用10对微卫星引物对300个样品DNA进行PCR扩增,并进行聚丙烯酰胺凝胶电泳分析.5个美国白蛾种群的多态位点百分率P=98.36%;多态位点百分率的大小顺序为:沧州种群、烟台种群、秦皇岛种群、丹东种群、石家庄种群;美国白蛾整个群体的遗传分化:34.38%的变异存在于种群间,65.62%的变异存在于种群内,遗传距离变化范围为0.138 6～0.322 4.用UPGMA法对Nei's遗传距离作聚类分析的结果表明:种群的分化程度与分化时间和入侵来源密切相关.影响美国白蛾种群遗传多样性与遗传分化的主要因素是经度、平原比率、年降水量、纬度、入侵时间.美国白蛾种群现有遗传结构的形成与其生活史特性及入侵生态学特性有关.     

不同种源红松遗传多样性的研究

利用ISSR分子标记技术,对露水河红松种子园内7个无性系种源92个个体的遗传多样性进行了分析.通过14个ISSR引物的扩增,共检测到100个位点,多态位点58个.7个种源的多态位点百分比、Shnnon基因多样性指数、Nei基因多样性指数和有效等位基因指数所体现的遗传多样性变化规律一致,永华种源最低,西林河种源最高,依次为:西林河种源＞宏伟种源＞联营种源＞丽林种源＞东升种源＞寒月种源＞永华种源.对7个种源进行遗传聚类分析,以0.025遗传距离划分,可以将7个种源分为3个种源区.红松种源的遗传距离和地理距离相关性不明显.     

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。     

湖南桂阳马尾松种子园遗传多样性的ISSR分析

本研究从100条ISSR引物中筛选出11条多态性引物,对湖南桂阳马尾松第二代种子园共87份样品进行遗传多样性分析,共扩增得到246个多态位点。采用PAUP4.0软件分析,获得两个主要群体(广西群体和城步群体),在城步群体内,湖南和贵州两省的家系被分开。再对两个主要群体采用POPGEN32软件分析,结果表明:在桂阳第二代种子园内总的多态位点百分率达98.80%,总的Shannon信息指数为0.583 7,Nei's基因多样性指数为0.400 3,2个群体的多态位点百分率分别为93.57%、98.80%,各群体间的基因分化系数为0.036 3,基因流为13.258 6。这表明桂阳第二代马尾松种子园的遗传多样性水平高,个体间的基因多样性变异大,该种子园所采用的建园方式是可取的。     

黄心夜合的遗传多样性研究

运用随机扩增多态DNA（RAPD）技术,对黄心夜合[Michelia martinii（Levl.）Levl.]自然分布区的6个自然种群遗传多样性进行了研究。从100个随机引物中筛选出能产生清晰、稳定的多态性标记引物18个,共检测出110个位点,其中多态性位点为96个,占87.27%;在物种水平上,有效等位基因数目（Ne）,Nei’s基因多样性系数（He）和Shannon表型多样性指数（I）分别为1.735 2,0.416 3和0.597 1;总的遗传变异量（Ht）为0.339 8,其中居群内遗传变异量（Hs）为0.258 7,各居群间的遗传分化系数（Gst）达到0.323 1.应用UPGMA法对遗传距离进行聚类分析并构建树系图,结果表明：黄心夜合自然种群具有较高的遗传多样性,其种群间的遗传差异与其地理分布有关。     

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.     

运用AFLP技术分析筇竹种群遗传多样性

利用AFLP分子标记技术对筇竹2个种群的遗传多样性进行了分析,筛选出10对多态性和清晰度较高的引物组合,共获得680个AFLP位点,其中多态性位点662个,平均多态性检出率为97.20%,并用PopGen32软件对AFLP多态性数据进行分析,结果表明,供试2个筇竹种群均具有丰富的遗传多样性,多态位点百分率分别为89.86％和91.95％,等位基因数分别为1.898 6和1.919 5,有效等位基因数分别为1.585 0和1.568 3,种群内遗传多样性为0.332 1,种群水平平均Nei’s 遗传多样性为0.394 9,Shannon信息指数为0.575 4,基因流为2.900 9,遗传一致度为0.821 9,遗传距离平均值为0.196 1。并根据遗传距离进行了UPGMA聚类分析。     

