Genetic diversity and relationships among Canavalia ensiformis (L.) DC. Accessions as revealed by sequence-related amplified polymorphism markers

Canavalia ensiformis is an under-exploited legume that has been used as forage, green manure, and a cover crop. Thus far, studies of the C. ensiformis germplasm have focused on morphological traits, which cannot be used to distinguish all known accessions or to evaluate their genetic diversity precisely. In this study, sequence-related amplified polymorphism (SRAP) markers were used to assess the genetic diversity and relationships among 29 C. ensiformis accessions originating from 16 countries. In total, 274 clear bands were amplified and 144 of them (52.6%) were polymorphic. The polymorphism information content values (PIC) ranged from 0.10 to 0.43, with an average of 0.27. An analysis of molecular variance (AMOVA) revealed that the most significant variation (92.0% of the total) occurred among accessions; the remaining 8.0% was attributed to variation within accessions. A cluster analysis and principal coordinates (PCoA) analysis produced similar results, whereby the 29 C. ensiformis accessions were divided into 5 clusters, each of which was composed of different accessions with different phenotypic traits. This study provides the theoretical basis for future biodiversity studies and breeding programs.     

Genetic diversity and phylogenetic relationship of kenaf (Hibiscus cannabinus L.) accessions evaluated by SRAP and ISSR

Understanding genetic diversity and phylogenetic relationships is useful for plant breeding. In this study, we assessed the genetic diversity in a panel of 84 accessions of kenaf from 26 countries using SRAP and ISSR markers. The kenaf accessions could be divided into L1 (60 cultivated varieties) and L2 (24 wild accessions) at the level of 0.145 genetic dissimilarity coefficient by UPGMA. The L₂ group was further divided into two subgroups (16 relative-wide and 9 origin wide accessions) at the level of 0.207 genetic dissimilarity. Out of the 9 wild accessions in the L₂ group, 6 were from Tanzania and the remaining 3 lines were from Kenya. These results suggest that the center of origin for kenaf might be Tanzania and Kenya.     

Genetic diversity in Vicia amoena (Fabaceae) germplasm resource in China using SRAP and ISSR markers

The genetic diversity in 17 germplasms of Vicia amoena L. from north China was analyzed using SRAP and ISSR markers. Three hundred and sixty-eight (94.11%) polymorphic bands (211 and 157 obtained from 20 pairs of SRAP and ISSR primers, respectively) were scored. Although SRAP was more effective than ISSR markers with higher PIC, RP and larger variation range of genetic distance, both the markers were useful for assessing V. amoena genetic diversity. Cluster analysis showed that the 17 germplasms were clustered into 5 groups. The results of principal coordinate analysis supported UPGMA clustering. The germplasms from source areas where the annual average temperature ranged from −1.0 to 5 °C exhibited the highest level of genetic diversity with the highest PPI, I and H. These results have important implications in genome mapping, breeding purposes, and germplasm conservation.     

Genetic diversity among the Turkish common bean cultivars (Phaseolus vulgaris L.) as assessed by SRAP,POGP and cpSSR markers

The genetic diversity among the Turkish cultivars of common bean (Phaseolus vulgaris L.) was estimated by studying the Sequence Related Amplified Polymorphism (SRAP), Peroxidase Gene Polymorhism (POGP), and Chloroplast Simple Sequence Repeats (cpSSR) markers. The unweighted pair group method arithmetic average (UPGMA) and Neighbor joining (NJ) algorithm resulted in a dendrogram representing the genetic relationship among major common bean cultivars grown in Turkey. The dendrogram generated two groups possibly representing two different major gene pools. By using three different marker systems, 194 alleles were detected and 118 were found to be polymorphic. For SRAP, POGP and cpSSR, 64, 64 and 26% polymorphism ratio were obtained, respectively. Principal Component Analysis (PCA) was also carried out to determine genetic variation among common bean genotypes and three different groups were generated. The individuals were placed into three different populations in structure analysis. Three populations created in structure analysis were exactly corresponded to the three groups in PCA. Analysis of Molecular Variance (AMOVA) was used to partition the genetic variations. The percentage of the variance was approximately 59%, 3%, and 38% among groups, among populations within groups and, within populations, respectively. The percentages of variation were found to be significantly high within the populations and among the groups.     

