应用SSR和ISSR标记分析栽培香稻品种的遗传多样性

本研究利用24对SSR引物和36个ISSR引物,分析33份来源于亚洲10个国家的香稻品种的遗传多样性。分别获得93条和181条多态性片段,每个SSR座位可检测3～8个等位基因,平均为4．23个;每个ISSR引物可检测3～8个多态性位点,平均为5．03个。根据SSR和ISSR标记计算的品种间遗传相似系数分别在0．294～0．884之间和0．595～0．867之间。聚类分析表明,利用两种标记所得的聚类结果基本上一致,与品种所处的3种气候类型变化基本相符。进一步证实SSR和ISSR标记是研究水稻种质资源分类有效的工具。     

Genetic relationships of sesame germplasm collection as revealed by inter-simple sequence repeats

Inter‐simple sequence repeats (ISSR) polymorphism was used to determine genetic relationships among 75 Sesamum indicum L. accessions of Korean and exotic sesame. Fourteen reliable ISSR primers were selected for the assessment of genetic diversity, yielding 79 amplification products. Of these polymerase chain reaction products, 33% revealed polymorphism among the 75 accessions. Genetic distances ranged from 0 to 0.255, with a mean genetic distance of 0.0687. The 75 accessions were divided into seven groups on the basis of unweighted pair‐group method with arithmetic averages (UPGMA) cluster analysis. The largest group consisted of 25 Korean cultivars, eight Korean breeding lines and 17 world‐wide accessions. The other groups included 25 accessions, several of which contained useful traits. The dendrogram did not indicate any clear division among sesame accessions based on their geographical origin. However, all Korean sesame cultivars except ‘Namsankkae’ were clustered in the same group, indicating a narrow gene pool. Some of the Korean breeding lines were spread along the dendrogram, showing enlargement of genetic diversity. The genetic diversity data uncovered in this study can be used in future breeding programmes.     

Analysis of molecular variance and population structure in southern Indian finger millet genotypes using three different molecular markers

The genetic relationship among 42 genotypes of finger millet collected from different geographical regions of southern India was investigated using random amplified polymorphic DNA (RAPD), inter simple sequence repeats (ISSR), and simple sequence repeats (SSR) markers. Ten RAPD primers produced 111 polymorphic bands. Five ISSR primers produced a total of 61 bands. Of these, 23 bands were polymorphic. The RAPD and ISSR fingerprints revealed 71.3 and 37.4% polymorphic banding patterns, respectively. Thirty-six SSR primers yielded 83 scorable alleles in which 62 were found to be polymorphic. Out of 36 SSR primers used, 14 primers (46.6%) produced polymorphic bands. The SSR primer UGEP7 produced a maximum number of six alleles. Mean polymorphic information content (PIC) of RAPD, ISSR and SSR were 0.44, 0.28, and 0.14, respectively. Molecular variances among the population were 2, 11, and 1% for RAPD, ISSR, and SSR markers, respectively. SSR produced 99% molecular variance within individuals. RAPD and ISSR markers produced a low level of molecular variance within individuals. The STRUCTURE (model-based program) analysis revealed that the 42 finger millet genotypes could be divided into a maximum of four subpopulations. Based on the Bayesian statistics, each RAPD and SSR marker produced three subpopulations (K=3), while ISSR marker showed four subpopulations (K=4). This study revealed that RAPD and SSR markers could narrow down the analysis of population structure and it may form the basis for finger millet breeding and improvement programs in the future.     

Morphological and molecular characterization of endangered medicinal plant species Coleus forskohlii collected from central India

In recent years, Coleus forskohlii has been considered plant as an important medicinal. Because of the continuous collection of roots from the wild sources, this plant has been included in the list of endangered species. This has necessitated the use of biotechnology in conservation and sustainable management of this endangered plant species. Morphological and molecular characterization of this herb will enhance our understanding in improving the optimal yields of Forskolin through breeding. To assess the morphological and molecular genetic diversity in 18 C. forskohlii genotypes collected from different places of central India, RAPD, ISSR, and AFLP marker systems were employed. Eleven RAPD, ten ISSRs and eight AFLP primers produced 101, 80, and 483 fragments, respectively. Among the three marker system used in this study, RAPD and ISSR showed 61.39 and 68.75% polymorphism, respectively, while eight AFLP primer combinations produced 70.81% polymorphism. UPGMA cluster analysis method group genotypes in two clusters with all marker systems separately and after combined analysis. Results show that both morphological and molecular factors are effective in observing variations. Our results also indicate that the RAPD, ISSR, and AFLP approaches, along with pharmaceutically important morphological trait analysis, seemed to be best-suited for assessing the genetic relationships among distinct C. Forskohlii genotypes with high accuracy.     

