基于种实性状的无患子天然群体表型多样性研究

无患子(Sapindus mukorossi Gaertn.)是我国长江以南地区传统的重要绿化树种,其果皮富含皂苷,种仁富含油脂,是国家林业局审定的新型木本油料树种之一。为揭示无患子群体间和群体内种实表型性状变异式样,采用单因素方差分析、巢式方差分析、相关分析和主成分分析等方法,对无患子13个天然群体的10个种实表型性状进行比较分析,研究其群体间和群体内种实表型多样性以及表型变异与地理生态因子间的相关性。结果表明:无患子种实表型性状变异系数平均为7.34%,在群体间和群体内均存在丰富的表型变异。表型性状分化系数平均为62.21%,群体间变异(39.93%)大于群体内(27.46%),是无患子种实表型性状变异的主要来源。多数性状在群体间差异显著,不同程度的表现出边缘群体易于分化的特点,但地理变化规律不连续,而在群体内不同性状的差异性亦不一致。种子形态受群体地理生态的影响较果实形态大,西北部群体种子趋于椭圆形,东部、南部则趋于圆球形;地理纬度、年平均气温与多数种实性状间呈显著相关,是无患子种实表型性状变异的主要地理生态影响因子。可见,无患子种实表型性状在群体间、群体内变异都较为丰富,这些变异是由遗传和环境因素共同作用的结果。群体间和群体内多层次的变异为无患子优良种质资源保育和利用提供了物质基础。     

基于mtDNA Cyt b序列分析齐口裂腹鱼群体遗传多样性

研究测定了长江上游4个齐口裂腹鱼(Schizothorax prenanti)野生群体(重庆巫溪、重庆城口、四川雅安、四川阿坝)共104个个体的线粒体Cyt b基因部分序列, 以探讨齐口裂腹鱼野生群体的遗传多样性和遗传结构。结果表明: 在104个个体Cyt b序列中共检测到43个多态性位点, 25个单倍型。4个齐口裂腹鱼群体的单倍型多样性介于0.704—0.884, 核苷酸多样性介于0.007—0.012。群体间Kimura双参数遗传距离介于0.008—0.017, 其中四川雅安群体与四川阿坝群体间遗传距离最近, 基因交流频繁。重庆城口群体与四川雅安群体间遗传距离最远, 基因交流受阻。AMOVA分析表明, 齐口裂腹鱼的遗传分化主要来自群体内部, 且组群间、组群内群体间和群体内存在显著的遗传分化。中性检验得到Tajima’s D和 Fu’s F_s的值不显著, 且歧点分布图呈多峰, 表明长江上游4个齐口裂腹鱼野生群体未经历过种群扩张。研究旨为齐口裂腹鱼野生资源保护提供必要参考意见, 同时为齐口裂腹鱼种质资源合理开发和利用提供理论依据。     

浙江省境内七子花天然种群遗传多样性研究

利用RAPD技术对浙江省境内的七子花9个天然种群遗传多样性和遗传分化进行研究.结果表明,12种随机引物对180棵植物进行检测,共得到164个可重复的位点.多态位点百分率在14.60%～27.44%(平均为20.73%),以括苍山种群最高,其次是四明山种群,最低是观音坪种群.Shannon指数和Nei指数均反映出七子花各种群具有较低的遗传多样性,但遗传分化明显.Shannon指数显示种群内遗传多样性只占总遗传多样性的27.28%,而种群间遗传多样性却占72.72%;Nei指数表明种群内的遗传变异较小,种群间的遗传变异较大,种群间的遗传分化系数为0.7157.七子花种群间的基因流为0.1987,遗传相似度平均为0.7306,遗传距离平均为0.3150,各种群间的遗传分化明显.根据遗传距离聚类分析,大致可以将9个七子花种群分为东部和西部两大类群.     

