不同生境臭柏种群的遗传多样性分析及其与环境因子的相关性

毛乌素沙地臭柏群体是一个生态过渡带。为了进一步阐明分子变异和基因流与生境或生态过渡带的联系,应用RAPD标记开展了臭柏群体的分子生态学研究。采用随机扩增多态性DNA(RAPD)方法对臭柏(Sabina vulgaris.)的3个种群进行了研究.用11个随机引物扩增出129条清晰谱带,其中117条为多态性谱带。利用POPGENE3.2软件对数据进行处理,结果如下:(1)臭柏有着较丰富的遗传多态性,多态位点百分率达90.70%,各种群多态位点百分比在69.77%~72.87%之间.(2)臭柏的种群间分化较小Gst=0.1872,81.38%的遗传变异存在于种群内,各种群的遗传一致度都在86.22%.(3)聚类分析显示,生境相近的种群被聚到了一起,反映了臭柏种群的遗传分化和生境有着一定的相关性.又利用Nei,s指数统计了RAPD数据,也证实了大部分的遗传变异存在于群体之内。臭柏群体内的遗传多样性与土壤总钾呈显著的负相关。     

内蒙古地区天然臭柏种群遗传多样性的RAPD分析

应用随机扩增多态性DNA(RAPD)标记法研究了内蒙古地区臭柏种群的遗传分化,所用的18条引物对4个臭柏种群的55个样本扩增出124个位点,其中多态位点100个,多态率达80.7%。种内的平均Nei's多样性指数和Shannon's多样性指数分别为0.286和0.428,种群内分别为0.232和0.347,基因多样性变化趋势为毛乌素沙地(0.258,0.386)>阴山山脉西部(0.258,0.376)>浑善达克沙地(0.231,0.345)>内蒙古贺兰山(0.184,0.281)。臭柏种群总的基因多样性(Ht=0.288),大于种群间的基因多样性(Hs=0.233)。种群间的遗传分化系数(Gst)为0.183,种群内的遗传变异占总遗传变异的81.7%。臭柏种群间的平均遗传距离为0.086,平均相似性系数为0.918,4个种群之间有比较相似的遗传多样性,由于地理隔离,种群间也存在分化。     

6个白榆种群遗传多样性的RAPD分析

以科尔沁和浑善达克沙地的6个天然白榆种群为研究对象,采用RAPD分子标记技术,从35条引物中筛选出扩增多态性较多且扩增产物稳定的17条10bp引物。对6个白榆种群的180个叶片样品的基因组DNA进行扩增,共检测到181个位点,多态位点有96个,多态位点百分比为52.89%;不同种群内的遗传多样性水平差异不大,Nei’s多样性指数(h)和Shannon’s多样性指数(I)为0.2611和0.3814,遗传多样性主要存在于种群内;群间的遗传分化系数Gst为0.3768,种群内的遗传变异所占比例为62.32%;6个种群的遗传距离显示,科尔沁沙地和浑善达克沙地白榆各种群间的遗传距离不明显。     

内蒙古地区黄柳遗传多样性的RAPD分析

黄柳是内蒙古中东部地区重要的固沙先锋植物。采用RAPD分子标记技术,对内蒙古境内黄柳4个天然种群的遗传多样性和遗传结构进行了分析。用13个引物对4个种群的36个个体进行扩增,共检测到153个位点,其中有128个多态位点,多态位点百分比(PPB)达83.66%,种群内的多态位点百分比变化范围为88.24%-96.08%,说明黄柳种群的遗传多样性较为丰富。遗传分化系数(Gst=13.79%)表明黄柳的遗传变异主要以种群内的遗传变异为主(86.21%),种群间的基因流较大(Nm=3.13)。对黄柳种群间的遗传距离与地理距离做相关性分析,发现二者呈极显著正相关关系(r=0.953,P<0.01)。黄柳的繁育方式和种群间频繁的基因流等因素可能是造成上述结果的主要原因。应就地保护和合理利用黄柳的遗传资源,以维持其较高的遗传多样性。     

