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1.
Genetic variations and relationships among cultivated and wild genotypes of five taxa of Indian Luffa were examined using inter simple sequence repeats (ISSR), directed amplification of minisatellite DNA (DAMD) markers and morphological characterization. Morphometric evaluation of 21 discrete characters in 51 representative accessions segregated the five taxa of Luffa in three main clusters: the two wild species (L. echinata, L. graveolens) in the first, and the cultivated L. aegyptiaca (smooth gourd) and L. acutangula (ridged gourd)/L. hermaphrodita (Hermaphrodite luffa) in the second and third clusters, respectively. Cumulative data analysis of 15 ISSR and seven DAMD markers revealed high percentage polymorphism (97.67 %), moderate genetic distance (0.06–0.72, avg. 0.51), and low heterozygosity and Shannon index values (H = 0.15; I = 0.22) across all the 76 genotypes assayed. A UPGMA dendrogram, based on the combined marker data, resolved the five taxa in two main clusters with high bootstrap support. The morphological and molecular trees showed incongruence in the number of main clusters resolved and in the disposition of the wild and cultivated taxa in different sub-clusters. The cluster analyses and PCoA plots revealed a nested grouping of the hermaphrodite luffa within the ridge gourd group. The Bayesian STRUCTURE analysis identified three genetic clusters for the five assumed taxa. Outcrossing test revealed a mixed mating system in Indian Luffa. This is the first ever report on the mating system in Luffa using molecular markers. The study also demonstrates the utility of using more than one DNA marker in the assessment of molecular diversity in a widely cultivated crop genus like Luffa with a narrow genetic base.  相似文献   

2.
Western Ghats, one of the megadiversity hotspots, hold a rich treasure of diversity in Momordica L. comprising M. charantia var. muricata, M. charantia var. charantia, M. dioica and M. sahyadrica. Vernacular names of these species vary from place to place. Traditional uses of these species comprising food, medicinal and cosmetic, culinary preparations, vernacular names in local dialects and taboos and religious beliefs relating to their domestication and folk taxonomy are dealt with in this paper.  相似文献   

3.
Solanum trilobatum L. is an Indian medicinal plant containing rich amount of steroidal glyco-alkoloids that can be used as precursor for commercial steroid production. Two efficient marker systems such as Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeats (ISSR) were used for the first time to assess the genetic diversity across 14 S. trilobatum accessions obtained from five South Indian states. Twenty out of 60 RAPD primers generated 189 distinct bands of which 160 were polymorphic with an average of 8 polymorphic bands per primer. A maximum of up to 15 fragments were amplified with an average of 9.45 bands per primer and the amplicons varied in size between 100 and 3,000 bp. The percentage of polymorphism ranged from 55.5 to 100, with an average of 84.6. ISSR profiling using 7 out of 20 primers amplified 83 bands and the number of amplified fragments varied from 2 to 16 with a size range of 200–1,800 bp. Totally 72 polymorphic bands were obtained using 7 ISSR primers at an average of 10.28 polymorphic bands per primer. Polymorphism percentage varied from 50 to 100 among the selected accessions resulting in an average percentage of polymorphism of 86.7. The PIC values ranged from 0.49 to 0.93 for RAPD and 0.16 to 0.90 for ISSR primers. The study pointed out that ISSR markers were more efficient than RAPD markers in evaluating the degree of genetic variation in S. trilobatum. The UPGMA cluster analysis grouped all Tamil Nadu accessions in one cluster and other state accessions in another cluster. The Principal component analysis also substantiates this clustering pattern. Thus the phylogenetic relationship and a high genetic variation revealed in the present study could provide a baseline data for conservation and improvement of this plant in future. Also the molecular markers identified in this study will be helpful in authentication of this species to prevent adulteration in herbal medicine.  相似文献   

