用RAPD标记评估我国棉花品种遗传多样性

利用ＲＡＰＤ标记对１７个不同来源的我国棉花品种（系）进行遗传多样性评估。２００个随机引物扩增出１１３条多态性片段。１７个品种（系）依据染色体组的不同可以分为３大类。它们之间遗传相似性系数从０．２０００到０．８４５１。３个大面积推广品种鄂荆１号,中棉所１２号和苏棉３号遗传基础十分相近。陆地棉与阔叶棉杂交产生的野生种质系７５８１,与其他陆地棉品种（系）遗传差异显著。不同育种单位在育种过程中种质使用具有     

螅状独缩虫(Cachesium polypinum)遗传多样性的RAPD分析

用随机扩增多态ＤＮＡ（ＲＡＰＤ）技术对武汉的汉口（ＣＰ－１）、汉阳（ＣＰ－２）和武昌（ＣＰ－３）三个地区缘毛类的螅状独缩虫（Ｃａｃｈｅｓｉｕｍ ｐｏｌｙｐｉｎｕｍ）进行了遗传多样性分析。结果表明：这种动物存在广泛的变异,三个地域群体之间的遗传相似度为０．６５２２－０．７３８５（平均值为０．６９２１）,各群体之间遗传相似度大小依次为：ＣＰ－２－ＣＰ－３〉ＣＰ－１－ＣＰ－２〉ＣＰ－１－ＣＰ－３。本文对     

利用RFLP、SSR、AFLP和RAPD标记分析玉米自交系遗传多样性的比较研究

利用 ＲＦＬＰ、ＳＳＲ．ＡＦＬＰ和ＲＡＰＤ ４种分子标记方法研究了 １５个玉米（Ｚｅａ ｍａｙｓ Ｌ．）自交系的遗传多样性,同时对４种标记系统进行比较。在供试材料中筛选到具多态性的ＲＦＬＰ探针酶组合５６个,６６对ＳＳＲ引物,２０个ＲＡＰＤ引物和９个ＡＦＬＰ引物组合,分别检测到多态性带１６７、２０１、８７和１０８条。ＳＳＲ标记位点的平均多态性信息量（ＰＩＣ）最大（０．５４）,ＡＦＬＰ标记位点最小（０．３６）,但ＡＦＬＰ标记具有最高的多态性检测效率（Ａｉ,３２．２）。４种分子标记所得遗传相似系数相关性显著,比较相关系数表明 ＲＡＰＤ可靠性较低。依据 ４种分子标记结果将 １５个供试自交系划分为塘四平头、旅大红骨、兰卡斯特、瑞德和ＰＮ共５个类群,与系谱分析基本一致。认为ＳＳＲ和ＲＦＬＰ两种分子标记方法适合进行玉米种质遗传多样性的研究。     

巴马小型猪群体遗传结构的随机扩增多态DNA分析

目的分析巴马小型猪的群体遗传结构。方法应用经过筛选的 ３１条引物对巴马小型猪个体基因组ＤＮＡ进行ＲＡＰＤ扩增,利用从ｉｎｔｅｒｎｅｔ网上下载的软件ＲＡＰＤ ｉｓｔａｎｃｅ Ｐａｃｋａｇｅ ｖｅｒ－ｓｉｏｎ１．０４软件对实验结果进行分析,计算不同个体间的相似系数。结果经ＲＡＰＤ反应,共扩增出２７５条带,其中多态性带８５条,多态性带频率在０～６６．７％之间,平均为２７．７％。不同个体猪拥有的ＲＡＰＤ条带具有差异,但拥有相同条带个体猪比率较高。该群体猪的相似系数（Ｆ）为０．９２８（０．７８～０．９７）,平均等位基因频率（ｑ）为０．７３２,最低平均杂合率（Ｈ）为０．２８６。结论巴马小型猪个体具有较好的遗传一致性和遗传稳定性。     