Assessment of genetic diversity within and among Basmati and non-Basmati rice varieties using AFLP,ISSR and SSR markers

Molecular markers provide novel tools to differentiate between the various grades of Basmati rice, maintain fair-trade practices and to determine its relationship with other rice groups in Oryza sativa. We have evaluated the genetic diversity and patterns of relationships among the 18 rice genotypes representative of the traditional Basmati, cross-bred Basmati and non-Basmati (indica and japonica) rice varieties using AFLP, ISSR and SSR markers. All the three marker systems generated higher levels of polymorphism and could distinguish between all the 18 rice cultivars. The minimum number of assay-units per system needed to distinguish between all the cultivars was one for AFLP, two for ISSR and five for SSR. A total of 171 (110 polymorphic), 240 (188 polymorphic) and 160 (159 polymorphic) bands were detected using five primer combinations of AFLP, 25 UBC ISSR primers and 30 well distributed, mapped SSR markers, respectively. The salient features of AFLP, ISSR and SSR marker data analyzed using clustering algorithms, principal component analysis, Mantel test and AMOVA analysis are as given below: (i) the two traditional Basmati rice varieties were genetically distinct from indica and japonica rice varieties and invariably formed a separate cluster, (ii) the six Basmati varieties developed from various indica × Basmati rice crosses and backcrosses were grouped variably depending upon the marker system employed; CSR30 and Super being more closer to traditional Basmati followed by HKR228, Kasturi, Pusa Basmati 1 and Sabarmati, (iii) AFLP, ISSR and SSR marker data-sets showed moderate levels of positive correlation (Mantel test, r = 0.42–0.50), and (iv) the partitioning of the variance among and within rice groups (traditional Basmati, cross-bred Basmati, indica and japonica) using AMOVA showed greater variation among than within groups using SSR data-set, while reverse was true for both ISSR and AFLP data-sets. The study emphasizes the need for using a combination of different marker systems for a comprehensive genetic analysis of Basmati rice germplasm. The high-level polymorphism generated by SSR, ISSR and AFLP assays described in this study shall provide novel markers to differentiate between traditional Basmati rice supplies from cheaper cross-bred Basmati and long-grain non-Basmati varieties at commercial level.The first two authors have equal contribution     

Molecular diversity and population structure of the Ethiopian lentil (<Emphasis Type="Italic">Lens Culinaris</Emphasis> Medikus) genotype assessment using SSR markers

Knowledge of genetic diversity in germplasm is essential for formulating effective germplasm collection, conservation, utilization strategies in and crop improvement programs. It also provides an opportunity to take corrective steps infusing new genes to avoid risks associated with a narrow genetic bases. Genetic diversity analysis of 119 lentil genotypes of including 83 germplasm and 36 exotic genotypes from International Center for Agricultural Research in the Dry Areas was studied using 27 primers of simple sequence repeat (SSR) marker. Molecular analysis of variance showed variations of 82% within and 18% of the among population variance was explained. Degree of polymorphism observed among the populations was 100%. A total 122 alleles were detected, with 2 to 7 alleles per locus, with a mean of 4.52 alleles per locus. The estimated gene diversity value for 27 loci was 0.64. The average Shannon’s information index value of 1.19 was obtained showed the existence of high genetic variation within the genotypes. The genetic similarity indices ranged from 0.21 to 1.00. The SSR markers showed an average polymorphic information content (PIC) value of 0.58. Cluster analysis grouped the genotypes into five major clusters as distinct genetic populations. Diversity analyses revealed the existence of a high level of genetic variation among genotypes. This molecular diversity information provides a basis for future germplasm collection, utilization, and conservation strategies in gene banks and introducing exotic germplasm to widen the genetic base of the current lentil breeding population.     