Genetic diversity analysis of Pinellia ternata based on SRAP and TRAP markers

An assessment of the genetic diversity and variation of Pinellia ternata collected from 43 populations in China was undertaken using SRAP + TRAP markers. A total of 13 SRAP primers in addition to 3 TRAP primer combinations yielded 292 bands in total of which 286 were polymorphic (98.0%), with an average of 16 for each. The PIC value ranged from 0.88 to 0.95, with a mean polymorphic information content (PIC) of 0.92 over all the primers. A cluster analysis was conducted based on the unweighted pair group method with arithmetic average (UPGMA), and a principle coordinate analysis (PCA) was performed relying on Nei's genetic distance, both of which showed similar outcomes in that the results of clustering did not correlate to the geography locations but showed an association with morphology. An analysis of molecular variance (AMOVA) was performed to detect the source of variation; the results indicated that the main variation existed within populations (67.2%), whereas there was still 32.8% differentiation existing among the populations.     

油莎豆SRAP指纹图谱构建及遗传多样性分析

利用SRAP分子标记构建了14份不同地理来源、表型具有差异的油莎豆品系的分子指纹图谱并进行遗传多样性分析。结果表明100对引物中共有多态性引物42对,扩增出多态性带328条,平均每对引物7.8条。28对引物在12个品系上具有特征谱带,除品系4和14外,均可用1对引物进行鉴定;采用引物组合法仅用Me2/Em6和Me8/Em11这2对引物就可将14份材料区分开,并利用这2对引物构建了上述品系的数字指纹图谱。UPGMA聚类分析表明,所有参试材料间的遗传距离在0.12～0.75之间,平均为0.42,表明我国不同地理来源的油莎豆品系遗传差异较大,具有较为丰富的遗传多样性。     

基于SRAP分子标记的海南沼虾种群遗传多样性

为了调查我国海南沼虾(Macrobrachium hainanense)不同地理种群遗传多样性及遗传分化状况,本文采用序列相关扩增多态性(sequence-related amplified polymorphism,SRAP)标记对我国南方瓯江(OJ)、闽江(MJ)、珠江(PR)、万泉河(WQ)、昌化江(CH)等5个海南沼虾种群的遗传多样性进行了研究。共得到255个清晰、稳定的位点,平均多态位点比例为47.05%,由小到大依次为:PR(43.92%)=WQ(43.92%)相似文献   

喜马拉雅旱獭线粒体DNA控制区遗传多样性及系统发育

喜马拉雅旱獭是青藏高原的优势种,数量多、分布广,全面了解其遗传背景对该地区旱獭资源的保护与合理利用具有重要的意义。本研究以青藏高原云南、西藏和青海三省区共13个地理种群计258只旱獭为研究对象,PCR扩增获得线粒体DNA控制区基因部分序列(887 bp),并运用种群遗传学方法进行遗传多样性分析。结果显示:258份样品共发现了84个变异位点(9.40%),定义了68种单倍型,其单倍型多样性(h)平均值为0.968±0.003、核苷酸多样性(π)平均值为0.017 25±0.016 37,种群总体遗传多样性较高。AMOVA方差分析显示13个地理种群间存在着明显的遗传分化(Fst=0.620 67,P<0.001),种群间基因交流多数较低(Nm<1)。基于单倍型构建的系统发育树中13个地理种群的喜马拉雅旱獭聚为两支,其中来自青藏高原西南地区(西藏安多、青海格尔木、青海囊谦、云南迪庆)的18个单倍型聚成一个大的分支(A支),其余50个单倍型聚为一个大的分支(B支),在NETWORK网络图中也可见到相似网络拓扑结构。研究结果显示青藏高原喜马拉雅旱獭种群以唐古拉山脉为界分为两个大的种群,说明地理隔离是影响喜马拉雅旱獭种群动态变化的主要因素。     