Genetic diversity and genetic differentiation of natural Pinus koraiensis population

Genetic diversities and genetic differentiations of the four Pinus koraiensis populations （Gaofeng Forestry Farm at Tangwanghe in Yichun City, Erdaobaihe Town in the Changbai Mountains, Shcngshan Forestry Farm in Heihe City, in China, and the suburb of Vladivostok City in Russia） were analyzed by using ISSR PCR technique. The results of 15 primers amplification showed that the ratio of polymorphic site of P koralensis population was 60.7%. Euch primer had 3.6 polymorphic sites, The diversity levels of the four P. koraiensis populations were rather higher compared with those of other Pinaceae species. The genetic diversity levels of t： koraiensis populations grown in the center region were higher than those grown in the edge zone. The genetic diversity of r3 koraiensis mainly came from the interiot of the population, accounting for 73% of total genetic diversity. There were no positive correlation between genetic distances and geographical distances for the four P koraiensis populations. The gradual decrease of natural distribution region of P. koraiensis was due to anthropic destroy and environmental factors （i.e. fire and wind throw）, rather than the lower genetic diversity.     

Genetic diversity of Populus euphratica populations in northwestern China determined by RAPD DNA analysis

Five Populus euphratica Oliver populations in northwestern China were analyzed using RAPD DNA markers to determine genetic diversity among and within populations. One hundred-and-five polymorphic bands were observed, ranging in size from 250 bp to 1700 bp, using 10 primers. Only one population on the north side of the Tianshern Range had a unique band common to all individuals that was not found in individuals from populations in the Tarim River valley. Intra-population genetic diversity was high in two populations along the Tarim River and low in the other three populations. There was no significant correlation between genetic distances and geographic distances. The result of correspondence analysis shows that the individuals from the three populations with low genetic diversity are isolated from each other. The result of cluster analysis based on genetic distance shows that the population in the Tianshern Range is genetically distant from the other populations. These results suggest that the Tianshern Range population was genetically isolated from the other populations.     

红松种子园单株ISSR-PCR遗传多样性分析

以林口青山红松无性系种子园216个单株生健康嫩叶为试验材料,利用ISSR-PCR分子标记技术分析其遗传多样性的试验结果表明:从100条引物中共筛选出11条具有多态性的ISSR引物,经ISSR-PCR扩增后共获得102个位点,多态性谱带102条,多态位点比率为100%,单株有效等位基因数变动范围为1.0046~2.000,群体总基因多样性指数为0.3333,Shannon多样性指数为0.0164~0.6931,期望杂合度为0.0046~0.5000,红松种子园单株具有丰富的遗传多样性。     

An analysis of the pattern of genetic variation in Vitellaria paradoxa using RAPD markers

Vitellaria paradoxa C.F.Gaertn. is one of the most economically and socially important tree species in the Sudano-Sahelian region. Little is known of the pattern of variation within its natural range. Eight populations covering most of the natural range from Senegal to Uganda were sampled and leaves of 118 individual trees were collected. An analysis of molecular diversity was carried out using random amplified polymorphic DNA (RAPD) markers. Fifteen random primers generated 67 polymorphic and 15 monomorphic RAPD loci ranging from size 1670 bp to 280 bp. Shannon's diversity index varied from Central Africa/Ndele (0.374) to Uganda/Amoya (0.350) but the differences between populations were smaller than the population standard errors. Correspondence analysis of unrooted neighbour-joining trees suggested that genetic distances between populations were correlated with geographic distances. This trend was confirmed by a Mantel test giving a coefficient of correlation between genetic and geographic distances of R = 0.88 (P = 0.0001). Result of AMOVA (analyses of molecular variance) showed that 14.8% (P = 0.002) of the RAPD variation was distributed among populations. Nested analysis of variance indicated that variance between the western and eastern groups of population represented 8.7% (P = 0.001) of the total variation and the variation amongst populations within group was 9.5% (P = 0.001). Eighty two percent of the variation was explained by variation amongst individuals within populations. The origin of genetic structure and level of diversity may be explained by the glacial refugia, the biological traits of Vitellaria paradoxa and by the impact of semi-domestication. Based on these results, sampling options of the natural populations are suggested for in or ex situ conservation. For the development of Vitellaria paradoxa breeding population, the sampling should consist of many individual trees selected within a few populations to capture a large proportion of variation.This revised version was published online in November 2005 with corrections to the Cover Date.     