Genetic diversity,structure and fruit trait associations in Greek sweet cherry cultivars using microsatellite based (SSR/ISSR) and morpho-physiological markers

It is important to couple phenotypic analysis with genetic diversity for germplasm conservation in gene bank collections. The use of molecular markers supports the study of genetic marker-trait associations of biological and agronomic interest on diverse genetic material. In this report, 19 Greek traditional sweet cherry cultivars and two international cultivars, which were used as controls, were grown in Greece and characterized for 17 morpho-physiological traits, 15 simple sequence repeat (SSR) loci and 10 inter simple sequence repeat (ISSR) markers. To our knowledge, this is the first report on molecular genetic diversity studies in sweet cherry in Greece. Principal component analysis (PCA) of nine qualitative and eight quantitative morphological parameters explain over 77.33% of total variability in the first five axes. The SSR markers yielded a combined matching probability ratio (MPR) of 9.569 × e−12. The 15 SSR loci produced a total of 92 alleles. Ten ISSR primers generated 91 bands, with an average of 9.1 bands per primer. Expected heterozygosity (gene diversity) values of 15 SSR loci and 10 ISSR markers averaged at 0.683 and 0.369, respectively. Based on stepwise multiple regression analysis (MRA), SSR alleles were found associated with harvest time and fruit polar diameter. Furthermore, three ISSR markers were correlated with fruit harvest and soluble solids and four ISSR markers were correlated with fruit skin color. Stepwise MRA identified six SSR alleles associated with harvest time with a high correlation (P < 0.001), with linear associations with high F values. Hence, data analyzed by the use of MRA could be useful in marker-assisted breeding programs when no other genetic information is available.     

Fingerprinting in cucumber and melon (<Emphasis Type="Italic">Cucumis</Emphasis> spp.) Genotypes using morphological and ISSR markers

In the present investigation, 13 Cucumis genotypes from different geographical areas of India were screened for genetic diversity using 19 morphological traits and 15 ISSR primers. The analysis of morphological traits grouped the accessions into six clusters. Cluster V contained the maximum number of genotypes namely Kanivellari, Long Green, Andaman Local, Perundurai Local, and Sempatti Local. Clusters I and VI contained the minimum number of genotypes. Among all the characters, the highest mean value was observed in fruit length (23.38) and the lowest mean value was observed in stripes on the blossom end (1.31). The 15 ISSR primers generated 109 polymorphic alleles. The average number of ISSR alleles generated was 8.3 per primer and the level of polymorphism was 87.20%. The ISSR primer UBC 825 was highly informative with a PIC value of 0.8934. The 13 genotypes were grouped into six clusters based on ISSR markers. Cluster III contained the maximum number of genotypes, namely Kanivellari, Sankagiri Local, Perundurai Local, Long Melon, and Sempatti Local, while Clusters I, II, IV, and V (Karur Local, Andaman Local, Edapaddi Local, and N 78, respectively) contained the minimum number of genotypes. The ISSR profile generated genotypes specific allele namely, UBC 812_700bp and UBC 812_1000bp for Cluster VI which contained Cucumis genotypes collected from the northern part of India. Similarly, UBC 808 produced specific allele UBC 808_650bp formed in Cluster III which contained genotypes collected from Tamil Nadu and Kerala.     

Appraisal of RAPD and ISSR markers for genetic diversity analysis among cowpea (Vigna unguiculata L.) genotypes

The genetic variability and relationships among 11 cowpea genotypes representing two cultivars and nine elite genotypes were analyzed using 22 random amplified polymorphic DNA (RAPD) and nine inter-simple sequence repeat (ISSR) markers. ISSR markers were more efficient than RAPD assay with regards to polymorphism detection. But the average numbers of polymorphic loci per primer and resolution power were found to be higher for RAPD than for ISSR. Also, the total number of genotype specific marker loci, Nei’s genetic diversity, Shannon’s information index, total heterozygosity, and average heterozygosity were prominent in RAPD as compared to ISSR markers. The regression test between the two Nei’s genetic diversity indices showed low regression (0.3733) between ISSR and RAPD + ISSR-based similarities but maximum (0.9823) for RAPD and RAPD + ISSR-based similarities. The RAPD- and ISSR-generated cultivar- or genotype-specific unique DNA fingerprints able to identify the most diverse genotypes. A dendrogram constructed based on RAPD and ISSR combined data indicated a very clear pattern of clustering according to the groups (cultivars and elite genotypes). The results of principal coordinate analysis were comparable to the cluster analysis. Cluster analysis showed that most diverse genotypes (GP-125 — small size with good seed quality; GP-129, GP-90L — big size with poor seed quality) were separated from moderately diverse cultivars and genotypes. The genetic closeness among GP-129 and GP-90L, JCPL-42, and JCPL-107 could be explained by the high degree of commonness in these genotypes.     