西双版纳地区流苏石斛遗传多样性的ISSR 分析

采用ISSR 分子标记技术, 对西双版纳分布的兰科濒危植物流苏石斛( Dendrobium fimbriatum) 5 个居群共114 个个体的遗传多样性进行了研究。从100 条引物中筛选出了12 条用于扩增, 共检测到117 个位点, 其中105 个为多态位点。分析结果表明, 流苏石斛居群水平遗传多样性较低。在物种水平上, 流苏石斛多态位点百分率PPB 为89 .74% , Nei′s 基因多样性指数H 为0 . 3227 , Shannon′s 多样性信息指数Hsp 为0 . 4779 ; 在居群水平上, 各个居群的多态位点百分率PPB 差异较大( 6.84% ～ 39.32% ) , 平均值为23.93% , Nei′s 基因多样性指数H 为0 . 0871 , 各个居群的Shannon′s 多样性信息指数Ho 平均为0.1290。AMOVA 分析的结果显示, 流苏石斛的遗传变异大多数存在于居群间, 占总遗传变异的74 . 79%。基于Nei′s遗传多样性分析得出的居群间遗传分化系数Gst = 0 . 7443。各居群间的Nei′s 遗传一致度( I) 范围为0 . 5882～0 . 8331。Mantel 检测发现, 居群间的遗传距离和地理距离之间无显著的正相关关系( r= 0.2419, P=0.2416) 。鉴于流苏石斛的遗传多样性现状和居群遗传结构, 我们建议对流苏石斛居群所有个体实施及时的就地保护, 同时建立迁地保护居群, 促进基因交流。     

Genetic diversity of forest arabica coffee (Coffea arabica L.) in Ethiopia as revealed by random amplified polymorphic DNA (RAPD) analysis

Genetic diversity within the forest Coffea arabica L. gene pool in Ethiopia has not been extensively examined with molecular markers. In the present study, a total of 75 polymorphic RAPD bands generated by twelve random primers were used to assess genetic diversity among 144 genotypes representing 16 C. arabica populations. The number of polymorphic bands detected with each primer ranged from 2 to 9 with a mean of 6.25 bands per primer. Banding patterns ranged in percentage polymorphism from 37% to 73% with an overall mean of 56% for the populations analyzed. The amount of genetic variation among populations estimated by Shannon-Weaver diversity index was (H = 0.30). The within population and between populations differentiation values were 0.65 and 0.35, respectively. Genetic differentiations within and between zones of sample collection sites were 0.80 and 0.20, respectively. Within population average similarities estimated by simple matching coefficients ranged from 0.72 to 0.85, with an overall average of 0.78. In the cluster analysis that used individual samples as operational taxonomic units, most of the representatives of the same population failed to cluster before they joined members of other populations. Nevertheless, most of the populations were clustered on the basis of their geographic closeness and an east west differentiation was observed at approximately 75% similarity. The results obtained provide information on how to select sites for in situ conservation of C. arabica germplasm.     

西双版纳地区流苏石斛遗传多样性的ISSR分析

采用ISSR分子标记技术,对西双版纳分布的兰科濒危植物流苏石斛（Dendrobium fimbriatum）5个居群共114个个体的遗传多样性进行了研究。从100条引物中筛选出了12条用于扩增,共检测到117个位点,其中105个为多态位点。分析结果表明,流苏石斛居群水平遗传多样性较低。在物种水平上,流苏石斛多态位点百分率PPB为89．74％,Nei’s基因多样性指数日为0．3227,Shannon’s多样性信息指数见。为0．4779;在居群水平上,各个居群的多态位点百分率PPB差异较大（6．84％～39．32％）,平均值为23．93％,Nei’s基因多样性指数H为0．0871,各个居群的Shannon’s多样性信息指数见平均为0．1290。AMOVA分析的结果显示,流苏石斛的遗传变异大多数存在于居群间,占总遗传变异的74．79％。基于Nei’s遗传多样性分析得出的居群间遗传分化系数Gst=0．7443。各居群间的Nei’s遗传一致度（I）范围为0．5882～0．8331。Mantel检测发现,居群间的遗传距离和地理距离之间无显著的正相关关系（r=0．2419,P=0．2416）。鉴于流苏石斛的遗传多样性现状和居群遗传结构,我们建议对流苏石斛居群所有个体实施及时的就地保护,同时建立迁地保护居群,促进基因交流。     

