辣椒种质遗传多样性的RAPD和ISSR及其表型数据分析

用RAPDI、SSR分子标记及28个表型性状数据对辣椒属5个栽培种的13份材料进行了分析,结果表明:23条RAPD引物共扩增出209条带,平均每个引物扩增出9.09条,多态性位点比率为83.73%;16条ISSR引物共扩增出94条带,平均每个引物扩增出5.88条,多态性位点比率为79.79%.与RAPD相比,ISSR标记检测到的有效等位基因数(Ne)及Shannon多样性指数(I)、遗传离散度(Ht)和遗传分化系数(Gst)等遗传多样性参数都较大,多态性位点比例在亲缘关系较近的一年生辣椒(Capsicum annuum)种内较高,说明ISSR有更高的多态性检测效率,并且适合亲缘关系较近的种群间遗传多样性分析.基于RAPDI、SSR的聚类与基于表型数据的聚类之间存在极显著正相关,且都能将C.annuum与其它栽培种区分开来.     

Determination of genetic diversity among Saccharina germplasm using ISSR and RAPD markers

Various species of genus Saccharina are economically important brown macroalgae cultivated in China. The genetic background of the conserved Saccharina germplasm was not clear. In this report, DNA-based molecular markers such as inter simple sequence repeats (ISSR) and random amplified polymorphic DNA (RAPD) were used to assess the genetic diversity and phylogenetic relationships among 48 Saccharina germplasms. A total of 50 ISSR and 50 RAPD primers were tested, of which only 33 polymorphic primers (17 ISSR and 16 RAPD) had an amplified clear and reproducible profile, and could be used. Seventeen ISSR primers yielded a total of 262 bands, of which 256 were polymorphic, and 15.06 polymorphic bands per primer were amplified from 48 kelp gametophytes. Sixteen RAPD primers produced 355 bands, of which 352 were polymorphic, and 22 polymorphic bands per primer were observed across 48 individuals. The simple matching coefficient of ISSR, RAPD and pooled ISSR and RAPD dendrograms ranged from 0.568 to 0.885, 0.670 to 0.873, and 0.667 to 0.862, revealing high genetic diversity. Based on the unweighted pair group method with the arithmetic averaging algorithm (UPGMA) cluster analysis and the principal components analysis (PCA) of ISSR data, the 48 gametophytes were divided into three main groups. The Mantel test revealed a similar polymorphism distribution pattern between ISSR and RAPD markers, the correlation coefficient r was 0.62, and the results indicated that both ISSR and RAPD markers were effective to assess the selected gametophytes, while matrix correlation of the ISSR marker system (r = 0.78) was better than that of the RAPD marker system (r = 0.64). Genetic analysis data from this study were helpful in understanding the genetic relationships among the selected 17 kelp varieties (or lines) and provided guidance for molecular-assisted selection for parental gametophytes of hybrid kelp breeding.     

利用RAPD和ISSR分子标记分析怀地黄种质遗传多样性

用RAPD与ISSR技术对怀地黄的8个品种和2个脱毒品系进行了种质遗传多样性分析。分别从80条RAPD引物和44条ISSR引物中筛选出适合怀地黄种质分析的17条RAPD引物和10条ISSR引物,用于RAPD和ISSR分析。17条RAPD引物共扩增出177条带, 多态性位点数为109; 多态性位点比率为61.58%;平均多样性指数(I)为0.3135;每个位点的有效等位基因数（Ne）是1.3641; 10条ISSR引物共扩增出110条带. 多态性位点数为79; 多态性位点比率为71.58%;平均多样性指数(I)为0.3577;每个位点的有效等位基因数（Ne）是1.4037。 基于扩增条带数据库建立了各自的Jaccard遗传相关系数矩阵,构建了相似的分子树状图,将10个供试材料分为2类:一类群含组培85.5、大田85.5、组培9302、大田9302、金状元和金白6个材料;另一类群含北京1号、大红袍、地黄9104和野生地黄4个材料。两种分子标记的分析结果呈极显著正相关(r＝0.649)。结果表明,RAPD与ISSR标记适合于怀地黄种质遗传多样性分析,ISSR标记技术是一种多态性和重复性优于RAPD技术的实用技术。     