云南纵坑切梢小蠹四个地理种群同工酶比较研究

采用不连续聚丙烯酰胺凝胶电泳技术研究了纵坑切梢小蠹（Ｔｏｍ ｉｃｕｓ ｐｉｎｉｐｅｒｄａ Ｌ．）４ 个自然种群的９ 个同工酶基因座。４ 个种群均在Ｅｓ－ １、Ｅｓ－ ２、Ｅｓ－ ４、Ｍｄｈ－ １、Ｍｄｈ－ ２ 及ＡＡＴ－ １ 基因座上存在遗传多态现象。路南长湖、楚雄、蒙自３ 种群间的遗传距离为０．００３６～０．０１７３, 平均值为０．０１０５, 表明其遗传结构基本相似。丽江种群与上述３ 种群之间的遗传距离为０．１４２１～０．２０３５, 平均值为０．１７６５,表明丽江种群与上述三种群已有了遗传分化。丽江种群近交系数较大,近亲繁殖程度较高。种群遗传结构的差异可能与不同蠹害程度之间存在一定的内在联系。     

野生和近交稀有Ju鲫的遗传多样性

用ＲＡＰＤ技术对稀有Ｊｕ鲫近交１０代及３个野生群体的遗传多样性和群体间差异进行了研究。无论从多态位点的比例,个体间的共带率还是多样性指数来看,近交１０代的遗传多样性极低。在２２６个ＲＡＰＤ位点中,野生群体有近半数的位点是多态的,Ｓｈａｎｎｏｎ多样性指数在０．２９１１－０．３２３５间,表明自群本保持了较丰富遗传多样性。近交１０代与野生群体间遗传差异十分明显。野生群体间在１１－１９个位点上的表型频率存     

中华鲟天然群体蛋白质水平遗传多样性贫乏的初步证据

为阐明我国Ⅰ级珍稀水生保护动物中华鲟天然群体的遗传结构和遗传多样性特征,为其资源的监测量民保护提供科学依据,采用聚丙烯酰胺梯度凝胶电泳技术对中华鲟天然群体进行了蛋白质遗传多态性研究。共研究了１５种蛋白质,有４种蛋白无活呈活性很低,在有活性的１１种蛋白中人测得２６个座位;在２６个座位中,只有１个座位（ＭＤＨ－１）为多态座位。中华鲟多态座位比例（Ｐ）为３．９０％,遗传杂合度（Ｈ）为０．０４,均远远低于     

不同采样策略对细距堇菜遗传多样性估算的影响

采用水平淀粉凝胶电泳技术对分布于北京金山、檀枯寺、香山樱桃沟的细距堇菜（Ｖｉｏｌａ ｔｅｎｕｉｃｏｒｎｉｓ Ｗ．Ｂｅｃｋ．）的遗传变异和群体分化进行了初步研究。对８个酶系统１１个等位酶位点的检测表明,该种在上述地区的遗传变异水平明显高于多年生草本的平均值,多成位点百分率Ｐ＝７２．７％,等位基因平均数Ａ＝２．４,平均期望杂合度Ｈｅ＝０．２４３;群体间的遗传分化略小于多年生草本的平均值,杂和性基因多样     

朱砂叶螨抗氧化乐果品系选育及遗传分析

对采自棉田的朱砂叶螨种群使用氧化乐果选择压（６６．６７－１３３．３３μｌ／ｌ）１６次筛选后,抗氧化乐果由８、３３倍上升到３６、９３倍。利用此抗性品系（Ｒ）和采自河南省固始县的敏感品系（Ｓ）杂交和回交,研究了朱砂叶螨抗氧化乐果的遗传方式,正交和反交（ＳＲ和ＲＳ）Ｆ１代的ＬＣ－Ｐ线介于Ｓ与Ｒ之间偏向Ｒ方,显性系数ＤＳＲ和ＤＲＳ分别为０．５６７９和０．５６５９,表明抗性是由不完全显性基因控制,对Ｆ１杂合     

