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...     

Allozymes Genetic Diversity of Quercus mongolica Fisch in China

INTRODUCTION Analysis of the amount and distribution of genetic variation within and among populations of a species can increase the understanding of the historical processes underlying the genetic diversity (Dumolin- Lapegue et al. 1997) and can also provide important basic information for breeding programmes and for the establishment of programmes to conserve genetic resources. Moreover, information on the genetic structure allows for a more representative sample of the species’ gene p…     

毛红椿天然群体遗传多样性及取样策略探讨

[目的]研究毛红椿天然群体遗传多样性取样策略,为其种质资源收集、保存和遗传多样性保护等提供参考依据。[方法]利用8对微卫星分子标记进行毛红椿天然群体遗传多样性和空间自相关分析,综合制定其天然群体合理取样策略。[结果]毛红椿天然群体等位基因数平均为7.5个,期望杂合度(H_e)和多态性信息指数(PIC)均值分别为0.643 7和0.636 0,基因分化系数(G_(ST))均值为0.290 7。在遗传多样性取样策略方面,提出了根据毛红椿群体基因分化系数来确定取样群体遗传变异所占总变异比例的运算公式为1-(G_(ST))~(n-1),其中,n为取样群体的数量。当取样群体达到4个时,基本上能包括该树种97.5%的遗传变异;同时确定了目标群体的选择方法,应选择与其它群体间基因分化系数均值较大的4个群体,即贵州册亨(CH)、浙江遂昌(SC)、浙江仙居(XJ)和云南师宗(SZ)。通过构建云南宾川(BC)、云南师宗(SZ)和江西宜丰(YF)群体内取样单株数量与基因多样性和等位基因之间的捕获曲线,确定了群体内取样单株数量应达到15个以上;毛红椿天然群体内300～520 m范围内的单株间存在相似关系,超出此范围个体间差别较大,说明在进行群体内单株取样时,单株间距应大于520 m。[结论]取样群体数量、群体间遗传分化系数、群体内单株数量以及单株间距离等影响了毛红椿取样群体的遗传多样性。毛红椿天然群体遗传多样性取样策略为取样群体4个、每个群体最少取样15个单株,单株间距大于520 m。     

Genetic Variation among 11 Abies concolor Populations Based on Allozyme Analysis

In order to obtain information on the genetic structure of Abies concolor and the genetic variation among 11 popula- tions introduced from America to China, allozyme analysis based on starch gel electrophoresis technology was used. 24 loci of 10 allozyme systems were mensurated, and the genetic structure and genetic diversity of the 11 populations of A. concolor evaluated. The results show that the genetic variation among is significant, and the genetic variation within A. concolor populations is more important. In contrast with other conifers, the variation of A. concolor is above the average level of conifers, and higher than the same level of Abies. The percentage of polymorphic loci (P) was 62.5%, the number of alleles per locus (A) 2.08, the number of ef- fective alleles per locus (Ae) was 1.37, the expected heterozygosity (H) 0.204, and the Shannon information index (I) 0.351 7. There is a short genetic distance (D=0.061) and a low gene flow (Nm=0.839 4) among the 11 introduced populations of A. concolor with high genetic variation. The genetic differentiation coefficient (Gst) was 0.229 5, which is higher than that of the mean in Abies or Pinus.     

Genetic Variation and Population Structure in Korean Endemic Species: V. Corylopsis coreana (Hamameliaceae)

The allozyme diversity of ten Korean populations of Corylopsis coreana Nakai, a shrub endemic to Korea, were examined. Although Korean populations are isolated, they maintain moderate levels of allozyme variation (average percent of loci polymorphic=22.4%, mean number of alleles per polymorphic locus=3.97, mean expected heterozygosity=0.109) compared to the means of 26 woody endemic species. A high level of heterozygote deficiency was observed in populations of C. coreana (mean F _IS=0.232). Significant heterogeneity in allele frequencies were detected between populations at all polymorphic loci (p<0.001), among-population genetic differentiation accounted for 12.3% of the total variation. Indirect estimates of the number of migrants per generation (Nm) (1.77, calculated from G _ST) indicate that gene flow is moderate among populations of C. coreana. The allozyme diversity and population structure in C. coreana may be attributed to relatively long-distance flight of pollinators in early spring, gravity seed dispersal, restricted distribution, and high density in the standing populations of the species.     

Genetic characterization of English yew (Taxus baccata L.) populations in Bosnia and Herzegovina

The genetic structures of six populations of English yew (Taxus baccata L.) from different parts of Bosnia and Herzegovina have been characterized by means of isozyme analyses. Using six polymorphic gene loci, a total of 16 alleles have been found with a number of nine alleles, which were in common in all populations. In general, the values of observed heterozygosity reflect a very high level of individual genetic variation. Great differences in the relative allele frequencies lead to relatively high gene pool distances between the populations. Whereas the genetic structures of four populations corresponded essentially with the results of publicized investigations of yew populations from other parts of Europe, two occurrences show great differences. The possible reasons of these peculiarities are discussed. Based on the results of the genetic analyses, different measures for the maintenance and development of the genetic resources are recommended. The conservation management on the population level can prevent the possible loss of genetic adaptation as far as the reasons of genetic differences and their importance are not discovered to a sufficient extent.     