Evaluation of genetic diversity in Lentinula edodes strains using RAPD, ISSR and SRAP markers

Random amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) and sequence-related amplified polymorphism (SRAP) markers were used to evaluate the genetic diversity among 23 elite Lentinula edodes strains in China. A total of 138, 77 and 144 bands were detected by 16 RAPD primers, 5 ISSR primers and 23 SRAP primer combinations, among which 58.8%, 73.5% and 56.3% was polymorphic, respectively. By UPGMA clustering, a dendrogram was constructed based on each analysis. The three dendrograms showed that 23 L. edodes strains were clustered into three or four groups. The grouping exhibited similar structure and was generally consistent with their pedigrees. Twenty-three L. edodes strains shared great similarity indicated that the low level of genetic diversity of L. edodes strains and their relationship between each other. The important source of breeding material, such as wild and exotic types, must be introduced in order to broaden genetic base and decreases genetic vulnerability of L. edodes.     

RAPD and ISSR fingerprints as useful genetic markers for analysis of genetic diversity, varietal identification, and phylogenetic relationships in peanut (Arachis hypogaea) cultivars and wild species.

Abstract: Twenty-one random and 29 SSR primers were used to assess genetic variation and interrelationships among subspecies and botanical varieties of cultivated peanut, Arachis hypogaea (2n = 4x = 40), and phylogenetic relationships among cultivated peanut and wild species of the genus Arachis. In contrast with the previous generalization that peanut accessions lack genetic variation, both random and SSR primers revealed 42.7 and 54.4% polymorphism, respectively, among 220 and 124 genetic loci amplified from 13 accessions. Moreover, the dendrograms based on RAPD, ISSR, and RAPD + ISSR data precisely organized the five botanical varieties of the two subspecies into five clusters. One SSR primer was identified that could distinguish all the accessions analysed within a variety. Although the polymorphic index content varied from 0.1 to 0.5 for both ISSR and RAPD markers, primer index values were substantially higher for RAPD primers (0.35-4.65) than for SSR primers (0.35-1.73). It was possible to identify accessions, particularly those of divergent origins, by RAPD and (or) ISSR fingerprints. Based on these results, marker-based genetic improvement in A. hypogaea appears possible. None of the 486 RAPD and 330 ISSR amplification products were found to be commonly shared among 13 species of section Arachis and one species each of sections Heteranthae, Rhizomatosae, and Procumbentes. Dendrograms constructed from RAPD, ISSR, and RAPD + ISSR data showed overall similar topologies. They could be resolved into four groups corresponding to the species grouped in four taxonomic sections. The present results strongly support the view that Arachis monticola (2n = 4x = 40) and A. hypogaea are very closely related, and indicate that A. villosa and A. ipaensis are the diploid wild progenitors of these tetraploid species.     

Comparative Evaluation of RAPD, ISSR and Anchored-SSR Markers in the Assessment of Genetic Diversity and Fingerprinting of Oilseed Brassica Genotypes

Forty-two genotypes representing oilseed Brassica species were analyzed for the level of genetic diversity and molecular identity using Random Amplified Polymorphic DNA (RAPD), Inter-Simple Sequence Repeat (ISSR) and 5'-Anchored Simple Sequence Repeat (ASSR) markers. DNA profiles revealed high degree of interspecific polymorphism, while the level was considerably low within a species, particularly in B. juncea. The UPGMA clusters clearly delineated genotypes of the respective Brassica species. Comparison of cophenetic matrices indicated a high degree of correspondence between dendrograms generated by different marker systems. A minimum of 10 random primers (approximately 105 bands) were required for the RAPD profiles to generate the expected cluster. Comparatively less number of primers was required to do the same in case of ISSR (4 primers) and ASSR (3 primers). The principal component analysis revealed similar genetic relationship among the genotypes as in cluster analysis. Although none of the DNA profiles could individually identify all the B. juncea genotypes, a combined DNA profile consisting 125 markers from the informative primers of all the three DNA marker systems could do the same. A positive correlation was found among the marker utility parameters (calculated for individual primers of different marker systems) such as marker index (MI), resolving power (Rp) and discrimination coefficient (D) with the number of genotypes identified by each primer with a few exceptions. Single plant analysis for a set of five B. juncea varieties revealed absence of intra-varietal heterogeneity in case of ASSR profiles, thereby suggesting its utility in varietal identification and differentiation.     