毛乌素沙地根茎灌木羊柴的遗传多样性和克隆结构

采用淀粉凝胶电泳技术对毛乌素沙地根茎灌木羊柴（ＨｅｄｙｓａｒｕｍｌａｅｖｅＭａｘｉｍ．）８个群体的遗传多样性和克隆结构进行了初步研究。利用１０个酶系统１５个等位酶位点的检测表明,羊柴群体具有较高的遗传变异水平,多态位点百分率Ｐ＝３７．０,等位基因平均数Ａ＝１．４８,平均期望杂合度Ｈｅ＝０．１０１;但８个群体间的分化很小（Ｆｓｔ＝０．０６７）;固定沙丘群体和半固定沙丘群体在等位酶水平上的变异性无显著差异。通过７个多态位点的研究表明,羊柴群体中的克隆多样性很高（Ｄ＝０．９１５６）,但不同克隆在规模上相差很大。同时,群体间的克隆分化较大,广布基因型仅占３．２％。克隆空间结构的分析表明,羊柴的基株分布为游击型构型,克隆之间的镶嵌明显。     

广东高州普通野生稻(Oryza rufipogon Griff)的遗传多样性和居群遗传分化研究

利用30对SSR引物对广东高州普通野生稻3个群体进行了遗传多样性分析和居群遗传分化研究.结果表明,30对引物中只有20对表现出多态,多态位点比率P为66.7%;在20个多态位点中共检测出81个等位变异,平均等位变异数(Ap)为4.05 个;3个群体总的遗传多样性(Ht)为0.61,其中,居群内的遗传多样性为居群间的遗传多样性的3倍多,说明总的遗传多样性主要来自居群内;虽然居群间的遗传分化系数(G ST)较低,仅为0.2427,但当遗传相似系数临界值增加时,3个群体在聚类图上相对独立 ,说明3个群体既存在着高度的遗传相似性,又具有一定程度的遗传分化,可以作为3个居群进行原生境保护.     

Study on DNA Diversity of Liaodong Oak Population at Dongling Mountain Region,Beijing

Random amplified polymorphic DNA(RAPD) and DNA amplification fingerprinting (DAF) markers were used in detecting genetic structure and DNA diversity of two Liaodong oak ( Quercus liaotungensis Koidz. ) populations at Dongling mountain region, a suburb of Beijing City. Shannon's index of phenotypic diversity was used to partition diversity into components within and between populations. Two hundred and five bands from twelve primers were analyzed. The results showed very high genetic variability within the Liaodong oak populations. The diversity in the central population was higher than that of the marginal one. 95 % of total genetic diversity occurred within populations and the coefficient of gene differentiation was 0.05. Significant difference of gene frequency has been detected in a few loci between populations. The study of different age groups of the oak trees implied that deforestation exerted certain impacts on the genetic structure of the Liaodong oak.     

濒危植物长叶榧群体遗传多样性的RAPD分析

借助随机扩增多态DNA方法,分析了中国特有的濒危植物长叶榧的遗传多样性和遗传分化．结果表明：12个随机引物在9个长叶榧自然群体180个样品中可检测到180个可重复位点,其中多态位点119个．长叶榧物种水平的遗传多样性较高,多态位点百分率（P）为66．11％,Shannon信息指数（,）为0．3087,Nei指数（h）为0．2015;而群体水平的遗传多样性较低,P、I和h分别平均为23．76％、0．1221和0．0813．AMOVA分子变异显示,42．57％变异来源于群体内,57．43％变异来源于群体间,群体间的遗传分化系数（Gst）为0．5965,群体间的遗传分化程度高．长叶榧群体间的基因流很低,为0．3382．瓶颈效应、群体隔离和群体间基因流低等因素都加剧了长叶榧群体间的遗传分化．9个长叶榧群体间的平均遗传距离为0．1630．通过UPGMA进行聚类,可将9个长叶榧群体分为浙江和福建两大类群．建议在迁地保护时应尽量避免在群体之间实施种质迁移．     