基于SSR分子标记的中国黄连木遗传多样性分析北大核心CSCD

该研究利用筛选出的7对SSR引物,对中国20个省、市、自治区的210份种质资源进行分子标记试验,分析中国黄连木种质资源遗传多样性、亲缘关系、遗传分化特点并构建DNA分子身份证,为黄连木的资源保护、种质利用提供理论依据,结果表明:(1)7对引物在210份种质中共扩增出158个等位基因位点,平均每对引物的等位基因数为22.571个。(2)基因多样性(GD)变化幅度为0.654~0.913,平均为0.804;期望杂合度(He)变化范围0.257~0.771,平均为0.532;多态信息含量(PIC)变化范围0.639~0.907,平均为0.784。(3)从不同地区黄连木群体的遗传多样性来看,观测杂合度(Ho)介于0.373~0.600之间,平均值为0.520;期望杂合度(He)介于0.632~0.811之间,平均值为0.737;从各群体间遗传分化指数(Fst)来看,黄连木各地区群体间的遗传分化值在0.015~0.099之间,各群体间的遗传分化处于中等以下水平。(4)分子方差分析(AMOVA)结果显示,黄连木的遗传分化变异以群体内为主,占总变异量的94%,群体间的变异占6%。(5)UPGMA聚类、群体遗传结构分析和PCoA分析结果相一致,全部种质被划分为两大类,西南地区群体单独为一类,其他地区单独为一类。(6)利用7对SSR引物构建了210份黄连木种质的DNA分子身份证。     

青钱柳天然群体种子性状表型多样性

以青钱柳分布区内的9个天然群体种子为试材,对种子千粒重、体积、直径、厚度和径厚比5个表型性状进行了系统的比较分析,采用方差分析、相关分析及聚类分析等方法对群体间和群体内的表型多样性进行探讨.结果表明: 青钱柳种子千粒重、体积、直径及厚度在群体间和群体内均达到显著或极显著差异,而种子径厚比仅在群体内存在极显著差异,说明青钱柳种子性状在2个层次上都具有丰富的多样性.各性状的平均表型分化系数（V）为20.54%,即群体间的变异远低于群体内的变异（79.46%）.种子性状与地理因子相关程度存在差别,且受年均气温的影响最大.利用群体间欧氏距离进行系统聚类分析,青钱柳群体可以划分为三类.     

Planchonella, first record of gynomonoecy for the family Sapotaceae

Inter-simple sequence repeat (ISSR) markers were used to investigate the levels and pattern of genetic variation within and among populations of Pteroceltis tatarinowii Maxim., an endangered plant endemic to China. Of the 76 primers screened, 11 produced highly reproducible ISSR bands. A total of 118 bands were presented from the 11 selected primers across all individuals of five natural populations, corresponding to an average of 10.73 bands per primer. The size of the ISSR bands ranged from 200 to 2,000 bp. The percentage of polymorphic loci at the population level ranged from 77.97 to 86.44%, with an average value of 82.54%. Genetic differentiation among populations was revealed based on Nei’s genetic diversity analysis (19.41%) and the nonparametric analysis of molecular variance (20.62%). The Mantel test showed a significant positive correlation between geographic distance and genetic distance (r = 0.7758, P < 0.05), indicating a role of geographic isolation in shaping the present population genetic structure of P. tatarinowii. The size of the natural populations of P. tatarinowii was noted in field observations to be very small, chiefly owing to habitat destruction and overexploitation in the past decades. Therefore, effective measures for preserving genetic diversity of this species at the population level are needed and should include protecting its natural habitats and increasing the numbers of individuals. To meet the commercial demand for this species, P. tatarinowii plantations and cultivation facilities should be established as an alternative source of raw materials.     