DNA typing and genetic relations among populations of Kelussia odoratissima using ISSR and SRAP markers

Kelussia odoratissima is well known for its medicinal importance. It has been announced as an endangered species. Thus, examining the genetic variation and conservation of this plant is necessary. In the present study, inter simple sequence repeat (ISSR) and sequence-related amplified polymorphism (SRAP) molecular markers were employed for the first time to access the genetic diversity and relationships of 77 wild individual plants of K. odoratissima collected from seven populations in Central Zagros region of Iran. A total of 146 bands were amplified by 12 ISSR primers, of which 129 (87.80 %) were polymorphic, while 69 polymorphic bands (83.30 %) were observed among 86 bands amplified by 11 SRAP primers. Polymorphic information content (PIC = 0.32), resolving power (Rp = 7.80), and marker informativeness (MI = 3.48) generated by ISSR primers were higher than that of SRAP analysis (PIC = 0.30, Rp = 5.61, and MI = 1.88). The study indicated that ISSR were more effective than SRAP markers for assessing the degree of genetic variation of K. odoratissima. In both UPGMA dendrograms of ISSR and SRAP, in most cases, individuals from each population were clustered in various groups without clear separation, which demonstrates the high variability of this germplasm in Iran. UPGMA cluster analysis revealed inconsistencies in the clustering patterns, as the Mantel’s test between the dendrograms for ISSR and SRAP data indicated a poor fit for the ISSR and SRAP data types (r = 0.10). Besides, principal coordinate analysis results showed that the first three principal coordinates account for 65.57 % of the total variation and studied seven populations were separated from each other and placed into five groups. These results have an important implication for K. odoratissima germplasm characterization, improvement, and conservation.     

Assessment of genetic fidelity of micropropagated date palm (Phoenix dactylifera L.) plants by RAPD and ISSR markers assay

RAPD (Random Amplified Polymorphic DNA) and ISSR (Inter-Simple Sequence Repeats) markers assay were employed to validate the genetic stability of date palm (Phoenix dactylifera L.) plants multiplied through somatic embryogenesis with upto forty two in vitro subcultures. Out of the 160 RAPD and 21 ISSR primers screened, 30 RAPD and 12 ISSR primers produced a total of 347 (246 RAPDs + 101 ISSRs) clear, distinct and reproducible amplicons, which were monomorphic across all micropropagated plants (27) studied. Thus, a total 8592 bands (number of plants analysed x number of amplicons with all the primers) were generated which exhibited homogeneous banding patterns with both RAPD and ISSR markers. These results indicate that the micropropagation protocol developed by us for rapid in vitro multiplication is appropriate and suitable for clonal propagation of date palm and corroborated the fact that somatic embryogenesis can also be used as one of the safest modes for production of true-to-type plants.     

Phylogeny ofRubiaceae-Rubieae inferred from the sequence of a cpDNA intergene region