利用SRAP标记分析中国野生石蒜的遗传多样性

采用SRAP（Sequence-related amplified polymorphism,序列相关扩增多态性）标记对中国13个省24份野生石蒜（Lycoris radiata）资源94个样品进行了检测。10个引物组合共扩增出218条带,其中173条为多态性条带,多态性百分比达79.36%。石蒜的观测等位基因数（na）、有效等位基因数（ne）、基因多样性指数（h）、Shannon信息指数（I）分别为1.7936、1.4131、0.2415和0.3664。石蒜不同种源间的遗传分化系数（Gst）达0.9547、基因流（Nm）仅0.0136,表明种源间遗传分化显著,遗传变异主要存在于种源间。根据Nei′s遗传距离对24份种源进行UPGMA聚类,所有石蒜种源聚成两大类,第I大类由7份种源组成,除江苏连云港的石蒜（JS3）外,均来自我国西南或西北地区;其余的17份种源构成第II大类,它们遍及华南、华中和华东地区;各大类中的分支结果与野生石蒜外部形态及生长发育习性有一定联系。将石蒜种源的遗传多样性与其所处的经度、纬度、海拔、年均降雨量、年均温等进行相关性分析,结果显示它们之间的相关性均不显著,即石蒜对环境依赖性小,能分布在各种生境中。根据以上结果,我们认为野生石蒜具有较丰富的遗传多样性,而种源间遗传分化显著的原因主要是基因流的隔离。研究结果对我国的野生石蒜资源的开发利用与保护有重要意义。     

Seed traits,nutrient elements and assessment of genetic diversity for almond (Amygdalus spp.) endangered to China as revealed using SRAP markers

Almond (Amygdalus spp.) is one of the most important nut fruits worldwide and its seed has been recognized as a health nutrient supply for human consumption. In this study, we characterized the major seed traits and fruit nutrient elements among four Chinese wild almonds (Amygdalus mongolica Maxim., Amygdalus pedunculata Pall., Amygdalus tangutica Batal., and Amygdalus triloba (Lindl) Ricker.) in addition to commercial two cultivars (Amygdalus communis L.), as well as their genetic diversity and natural variations using SRAP marker, aiming at exploiting valuable traits for breeding new cultivars. Our results show that the wild almond species are rich in crude fat, Ca, Ma, Fe and Zn compared to the cultivars analyzed. Our study also identified a relatively high level of genetic diversity (h = 0.3363, I = 0.5075) among species analyzed as evidenced by fact that 161 out of a total of 162 bands amplified with fourteen SRAP primer combinations reveal polymorphism among species analyzed. AMOVA analysis reveals a high level of genetic differentiation among populations (Φ_ST = 0.4474) but The UPMGA cluster analysis indicates that A. communis and A. mongolica are more closely related. Potential utilization of the wild almond species and their valuable traits for breeding new cultivars is discussed.     

Genetic diversity among Chinese Hami melon and its relationship with melon germplasm of diverse origins revealed by microsatellite markers

Thick-skinned melon called Hami melon is the most widely cultivated and exported type of melon in China, and mainly grown in Xinjiang province. Here the genetic variation of 64 melon genotypes including 43 Xinjiang Hami melon accessions was analyzed using 36 simple sequence repeat (SSR) markers yielding 145 alleles. The polymorphic information content of SSR markers ranged from 0.09 to 0.83 (average 0.45). Based on the SSR markers, the melon accessions were clustered into 2 major groups (thick and thin-skinned melons). In addition, the sub-cluster analysis based on SSR markers partitioned different botanical groups, even separating similar agronomic trait groups (Xinjiang landraces var. ameri and var. inodorus). SSR analysis showed that 4 SSR markers (CMBR150, CMCTT144, CMBR84 and CMBR12) produced polymorphic bands of different sizes between these two botanical groups. Those four molecular markers might be related to melon fruit maturing time. A considerably low level of genetic diversity was detected in Xinjiang melon accessions. Genetic distances indicated the relatively narrower genetic base but specific taxonomic status of Xinjiang landraces compared with foreign reference accessions.     

Genetic diversity analysis of Perinereis aibuhitensis based on ISSR and SRAP markers of Chinese coast populations

The objective of this study was to obtain an overview of the genetic relationships within Perinereis aibuhitensis using Inter-Simple Sequence Repeat (ISSR) and Sequence-Related Amplified Polymorphism (SRAP) markers that were derived from related populations residing in the Chinese coasts. The percentage of polymorphic bands, Nei's gene diversity and Shannon's information index revealed a high level of genetic diversity at the species level. The analysis of molecular variance revealed that 81.22% (ISSR) and 76.29% (SRAP) of variability were partitioned among individuals within populations, which indicated the coherent trend by Nei's genetic differentiation (Gst) (0.2568/0.2876). The gene flow number (Nm) was 1.4470/1.2385, which indicated that there was limited gene exchange between populations. The phylogenetic tree of the ten P. aibuhitensis populations was separated into four major clusters using the neighbor-joining (NJ) method. These results provide a simple and useful basis for P. aibuhitensis germplasm research and aquaculture breeding.     

