内蒙古高原小叶锦鸡儿(Caragana microphylla)、中间锦鸡儿(C. davazamcii)和柠条锦鸡儿(C. korshinskii)的遗传多样性及遗传关系

采用RAPD技术对10个具较大地理跨度的小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿种群的遗传多样性和遗传关系进行了研究.共检测到678个位点,多态条带比率(PPB)为100%;特有位点41个,占6.05%.总体上3种锦鸡儿的遗传多样性表现出自东向西递减的趋势,分析表明其与生长地点年均气温呈显著负相关.AMOVA表明:3种锦鸡儿种间变异只占总体变异的6.08%,且显著性检验表明这种变异不显著;种内种群间的变异占总变异的11.90%;总变异的主要部分来自种群内部(82.02%). 3种锦鸡儿各种群总体分析结果表明:种群内变异比率Hpop/Hsp为0.8013,基因分化系数Gst为0.1603,种群每代迁移数Nm为2.6192,显示种群间存在一定强度的基因流,3种锦鸡儿间表现为异交性.3种锦鸡儿多样性高低及种群聚类分布格局都表现出一定的地理连续性.     

大别山山核桃天然群体遗传结构的初步分析

利用RAPD分子标记技术检测了大别山山核桃3个天然居群的遗传多样性和遗传结构。20条10 bp随机引物共检测到238个扩增位点,其中多态性位点162个,多态位点百分率(PPB)为68.1%。居群水平Shannon’s多态性信息指数(I)介于0.2651~0.2801之间;居群水平Ne i’s基因多样性指数(H)介于0.1789~0.1890之间。遗传变异计算显示大别山山核桃居群间基因分化系数(Gst)为0.4063,分子方差分析(AMOVA)表明居群间基因分化水平为0.4177,居群间基因流(Nm)为0.7306,说明大别山山核桃大部分变异存在于居群内,居群间基因交流相对较少。这一结果符合大别山山核桃风媒、异交的繁育系统特点,但其居群间基因分化程度明显高于异交植物的平均水平(Gst=0.1930)。地理隔离、居群内近交及居群间基因流受阻可能是形成目前大别山山核桃天然群体遗传结构的主要因素。     

栲树天然群体遗传结构的RAPD分析

利用RAPD分子标记对 5个栲树 (CastanopsisfargesiiFranch .)天然群体共计 188个个体的遗传多样性和群体遗传结构进行了分析。 4 1个随机寡核苷酸引物共检测到 385个位点 ,其中多态位点 15 7个 ,占 4 0 .78%。物种水平的Shannon多样性指数I=0 .4 5 97,Nei基因多样度h =0 .2 96。遗传变异分析表明 ,栲树群体的遗传变异主要存在于群体内 ,利用Shannon多样性指数估算的分化 (Hsp_Hpop) /Hsp=0 .0 4 76 ,遗传分化系数Gst =0 .0 4 2 9,分子方差分析 (AMOVA)也证实了这一结论 ,群体内的变异组分占了 94 .97% ,群体间变异只占 5 .0 3%。AMOVA分析结果的显著性检验也表明 ,群体间及群体内个体间均呈现出显著分化 (P <0 .0 0 1)。     

濒危植物三棱栎遗传多样性的RAPD分析

用随机扩增多态DNA (RAPD)标记对 5个三棱栎 (Trigonobalanusdoichangensis)居群共 99个个体进行遗传多样性和居群遗传结构分析。 16个引物共检测到 15 7个位点 ,其中多态位点 83个 ,占 5 2 87%。物种水平Shannon多样性指数I =0 2 4 31,Nei基因多样度h =0 15 95 ,种内总遗传变异量Ht=0 16 0 0 ,居群内遗传变异量Hs =0 0 74 9,居群间变异量大于居群内变异量 ,表明三棱栎的遗传变异主要存在于居群之间。与同科植物相比 ,三棱栎遗传多样性较低 ,遗传分化系数Gst =0 5 32 0 ,说明居群间的遗传变异占 5 3 2 0 % ,居群间已出现强烈的遗传分化。当地人的强烈活动造成的生境破碎化和居群隔离 ,以及三棱栎演化过程中的地史变化对其种群发展的影响等 ,可能是造成其居群间强烈的遗传分化和较低遗传多样性的原因。基于本研究结果 ,提出了三棱栎遗传多样性的保护策略。     