Analysis of genetic variation in grass carp (Ctenopharyngodon idellus) from native and colonized regions using ISSR markers

The grass carp (Ctenopharyngodon idella), a freshwater species native to China, have been introduced in more than 100 countries. In this paper, inter simple sequence repeat (ISSR) markers were used to evaluate genetic variation within and among grass carp populations sampled from its native (China) and colonized habitats (USA, Hungary, and Japan). Twenty-two ISSR primers were used to generate 207 bands, of which 82 (39.61 %) were polymorphic. The highest genetic diversity was observed in the Yangtze River population, whereas the lowest diversity was found in the Tone River population (Japan). Compared with colonized populations, the native populations possess approximately twice as much genetic diversity. The AMOVA analysis showed a relatively high level of genetic variation within populations. Significant genetic differences were revealed both among the native populations and between pooled native and colonized populations.     

不同生境夏蜡梅群体遗传多样性的RAPD分析

利用RAPD技术对天台大雷山4个不同生境：灌丛、常绿阔叶林、杉木林和竹林中的夏蜡梅群体进行遗传多样性研究。12个随机引物在80个个体中共检测到182个可重复的位点,其中多态位点为49个,总的多态位点百分率为26.92%。4个群体的多态位点百分率在6.04%~11.54%之间,平均为8.93%,其中竹林群体最高,常绿阔叶林群体最低,大小顺序为竹林群体＞灌丛群体＞杉木林群体＞常绿阔叶林群体,Shannon指数和Nei指数估算结果为灌丛群体最高,其次是竹林群体,第三是杉木林群体,最低的是常绿阔叶林群体。AMOVA分子差异分析表明夏蜡梅群体间遗传分化程度高,71.91%的变异存在于群体间,28.09%的变异存在于群体内,群体间的基因分化系数（G_ST）为0.627 4。夏蜡梅群体间的基因流很低,N_m=0. 297 0。聚类分析结果表明杉木林群体和灌丛群体最先聚在一起,再与常绿阔叶林群体相聚,最后与竹林群体聚在一起。可见,夏蜡梅在各生境间有着不同的遗传多样性,且在各生境间发生了明显的遗传分化。     

短柄枹种群遗传多样性的ISSR分析

利用ISSR分子标记方法对分布在浙江省境内的7个短柄枹种群的遗传多样性和遗传分化进行了分析。从100个引物中筛选出12个用于正式扩增的ISSR引物,在7个种群140个个体中共检测到132个位点,其中多态位点118个,多态位点百分率(P)为89.39%,各种群P平均为58.87%。短柄枹总的Shannon信息指数(I)为0.493 3、Nei指数(h)为0.334 7,各种群I平均为0.336 2、h平均为0.229 1。P、I、h均显示云峰种群最高,天台山种群最低。AMOVA分子差异分析表明,67.97%的变异存在于种群内,32.03%的变异存在于种群间,种群间的基因分化系数(G_ST)为0.315 4。短柄枹种群间的基因流为(N_m)为1.085 3。7个种群的平均遗传距离为0.173 9。利用UPGMA法对7个种群进行聚类,结果显示天台山和雪窦山种群聚成一类,其它5个种群聚成另一类。     

Genetic Variation and Differentiation of Larix decidua Populations in Swiss Alps (in English)

Genetic diversity within and among six subpopulations of Larix decidua Mill. from two altitudinal transects of Swiss Alps was investigated using 6 enzyme systems coding for 8 loci. Globally, the mean proportion of polymorphic loci was 22.9%, the average number of alleles per locus was 1.3, and the mean expected heterozygosity was 0.095. Only 5.8% of the genetic variation resided among populations. The mean genetic distance was 0.006. Several significant differences of gene frequencies were found between different age classes. Positive values of the species mean fixation index observed in this study suggested a considerable deficit of heterozygotes in the populations of L. decidua of Swiss Alps. At one of the sites (Arpette), the highest subpopulation in elevation gave the lowest level of genetic diversity (as evidenced by the lowest proportion of polymorphic loci and the lowest mean expected heterozygosity) and the largest value of genetic distance when compared to other subpopulations. The genetic differences between the highest subpopulation and the other ones suggest that the founder effect may be an important factor influencing genetic differentiation of L. decidua populations at Arpette transect.     