濒危植物新疆沙冬青遗传多样性的RAPD分析

以新疆乌恰县境内自然分布的6个新疆沙冬青(Ammopiptanthus nanus(M.Pop.)Cheng f.)居群的120份样品为研究对象,采用RAPD分子标记对其遗传多样性水平和种群遗传结构进行分析。结果表明:从33个随机引物中筛选出8个多态性较高且扩增稳定的引物,共扩增出41条DNA条带,多态位点26个,多态性比率(PPB)占63.41%,物种水平遗传多样性相对丰富,居群水平遗传多样性水平较低,各居群间的遗传多样性水平差异不大,Nei's基因多样性(h)指数和Shannon's信息多样性指数(I)分别为0.1169和0.1707,居群间遗传分化系数Gst为0.4171,遗传变异主要存在于居群内,居群之间产生了一定的遗传分化,基因流Nm为0.6989。根据UPGMA聚类图,6个居群可划分为两支,一支是吾合沙鲁居群和2个肖尔布拉克居群,另一支是康苏居群、巴音库鲁乡的托帕尔居群和阿合其居群。新疆沙冬青6个自然居群的遗传距离的分子聚类结果与其地理分布位置密切相关。     

内蒙古亚洲小车蝗种群遗传多样性和遗传分化的ISSR分析（英文）

亚洲小车蝗Oedaleus asiaticus Bei-Bienko是我国北方草原和农牧交错区的主要害虫。为评价内蒙古地区亚洲小车蝗种群的遗传多样性和遗传分化,应用ISSR标记方法对内蒙古15个亚洲小车蝗种群遗传多样性及遗传分化进行了分析。结果表明,7条引物扩增出85条ISSR条带,均为多态性条带。多态性比例(P)、Nei’s遗传多样性指数(H)和香农多样性指数(I)分别为82.59%、0.2319和0.3421,表明亚洲小车蝗种群具有较高的遗传多样性。基因流(Nm)和基因分化系数(Gst)分别为1.2298和0.3352,表明亚洲小车蝗不同地理种群具有明显的遗传分化。遗传距离与地理距离呈极显著正相关关系。表明地理距离和地形差异可能是形成亚洲小车蝗种群遗传分化的主要原因。     

大赖草种群遗传多样性的AFLP分析

采用荧光AFLP标记对大赖草(Leymus racemosus(Lam.)Tzvel)的6个天然种群进行了遗传多样性和遗传结构进行分析,6对选择性扩增引物共扩增出1269条清晰的条带,其中多态性位点1203个(PPL=80.61％).在物种水平上,Nei's遗传多样性指数H=0.188,Shannon多态性信息指数I=0.313;在种群水平上,H =0.177;I=0.288.遗传分化系数Fst为0.1009,表明有10.09％的遗传变异存在于种群之间,基因流Nm为4.4554＞1,说明种群间基因交流可以阻止由于遗传漂变导致的遗传分化,遗传分化呈现均质化的趋势.PCoA聚类结果表明,大赖草种群间的遗传距离与地理距离有一定的相关性,但未达到显著水平.该研究结果显示,遗传多样性水平不仅与物种本身特性和研究方法有关,濒危植物并不一定表现为遗传变异水平的降低而濒危,还与人类活动与气候环境密切相关.     

新疆野生啤酒花群体遗传多样性的RAPD分析

用RAPD技术分析新疆7个啤酒花(Humulus lupulus L.)的天然居群遗传多样性及群体间的遗传分化,12个随机引物共检测到121个可重复的位点,其中多态位点119个,占总位点的98.35%.由Shannon表型多样性指数和Nei基因多样性指数估计,居群内遗传分化百分比分别为63.55%和65.65%,表明啤酒花种内的遗传变异主要存在于群体内.分析认为,新疆境内啤酒花自然居群的遗传多样性很丰富,居群间产生了一定的分化.啤酒花居群的基因流Nm=1.0037,相对有限的基因流可能在居群遗传分化的维持中起着作用.     