茶条槭自然种群种子和果实表型多样性研究

为探析茶条槭(Acer ginnala)种子和果实表型差异程度及变异规律,该研究采用巢式方差分析、主成分分析、聚类分析等方法,对茶条槭主要分布区内7个种群种子和果实的12个表型性状进行比较研究,分析茶条槭种群间和种群内的表型多样性以及与地理生态因子的关系。结果表明:除种子长/宽(SLW)外,其它11个表型性状在茶条槭种群间和种群内均具有显著差异;各性状平均变异系数(CV)为13.90%,变异幅度为8.14%～32.08%;种群间翅果性状的平均变异系数(15.63%)高于种子性状的平均变异系数(8.71%),表明种子性状的稳定性高于果实性状。主成份分析中,果实形态特征对茶条槭种群表型的贡献率大于种子贡献率。种群间表型分化系数为35.47%,说明种群内变异(64.53%)大于种群间变异(35.47%),暗示变异主要来源于种群内变异。茶条槭种子和果实表型性状受地理生态因子影响较小,主要受自身遗传因素的影响。基于种群间欧式距离的聚类分析将茶条槭7个种群分为2大支,没有严格按照地理距离而聚类,表明茶条槭种群表型性状变异的不连续性。茶条槭不同种群种子和果实具有较高的表型多样性,与其分布范围和生物学特性有关。     

山核桃种质资源遗传多样性的RAPD分析

运用RAPD分子标记技术对山核桃种质资源的五处天然居群遗传多样性进行了初步研究。20条10bp随机引物共检测出252个扩增位点,其中多态性位点168个,多态性位点比率为66.7%。依据Shannon’s表型多样性指数,山核桃种质资源的遗传多样性水平相对较高,群体内变异占总变异的60.32%,居群间变异率为39.68%。五处天然居群中,岛石居群遗传多样性水平最高,为0.2800,临目居群最低,为0.1992。群体内平均遗传距离为0.0914,居群间平均遗传距离为0.1188。丰富的遗传多样性可保证山核桃种质群体能够持续生存和发育,也为山核桃选优、品种改良及遗传育种工作奠定了遗传学基础。     

渐危植物浙江楠群落结构及叶片性状多样性

浙江楠为商品材“金丝楠木”的原植物之一,天然分布区窄,属国家二级保护渐危种,在全球气候变化背景下,研究其天然种群所在森林群落的结构特征及其多样性具有重要意义.本研究以浙江楠天然分布区内13个典型种群为对象,研究其所在群落的群落结构特征、物种多样性和叶片表型变异特征.结果表明: 浙江楠天然种群所在群落的结构复杂,物种多样性较高,13个群落的16块样地内共有维管束植物87科162属235种,其中种子植物79科151属221种;重度干扰导致浙江开化、浙江临安等群落的乔木层物种多样性指数显著低于其他群落,而中度干扰提高了福建建宁群落灌木层物种多样性,轻度干扰则利于浙江楠种群自然更新.叶片表型作为楠木属植物重要的分类依据,叶片表型性状在种群间、种群内均存在丰富变异,平均变异系数为17.2%,变异幅度为10.4%～27.5%.种群间的变异(53.6%)大于种群内的变异(17.0%),平均表型分化系数为75.1%,种群间变异是浙江楠叶片表型变异的主要来源.基于欧式距离(10 cm)将13个天然种群划分为两大类群,但变异呈随机性.     

Effect of gene flow on spatial genetic structure in the riparian canopy tree Cercidiphyllum japonicum revealed by microsatellite analysis

Few studies have analyzed pollen and seed movements at local scale, and genetic differentiation among populations covering the geographic distribution range of a species. We carried out such a study on Cercidiphyllum japonicum; a dioecious broad-leaved tree of cool-temperate riparian forest in Japan. We made direct measurement of pollen and seed movements in a site, genetic structure at the local scale, and genetic differentiation between populations covering the Japanese Archipelago. Parentage analysis of seedlings within a 20-ha study site indicated that at least 28.8% of seedlings were fertilized by pollen from trees outside the study site. The average pollination distance within the study site was 129 m, with a maximum of 666 m. The genotypes of 30% of seedlings were incompatible with those of the nearest female tree, and the maximum seed dispersal distance within the study site was over 300 m. Thus, long-distance gene dispersal is common in this species. The correlation between genetic relatedness and spatial distance among adult trees within the population was not significant, indicating an absence of fine-scale genetic structure perhaps caused by high levels of pollen flow and overlapping seed shadows. Six populations sampled throughout the distribution of C. japonicum in Japan showed significant isolation-by-distance but low levels of genetic differentiation (F(ST) = 0.043), also indicating long-distance gene flow in C. japonicum. Long-distance gene flow had a strong influence on the genetic structure at different spatial scales, and contributes to the maintenance of genetic diversity in C. japonicum.     