A phylogenetic analysis of 25 species, representing eight genera of theRubieae tribe (Rubiaceae), has been made using the DNA sequence of the chloroplastatp B-rbc L intergene region. Six tropical genera from other tribes ofRubiaceae have been used as outgroups. Whatever the method of analysis (distance, parsimony or maximum likelihood), five groups are clearly separated and described as informal clades. Their relative relationships are not clearly resolved by the parsimony analysis, resulting in eight equally parsimonious trees, 327 steps long, with a consistency index (CI) of 0.749 (excluding uninformative sites). TheRubieae tribe appears monophyletic from the data available. Some new and partly unexpected phylogenetic relationships are suggested. The genusRubia forms a separate clade and appears to be the relatively advanced sister group of the remaining taxa. TheSherardia clade also includes the generaCrucianella andPhuopsis. Galium sect.Aparinoides appears closely attached to theAsperula sect.Glabella clade. The remaining taxa ofGalium are paraphyletic:Galium sect.Platygalium (in theCruciata clade) is linked to the advanced generaCruciata andValantia; the more apomorphic groups ofGalium form theGalium sect.Galium clade, including the perennial sectionsGalium, Leiogalium, andLeptogalium as well as the annual (and possibly polyphyletic) sect.Kolgyda.     

Evaluation of genetic diversity of <Emphasis Type="Italic">Clinacanthus nutans</Emphasis> (Acanthaceaea) using RAPD,ISSR and RAMP markers

Three polymerase chain reaction (PCR) techniques were compared to analyse the genetic diversity of Clinacanthus nutans eight populations in the northern region of Peninsular Malaysia. The PCR techniques were random amplified polymorphic deoxyribonucleic acids (RAPD), inter-simple sequence repeats (ISSR) and random amplified microsatellite polymorphisms (RAMP). Leaf genomic DNA was PCR amplified using 17 RAPD, 8 ISSR and 136 RAMP primers . However, only 10 RAPD primers, 5 ISSR primers and 37 RAMP primers produced reproducible bands. The results were evaluated for polymorphic information content (PIC), marker index (MI) and resolving power (RP). The RAMP marker was the most useful marker compared to RAPD and ISSR markers because it showed the highest average value of PIC (0.25), MI (11.36) and RP (2.86). The genetic diversity showed a high percentage of polymorphism at the species level compared to the population level. Furthermore, analysis of molecular variance revealed that the genetic diversity was higher within populations, as compared to among populations of C. nutans. From the results, the RAMP technique was recommended for the analysis of genetic diversity of C. nutans.     

利用RAPD和ISSR标记分析烤烟品种间遗传关系

利用RAPD和ISSR标记对22份烤烟(Nicotiana tabacumL.)品种进行了遗传关系研究。在RAPD分析中筛选到13个引物,共扩增出167条带,其中多态性带50条,多态性比率为29.9%;在ISSR分析中筛选出7个引物,共扩增出96条带,其中多态性带44条,多态性比率为45.8%。两种标记相结合估算出的品种间遗传相似系数在0.881~0.979之间,平均为0.933。单独基于RAPD标记和ISSR标记的聚类结果有一定差异;两种标记结合起来的聚类分析结果与系谱信息吻合程度更高。定向选择可能对烤烟品种间遗传关系有较大影响;国外引进品种与国内育成品种并未完全分开,表明分子水平的遗传关系和地理来源间缺乏必然联系。     

Analysis of genetic diversity through AFLP,SAMPL, ISSR and RAPD markers in <Emphasis Type="Italic">Tribulus terrestris</Emphasis>, a medicinal herb

Tribulus terrestris is well known for its medicinal importance in curing urino-genital disorders. Amplified fragment length polymorphism (AFLP), selective amplification of microsatellite polymorphic loci (SAMPL), inter-simple sequence repeat (ISSR) and randomly amplified polymorphic DNA (RAPD) markers were used for the first time for the detection of genetic polymorphism in this medicinal herb from samples collected from various geographical regions of India. Six assays each of AFLP and SAMPL markers and 21 each of ISSR and RAPD markers were utilized. AFLP yielded 500 scorable amplified products, of which 82.9% were polymorphic. SAMPL primers amplified 488 bands, 462 being polymorphic (94.7%). The range of amplified bands was 66 [(TC)₈G + M-CAG] to 98 [(CA)₆AG + M-CAC] and the percentage polymorphism, 89.9 [from (CT)₄C (AC)₄A + M-CTG] to 100 [from (GACA)₄ + M-CTA]. The ISSR primers amplified 239 bands of 0.4–2.5 kb, 73.6% showed polymorphism. The amplified products ranged from 5 to 16 and the percentage polymorphism 40–100. RAPD assays produced 276 bands, of which 163 were polymorphic (59%). Mantel test employed for detection of goodness of fit established cophenetic correlation values above 0.9 for all the four marker systems. The dendrograms and PCA plots derived from the binary data matrices of the four marker systems are highly concordant. High bootstrap values were obtained at major nodes of phenograms through WINBOOT software. The relative efficiency of the four molecular marker systems calculated on the basis of multiplex ratio, marker index and average heterozygosity revealed SAMPL to be the best. Distinct DNA fingerprinting profile, unique to every geographical region could be obtained with all the four molecular marker systems. Clustering can be a good indicator for clear separation of genotypes from different regions in well-defined groups that are supported by high bootstrap values.     