白皮松天然群体遗传多样性的EST-SSR分析

为探讨白皮松群体间遗传变异规律,使用7对EST-SSR引物对分布区内21个白皮松天然群体的遗传多样性及遗传分化水平进行了研究。结果表明:7对引物在21个白皮松天然群体的663个单株中共检测到14个多态性位点。各群体间有效等位基因数(Ne)、Shannon’s信息指数(I)、观测杂合度(Ho)、期望杂合度(He)、Nei’s期望杂合度(Nei’s)分别为1.156 5 1.601 9、0.133 5 0.492 5、0.138 4 0.397 3、0.0860 0.342 8、0.084 6 0.337 4。白皮松群体间遗传分化系数(Fst)平均为0.215 2,基因流(Nm)值平均为0.911 9,群体间基因交流总体较少,遗传分化较大。白皮松多样性水平在分布区内呈规律性变化,多样性分布的中心区域主要在西部、南部,具有从西向东,从南向北依次减少的趋势。     

燕山山脉西伯利亚杏的遗传多样性和遗传结构

以西伯利亚杏分布的核心区域燕山山脉地区的17个群体为材料,利用9对微卫星标记进行遗传多样性和遗传结构的分析。在533个个体扩增得到203个等位基因,每位点平均等位基因数为22.556个。分析表明燕山山脉西伯利亚杏群体具有较高的遗传多样性,每位点平均有效等位基因数(Ne)为5.714,多态位点百分率(P)为100%,期望杂合度(He)为0.788。根据有效等位基因数(Ne)、期望杂合度(He)和Shannon信息指数(I)3个遗传多样性参数,遗传多样性最高的群体为北京八达岭,其次为平泉榆树林子,而最低的群体为崇礼驿马图。群体间总的遗传分化系数FST为0.065,总的基因流Nm为3.836。分子方差分析(AMOVA)结果显示燕山山脉地区西伯利亚杏群体的遗传变异主要存在于群体内(95.62%)。Mantel检验发现遗传距离与地理距离呈显著相关性(r=0.5894,P<0.0001)。UPGMA聚类结果显示,地理距离接近的群体聚在一起,进一步验证了Mantel检验结果。基于上述分析结果,提出西伯利亚杏的种质收集策略。研究结果为西伯利亚杏可持续利用与保护提供一定的理论依据。     

天然马尾松群体遗传结构的研究

醇溶蛋白是种子的贮藏蛋白 ,在对麦类植物的醇溶蛋白研究中 ,发现醇溶蛋白的电泳谱带的带纹多少及组合方式完全受基因型所控制 ,几乎不受环境的影响 ,可以构成品种的指纹 (Ｄｒａｐａｒ,1 987;Ｚｉｌｌｍａｎｅｔａｌ.,1 979) .因而几年来 ,国内外已将醇溶蛋白电泳分析应用到遗传育种、种子鉴定、资源保存利用以及物种起源、演化分类研究等方面 (颜启传等 ,1 992 ;傅宾孝等 ,1 993;吴若菁等 ,1 997;2 0 0 0 ;杨瑞武等 ,2 0 0 0 ;王志容等 ,2 0 0 0 ;李名旺等 ,2 0 0 0 )。马尾松 (Ｐｉｎｕｓｍａｓｓｏｎｉａｎａ)广泛分布于我国南方 ,是主…     

蒙古栎天然群体等位酶遗传多样性研究

以中国蒙古栎全分布区的8个天然群体和辽东栎1个天然群体为研究对象,进行了水平淀粉凝胶电泳技术的同工酶分析,共分析了13种酶系统产生22个位点。结果表明:(1)蒙古栎在种和群体水平的遗传变异水平较低,多态位点百分率P分别为52.38%、28.976%,期望杂合度He分别为0.099、0.085,观测杂合度Ho分别为0.092、0.088;(2)蒙古栎群体间遗传分化程度较高,分化度Gst为0.107,遗传多样性中的遗传变异量89.27%存在于群体内;蒙古栎群体水平的基因流Nm值为2 080。(3)蒙古栎群体间的平均遗传距离D较低,为0.0121,各群体之间的遗传一致度I为0.974～1.00;(4)东灵山辽东栎群体的遗传多样性较低,多态位点百分率P为36 36%,期望杂合度He为0.083,观测杂合度Ho为0.070;(5)利用群体间遗传距离进行的UPGMA聚类结果表明,蒙古栎自然分布区的东北部的4个群体和西南部的2个群体分别聚为一亚类,这与其地理分布格局大致吻合,但群体间遗传距离与地理距离无明显的相关性。(6)长期的砍伐和破坏,造成有效群体较小,而且经受繁殖瓶颈效应,是蒙古栎遗传多样性下降的主要原因。     