濒危灌木长叶红砂遗传多样性的RAPD分析

应用RAPD分子标记对濒危灌木长叶红砂(Reaumuria trigyna)种群遗传多样性进行了分析.应用18条随机引物对长叶红砂5个种群的95个个体进行扩增,检测到118个位点,其中多态位点105个.结果表明:长叶红砂种群的多态位点比率(P)为88.98%,显示出长叶红砂种群存在较高的遗传多样性.Shannon多样性指数(0.4966)、Nei基因多样性指数(0.3303)和基因分化系数(Gst=0.1425)的分析结果显示,长叶红砂种群遗传变异大多存在于种群内,种群间的遗传分化占14.25%.聚类分析表明,长叶红砂种群遗传距离与地理距离之间无直接相关关系.遗传多样性水平与物种特性和所处不同群落有关,濒危植物并不一定表现为遗传变异水平的降低.     

RAPD analysis of genetic diversity and population genetic structure of Stipa krylovii Reshov. in Inner Mongolia steppe

Random amplified polymorphic DNA (RAPD) analysis was used to characterize the genetic diversity and population genetic structure of Stipa krylovii populations in Inner Mongolia steppe of North China. Thirteen 10 bp oligonucleotide primers, which generated 237 RAPD bands, were used to analyze 90 plants of five populations from three regions, meadow steppe, typical steppe and desert steppe, from the east to the west. The genetic diversity of Stipa krylovii that was revealed by observed number of alleles (na), expected number of alleles (ne), Nei's diversity index (h), Shannon's diversity index (H), amplificated loci, polymorphic loci and the percentage of polymorphic loci (PPB) increased from the east to the west. The Pearson's correlation analysis between genetic diversity parameters and ecological parameters indicated that the genetic diversity of Stipa krylovii was associated with precipitation and cumulative temperature variations along the longitude (humidity were calculated by precipitation and cumulative temperature). Dendrogram based on Jaccard's genetic distance showed that the individuals from the same population formed a single sub-group. Although most variation (56.85%) was within populations, there was high genetic differentiation among populations of Stipa krylovii, high differentiation within and between regions by AMOVA analysis. Either Nei's unbiased genetic distance (G(ST)) or gene flow (Nm) among pairwise populations was not correlated with geographical distance by Mantel's test (P > 0.05), suggesting that there was no consistency with the isolation by distance model in these populations. Natural selection may have played a role in affecting the genetic diversity and population structure, but habitat destruction and degradation in northern grassland in China may be the main factor responsible for high genetic differentiation among populations, within and among regions.     

内蒙古典型草原羊草种群遗传分化的RAPD分析

运用 RAPD技术对内蒙古典型草原不同生境 8个羊草种群进行分析。采用 2 4个随机引物 (10 nt)在 8个种群中共检测到2 2 4个扩增片断 ,其中多态性片断 173个 ,总的多态位点百分率达 77.2 % ,特异性片断 2 2个 ,占 9.82 % ,平均每个引物扩增的DNA带数为 9.3 3条。利用 Nei指数和 Shannon指数估算了 8个种群的遗传多样性 ,并计算种群相似系数和遗传距离 ,运用UPGMA法进行聚类分析。结果表明 :羊草大部分的遗传变异存在于种群内 ,只有少部分的遗传变异存在于种群间 ,Nei指数和Shannon指数计算结果分别为 85.4%和 66.8% ;羊草不同种群的遗传多样性存在差异 ;8个羊草种群平均遗传距离为 0 .2 3 16,变异范围为 0 .1587～ 0 .2 70 0 ,说明 8个羊草种群间的遗传变异不大 ,即 :在较小地理范围内羊草的遗传分化程度较小 ;8个种群可聚为 3个类群 ,聚类结果显示生境相似的种群能够聚在一起 ,而地理距离最近的种群不一定归为一类 ,说明小范围内羊草种群间的遗传分化与地理距离不存在相关性 ,而与其生境间的相似度相关。影响遗传相似性的不是单一因子而是各种因子的综合作用 ,较小地理范围内羊草种群间的遗传分化主要是由环境的异质性所引起的     

