十二个油松种群遗传多样性的RAPD分析

运用RAPD分子标记技术,对12个油松天然居群中192个单株进行遗传多样性分析。用筛选出的20条引物共扩增出289个条带,其中多态性条带220个,多态性条带百分率为76.12%。用NTSYS-PC软件计算遗传相似性系数进行聚类分析。结果表明:192份油松材料间的SC值变化范围为0.5986～0.9654,平均为0.7379。采用UPGMA法,在SC值为0.76的水平上可将供试材料聚为3类。表明我国油松天然种群间产生一定程度的变异,在分子水平上呈现出遗传多态性。     

红麻种质资源遗传多样性的ISSR分析

采用ISSR分子标记对38份红麻品种进行遗传多样性分析。利用自行筛选的引物共扩增出117条带,其中多态性条带98条,多态性条带比率为83.7%。品种之间的遗传相似系数为0.36～0.98,表明部分红麻品种间存在显著的遗传分化。聚类分析表明:红麻栽培品种间基因型差异较小,亲缘关系较近,遗传基础相对狭窄;而野生种、近缘种和栽培种之间存在着较大的遗传差异性。     

10 个山茶岛屿天然居群的遗传多样性分析

 采用ISSR 分子标记对舟山群岛、长门岩岛、鹿儿岛、四国岛和五岛的10 个山茶（Camellia japonica）居群的遗传多样性和分化程度进行分析。20 条随机引物扩增出210 个可分析位点,多态性百分比（PPL）为90%。试验结果显示,山茶居群水平的Nei’s 基因多样性指数为0.2732,Shannon 信息多态性指数为0.4003,表明其具有较高的遗传多样性。鹿儿岛、四国岛和五岛的居群相对于舟山群岛和长门岩岛居群而言,遗传多样性水平更高。10 个居群间遗传分化系数Gst = 0.2028;地理距离与遗传距离之间具有显著相关性（r = 0.9081,P < 0.05）,表明岛屿地理隔离对山茶居群间的遗传分化具有重要影响。UPGMA 聚类显示了居群间的亲缘关系,同岛内居群间亲缘关系更近,长门岩岛居群与舟山群岛居群亲缘关系近于和鹿儿岛、四国岛以及五岛居群间的亲缘关系。     

野生天门冬遗传多样性的ISSR分析

通过ISSR技术对19个野生天门冬居群共67个个体进行遗传多样性分析.结果表明:用13个随机引物共扩增出125条清晰条带,其中92条具多态性,平均多态性位点比率为73％,建立了不同居群的ISSR标记;Nei's基因多样性指数H=0.19,Shannon,s多样性指数I=0.30,遗传分化指数Gst=0.8206.聚类分析表明,青海、云南和贵州省的5个居群聚为一大支,其它居群为另一大支.野生天门冬种内具有较高的遗传多样性,遗传变异主要存在于居群间;ISSR标记可以作为研究天门冬遗传多样性及居群鉴定的有效标记.     

苦瓜种质资源ISSR遗传多态性分析

利用ISSR分子标记对30份苦瓜种质进行遗传多态性分析,从23个引物中筛选出13条重复性好,条带清晰的引物进行PCR扩增,共扩增出79条带,其中58个为多态性条带,占总带数的73.4%,每个引物扩增的条带数为4~10条,平均6.07条。对ISSR结果进行聚类分析,结果表明,30份苦瓜种质间的遗传距离为0.025~0.520。在遗传距离为0.21处可将30份苦瓜种质划分成6个品种群,其亲缘关系与种质地理分布和植物学性状特征等有一定关联。     