Lack of genetic variation of an invasive clonal plant Eichhornia crassipes in China revealed by RAPD and ISSR markers

Random amplified polymorphic DNAs (RAPDs) and inter-simple sequence repeats (ISSRs) markers were used to analyze genetic structure of six populations of invasive plant Eichhornia crassipes that were sampled from its introduced regions in Southern China. Using 25 RAPD primers and 18 ISSR primers, 172 RAPD bands and 145 ISSR bands were produced respectively. But no polymorphic band was detected either within population or among populations by both markers, indicating the genetic diversity of E. crassipes in Southern China is extremely low, and all populations most likely consist of the same genotype. This study suggested that some other adaptability related factors, other than the genetic diversity, are responsible to the E. crassipes rapid expansion in China.     

Genetic divergence and allelic-specificity in relation to expression of voltinism in silkworm using ISSR and RAPD fingerprinting

The silkworm B. mori is a multicellular organism revealing genetic resources which makes an ideal model for lepidoptera for the present investigation. With the objective of targeting distinctive markers for utilization in future breeding programmes, Bivoltine and Polyvoltine silkworm strains were used by inter-simple sequence repeats (ISSR) and random amplified polymorphic-DNA (RAPD) fingerprinting to detect their genetic versatility and volatility. Six ISSR primers generated 99 markers, of which 76.76% were found to be polymorphic with an average number of observed alleles (N _a) (1.86 ± 0.40), an effective number of alleles (N _e) (1.43 ± 0.30) as well as six RAPD primers that produced a total of 95 bands, developing 61.05% polymorphism with N _a (1.93 ± 0.51) and N _e (1.18 ± 0.30). The dendrogram produced by UPGMA analysis, based on Dice’s coefficient, clustered four races into two major groups which accurately segregated them according to their inheritance of voltinism. In this research, the ISSR markers were more accurate than the RAPD markers and ISSR also displayed better polymorphism. The outcome showed that the bivoltine strains exhibited higher allelic expressions with ISSR primers when compared to the polyvoltine strains. Despite exhibiting their unique race by certain DNA markers, most of the primers represented voltinism-specificity. Hence molecular marker amplification is a beneficial approach to reveal genetic divergence among closely related strains, and molecular characterization of phylogenetic relationships in addressing evolutionary evidences of individuals.     

Molecular genetic diversity of Satureja bachtiarica

Fifty-seven genotypes from eight population of Satureja bachtiarica was evaluated using fifteen ISSR and eleven RAPD markers. DNA profiling using RAPD primers amplified 84 loci, among which 81 were polymorphic with an average of 7.36 polymorphic fragments per locus. Also, using RAPD markers maximum and minimum polymorphic bands observed for Semyrom (77.38 %) and Farsan (40.48 %) populations, respectively. Semyrom population recorded the highest unbiased expected heterozygosity (0.259) and Shannon’s Indices (0.38). While, the lowest values of unbiased expected heterozygosity (0.172) and Shannon’s Index (0.245) were recorded for Eghlid and Farsan populations, respectively. On the other hand, ISSR primers produced 136 bands, from which 134 were polymorphic with an average of 9.06 polymorphic fragments per primer (98.52 %). The ISSR markers evaluation revealed that maximum and minimum polymorphic bands observed for Semyrom (66.18 %) and Farsan (31.62 %), respectively. Shahrekorud population recorded the highest unbiased expected heterozygosity (0.211) and Shannon’s Indices (0.301). While, the lowest value of unbiased expected heterozygosity (0.175) observed for Farsan and Yazd populations and the lowest Shannon’s Index (0.191) recorded by Farsan population. The overall results of the study revealed that both ISSR and RAPD markers were effective for evaluation of genetic variation of S. bachtiarica.     