利用ISSR标记对12种五针松亲缘关系的研究

采用ISSR 标记技术,对12 种五针松的亲缘关系进行分析。利用筛选出的12 个ISSR 引物共检测到117 个位点,多态条带比率(PPB)在9.40%～33.33 %之间,遗传分化最高的是偃松,最低的是柔枝松。12 种五针松的基因多样性(Ht)为26.21%,其中种内基因多样性(Hs)为7.66%,种间基因多样性(Dst)为18.55%,五针松种间变异占总变异的70.78%。遗传距离聚类,将12 种五针松分为2 个类群,第一类群包括乔松、华山松、海南五针松、华南五针松、北美乔松、山白松和云南五针松;第二类群包括美国白皮松、偃松、、柔枝松、西伯利亚红松和红松。图1 表3 参6。     

Genetic diversity and population genetic structure of Python bivittatus in China

The Burmese python(Python bivittatus) has recently suffered large population declines in the wild in China due to illegal capture, overexploitation, deforestation and the loss of its natural habitat. Greater knowledge of the genetic diversity and structure of wild P. bivittatus populations is needed to help ensure its effective management.In this study, we investigated the genetic diversity and population genetic structure of wild P. bivittatus in China in detail. 109 P. bivittatus individuals from five distribution areas in Guangdong(GD), Guangxi(GX), Hainan(HN),Fujian(FJ) and Yunnan(YN) province of China were collected, and their genetic structure and diversity were analyzed. Eight highly polymorphic microsatellite loci were utilized to reveal high levels of genetic diversity in the P. bivittatus population. Genetic diversity was highest in GX, and lowest in GD. All geographic populations demonstrated a bottleneck effect indicating recent population decline. Fstand AMOVA analyses revealed that there was moderate genetic differentiation among the five populations, and that only 10.59 % of total genetic diversity occurred among populations. Fstvalues between populations were positively correlated with their geographical distances. Genetic structure analyses revealed that the HN,GX and GD populations, which were geographically closest, were assigned to a genetic cluster, while the YN and FJ populations constituted a single cluster,respectively.     

Genetic diversity analysis of Sinojackia microcarpa,a rare tree species endemic in China,based on simple sequence repeat markers

Although most Sinojackia species are endangered, they contribute greatly to the biodiversity of local ecosystems. Sinojackia microcarpa, an endangered species, is distributed only in three provinces of eastern China. Determining the genetic diversity of S. microcarpa provides key information for germplasm evaluation and species conservation. Here we used simple sequence repeat (SSR) markers to investigate the genetic diversity of eight natural populations of S. microcarpa. Leaf samples were collected from 144 individuals in 8 wild populations. The 156 bands were generated from 14 pairs of informative SSR primers, with an average percentage of polymorphic bands of 45.67%. The average values of Nei’s genetic diversity (He) and Shannon’s diversity index (I) were 0.1007 and 0.1658, respectively. The total genetic variation of S. microcarpa existed mainly within the eight populations, rather than among populations, and reached 86.41%. A cluster analysis showed that the eight wild populations of S. microcarpa could be classified into four groups, at a threshold of 4.0, based on an analysis of the SSR genotypes. Furthermore, there was a significant association between the phylogenetic relationships and the geographic locations of the S. microcarpa populations. In particular, populations from Fuyang, Jiande, and Lin’an in Zhejiang Province had close phylogenetic relationships and geographic distances. In addition, these three populations had the highest genetic diversity and the most individuals, suggesting that these three locations may be the S.microcarpa distribution center. This study serves as a model for studying the genetic diversity of endangered plant species.     