Genetic diversity and genetic relationships in Hyacinthaceae in India using RAPD and SRAP markers

Genetic diversity and relationship among three genera namely Drimia, Dipcadi and Ledebouria of Hyacinthaceae in India was studied using RAPD and SRAP markers. Twenty one RAPD primers and nine SRAP were used for analyzing 41 accessions. RAPD gave an average 12.6 markers per primer, while SRAP generated 10.1 markers per primer pair. The family emerged very diverged with high polymorphism. The study resolved the three genera into monophyletic groups corresponding to three subfamilies; Urginoideae, Hyacinthoideae and Ornithogaloideae. Drimia wightii emerged a very distinct species and species specific markers were obtained with both marker systems. AMOVA analysis also revealed the genera to be quite well diverged. The two markers showed high correlation (r = 0.932) in Mantel matrix crresspondance test. The combined data also showed a very good correlation with the respective markers individually.     

中国半夏属植物亲缘关系的SRAP分析

利用序列相关扩增多态性(SRAP)标记对中国半夏属植物5个种的亲缘关系进行了研究.38个引物组合在半夏属植物的5个种中共扩增出752条清晰的谱带,其中628条谱带具有多态性,多态性比率为83.51％,显示出较高的多态性比率;各物种间的遗传相似系数在0.6513～0.7312之间,聚类分析和主坐标分析结果表明,5种半夏属植物被聚为两大类:掌叶半夏单独聚为一类(Ⅱ),而其它4个种聚为一类(Ⅰ).第Ⅰ类可再分为A和B两个亚类:A亚类包括半夏和石蜘蛛;B亚类包括盾叶半夏和滴水珠.滴水珠和盾叶半夏的亲缘关系最近,其次是半夏和石蜘蛛,而掌叶半夏和其它4个种的亲缘关系都较远,这说明掌叶半夏与半夏属其它种呈姐妹群关系.本研究结果对我国半夏属植物资源的开发利用与保护具有重要意义.     

利用SRAP标记研究四川高原青稞育成品种的遗传多样性

利用SRAP(Sequence-related Amplified Polymorphism)分子标记技术, 对25份来自四川高原的青稞育成品种进行了遗传多样性研究。结果表明: 64对引物组合共检测出999条清晰条带, 62对可以获得多态性条带, 多态性引物组合占96.9%, 共产生225条多态性条带, 占总条带数的22.5%。64对引物组合共扩增出333种等位变异, 平均每个引物组合检测到5.20种等位变异。遗传多样性在0(me9/em14, me9/em15)~0.8928(me6/em18)之间, 平均为0.5126。聚类分析结果表明, 25份材料可分成A、B、C 3大类, 材料聚类与其来源地有明显的相关性。25份材料间的平均遗传距离较小(0.3240), 平均遗传多样性较低(0.5126), 遗传基础较为狭窄。     

Genetic diversity and structure among natural populations of Sindora glabra in Hainan Island,China as revealed by ISSR markers

Sindora glabra, one of the second-class national protective plants in China, has important ecological and commercial values. To understand the genetic diversity and structure of S. glabra, eleven natural populations from four areas of Hainan Island in China were analyzed by inter-simple sequence repeat (ISSR) markers. Thirteen primers were screened out and used to amplify 157 DNA samples. A total of 122 bands were obtained, among which 114 (93.4%) bands were polymorphic. Genetic parameters including average number of effective alleles (1.547), Nei's gene diversity (0.321), Shannon's information index (0.482), and gene differentiation coefficient (0.1944) revealed a high level of genetic diversity maintained in S. glabra populations. The variation within populations accounted for 85.6% of total variation based on analysis of molecular variance. Genetic distance analysis showed that 11 populations could be divided into three groups and populations from the same areas were classified as one group, suggesting that high genetic diversity of S. glabra was attributable to geographic isolation. Together, introduction of germplasm from distant natural distribution areas would be a sound strategy for germplasm resource conservation of S. glabra and selection of elite individuals from populations of far relationship for hybridization is of great importance for breeding improvement programs in future.     