乌腺金丝桃ISSR反应体系的构建及其遗传多样性分析

以14份乌腺金丝桃为试材,采用L_(16)(4~5)正交实验设计,建立并优化乌腺金丝桃的ISSR-PCR反应体系,并利用优化的反应体系分析供试材料间的遗传多样性。结果表明:20μL ISSR-PCR反应体系中应含有Taq DNA聚合酶1.0U,dNTPs 0.2mmol·L~(-1),Mg~(2+)2.0mmol·L~(-1),模板DNA 45ng。从45条ISSR引物中筛选出11条多态性引物,利用筛选的多态引物对14份乌腺金丝桃材料进行了ISSR遗传多样性分析,共扩增出85条带,其中多态性条带57条,占67.06%;4个乌腺金丝桃居群的遗传相似系数介于0.375 1~0.725 2,平均值为0.541 6;通过UPGMA进行聚类分析表明,14份材料可分为3个类群4个亚群。乌腺金丝桃居群间遗传多样性水平明显高于居群内,其遗传距离与地理距离具有一定的相关性。     

平菇ISSR遗传多样性分析

以53个平菇菌种为试材,采用ISSR标记技术,对采自多地的平菇材料进行遗传多样性检测,以期为平菇优良品种选育和亲缘关系的研究提供分子生物学依据。结果表明:从27个ISSR引物中共筛选出14个多态性明显的引物;在53份供试材料中共扩增出189条谱带,其中多态性条带189条,多态性为100%;材料间遗传相似系数范围在0.44~0.99,聚类分析结果显示,在0.62水平上53株菌株分为8组,多数菌株之间遗传相似性较低。这表明供试菌株在DNA水平上存在比较显著的遗传变异和丰富的遗传多样性;同时发现供试材料间的聚类与地域无明显相关性。     

石榴种质资源遗传多样性及亲缘关系的ISSR分析

利用ISSR标记技术对47个石榴品种遗传关系进行了分析。筛选出多态性高的6条ISSR引物,共扩增出120条DNA条带,其中多态性带109条,多态性百分率为90.83%,有效等位基因数(Ne)、Nei’s基因多样(H)、Shan-non信息指数(I)分别为1.294 5±0.309 4、0.189 7±0.161 8、0.309 1±0.219 8,遗传距离(Dg)变异为0.075 0～0.400 0,表明石榴品种间存在比较丰富的遗传多样性。利用UPGMA法构建分子树状图,将47个石榴品种分为5个类群。同时检测到15条特异性条带,可用于供试石榴中的11个品种鉴定的参考性标记。     

五个野生木耳属菌株的ISSR分析

以7个栽培菌株为参照,采用ISSR分子标记技术对5个野生木耳属菌株进行分析,使用NTSYSpc2．1生物软件对12个供试菌株进行聚类分析,构建系统树。试验筛选出了11个扩增谱带清晰、多态性好的ISSR引物,共扩增出78条清晰易辨的多态性谱带。聚类分析结果表明,利用ISSR技术可将全部供试材料区分开,遗传相似系数变异范围为0．108~0．822,在相似系数为0．51时,12个菌株聚为6个群,其中5个野生菌株各自聚为不同类群,遗传差异较大。     

巨大革耳遗传多样性的ISSR分析

为确定巨大革耳种质资源问的亲缘关系,本文应用ISSR分子标记技术,对来源不同地区的野生或栽培的9个巨大革耳菌株进行遗传多样性分析。从20个引物筛选获得4个ISSR多态性引物对巨大革耳菌株扩增,获得23条多态性条带,多态性比率为85．19％;对扩增结果进行聚类分析,当遗传距离为20％时,9个菌株聚为2类：I类包括C．m0002菌株;Ⅱ类包括其它的8个菌株。其中C．m0002菌株与其它8个菌株的遗传距离很远。经栽培出菇实验,结果表明,C．m0002菌株的子实体似多脂鳞伞（黄伞）,是同名异种;其它8个菌株均为巨大革耳。ISSR分析的结果与子实体形态特征一致。     

我国南方长茄种质资源的ISSR标记分析

从分子水平用ISSR标记法对南方长茄资源的遗传多样性进行分析,从100个ISSR引物中共筛选出12个多态性明显、条带清晰、反应稳定的引物,对57个样品DNA共扩增出116条谱带,平均每个引物扩增出9·67条带,其中多态性位点84个(71%)。品种间遗传相似系数在0·51~0·98之间,表明茄子栽培种内品种间的遗传基础相对较狭窄。利用UPGMA聚类分析,能将57个南方长茄品种划分为6个类群,类群的划分与地方来源没有很大的关系。     