Genetic differentiation in relation to seed weights in wild soybean species (Glycine soja Sieb. & Zucc.)

Seed weight is one of the most important botanical and phylogenetic characteristics. The study objective was to understand whether there is genetic difference in different seed weights of wild soybean (Glycine soja Sieb. & Zucc.). A total of 563 wild soybean samples, which belonged separately to genebank germplasm accessions (220 samples), one regional population samples (293 plants) and one natural population (150 plants), were analyzed using microsatellite markers. Of four size classes, the smallest seed size type had the highest coefficient of variation in seed weight; small and large seed types had relatively great genetic differences. In the national genebank germplasm accessions, genetic diversity gradually decreased from quantitatively dominant small and middling seed types to less frequent large seed types. In the regional and natural populations, generally, small to middling seed sizes had higher genetic diversity than the smallest and larger seed sizes. Cluster analysis revealed genetic differences in seed size traits. The semi-wild type (Glycine gracilis Skvortzow) was the most genetically differentiated from other seed sizes. However, it was also clearly shown that the phylogenic genetic differentiation among seed sizes was less than the genetic differentiation among geographical habitat populations in the wild soybean species.     

黄芩种质资源ISSR遗传多样性的分析及评价

采用ISSR分子标记技术对6个野生或栽培居群共147份黄芩种质进行遗传多样性分析和评价。分析结果表明,51个ISSR引物中筛选出18条扩增条带清晰、重复性好和多态性高的引物,共扩增出485条清晰的条带,其中466条具有多态性,平均多态性位点比率为96.08%,平均Nei’s基因多样性指数和Shannon’s信息指数分别为0.244 4和0.388 9,等位基因数（Na）和有效等位基因数（Ne）分别为1.993 8和1.383 9,遗传分化指数G_st=0.122 3,遗传一致度（I）和遗传距离（D）分别为0.951 5和0.050 1,说明收集的黄芩种质资源在总体上具有较高的遗传多样性,不同居群间存在一定的遗传分化和基因交流,遗传变异主要存在于居群内。分子聚类结果表明,同一地区的种质并没有按照收集来源完全聚类,可能与种质不同起源或民间栽培引种有关。在DNA分子水平揭示黄芩种质资源的遗传多样性水平,将为进一步黄芩种质资源评价、保存和新品种选育等利用提供依据。     

中国野生大豆遗传资源搜集基本策略与方法

遗传资源搜集原则是通过种子采集追求样本具有最高程度的遗传多样性。为了合理而有效地搜集野生大豆资源,近年来通过野生大豆居群考察和遗传多样性分析,初步明确了野生大豆资源居群的遗传多样性分布动态:遗传多样性地理的和生态的区域性、生态系统内居群的遗传相关性及各种生境下居群遗传多样性差异,从理论上奠定了野生大豆资源合理有效搜集的依据。根据居群遗传多样性的分布规律,初步建立了居群野生大豆资源的搜集策略和方法。     

浙江楠种群表型变异

以探讨浙江楠(Phoebe chekiangensis)种群间和种群内的表型变异程度和变异规律为目的, 对其分布区9个种群的10个表型性状进行了研究。采用巢式方差分析、变异系数、多重比较和相关分析等多种分析方法, 对种群间和种群内的表型多样性及其与地理生态因子的相关性进行了讨论。研究结果表明: 浙江楠叶片、种子等表型性状在种群间和种群内均存在着丰富的变异, 10个性状在种群间、种群内的差异均达极显著水平; 种群内的变异(21.74%)大于种群间的变异(18.45%), 表型性状的平均分化系数为41.43%, 种群内变异是浙江楠表型变异的主要变异来源。各性状平均变异系数为12.78%, 变化幅度为6.50%-19.38%。种群间叶片的平均变异系数(16.99%)高于种群间种子的平均变异系数(8.58%), 表明种子的稳定性高于叶片。叶宽、叶面积与叶片其他性状间多呈显著或极显著相关, 种子千粒重与种子宽、种子体积显著正相关; 而种子和叶片的各性状间多无显著相关性。种子宽、种子体积和种子千粒重随着海拔的增加出现减小的趋势, 种子体积受纬度控制, 随着纬度的增大表现出增大的趋势。     