蓖麻品种遗传多样性与亲缘关系的SRAP分析

利用SRAP技术对81份蓖麻品种材料亲缘关系进行了分析,实验选用20对SRAP引物组合,在81份蓖麻材料中共扩增出263条带,多态性条带计214条,多态性条带比率（PPB）为81.37%,遗传相似系数变幅范围在0.32558～0.92973,显示了蓖麻品种的遗传多样性较丰富。从分子聚类结果分析表明,在相异系数0.43为阈值时,可将81份蓖麻材料分为4个类群L1-1、L1-2、L1-3和L1-4;若在相异系数0.287为阈值时,又可将L1-4大类群分为两个亚类群L2-1和L2-2。从聚类图得知,聚在同一亚类群的蓖麻品种大多数所处的地域相近或者是由同一育种单位所选育,其类内的品种基因型遗传相似系数较高,类间的品种遗传差异相对较大,该分子聚类树状图可为蓖麻栽培种种质资源遗传多样性与亲缘关系在育种的利用上提供科学依据。     

Genetic diversity and population structure of Opisthopappus longilobus and Opisthopappus taihangensis (Asteraceae) in China determined using sequence related amplified polymorphism markers

The genetic diversity and structure of four Opisthopappus longilobus and nine Opisthopappus taihangensis populations from Mts. Taihang were analyzed using SRAP markers. The results showed that O. longilobus (PPB = 95.16%, H = 0.349, I = 0.517) and O. taihangensis populations (PPB = 94.58%, H = 0.332, I = 0.504) had high genetic diversity. The genetic diversity within populations varied according to two species. Low genetic differentiation was detected among O. longilobus (Φ_ST = 0.105) and O. taihangensis (Φ_ST = 0.188) populations, respectively. Significantly genetic variation was found between O. longilobus and O. taihangensis (Φ_ST = 0.232). The dendrogram generated from pairwise genetic distance among all populations showed two distinct clusters, each corresponding to one species. A Mantel test revealed insignificant positive correlation between genetic distances and geographic distances (r_{O. longilobus} = 0.3021; r_{O. taihangensis} = 0.3658; P > 0.05). Those results indicated that self-compatibility, effective gene flow, biological traits, and historical factors may be the main factors causing geographical differentiation in the structure of O. longilobus and O. taihangensis populations.     

Genetic diversity assessment of a germplasm collection of Salvia miltiorrhiza Bunge. based on morphology,ISSR and SRAP markers

Salvia miltiorrhiza is one of the most important traditional Chinese medicinal plants for its therapeutic effects. In the present study, morphological traits, ISSR (inter-simple sequence related) and SRAP (sequence-related amplified polymorphism) markers were used to analyze the genetic diversity of 59 S. miltiorrhiza phenotypes. Out of the 100 ISSR primers and 100 SRAP primer combinations screened, 13 ISSRs and 7 SRAPs were exploited to evaluate the level of polymorphism and discriminating capacity. The results showed that the 13 ISSRs generated 190 repeatable amplified bands, of which 177 (93.2%) were polymorphic, with an average of 13.6 polymorphic fragments per primer. The 7 SRAPs produced 286 repeatable amplified bands, of which 266 (93.4%) were polymorphic, with an average of 38.1 polymorphic fragments per primer. Cluster analysis readily separated different morphological accessions, wild and cultivated controls based on morphological traits, ISSR and SRAP markers. The study indicated that morphological traits, ISSR and SRAP markers were reliable and effective for assessing the genetic diversity of phenotypic S. miltiorrhiza accessions. The overall results suggested that the introduction of genetic variation from morphology-based germplasms enlarged the genetic base for the collection, conservation and further breeding program of S. miltiorrhiza germplasm.     

Analysis of diversity and relationships among Chinese orchid cultivars using EST-SSR markers

Chinese orchid (Cymbidium spp.) is an important potted flower with extremely high ornamental value in China. It is important to identify the genetic diversity of its germ plasma resources for development and evaluation of its cultivars. A set of 13 expressed sequence tag (EST)-derived simple sequence repeat (SSR) was used to analyze 103 cultivars of six species of Chinese orchid, namely Cymbidium goeringii, C. faberi, Cymbidium ensifolium, C. kanran, C. sinense and C. goeringii var. longibracteatum. The 13 SSR primer pairs generated a total of 168 polymorphic bands, with an average of 12.92 bands per primer and a range of 6–24 bands which clearly revealed the difference between cultivars inter- or intra-species of Chinese orchid. Cluster analysis based on UPGMA, NJ and PCoA method showed a dendrogram with three basic clusters and splitting feature of C. ensifolium and C. goeringii which partially congruent with the current taxonomic classification.