A comparison of the genetic diversity in Dipteronia sinensis Oliv. and Dipteronia dyeriana Henry

Dipteronia is an endemic genus to China and includes only two species, Dipteronia sinensis and D.dyeriana.Based on random amplified polymorphic DNA (RAPD) markers,a comparative study of the genetic diversity and genetic structure of Dipteronia was performed.In total,128 and 103 loci were detected in 17 D.sinensis populations and 4 D.dyeriana populations,respectively,using 18 random primers.These results showed that the proportions of polymorphic loci for the two species were 92.97% and 81.55%,respectively,indicating that the genetic diversity of D.sinensis was higher than that of D.dyeriana.Analysis,based on similarity coefficients,Shannon diversity index and Nei gene diversity index,also confirmed this result.AMOVA analysis demonstrated that the genetic variation of D.sinensis within and among populations accounted for 56.89% and 43.11% of the total variation,respectively,and that of D.dyeriana was 57.86% and 42.14%,respectively.The Shannon diversity index and Nei gene diversity index showed similar results.The abovementioned characteristics indicated that the genetic diversity levels of these two species were extremely similar and that the interpopulational genetic differentiation within both species was relatively high.Analysis of the genetic distance among populations also supported this conclusion.Low levels of interpopulational gene flow within both species were believed to be among the leading causes for the above-mentioned phenomenon.The correlation analysis between genetic and geographical distances showed the existence of a remarkably significant correlation between the genetic distance and the longitudinal difference among populations of D.sinensis (p＜0.01),while no significant correlation was found between genetic and geographical distances among populations of D.dyeriana.This indicated that genetic distance was correlated with geographical distances on a large scale rather than on a small scale.This result may be related to differences in the selection pressure on species by their habitats with different distribution ranges.We suggest that in situ conservation efforts should focus on establishing more sites to protect the natural populations and their habitats.Ex situ conservation efforts should focus on enhancing the exchange of seeds and seedlings among populations to facilitate gene exchange and recombination,and to help conserve genetic diversity.     

极度濒危植物五针白皮松的保护遗传学研究

用随机扩增多态(RAPD)方法对极度濒危植物五针白皮松(Pinus squamata X.W.Li)的遗传多样性和居群遗传结构进行了研究。14个随机引物共获得93条RAPD谱带,其中6条为多态带,多态位点百分率仅为6．45％,遗传多样性极低。Shannon指数I和Nei指数h在种内也只有0．020和0．030,两个亚居群间(半阴坡亚居群与半阳坡亚居群)遗传分化程度不高,遗传分化系数Gst只有0．110,与大多数松科植物近似,居群每代迁移数为4．032。五针白皮松极低的遗传多样性可能是由于它在演化过程中遭受过严重的灾害,造成严重的瓶颈效应,丧失其大部分遗传变异。在随后的演化过程中由于遗传漂变、自交衰退等小种群现象,导致遗传多样性的进一步丧失。另外,阔叶树种对其生存的挤压和人类的干扰也是导致五针白皮松遗传多样性降低的因素之一。本文最后对该结果的保护生物学意义进行了评价。     

羊草种群遗传分化的RAPD分析Ⅱ.RAPD数据的统计分析

对松嫩草原上分布的灰绿型和黄绿型羊草9个种群进行了15个引物的RAPD分析,统计结果表明,两类种群的扩增片段数和多态位点比率明显不同,黄绿型种群低于灰绿型,其值分别＜90与＞100,＜50％与＞70％,比较了7种不同统计方法据RAPD表型或基因型频率估算的种群遗传多样性,几种统计结果都揭示,黄绿型种群低于灰绿型种群,用F1s值矫正种群对Hardy-Weinberg平衡的偏离后,估算等位基因频率,通过Shannon指数和Nei指数估计羊草种群间分化分别为37．6％和35．7％,高于等位酶的分析,讨论比较了等位酶和RAPD分析结果的异同。     