黑龙江大小兴安岭红皮云杉种群更新与遗传多样性的研究

在大、小兴安岭地区12个红皮云杉种源分布区内,分别选取调查样方,进行红皮云杉种群更新研究,同时以12个种源的144个样本为材料,采用RAPD分子标记技术进行遗传多样性研究,在种群更新研究结果的基础上分析其遗传多样性,最终为谷地红皮云杉衰退机制研究提供种群水平及分子水平的相关证据。结果表明:红皮云杉在DNA水平上具有较高的遗传变异,多态位点百分率达到98.81%;红皮云杉种源总的Nei遗传多样性指数(H)为0.363 2,Shannon指数(I)为0.540 5;种源间和种源内遗传分化分别为27.72%和72.28%,12个红皮云杉种源间的基因分化指数Gst=0.277 2,基因流系数Nm为1.304 0;各种源间具有较高水平的遗传一致度,变化范围为0.751 10.948 1。遗传距离聚类分析表明,12个种源可聚为3大类:新青、乌伊岭、红星种源为第1类;五营、友好、美溪、乌马河、带岭、南岔、双丰种源为第2类;蒙克山、塔林为第3类。种群更新数据表明:大兴安岭和小兴安岭新青、乌伊岭、红星种源为进展种群,小兴安岭五营、友好、美溪、乌马河、带岭、南岔、双丰种源为衰退种群,与遗传距离聚类分析结果一致。这一研究结果可为进一步寻找谷地云冷杉林衰退机制提供一定的数据基础,也可为红皮云杉种群遗传多样性的保护以及种群生态恢复提供科学依据。     

仙茅属13个种群遗传多样性ISSR分析

为了解我国仙茅属植物种质资源分布情况及其亲缘关系,利用ISSR技术对来自湖南、广西、四川、云南、江西的13个种群的134份野生样本的遗传多样性进行了研究。利用筛选出的15条引物共扩增出256条清晰、重复性好的条带,多态性条带百分比达到91.79%;在种内水平上,多态性位点百分比为4.69%~29.30%,Shannon信息指数为0.028 3~0.160 5。13个种群中遗传多样性最高的为四川宜宾种群,多态性位点百分率为29.30%,Shannon多样性指数为0.160 5;云南9号种群遗传多样性最低,多态性位点百分率为4.69%,Shannon多样性指数为0.028 3。13个种群之间的遗传距离为0.187 1~0.513 1。根据遗传距离进行UPGMA聚类分析,13个种群共聚为2大类,四川宜宾与江西武功山种群最先聚在一起,二者的亲缘关系最近;广西雅长与四川盐边的种群聚在一起,说明二者亲缘关系较云南的较近。     

Genetic diversity and conservation of two threatened dipterocarps(Dipterocarpaceae) in southeast Vietnam

Two threatened dipterocarp species,Dipterocarpus costatus and Dipterocarpus alatus are well-known endangered species in lowland forests of southeastern Vietnam,primarily from habitat loss and over-exploitation of their wood.To develop conservation strategies for these species,we analyzed 242 samples using nine microsatellite markers to determine the genetic variability within and among five populations of D.alatus and three of D.costatus,representing the natural range of dipterocarps in Southeast Vietnam.Results indicated low levels of genetic variability within populations with an average gene diversity of 0.223 for D.alatus and 0.152 for D.costatus.Results of bottleneck tests indicated a reduction in population size of both species(P>0.05).Genetic differentiation among populations was high(FST=0.347 for D.costatus and 0.274 for D.alatus),indicating limited gene flow(Nm=0.662 for D.costatus and 0.47 for D.alatus)and isolated populations related to geographical distances.Analysis of molecular variance showed high genetic variation within populations(72.92%for D.alatus and 60.81%for D.costatus)compared to among populations.Bayesian analysis and UPGMA tree also indicated the two optimal genetic clusters related to geographical distances.These results will provide a platform for the conservation,management and restoration of these species.