Genetic variability in wild vs. cultivated Eruca vesicaria populations as assessed by morphological,agronomical and molecular analyses

In this study, the genetic diversity of 50 individuals of rocket, Eruca vesicaria, from five accessions, four of them wild type collected from different parts of Spain and one commercial, were evaluated using morphological, agronomical and inter simple sequence repeat DNA (ISSR) data. Molecular analysis was carried out using the ISSR technique with 20 primers. Out of these 20 primers, nine were polymorphic, producing a total of 395 DNA bands, 247 of which were polymorphic among the accessions. A dendrogram drawn on the basis of a similarity matrix using the UPGMA algorithm revealed that the 50 samples of rocket plants could be classified into three major clusters at a Nei's genetic distance of 0.36. The experiment shows that molecular markers such as ISSR are a good instrument for distinguishing and selecting rocket accessions to group different wild populations. In general, a high variation was observed for most of the 16 morphological and 6 agronomical traits showing significant differences. Some morphological traits such as leaf length, petiole length and lamina width explained 69.1% of the whole variation observed in the populations, and some agronomical traits such as leaf area, nitrate and chlorophyll contents accounted for 65.7%, but the clusters generated by means of agronomical and morphological variables were less evident than when ISSR markers used. Some accessions showed good qualities, such as small leaves, high chlorophyll content, late-flowering or low nitrate content. All these parameters, together with the high degree of genetic homogeneity found, could make the local accessions good candidates for a future breeding programme.     

Genetic structure of mulberry from different ecotypes revealed by ISSRs in China: An implications for conservation of local mulberry varieties

Mulberry is a perennial and economically important plant that has traditionally been used for feeding the silkworm. Evaluating genetic relationship is important for long-term improvement in mulberry yield, quality and resistance, and for germplasm conservation and identification. Population structure and genetic diversity of 8 mulberry populations from different ecotypes in China were analyzed by ISSR markers. Twelve ISSR primers generated a total of 83 amplification products, of which 50 were polymorphic, revealing 60.24% polymorphism among 66 mulberry local varieties, the mean PIC value was 0.1469. The total heterozygosity (H_T), heterozygosity within population (H_S), diversity between populations (D_ST) were 0.1600, 0.0851 and 0.0749, respectively. The coefficient of population differentiation (G_ST) was 0.4683, indicating that the variations among populations and those within populations contributed 46.8% and 53.2% to the total heterozygosity, respectively. The gene flow (N_m) was 0.5678, suggesting that genetic drift between populations can caused local genetic differentiation and therefore, population divergence. The mean genetic similarity coefficient was 0.8456, genetic similarity coefficient among 8 mulberry populations ranged from 0.8441 to 0.9640, indicating that genetic diversity of different populations existed variation. A dendrogram of all 66 local varieties of mulberry based on the genetic similarity using ISSR markers was generated by UPGMA cluster method. In the dendrogram, most varieties from the same ecotype clustered together.     

云锦杜鹃自然居群遗传多样性的ISSR分析

 利用ISSR技术对浙江省境内的5个云锦杜鹃自然居群的遗传多样性进行分析。12个引物共检测到170个位点, 其中多态位点150个, 多态位点百分率P (% ) 为88.24%。物种水平的Shannon信息指数( I) 为0.4317, Nei指数( h) 为0.2848, 表明物种水平的遗传多样性很高; 而居群水平的遗传多样性较低, P%平均为48123%, I平均为0.2682, h平均为0.1818。AMOVA分子差异分析显示40.03%的变异存在于居群间, 59.97%的变异存在于居群内, 居群间的遗传分化明显。居群间的基因流较低, 为0.8824。居群隔离、自交衰退可能是导致云锦杜鹃居群间遗传分化的主要原因。5个居群间的平均遗传距离为0.1755。聚类显示, 括苍山居群和天台山居群组成一组, 凤阳山居群和百山祖居群组成另一组, 干坑居群单独成一组。     