SPAR Markers-Assisted Assessment of Genetic Diversity and Population Structure in Finger Millet (<Emphasis Type="Italic">Eleusine Coracana</Emphasis> (L.) Gaertn) Mini-Core Collection

Finger millet is an important staple food crop of semi-arid tropics also known as “super cereal” and has a higher calcium content than any other crops. Thousands of germplasm are being maintained and its genetic characterization is essential for further utilization in crop improvement. This research was performed to estimate the diversity and population genetic structure in the mini-core collection of finger millet by using SPAR markers, namely RAPD, ISSR, and DAMD markers. Altogether, 32 primers were used in this study, which produced 408 bands among which 344 were polymorphic. Analysis by combining all three marker systems revealed 84.31% of polymorphism among 90 genotypes of finger millet. Average polymorphism information content (PIC) produced by the ISSR, RAPD, and DAMD markers were 0.79, 0.81, 0.62, and average Rp values were 12.84, 8.17, and 8.53, respectively. The Jaccard's similarity value ranged from 0.233-0.861. IE 6059 and IE 5870 genotypes showed the highest Jaccard's similarity value of 0.861 in UPGMA analysis. Neighbor joining-based phylogenetic analysis produced two major clusters and the genotypes were grouped based on their geographical region of origin. Principal component analysis and principal coordinates analysis also confirmed the results. In population STRUCTURE analysis, the genotypes were divided into two subpopulations (P1and P2). These results confirmed that the genotypes we have assessed were genetically diverse and were clustered based on their geographic region of origin. The information obtained from this study will be useful in population management strategies and selection of genotypes for an effective breeding program in the future.     

8份剑麻种质亲缘关系的ISSR和RAPD分析

为了揭示剑麻栽培品种的遗传多样性,利用ISSR和RAPD分子标记技术对8份剑麻种质的亲缘关系进行分析。结果表明,筛选后选用的8条ISSR引物和8条RAPD引物,分别产生了53条和66条扩增条带,其中多态性条带分别为44条和61条,多态性条带百分率分别为83.02%和92.42%。根据2种标记的扩增结果,用UPGMA法对8份剑麻种质进行聚类分析,供试材料之间具有较高的遗传多样性,其品种间遗传相似系数分别为0.59~0.80和0.52~0.76。2个标记的聚类结果基本一致,但有点差异,可将供试的8份剑麻种质划分为2类群,而且2个标记聚类结果呈显著相关性,相关系数为0.70。可见,剑麻种质资源的遗传多样性丰富。     

豇豆种质资源遗传多样性和亲缘关系的SRAP和SSR分析

为从分子水平上揭示豇豆种质资源间的亲缘关系,为其种质资源搜集、鉴定、利用和遗传改良提供一定的理论基础,利用SRAP和SSR分子标记对41份来自中国和马来西亚的豇豆种质资源进行遗传多样性研究。从65对SRAP引物和10对SSR引物中分别筛选获得稳定清晰且多态性强的31对SRAP引物和5对SSR引物,对41份栽培豇豆资源的DNA进行SRAP-PCR和SSR-PCR扩增。2种PCR扩增共获230条扩增条带,其中SRAP检测到196条扩增条带,平均每对引物扩增等位基因数为6.3条,多态性片段为161条,多态性比例为82.14%;SSR检测到34条带,平均每对引物扩增等位基因数6.8条,多肽性片段为25条,多态性比例为73.53%,表明本研究搜集的豇豆种质间的遗传多样性比较丰富。基于SRAP和SSR标记的结果,利用UPGMA构建了41份豇豆资源的聚类树状图,其遗传相似系数为0.1667~0.9516,大多在0.674以上。结果表明,SRAP和SSR分子标记能有效地将41份豇豆资源分开,且部分种质间的遗传距离较远,这为豇豆资源的开发利用及新品种的选育提供科学依据。

     