Evaluation of inter-simple sequence repeat analysis for mapping in Citrus and extension of the genetic linkage map

Inter-simple sequence repeat (ISSR) analysis was evaluated for its usefulness in generating markers to extend the genetic linkage map of Citrus using a backcross population previously mapped with restriction fragment length polymorphism (RFLP), random amplified polymorphic DNA (RAPD) and isozyme markers. ISSR markers were obtained through the simple technique of PCR followed by analysis on agarose gels, using simple sequence repeat (SSR) primers. Optimization of reaction conditions was achieved for 50% of the SSR primers screened, and the primers amplified reproducible polymorphic bands in the parents and progeny of the backcross population. Mendelian segregation of the polymorphic bands was demonstrated, with an insignificant number of skewed loci. Most of the SSR primers produced dominant loci; however co-dominance was observed with loci derived from three primers. A new genetic map was produced by combining the segregation data for the ISSR markers and data for the RFLP, RAPD and isozyme markers from the previous map and creating genetic linkages among all the markers using JoinMap 2.0 mapping software. The new map has an improved distribution of markers along the linkage groups with fewer gaps, and marker order showed partial or complete conservation in the linkage groups. The incorporation of ISSR markers into the genetic linkage map demonstrates that ISSR markers are suitable for genetic mapping in Citrus. Received: 3 February 2000 / Accepted: 12 May 2000     

Comparison of RAPD,ISSR, and AFLP Molecular Markers to Reveal and Classify Orchardgrass (Dactylis glomerata L.) Germplasm Variations

Three different DNA-based techniques, Random Amplified Polymorphic DNA (RAPD), Inter Simple Sequence Repeat (ISSR) and Amplified Fragment Length Polymorphism (AFLP) markers, were used for fingerprinting Dactylis glomerata genotypes and for detecting genetic variation between the three different subspecies. In this study, RAPD assays produced 97 bands, of which 40 were polymorphic (41.2%). The ISSR primers amplified 91 bands, and 54 showed polymorphism (59.3%). Finally, the AFLP showed 100 bands, of which 92 were polymorphic (92%). The fragments were scored as present (1) or absent (0), and those readings were entered in a computer file as a binary matrix (one for each marker). Three cluster analyses were performed to express–in the form of dendrograms–the relationships among the genotypes and the genetic variability detected. All DNA-based techniques used were able to amplify all of the genotypes. There were highly significant correlation coefficients between cophenetic matrices based on the genetic distance for the RAPD, ISSR, AFLP, and combined RAPD-ISSR-AFLP data (0.68, 0.78, 0.70, and 0.70, respectively). Two hypotheses were formulated to explain these results; both of them are in agreement with the results obtained using these three types of molecular markers. We conclude that when we study genotypes close related, the analysis of variability could require more than one DNA-based technique; in fact, the genetic variation present in different sources could interfere or combine with the more or less polymorphic ability, as our results showed for RAPD, ISSR and AFLP markers. Our results indicate that AFLP seemed to be the best-suited molecular assay for fingerprinting and assessing genetic relationship among genotypes of Dactylis glomerata.     