Genetic diversity of Chinese natural bermudagrass (Cynodon dactylon) germplasm using ISSR markers

Bermudagrass (Cynodon dactylon L.) is an important warm-season turfgrass. Although it is widely distributed in China, studies on the genetic variation and relationship among the large-scale indigenous bermudagrass were relatively insufficient, especially at molecular level. The purpose of this study was to assess the molecular variation and relationship among one commercial cultivar ‘Tift3’ and 95 wild bermudagrass accessions collected from 11 provinces in China by ISSR marker technique. The results indicated that 29 ISSR primers generated a total of 248 bands among which 242 (97.6%) were polymorphic bands. The genetic similarity coefficients among accessions ranged from 0.51 to 0.97 with an average of 0.74. All accessions could be clustered into 11 groups with UPGMA method. Accessions from the same or adjacent regions generally were clustered into the same group or subgroups. A few accessions, however, were greatly different from the majority of all accessions. The results suggested that ISSR marker is an effective tool for the study of genetic variation in Chinese natural bermudagrass.     

ISSR分子标记分析杏鲍菇菌株遗传差异研究

试验应用ISSR技术分析了杏鲍菇生产性菌株的DNA序列多态性,从20个引物中筛选出11个ISSR引物对12个杏鲍菇生产性菌株基因组DNA进行PCR扩增。结果表明,这些杏鲍菇菌株遗传相似系数为0.68～1.00。采用平均分类法UPGMA分析表明,在遗传相似系数为0.83处可将这12个杏鲍菇生产性菌株分成3类。     

佛手种质资源遗传多样性的ISSR 分析

 收集佛手（Citrus medica L. var. sarcodactylis Swingle）13 份、枸橙（C. medica var. yunnanensis Ding）1 份及香椽（C. medica L.）6 份,共20 份种质资源,其中14 份成功引种在佛手资源圃。在对其中 14 份资源生物学特性进行描述的基础上,采用ISSR 分子标记技术对20 份样品进行遗传多样性分析。筛 选出的11 条引物共检测到102 条DNA 条带,其中58 条为多态性条带,多态性条带比率为56.9%。各样 品之间的遗传相似性系数在0.608 ~ 0.990 之间。聚类分析结果表明,当遗传系数为0.798 时,可将供试材 料分为枸橙、香橼和佛手3 个类群,新发现的3 个芽变材料是佛手中一个新的类群。     

Germplasm diversity and genetic relationships among walnut (Juglans regia L.) cultivars and Greek local selections revealed by Inter-Simple Sequence Repeat (ISSR) markers

Inter-Simple Sequence Repeat (ISSR) markers were used for the assessment of genetic diversity among walnut (Juglans regia L.) selections from Greek native populations in comparison to internationally cultivated walnut genotypes. Similarity coefficient values from 0.13 to 0.93 (with an average of 0.48) were found among the 56 accessions examined, which indicated the presence of a high degree of genetic variability. Most international cultivars were grouped together while most Greek native populations could not be placed into a distinct group. The Greek native population genotypes were found more diverse than the international cultivars. The mean similarity coefficient values for the former and latter were 0.44 and 0.56, respectively. In the cultivar group, two subgroups were distinguished; one consisted of genotypes involving ‘Payne’ and the other ‘Franquette’ in their pedigrees. Some cultivars and populations could not be grouped according to their pedigrees or collection area. Analysis of molecular variance (AMOVA) revealed that a larger part of the genetic variation exists among Greek walnut populations within a collection region (89%) than among the regions (11%). The pairwise regional PhiPT values indicated that the most geographically distant regions are the most genetically differentiated. The high variability existing in the Greek germplasm in combination with their valuable agro-morphological traits suggested that it would be beneficial to utilize this native germplasm pool in walnut breeding programs and germplasm management activities to maximize genetic diversity in cultivated walnut.