福建不同生态类型鸭种（群）的遗传多样性研究

用40个10碱基随机引物对福建2个生态类型的7个地方鸭种的基因组池DNA进行了RAPD分析,从扩增产物表现为多态的引物筛选出9个特异性强的引物进行个体DNA的RAPD分析,并利用Shannon指数估算了2个生态区域鸭群的遗传多样性,探讨了它们与生态环境之间的关系及其变化规律．结果表明,福建境内的地方鸭种具有较高的遗传多样性,闽东沿海地区鸭群有67．97％的遗传变异来自群体内,32．03％来自于群体间;闽西山地丘陵地区鸭群有59．05％的遗传变异来自群体内,40．95％来自于群体间;闽东地区鸭群的遗传变异明显高于闽西地区鸭群．同时,用非加权组平均法(UPGMA)对各种群的聚类分析表明,闽西地区的连城白鸭、泰宁麻鸭、龙岩山麻鸭和三明麻鸭归为一类;闽东地区的龙海金定鸭和莆田黑鸭聚为一类．不同生态区域内鸭群的遗传变异与地理位置存在一定的相关性．     

Evolutionary implications of allozyme and RAPD variation in diploid populations of dioecious buffalograss Buchloë dactyloides

Buffalograss, Buchloë dactyloides, is widely distributed throughout the Great Plains of North America, where it is an important species for rangeland forage and soil conservation. The species consists of two widespread polyploid races, with narrowly endemic diploid populations known from two regions: central Mexico and Gulf Coast Texas. We describe and compare the patterns of allozyme and RAPD variation in the two diploid races, using a set of 48 individuals from Texas and Mexico (four population samples of 12 individuals each). Twelve of 22 allozyme loci were polymorphic, exhibiting 35 alleles, while seven 10-mer RAPD primers revealed 98 polymorphic bands. Strong regional differences were detected in the extent of allozyme polymorphism: Mexican populations exhibited more internal gene diversity (H_e= 0.20, 0.19) than did the Texan populations (H_e= 0.08, 0.06), although the number of RAPD bands in Texas (n= 62) was only marginally smaller than in Mexico (n= 68). F-statistics for the allozyme data, averaged over loci, revealed strong regional differentiation (mean F_RT=+ 0.30), as well as some differentiation among populations within regions (mean F_PR=+ 0.09). In order to describe and compare the partitioning of genetic variation for multiple allozyme and RAPD loci, we performed an Analysis of Molecular Variance (AMOVA). AMOVA for both allozyme and RAPD data revealed similar qualitative patterns: large regional differences and smaller (but significant) population differences within regions. RAPDs revealed greater variation among regions (58.4% of total variance) than allozymes (45.2%), but less variation among individuals within populations (31.9% for RAPDs vs. 45.2% for allozymes); the proportion of genetic variance among populations within regions was similar (9.7% for RAPDs vs. 9.6% for allozymes). Despite this large-scale concordance of allozyme and RAPD variation patterns, multiple correlation Mantel techniques revealed that the correlations were low on an individual by individual basis. Our findings of strong regional differences among the diploid races will facilitate further study of polyploid evolution in buffalograss.     

RAPD analysis of genetic diversity and population genetic structure of Stipa krylovii reshov. in Inner Mongolia steppe

Random amplified polymorphic DNA (RAPD) analysis was used to characterize the genetic diversity and population genetic structure of Stipa krylovii populations in Inner Mongolia steppe of North China. Thirteen 10-bp oligonucleotide primers, which generated 237 RAPD bands, were used to analyze 90 plants of five populations from three regions, meadow steppe, typical steppe and desert steppe, from the east to the west. The genetic diversity of Stipa krylovii that was revealed by observed number of alleles (na), expected number of alleles (ne), Nei’s diversity index (h), Shannon’s diversity index (H), amplificated loci, polymorphic loci and the percentage of polymorphic loci (PPB) increased from the east to the west. The Pearson’s correlation analysis between genetic diversity parameters and ecological parameters indicated that the genetic diversity of Stipa krylovii was associated with precipitation and cumulative temperature variations along the longitude (humidity were calculated by precipitation and cumulative temperature). Dendrogram based on Jaccard’s genetic distance showed that the individuals from the same population formed a single subgroup. Although most variation (56.85%) was within populations, there was high genetic differentiation among populations of Stipa krylovii, high differentiation within and between regions by AMOVA analysis. Either Nei’s unbiased genetic distance (G _ST) or gene flow (Nm) among pairwise populations was not correlated with geographical distance by Mantel’s test (P > 0.05), suggesting that there was no consistency with the isolation by distance model in these populations. Natural selection may have played a role in affecting the genetic diversity and population structure, but habitat destruction and degradation in northem grassland in China may be the main factor responsible for high genetic differentiation among populations, within and among regions. The text was submitted by the authors in English.     