RAPD- and allozyme analysis of genetic variability of Panax ginseng C.A. Meyer and P. quinquefolius L

Inter- and intraspecific variation of two ginseng species Panax ginseng and P. quinquefolius was estimated by studying 159 RAPD and 39 allozyme loci. Parameters of polymorphism and genetic diversity were determined and a tree was constructed to characterize the differences between individual plants, samples, and species. Genetic variation in P. ginseng proved to be lower than in P. quinquefolius. Gene diversity in the total P. ginseng sample was comparable with the mean expected heterozygosity of herbaceous plants. This suggests that wild P. ginseng plants in various areas of the currently fragmented natural habitat and cultivated plants of different origin have retained a significant proportion of their gene pool. The mean heterozygosity calculated per polymorphic locus for the RAPD phenotypes is similar to that of the allozyme loci and may be helpful in estimating gene diversity in populations of rare and endangered plant species.     

Genetic diversity in North American ginseng (Panax quinquefolius L.) grown in Ontario detected by RAPD analysis

Genetic diversity within North American ginseng (Panax quinquefolius L.) grown in Ontario was investigated at the DNA level using the randomly amplified polymorphic DNA (RAPD) method via the polymerase chain reaction (PCR). A total of 420 random decamers were initially screened against DNA from four ginseng plants and 78.8% of them generated RAPD fragments. Thirty-six of the decamers that generated highly repeatable polymorphic RAPD markers were selected for further RAPD analysis of the ginseng population. With these primers, 352 discernible DNA fragments were produced from DNA of 48 ginseng plants, corresponding to an average of 9.8 fragments per primer, of which over 45% were polymorphic. The similarity coefficients among the DNA of ginseng plants analyzed were low, ranging from 0.149 to 0.605 with a mean of 0.412, indicating that a high degree of genetic diversity exists in the ginseng population. Lower levels of genetic diversity were detected among 3-year-old ginseng plants selected on the basis of greater plant height than among the plants randomly selected from the same subpopulation or over the whole population, suggesting that genetic factors at least partly contribute to morphological variation within the ginseng population and that visual selection can be effective in identifying the genetic differences. The significance of a high degree of genetic variation in the ginseng population on its potential for improvement by breeding is also discussed.     

Genetic differentiation among Hemarthria compressa populations in south China and its genetic relationship with H. japonica

Within and among populations genetic variance of twelve Hemarthria compressa populations and one Hemarthria japonica population from China were analyzed using inter simple sequence repeat (ISSR). Twelve primers amplified a total of 165 genomic DNA fragments across a total of 148 individuals of which 156 were polymorphic (94.55%). 75.76% of the bands were unique to each species, while the average genetic distance (GD) between one population of H. japonica and twelve populations of H. compressa was 0.44, which suggest that there was distinct differentiation between these two species. In H. compressa, twelve primers produced 145 bands across 145 individuals. High genetic diversity was observed at species level. The percentage of polymorphic loci (P) was 86.21% and Shannon's information index of diversity (I) was 0.357. In contrast, there were relatively low levels of genetic diversity within population (P=32.93%, I=0.174). Analysis of molecular variance (AMOVA) showed that a considerable proportion of genetic variation (48.02%) resided among populations. The coefficient of gene differentiation (G(ST)=48.6%) also suggested that there was strong genetic differentiation among H. compressa populations in southern China. An indirect estimate of the number of migrants per generation (N(m)=0.264) indicated that gene flow was low among populations of this species. Relative high clonal diversity was found, and all local genotypes were found.