北方春玉米区长岭发垫刃线虫的分布及遗传多样性分析

 为明确长岭发垫刃线虫(Trichotylenchus changlingensis)的分布,2018年对黑龙江、吉林、辽宁、河北、内蒙古、甘肃6省(自治区)118个地块的玉米根际土壤中长岭发垫刃线虫进行分离及鉴定,结果表明:在6个省(自治区)20个地块的土样中分离到该线虫,分离比例为17.0%。同时采用ISSR分子标记技术对分离到的20个种群进行遗传多样性分析。结果共筛选出16条引物,扩增出93条多态性条带,多态性比率为93.55%。基因分化系数(Gst)为0.4771,遗传变异的47.71%存在于种群间,52.29%存在于种群内。基因流(Nm)值为0.5479,说明所调查地区种群间存在基因流,基因流动较小,但种群间已发生一定程度的遗传分化。UPGMA 聚类分析结果表明,这20个种群具有丰富的遗传多样性,但群体间的遗传关系远近与地理距离无显著相关性。     

内蒙古亚洲小车蝗种群遗传多样性和遗传分化的ISSR分析

亚洲小车蝗Oedaleus asiaticus Bei-Bienko是我国北方草原和农牧交错区的主要害虫。为评价内蒙古地区亚洲小车蝗种群的遗传多样性和遗传分化,应用ISSR标记方法对内蒙古15个亚洲小车蝗种群遗传多样性及遗传分化进行了分析。结果表明,7条引物扩增出85条ISSR条带,均为多态性条带。多态性比例（P）、Nei''s遗传多样性指数（H）和香农多样性指数（I）分别为82.59%、0.2319和0.3421,表明亚洲小车蝗种群具有较高的遗传多样性。基因流（Nm）和基因分化系数（Gst）分别为1.2298和0.3352,表明亚洲小车蝗不同地理种群具有明显的遗传分化。遗传距离与地理距离呈极显著正相关关系。表明地理距离和地形差异可能是形成亚洲小车蝗种群遗传分化的主要原因。     

不同干扰生境中荒漠小灌木红砂种群遗传多样性研究

应用RAPD标记技术对荒漠小灌木红砂(Reaumuria soongorica)种群在不同扰动下的遗传多样性进行了分析。18条随机引物对红砂6个种群的120个个体进行扩增,共检测102个位点,其中多态位点99个。研究结果表明:红砂种群的多态位点比率(P)为96.86%,显示了不同生境中红砂种群内存在较高的遗传多样性。Shannon多样性指数(0.5007)、Nei基因多样性指数(0.3307)和基因分化系数(Gst=0.1952)揭示了红砂种群遗传变异多存在于种群内,种群间的遗传分化则较小。聚类分析表明:红砂种群遗传距离与地理距离之间存在一定相关性;遗传多样性水平与物种特性和不同干扰生境有关,与生态因子无相关性。     

Genetic Structure of Mycosphaerella populorum (Anamorph Septoria musiva) Populations in North-Central and Northeastern North America

ABSTRACT In order to characterize the genetic variation of the poplar pathogen Mycosphaerella populorum (anamorph Septoria musiva), we have studied seven North American populations using the polymerase chain reaction random amplified polymorphic DNA (RAPD) technique. The fungal populations were sampled in 2001 and 2002 by obtaining 352 isolates from cankers and leaf spots in hybrid poplar plantations and adjacent eastern cottonwood (Populus deltoides). A total of 21 polymorphic RAPD markers were obtained with the six RAPD primers used. A fine-level scale analysis of the genetic structure within the populations revealed that subpopulations sampled on P. deltoides and on hybrid trees were not significantly differentiated. In contrast, analyses performed on the entire data set showed high levels of haplotypic diversity and moderate to high genetic differentiation, with 20% of the expected genetic diversity found at the interpopulation level. Moreover, a high and significant correlation between genetic and geographic distances among populations was found, suggesting isolation by distance of the sampled populations. Although the occurrence of the sexual stage of this fungus remained unclear in field populations, five of the six populations were at gametic equilibrium for RAPD loci, suggesting the occurrence of recombination episodes in Septoria musiva populations. Overall, S. musiva appears to consist of differentiated subpopulations, with both asexual and sexual recombination contributing to the local level of genetic structure.     