Molecular diversity analysis of Rhizoctonia solani isolates infecting various pulse crops in different agro-ecological regions of India

Genetic diversity of 89 isolates of Rhizoctonia solani isolated from different pulse crops representing 21 states from 16 agro-ecological regions of India, 49 morphological, and 7 anastomosis groups (AGs) was analyzed using 12 universal rice primers (URPs), 22 random amplified polymorphic DNA (RAPD), and 23 inter-simple sequence repeats (ISSR) markers. Both URPs and RAPD markers provided 100?% polymorphism with the bands ranging from 0.1 to 5?kb in size, whereas ISSR markers gave 99.7?% polymorphism with the bands sizes ranging from 0.1 to 3?kb. The marker URP 38F followed by URP13R, URP25F, and URP30F, RAPD marker R1 followed by OPM6, A3 and OPA12 and ISSR3 followed by ISSR1, ISSR4, and ISSR20 produced the highest number of amplicons. R. solani isolates showed a high level of genetic diversity. Unweighted pair group method with an arithmetic average (UPGMA) analysis grouped the isolates into 7 major clusters at 35?% genetic similarity using the three sets of markers evaluated. In spite of using three different types of markers, about 95?% isolates shared common grouping patterns. The majority of the isolates representing various AGs were grouped together into different sub-clusters using all three types of markers. Molecular groups of the isolates did not correspond to agro-ecological regions or states and crops of the origin. An attempt was made for the first time in the present study to determine the genetic diversity of R. solani populations isolated from different pulse crops representing various AGs and agro-ecological regions.     

Genetic variation,population structure and identification of yellow catfish, <Emphasis Type="Italic">Mystus nemurus</Emphasis> (C&;V) in Thailand using RAPD,ISSR and SCAR marker

Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers were used to investigate the genetic structure of four subpopulations of Mystus nemurus in Thailand. The 7 RAPD and 7 ISSR primers were selected. Of 83 total RAPD fragments, 80 (96.39%) were polymorphic loci, and of 81 total ISSR fragments, 75 (92.59%) were polymorphic loci. Genetic variation and genetic differentiation obtained from RAPD fragments or ISSR fragments showed similar results. Percentage of polymorphic loci (%P), observed number of alleles, effective number of alleles, Nei’s gene diversity (H) and Shannon’s information index revealed moderate to high level of genetic variations within each M. nemurus subpopulation and overall population. High levels of genetic differentiations were received from pairwise unbiased genetic distance (D) and coefficient of differentiation. Mantel test between D or gene flow and geographical distance showed a low to moderate correlation. Analysis of molecular variance indicated that variations among subpopulations were higher than those within subpopulations. The UPGMA dendrograms, based on RAPD and ISSR, showing the genetic relationship among subpopulations are grouped into three clusters; Songkhla (SK) subpopulation was separated from the other subpopulations. The candidate species-specific and subpopulation-specific RAPD fragments were sequenced and used to design sequence-characterized amplified region primers which distinguished M. nemurus from other species and divided SK subpopulation from the other subpopulations. The markers used in this study should be useful for breeding programs and future aquacultural development of this species in Thailand.     

用RAPD和ISSR检测的橡胶树野生种质和栽培品种的遗传多样性

用19个RAPD引物和12个ISSR引物对14份野牛橡胶树种质和我国的37份栽培品种进行了遗传多样性分析。RAPD引物共产生132条带,多态性带占88．6％,相似系数变化范围在0．432—0．947。ISSR引物其产生101条带,多态性带占87．1％,相似系数为0．505—0．941。平均基因杂合度分析表明野生种质比栽培品种具有较高的遗传多样性。根据UPGMA法对51份材料进行聚类分析,结果表明,ISSR分析中所有材料可分为2类：第一类为野生种质,第二类为栽培品种：而RAPD分析中野牛种质和栽培品种不能被分为明显的两人类。虽然ISSR和RAPD的聚类分析结果存在差异,但对两种方法进行的相关分析表明,他们之间仍存在极显著相关性,相关系数为0．574。品种PR107、热研217等一些栽培品种可以通过特异带在51份供试材料中被区分开。这些结果可以对橡胶树的育种上作起到一定的指导作用,同时RAPD和ISSR技术也是进行橡胶树品种鉴定和遗传多样性研究的有效手段。