白皮松种质资源鉴定与评价

采集白皮松3个新变异类型(盆仙白皮松、瑞王白皮松、9号树)、北京良种基地母树、北京市挂牌古树等共48个样品,应用SSR技术,对上述样品分别进行鉴定和多样性评价。结果表明:同一个变异类型的无性系与其原变异枝之间在所有位点上均不存在差异,说明其无性系及其原变异枝属于相同的基因型,"瑞王白皮松"和其母株(古树152)非变异枝间在SSR—Y5位点上存在差异,"瑞王白皮松"与"盆仙白皮松"在SSR—Y2位点上存在差异。"9号树"在Y2、Y5 2个位点上与"盆仙白皮松"、"瑞王白皮松"不同,而与其母树群体莽山良种基地的母树相同。可以通过上述位点的检测来鉴定3个不同的变异类型。"盆仙白皮松"、"瑞王白皮松"和"9号树"、古树群组、莽山群组间的遗传距离分别为0.021 1、0.011 4、0.081 3、0.063 8。"瑞王白皮松"与"盆仙白皮松"间、"瑞王白皮松"与古树间存在遗传上的差异。参试样品的有效等位基因数(Ne)、Shannon’s信息指数(I)、观测杂合度(Ho)、期望杂合度(He)、Nei’s多样性指数(Nei’s)的平均值分别为1.230、0.302、0.221、0.189、0.197。多样性水平略高于白皮松人工群体而与白皮松天然群体接近,说明参试样品具有较高的遗传多样性水平,具有选择利用的遗传基础较好。     

新疆额尔齐斯河流域苦杨与欧洲黑杨遗传多样性分析

应用SSR标记技术,对新疆额尔齐斯河流域河谷分布的苦杨(Populus laurifoli)和欧洲黑杨(Populus nigra)天然居群的遗传多样性和遗传分化进行了研究。结果显示:苦杨和欧洲黑杨的天然居群具有较高的遗传多样性,且苦杨明显高于欧洲黑杨。与苦杨居群相比,欧洲黑杨居群间基因流较高,居群间的遗传分化程度较小,变异主要源于居群内。苦杨和欧洲黑杨居群内的杂合度较高,各个居群的各项遗传参数都要小于物种水平。苦杨和欧洲黑杨均偏离Hardy-Weinberg平衡,表现为杂合子过量的现象。     

Factors shaping genetic structure within populations ofEurya japonica (Theaceae)

Starch-gel electrophoresis was used to resolve nine polymorphic enzyme loci from leaf tissue collected from 20 Korean populations ofEurya japonica in order to determine differences in allele frequencies between male and female trees. In addition, 84 adults were sampled and mapped in a population located on Naenaro Island in Korea to examine spatial genetic structure using spatial autocorrelation analysis. Allele frequencies between males and females gave few contribution to the genetic structuring within populations. Only nine (5%) of 180 cases were significantly different from both sexes in allele frequencies. On the other hand, Moran'sI was significantly different from the expected value in 31 (23.5%) of 132 cases. In the shortest distance (0<5m),I was significantly positive in 10 (22.7%) of 44 cases. The results indicate that a significant small scale genetic structure was detected in the population and patch widths were inferred to be approximately 5–7 m. A nonrandom distribution of genotypes may be indicative of restricted gene flowvia seed and pollen dispersal, and patchy establishments of genetically distinct individuals. These factors are responsible for shaping population genetic structure ofE. japonica.     

中国东北林蛙（Rana dybowskii）遗传多样性与分化研究

本文利用11个微卫星多态位点检测东北林蛙(Rana dybowskii)的遗传多样性和种群遗传结构。6个东北林蛙种群的75个个体分布于中国的小兴安岭和长白山地区。11个位点在所有种群中得到的等位基因数为2～10个不等,平均5.6个;平均期望杂合度(HE)为0.572,属于中度多态。基因分化系数(FST)分析表明小兴安岭和长白山地区的种群间遗传分化显著(P<0.001),基于Nei's DA遗传距离构建的UPGMA系统树和AMOVA的结果进一步验证了结论的准确性。因此, 建议将分布于小兴安岭和长白山的东北林蛙划分为两个单独的管理单元加以保护和管理。图2表7参46。     