大别山山核桃种群遗传多样性研究

为了更有效地保护和合理开发大别山山核桃(Carya dabieshanensis)资源,该文利用RAPD分子标记技术,对3个天然大别山山核桃种群的90个单株的遗传多样性、种群内和种群间的遗传变异进行了研究,结果表明:20对10 bp随机引物共检测到238条谱带,其中多态带为162条,占68.1%。遗传多样性分析结果显示: Shannon多样性指数为0.476 1,58.18%的变异分布于群体内,而种群间变异占了41.82%;Nei指数群体总基因多样度为0.314 5,群体内平均基因多样度(H_S)为0.186 5,群体间的基因多样度(H_ST)为0.128 0,群体Nei基因分化系数(G_ST)为0.406 7,说明40.67%的变异存在于种群间,群体内的变异占了总变异的59.33%,与Shannon多样性指数相比基本一致,均表明种群内有较丰富的遗传变异,这为优良品种选育提供广阔前景;种群间的基因流(N_m)为0.730 6,证明种群间遗传交换较小,这与环境适应性和高山阻隔有一定的关系。     

中国特有植物卧龙沙棘自然群体的RAPD分析

应用12个随机引物对卧龙沙棘全部2居群共28个个体进行了RAPD分析。结果表明,卧龙沙棘具有较丰富的遗传多样性,多态位点百分率为78.05%,Nei’s基因多样性h=0.2553,Shannon’s多态性信息指数Ι=0.3841。分布范围狭窄的卧龙沙棘在亚种水平的遗传多样性明显高于分布较广的中国沙棘。在居群水平上,卧龙沙棘同样具有很高的遗传多样性,平均多态位点百分率为63.42%,Nei’s基因多样性h=0.2193,Shannon’s多态性信息指数I=0.3287。卧龙沙棘的基因分化系数Gst=0.1425,表明遗传变异主要存在于居群内。AMOVA的结果也表明,在全部的遗传变异中,19.18%的遗传变异存在于居群之间,与Gst值基本一致。这一结果符合卧龙沙棘风媒、异交的繁育系统特点。     

在韩国境内Potentilla fragarioides var .sprengeliana的遗传多样性和种群结构(英文)

根据 2 2个等位酶位点遗传变异 ,探讨了韩国境内委陵菜 (PotentillafragarioidesL .var.sprengeliana)的遗传多样性和种群结构。酶位点的多态位点百分比为 5 9 1%。种和种群水平上的遗传多样性比较高 ,分别为Hes=0 .2 10 ,Hep=0 .199;而种群的分化水平则相对较低 (GST=0 .0 74)。 19个种群中随机交配的偏差为FIS=0 .331。每代迁移数的间接估计 (Nm=3.15 )表明该种在韩国的种群间基因流较高。另外 ,固定指数分析显示在一些种群和位点有轻微的杂合子缺乏。种群间平均遗传一致度为 0 985。这些韩国委陵菜种群存在于较为均一的生境 ,这很有可能是造成其种群遗传一致性较高的原因。     

Genetic diversity of Mexican brook lamprey <Emphasis Type="Italic">Lampetra (Tetrapleurodon) geminis</Emphasis> (Alvarez del Villar, 1966)