利用RAPD、ISSR标记分析白芨种质资源遗传多样性的研究

旨在分析不同地区野生驯化白芨居群间亲缘关系,为白芨资源保护和利用提供支撑。利用RAPD和ISSR标记技术从分子层面鉴别源于湖南、湖北、贵州、云南、江西等地的12个白芨资源遗传多样性差异,并通过UPGMA对该差异性进行了聚类分析。结果表明,在36条供试RAPD引物中有13条扩增带型清晰、多态性高,15条供试ISSR引物中有2条扩增带型清晰、多态性高,共获得40条多态性条带;通过UPGMA聚类分析表明,12份供试白芨种质资源间具有较高的遗传多样性,遗传距离最大可达0.975,供试材料总体上可分为两个支系,湖南、江西为一个支系,湖北、贵州和云南为一个支系。利用ISSR和RAPD标记可以从分子水平上揭示白芨的种质资源遗传多样性,同时,研究还发现ISSR标记能比RAPD标记扩增出更多的多态条带和获得更高的多态比率,且分析不受时间和地点限制,结果更稳定、可靠。本研究结果显示白芨居群间遗传差异性与地理距离呈现一定的相关性,对研究白芨物种的演化及遗传多样性提供了相关数据和理论支持。     

豇豆种质资源遗传多样性和亲缘关系的SRAP和SSR分析

为从分子水平上揭示豇豆种质资源间的亲缘关系,为其种质资源搜集、鉴定、利用和遗传改良提供一定的理论基础,利用SRAP和SSR分子标记对41 份来自中国和马来西亚的豇豆种质资源进行遗传多样性研究。从65 对SRAP引物和10 对SSR引物中分别筛选获得稳定清晰且多态性强的31 对SRAP引物和5 对SSR引物,对41 份栽培豇豆资源的DNA进行SRAP-PCR和SSR-PCR扩增。2 种PCR扩增共获230 条扩增条带,其中SRAP检测到196 条扩增条带,平均每对引物扩增等位基因数为6.3 条,多态性 片段为161 条,多态性比例为82.14%;SSR检测到34 条带,平均每对引物扩增等位基因数6.8 条,多肽性片段为25 条,多态性比例为73.53%,表明本研究搜集的豇豆种质间的遗传多样性比较丰富。基于SRAP 和SSR 标记的结果,利用UPGMA 构建了41 份豇豆资源的聚类树状图,其遗传相似系数为0.1667~0.9516,大多在0.674 以上。结果表明,SRAP和SSR分子标记能有效地将41 份豇豆资源分开,且部分种质间的遗传距离较远,这为豇豆资源的开发利用及新品种的选育提供科学依据。     

Molecular characterisation of cultivars of apple (Malus × domestica Borkh.) using microsatellite (SSR and ISSR) markers

In this study, two microsatellite-based methodologies (SSR and ISSR) were evaluated for potential use in fingerprinting and determination of the similarity degree between 41 commercial cultivars of apple previously characterised using RAPD and AFLP markers. A total of 13 SSR primer sets was used and 84 polymorphic alleles were amplified. Seven ISSR primers yielded a total of 252 bands, of which 176 (89.1%) were polymorphic. Except for cultivars obtained from somatic mutations, all cultivars were easily distinguishable employing both methods. The similarity coefficient between cultivars ranged from 0.20 to 0.87 for SSR analysis and from 0.71 to 0.92 using the ISSR methodology. Dendrograms constructed using UPGMA cluster analysis revealed a phenetic classification that emphasises the existence of a narrow genetic base among the cultivars used, with the Portuguese cultivars revealing higher diversity. This study indicates that the results obtained based on the RAPD, AFLP, SSR and ISSR techniques are significantly correlated. The marker index, based on the effective multiplex ratio and expected heterozygosity, was calculated for both analyses (MI = 1.7 for SSR and MI = 8.4 for ISSR assays) and the results obtained were directly compared with previous RAPD and AFLP data from the same material. The SSR and ISSR markers were found to be useful for cultivar identification and assessment of phenetic relationships, revealing advantages, due to higher reproducibility, over other commonly employed PCR-based methods, namely RAPD and AFLP. This revised version was published online in August 2006 with corrections to the Cover Date.     

Molecular evaluation of genetic variability in wild populations of mulberry (Morus serrata Roxb.)

Sixteen populations of the wild mulberry, Morus serrata Roxb., were analysed for their genetic diversity with the aim of using them in introgressive breeding programmes with cultivated relatives. Five genets from each population were collected from different natural populations of M. serrata present in Uttaranchal and Himachal Pradesh in India, and diversity of morpho‐anatomical traits and inter‐simple sequence repeat (ISSR) markers were studied. Significant amounts of genetic diversity were observed among these populations for morpho‐anatomical as well as DNA markers. The 17 ISSR primers generated a total of 95 DNA markers, 51 of which were polymorphic, revealing 67% polymorphism among the populations. The pair‐wise genetic distance, estimated from these DNA markers varied from 0.091 between Urgam‐3 and Kathpuria to 0.258 between Dakrakao‐1 and Dunda with an average genetic distance of 0.165. Clustering analysis grouped these 16 populations into three broad groups. The grouping showed a moderate correlation with the geographical distances. Based on the morphological traits and molecular genetic variability, plants of Urgam‐1, Bhowali farm, Nainitikar, Dunda or Korwa‐2 can be selected for breeding and conservation programmes.     