Random amplified polymorphic DNA markers reveal low genetic variation and a single dominant genotype in Eichhornia crassipes populations throughout China

Genetic variation within and between 34 populations of Eichhornia crassipes (water hyacinth) in China was surveyed using random amplified polymorphic DNA (RAPD) markers. A total of 1009 individuals were analysed, for which 12 RAPD primers amplified 69 reproducible bands, with 22 (32%) being polymorphic. The percentage of polymorphic loci (p) within a population ranged from 4.4% to 17.4%, and the mean Nei's gene diversity (H_e) was 0.046 ± 0.0145, indicating a low genetic diversity of E. crassipes in China. Each population contained at least four RAPD phenotypes (genotypes), and the same particular genotype was invariably dominant in all the populations sampled. The mean proportion of distinguishable genotypes was 0.29. Analysis of molecular variance revealed a large proportion of genetic variation (83.9%) residing within populations and a slightly larger proportion (88.1%) within localities, indicating a low genetic differentiation of E. crassipes populations, both locally and regionally. Human-mediated dispersal, vigorous clonal growth, and a generally low level of sexual reproduction were thought to be responsible for such a pattern of genetic structure.     

运用随机扩增多态性DNA标记检测中国东北大豆灰斑病菌株遗传变异

 运用致病力和DNA多态性检测中国东北地区的35个大豆灰斑病菌分离物的遗传变异、根据菌株在9个品种(系)上的致病力反应可将其分为7个组。利用13个随机引物扩增供试菌株共计产生105个RAPD标记,其中78.1%具有多态性。通过聚类分析计算了各菌株间的遗传距离,并产生树状图,发现同一地区内及不同地区间的病菌表现遗传变异、致病性和DNA多态性间具有一定相关性。     

我国南方地区主要根结线虫DNA变异的RAPD分析

 本试验用5组随机引物对来自我国南方地区的30个根结线虫种群进行RAPD分析,并从中筛选出多态性较好的引物12个。共扩增出179条DNA多态带,各供试种群间存在着丰富的遗传多态性。扩增结果表现出种间差异大于种内差异的共同趋势,这表明上述12个引物能够较客观地反映种群间亲缘关系的远近。北方根结线虫与另外3种线虫(南方根结线虫、爪哇根结线虫、花生根结线虫)的亲缘关系最远;在3种主要根结线虫中,爪哇根结线虫与南方根结线虫的亲缘关系相对较近。基于种群间的相似系数分析和应用UPGMA法构建的聚类树状图,显示出不同的根结线虫在较低的相似性系数范围聚类,而绝大多数种内的不同种群均以较高的相似性系数聚在一起,这与形态分类基本一致,反映了形态学分类的分子遗传本质,同时也表明了应用RAPD技术进行根结线虫亲缘关系分析和种类鉴定具有合理性和可行性。本文还对RAPD方法对南方根结线虫小种鉴定的可能性进行了初步探讨。     

Genetic diversity of the annual weed Monochoria vaginalis in southern China detected by random amplified polymorphic DNA and inter-simple sequence repeat analyses