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。     

云南红豆杉天然种群遗传多样性研究

采用垂直板式聚丙烯酰胺凝胶电泳，检测了云南红豆杉（Taxus yunnanensis)雌配子体的5种等位酶，并以10个基因位点编码的5个酶系统，分析了滇西北3个云南红豆杉天然种植的遗传多样性与遗传分化。结果表明，群体的多态位点比例是0．77；群体的平均杂合性观察值是0．302；预期值为0．3320；每个基因位点发现的等位基因数是2．05，有效等位基因平均数是1．466。对10个基因位点的基因多样性测定表明，种群间的分化占14．66％。总的基因多样性约85％产生于种群内。群体间的平均遗传距离是0．118。     

Genetic diversity of Castanopsis acuminatissima (Bl.) A. DC. in northern Thailand and the selection of seed trees for forest restoration

Castanopsis acuminatissima (Bl.) A. DC. is one of a number of framework species which are being planted to restore seasonally dry tropical forests in northern Thailand. This study describes the level of microsatellite variation within and among three populations of this species in three National Parks in northern Thailand: Doi Suthep-Pui, Doi Inthanon and Jae Sawn, using published primers developed for Castanopsis cuspidata var. sieboldii Nakai. The five microsatellite loci employed in this study detected a total of 54 alleles (n = 72). The informativeness of the microsatellite loci varied from six to 18 alleles, with an average of 10.8 alleles found over all loci. The mean observed heterozygosities in the three populations showed no significant deviations from Hardy-Weinberg expectations. The vast majority of genetic diversity was contained within the populations, with no significant differentiation between them (F_ST = 0.006). Algorithms were designed to capture microsatellite diversity, and the rationale for using microsatellite markers to inform genetic conservation is discussed. The implications for seed collection of C. acuminatissima for forest restoration are also discussed.     

枫香同工酶遗传多样性分析

对取自枫香16个群体的幼嫩叶片样品采用垂直板聚丙烯酰胺电泳技术进行了同工酶分析.结果表明:(1)群体间的遗传结构差异显著.在所分析的6个酶系统共6个位点中,各个位点的等位基因频率变化从0～1不等,16个群体中有9个群体存在稀有基因,6个群体存在特有基因,一共发现了4个稀有基因,3个特有基因;(2)枫香群体水平每位点等位基因数总平均为3个,每位点有效等位基因数总平均为1.855 7个,多态位点百分率总平均为100％,观察杂合度总平均为0.582,期望杂合度总平均为0.443,Shannon信息指数总平均为0.711 0.从整体上看,群体内的杂合子超过了哈代-温伯格平衡所要求的比例,杂合子过量.(3) UPGMA聚类分析显示,枫香16个群体中分为2大类,第1大类就是福建建瓯,其他15个群体即为第2大类.在第2大类中遗传距离较远的群体是重庆丰都、安徽黄山,它们与本类群体中其他13个群体的遗传距离较远,而该13个群体间的遗传距离较近,因此可以看出,福建建瓯与其他群体间的遗传距离是最远的,16个群体基本上呈现按地理距离聚类的趋势,与地理分布格局较吻合.     

Genetic diversity of American hazelnut in the Upper Midwest,USA

World hazelnut production is based on European hazelnut (Corylus avellana) and is limited by the narrow climatic requirements of this species. The cold hardiness and disease resistance of the American hazelnut (Corylus americana) offer opportunities to expand production to new areas including the Upper Midwest (USA). The American hazelnut is a phenotypically diverse species. This study used ten microsatellite marker loci to investigate genetic diversity in 1140 individuals sampled from 25 populations across Wisconsin, Iowa, Minnesota and North Dakota. Overall, the marker loci were highly polymorphic (H_o = 0.69, H_e = 0.78, PIC = 0.84) with 7–13 alleles per locus. There was very high genetic diversity within populations (90% of the total) and some tendency toward population differentiation. Mantel’s test showed that genetic distance among the populations was not correlated with geographic distance. We conclude that selection of individuals for use in breeding should be based primarily on phenotype (productivity, nut size, percent kernel, ease of harvest), with care to include representatives of genetically differentiated populations.     

Genetic structure of populations of beech (Fagus sylvatica L.) in Denmark

The genetic structure in Danish indigenous and introduced provenances of beech (Fagus sylvatica L.) is described. Ten stands are analysed based on variation revealed by seven enzyme systems. The present study reveals significant allele frequency differences between populations with a small absolute amount of genetic differentiation, with no pattern related to geographic distance. The genetic differentiation between indigenous populations measured by Wright's F _ST‐statistic does not deviate significantly from zero, and only 2.9% of the total genetic variation in the foreign populations was due to interpopulation differences, The allele frequencies in relatively small and isolated populations do not differ from the frequencies found in larger areas with beech forest. The low genetic differentiation of isozyme level between indigenous and foreign populations was opposed by significant differences in foliation performance measured on three pairs of neighbouring stands. Foliation performance in adjacent stands of indigenous and introduced beech indicates that quantitative characteristics must be considered separately from neutral variation at single loci.