Phenotypic variations in cones and seeds of natural Pinus kesiya var. langbianensis populations in Yunnan Province,China

以云南省思茅松(Pinus kesiya var. langbianensis)天然分布区的11个种群的16个种实性状为研究对象, 采用巢式方差分析、变异系数、相关分析和非加权配对算术平均法(UPGMA)等多种分析方法, 探讨思茅松种群间和种群内的表型变异。结果表明: 思茅松种实表型性状在种群间和种群内均存在着较丰富的差异, 种群内的变异(54.76%)大于种群间的变异(10.44%), 种群间平均分化系数为11.95%, 分化程度相对较小。球果总种子数的平均变异系数最高(35.51%), 其次是球果质量(35.1%), 种子大小的平均变异系数最小(8.86%), 成为最稳定的种实性状; 景谷县的表型多样性最丰富, 景洪市则最小。球果和种子大部分表型性状之间存在显著或极显著相关, 其中球果长和球果质量越大, 种鳞长、种子长、种翅长、千粒重、球果总种鳞数和球果总种子数就越大。生态因子中, 年平均气温对表型性状影响最大, 其次是1月平均气温和>5 ℃积温。利用种群间聚类分析可以把思茅松的11个种群分为2类4个亚类, 表型性状依据地理距离进行聚类, 聚类结果与年降水量和>5 ℃积温相关性显著。     

中国落叶松-杨栅锈菌遗传多样性研究

采用SSR分子标记技术对采自全国19个地区、不同年份的落叶松-杨栅锈菌Melampsora larici-populina（简称MLP）36个单孢子堆菌系的遗传多样性和种群遗传结构进行了研究。用5对SSR多态性引物共检测到62个观察等位基因（Na）,有效等位基因数（Ne）为5.42–9.82,平均有效等位基因数为7.05。供试MLP样本在5个SSR位点上的多态性信息量（PIC）变化范围为0.64–0.89,平均值0.79。平均观察杂合度（Ho）、平均期望杂合度（He）分别为0.36和0.86,不同位点的S     

Genetic diversity analysis of Hepatacodium miconioides at different altitude in Tiantal Mountain,Zhejiang Province,China and its relationship with environmental factors

The genetic diversity within and among populations of Hepatacodium miconioides collected at three different altitudes in Tiantai Mountain,Zhejiang Province and its relationships to environmental factors were analyzed by random amplified polymorphic DNA(RAPD)technique.Amplification using 12 random primers of 60 plants and 122 repetitive loci were produced.The percentage of polymorphic loci of three populations ranged from 18.85% to 23.77% with an average of 21.86%,indicating the relatively low genetic diversity of H.miconioides.The average Shannon index of phenotypic diversity(0.1329)and Nei index(0.0925)within populations were relatively low.A distinct genetic differentiation existed among populations Of H miconioides in spite of the relatively small geographical distribufion.The average genetic diversity within populations of H.miconioides accounted for 33.58% of the total genetic diversity while the genetic diversity among populations accounted for 66.42% as estimated by the Shannon index of phenotypic diversity,The genetic differentiation among populations of H.miconioides was 0.6546,as estimated by Nei index.The gene flow estimated from Gsr was only 0.2656 and it indicated that gene flow among populations of H.miconioides was relatively low.The mean value of the genetic identity among populations of H.miconioides was 0.7126 and the average of genetic distance of H.miconioides was 0.3412.The genetic identity between populations at the elevation of 990m and at the elevation of 780 m was the highest.The genetic identity between population at the elevation 500 m and other two populations was relatively low.The correlation analysis showed that the genetic diversity within populations was significantly related with the soil total nitrogen.