Lampreys are the only surviving representatives of the oldest known vertebrates. The Mexican lamprey L. geminis (nonparasitic), is particularly interesting, because it is an endemic, biogeographical relict, and a threatened species. RAPD markers were used to describe genetic diversity in L. geminis A total of 77 specimens were collected from five populations, three in the R'o Grande de Morelia-Cuitzeo basin and two in the R'o Duero-Lerma-Chapala basin, Mexico. Eighty-eight RAPD markers were obtained from eight primers. Genetic diversity within each population was estimated using Shannon's index (S), heterozygosity (H) and gene diversity (h). These estimates revealed significant variation within populations, although a variance homogeneity test (HOMOVA) showed no significant differences among populations or between basins. Nei genetic distance values indicate a low genetic differentiation among populations. Analysis of molecular variance (AMOVA) indicates that most of the genetic diversity occurs within populations (91.4%), but that a statistically significant amount is found among populations (P0.001). Principal coordinates and cluster analyses of RAPD phenotypes show that specimens are not grouped by geographical origin. The genetic diversity found within L. geminispopulations may be explained by its breeding system and an overlapping of generations. The scarce genetic differentiation among populations is likely to the low rate of DNA change that characterizes the lamprey group.     

采用RAPD和ISSR标记研究古尔班通古特沙漠东南缘梭梭种群的遗传结构

梭梭(Haloxylon ammodendron(CA Mey.)Bunge)是一种沙漠旱生优势树种,具有重要的生态和经济价值,然而,我们对梭梭种群的遗传多样性和遗传结构所知甚少.本文采用RAPD和ISSR标记对来自古尔班通古特沙漠东南缘的4个天然梭梭种群的遗传多样性和遗传结构进行了检测.5个RAPD引物和8个ISSR引物分别扩增出61和195条带,多态性位点比率分别为83.6%和89.7%,Shannon信息指数分别为0.333和0.367,RAPD和ISSR分析均表明梭梭种群的遗传多样性水平较高.利用分子方差分析(AMOVA)研究梭梭种群的遗传结构,结果表明,大部分遗传变异存在于种群内,通过RAPD分析发现138.2%的遗传变异发生在种群内;通过ISSR分析发现89.4%的遗传变异发生在种群内;而种群间的遗传分化很小.通过RAPD标记没有检测到种群间的遗传分化,ISSR分析表明10.6%的遗传变异发生在种群内.我们推测梭梭种群较高的遗传多样性水平可能源于对异质、高胁迫环境的长期适应,但还需要进一步的研究加以证实.种群间遗传分异低的主要原因是种群间存在强大的基因流.     

Patterns of Genetic Diversity and Population Structure of the Clonal Herb,Potentilla fragarioides var. sprengeliana (Rosaceae) in Korea

The genetic diversity and population structure of Potentilla fragarioides var. sprengeliana(Rosaceae) in Korea were investigated using genetic variation at 22 allozyme loci. The percent of polymorphic loci within the enzymes was 59.1%. The genetic diversity at the species level and at the population level was high (Hes=0.210; Hep=0.199, respectively), whereas the extent of the population divergence was relatively low (GST=0.074). FIS, a measure of the deviation from random mating within the 19 populations, was 0.331. An indirect estimate of the number of migrants per generation (Nm=3.15) indicates that gene flow is high among Korean populations of the species. In addition, analysis of fixation indices revealed a slight heterozygote deficiency in some populations and at some loci. The mean genetic identity between populations was 0.985. It is highly probable that the trend of genetic uniformity in a relatively homogeneous habitat is thought to be operated among Korean populations of P. fragarioides var.sprengeliana.     

黄海和东海小黄鱼遗传多样性的RAPD分析

小黄鱼（Pseudosciaena polyactis）是我国近海重要经济鱼类之一。本文分析了采自黄海和东海5个海区共计48个个体小黄鱼的随机扩增DNA多态性（RAPD）。从40个10 bp引物中选取20个用于群体遗传多样性分析,共检测出145个位点,其中132个（91.03%） 显多态性。用Shannon多样性指数量化的平均遗传多态度为1.93（1.50～2.44）,群体内和群体间的遗传变异比例分别为69%和31%;群体间的平均遗传相似度和遗传距离分别为0.9139和0.0861。用非加权配对算数平均法（UPGMA）聚类分析的结果表明,所分析的5个群体可分为3个地理群系,从分子水平上支持了过去有关学者把黄海和东海的小黄鱼划分为北、中、南3个地理群系的观点。