Two molecular genetic screening techniques, RAPD (random amplified polymorphic DNAs) and ISSR (inter-simple sequence repeats), were applied to detect the level and pattern of genetic diversity of Monochoria vaginalis, a common weed of rice fields, in seven populations from southern China. Among these populations, 116 bands were amplified by 18 RAPD primers, of which 34 bands (29.31%) were polymorphic, and 14 ISSR primers produced 111 bands with 87 polymorphic bands (78.38%). Within each population, a relatively low level of genetic diversity was detected by both RAPD and ISSR analyses, with a mean genetic diversity (H) of 0.0348 and 0.0551 respectively. Analysis of molecular variance of the data from the RAPD and ISSR markers detected that the majority of total genetic variation existed among populations (73.50% and 76.70% respectively) and only minor genetic variation within populations (26.50% and 23.30% respectively). Cluster analysis divided the seven populations into two groups, indicating that the genetic relationships among populations have relatively low correlation with their geographical distribution (Mantel test; r = 0.45 and 0.48 respectively). Our results indicated that both RAPD and ISSR markers were effective and reliable for accurately assessing the degree of genetic variation of M. vaginalis. Comparing the two techniques, ISSR markers were more efficient than the RAPD assay. The Mantel test gave r = 0.16, suggesting no correlation between these two molecular markers.     

Support for a stepwise mutation model for pathogen evolution in Australasian Puccinia striiformis f.sp. tritici by use of molecular markers

Since its initial detection in Australia in 1979, wheat yellow (stripe) rust ( Puccinia striiformis f.sp. tritici ) has evolved in Australia and New Zealand into more than 20 pathotypes with assorted virulence characteristics. This evolution is believed to have occurred in a stepwise fashion from an original single pathotype, with no subsequent new introductions. A combination of random amplified polymorphic DNA (RAPDs) and amplified fragment length polymorphisms (AFLPs) was used to examine the level of molecular variation in Australian and New Zealand isolates, and to compare this with variation amongst other isolates of P. striiformis . Using 60 RAPD primers on seven Australian isolates representing seven different pathotypes collected between 1979 and 1991, more than 300 potentially polymorphic loci were analysed and no polymorphisms were detected. Using the same primers on two UK isolates, 3% of loci showed a polymorphism. A similar level of polymorphism was found between UK isolates using AFLP primers, and between 5 and 15% of fragments were polymorphic between an isolate from the UK, an isolate from Denmark, and one from Colombia. However, no AFLP polymorphisms were found amongst 14 Australian and New Zealand isolates tested, at over 100 potentially polymorphic loci. The lack of molecular variation in the Australian and New Zealand collection is consistent with the stepwise mutation theory of pathotype evolution from a single introduction.     

结球甘蓝抗TuMV基因的RAPD和SCAR标记研究

 One hundred and forty-four F₂ individuals from a cross combination between 1047 (susceptible) and A21 (resistant) were analyzed for the presence of random amplified polymorphic DNA (RAPD) markers linked to Turnip mosaic virus (TuMV) resistant gene in cabbage by using bulked segregant analysis (BSA).Two polymorphic markers were screened out of 200 random primers.These two RAPD fragments were linked to the resistant gene at 7.7 cM and 8.38 cM respectively and converted to SCAR markers successfully.     

绿僵菌菌株遗传多态性与地理来源及寄主种群分化的关联性

采用RAPD-PCR分子标记技术分析了51株不同地理来源、寄主来源的绿僵菌Metarhizium anisopliae菌株的遗传多态性。从94条RAPD引物中筛选出18条引物,对所有试验菌株进行RAPD-PCR扩增,共获得96条扩增片段,其中81条片段表现多态性,占84.1%。聚类分析表明,供试的51株菌株间的相似性系数范围为0.52~0.98,表明菌株间存在丰富的遗传多态性。供试菌株在相似性系数0.7的水平可分为4个组群。按菌株DNA多态性与地理及寄主来源的聚类分析表明,大多数菌株的DNA多态性与地理或寄主有一定的相关性,即长期的地理环境和寄主适应性可能形成了种群的分化。