Molecular diversity of Egyptian cotton (<Emphasis Type="Italic">Gossypium barbadense</Emphasis> L.) and its relation to varietal development

Twenty-eight Egyptian cotton (Gossypium barbadense L.) genotypes (varieties and hybrids) were used for analysis of genetic diversity using DNA based markers (ISSR, SSR, and EST) and to study varietal development of cotton. The ISSR markers gave the highest percentage of polymorphic bands as well as polymorphic information content compared with the other molecular markers (i.e. EST and SSR markers). Using clustering analysis, no general clustering according to the pedigree history of the genotypes was observed. Using principal coordinate analysis (PCOORDA), cotton genotypes were separated by the first three principal coordinates (PC1, PC2, and PC3) accounting for 11.5, 8.6, and 7.2% of the total genetic variance, respectively. The cotton genotypes were distributed into three parts based on the first PC, each part containing a group of varieties having a common ancestor. ‘Giza 12’ variety was the common ancestor for the varieties included in the first part and ‘Ashmouni’ variety was the common ancestor for the varieties included in the second part, while both ‘Sakha 3’ and ‘Sakha 4’ varieties were common ancestors for the varieties included in the third part. The results of the PCOORDA also showed better resolution of the genetic diversity than cluster analysis especially in the illustration of the varietal development of cotton. That means that principal coordinate analysis can be strongly used either alone or in combination with cluster analysis to discuss both genetic diversity and varietal development in the cotton genotypes.     

Genetic diversity in groundnut (<Emphasis Type="Italic">Arachis hypogaea</Emphasis> L.) genotypes and detection of marker trait associations for plant habit and seed size using genomic and genic SSRs

Groundnut (Arachis hypogaea L.) an important oilseed crop in India is known to have narrow genetic base. Therefore, the assessment of genetic diversity and detection of marker-trait association are important objectives for the genetic improvement of groundnut. The present study involved the development of 192 SSR markers from Arachis genomic survey sequences. From these, seven polymorphic SSRs along with 15 other genomic SSRs, 19 genic SSRs, and three STS markers were used to detect genetic diversity among 44 groundnut genotypes. These polymorphic SSR markers amplified 155 bands (76 genomic and 79 genic), of these 128 bands (67 genomic and 61 genic) were polymorphic. The genomic SSR exhibited 88.1% and genic SSRs displayed 77.2% allelic polymorphism. The polymorphic information content (PIC) of the markers ranged from 0.04 to 0.95. The pair-wise genetic similarity ranged from 24.2 to 90.7% for genomic SSR and 32.9 to 97.9% for genic SSR markers. Cluster analysis based on the pooled data from both genomic and genic SSRs revealed a dendrogram which could distinguish all the genotypes. Further, the AMOVA analysis detected 16.7% genetic variation due to differences in seed size and 13.0% due to plant habit. Based on locus-by-locus AMOVA and Kruskal-Wallis ANOVA and further confirmation by discriminant analysis and general linear model, six markers were found to be associated with plant habit and four markers with seed size.     

云南茶树资源遗传多样性与亲缘关系的ISSR分析

以8个种群134份云南茶树资源为材料,应用ISSR标记方法,进行了遗传多样性与亲缘关系分析。结果表明,18个多态性ISSR引物对全部试验材料进行PCR扩增,共获得475条稳定的谱带,其中多态性谱带470条(占98.9%),遗传多样性丰富;应用Nei-Li相似系数法估算了134个材料间的相似系数为0.445~0.819,平均为0.512,说明茶树资源间的遗传基础较宽;对134份茶树资源的分子系统聚类分析(UPGMA)将资源分为3大组,聚类结果与地理距离没有明显的相关性;主成分分析(PCA)表明主成分分析的结果与系统聚类基本一致,但是主成分分析更加直观清晰地显示各个材料间的亲缘关系;大厂茶等8个种群间的遗传相似系数于0.850~0.987间,平均为0.92,表明不同种群间的遗传差异较小。