4.
Yam (Dioscorea spp.) is widely cultivated in China and many landraces are maintained by local farmers. However, there is little information available about their diversity and species identity. In this study, inter simple sequence repeat (ISSR) and sequence related amplified polymorphism (SRAP) techniques were used to assess genetic diversity within 21 yam landraces from seven cultivated populations. We observed high level of polymorphism among these landraces, specifically, 95.3 % for ISSR and 93.5 % for SRAP. Analysis of molecular variance revealed a significantly greater variation among the four yam species (40.39 %) and their populations (35.78 %) than within the populations (23.83 %). The unweighted pair group method arithmetic averages clusters and principal component analysis for 21 landraces formed four well-separated groups containing landraces of each of the four species, namely, Dioscorea opposita Thunb., Dioscorea alata L., Dioscorea persimilis Prain et Burkill, and Dioscorea fordii Prain et Burkill. The ISSR and SRAP primers were highly discriminatory among the 21 landraces; all 21 landraces could be easily differentiated using these primers. The average mean of gene flow (Nm = 0.1081) estimated from high genetic differentiation (Gst = 0.8222) suggested that gene flow among the populations was relatively restricted. The lack of genetic diversity within individual yam species suggests that it is critical to develop long-term strategies for enhancing genetic diversity within various yam species.  相似文献   

5.
Nepenthes khasiana Hook. f. belonging to monotypic family Nepenthaceae is a rare, endangered, dioecious member of the carnivorous plant found in North-East India. The plant is endemic to the Indian state of Meghalaya and is distributed throughout the state from West Khasi hills to East Khasi hills, Jaintia hills and East, West to South Garo hills from 1,000 to ca. 1,500 m altitude. Multi-locus analysis using PCR based Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeats (ISSR) markers were used for the first time to assess the genetic diversities of N. khasiana Hook. f. collected from different parts of Meghalaya. It was observed that RAPD analysis showed more polymorphism than ISSR fingerprinting in revealing genetic polymorphism in N. khasiana Hook. f. The result of cluster analysis by using UPGMA method showed that the groups based on pooled RAPD–ISSR genetic similarity were more similar than the groups based on RAPD. Furthermore, genetic similarity reveals variability within the population at Jarain of Jaintia hills, while between populations the Baghmara region differs from the others with at least 40% dissimilarity. The results show a broad range of genetic diversity within the populations of N. khasiana Hook. f.  相似文献   

6.
Wild species of safflower, Carthamus oxyacanthus Bieb., is highly crossable with cultivated species, C. tinctorius L. and could be directly exploited in broadening safflower gene pool and improving the crop for biotic and abiotic stress environments. In this study, genetic diversity among accessions of C. oxyacanthus and their relationships with cultivated safflower were evaluated using agro-morphological traits and polymorphic inter-simple sequence repeats (ISSR) markers. Significant variation was observed among accessions particularly for seeds per capitulum, seed yield per plant, harvest index and capitula per plant. Cluster analysis based on agro-morphological traits classified the wild accessions in two groups according to their geographical regions, and separated them from the cultivated genotypes. ISSR marker also revealed a high genetic variation among the accessions, and cluster analysis based on this marker divided genotypes into four groups, with cultivated ones in a separate clade. Genetic variation observed among the wild safflower germplasm at the DNA level was higher than the agro-morphological traits, indicating that ISSR is an effective marker system for detecting diversity among safflower genotypes and their genetic relationships. Accessions of C. oxyacanthus with high genetic relationship to cultivated species could be used for interspecific hybridization in breeding programs of safflower.  相似文献   

7.
Immature fruits of cultivated species of Luffa are commonly used as summer vegetable in India. Rich morphological variability occurs in cultivated species of Luffa in different growing regions of the country. To study morphological variability in cultivated and wild Luffa from different agro-ecological regions of India, a total of seventy accessions were assembled. Morphological variations in leaf, fruit and seed characters were found to delimit cultivated and wild Luffa species. Cluster analysis revealed two major clusters, one comprising of 36 accessions of Luffa acutangula and the other of 30 accessions belonging to L. aegyptiaca. A local cultivar “Satputia” (L. hermaphrodita) was classified along with cultivated L. acutangula and wild L. acutangula var. amara. Wild species namely L. graveolens and L. echinata were clustered closer to the L. acutangula.  相似文献   

8.
Genetic diversity is an area of concern for sustaining crop yield. Information on genetic relatedness/diversity among Gossypium arboreum L. cultivars/genotypes is scanty. We have used random amplified polymorphic DNA (RAPD) analysis to assess the genetic divergence/relationship among 30 genotypes/cultivars of G. arboreum. Of 45 primers surveyed, 63% were polymorphic. Out of the total number of loci amplified, 36% were polymorphic. The calculated genetic similarity between the cultivars/genotypes was in the range of 47.05–98.73%. Two genotypes, HK-244 and Entry-17, were the most distantly related. The average genetic relatedness among all the genotypes was 80.46%. However, most of the cultivated varieties showed a close genetic relationship, indicating a narrow genetic base in comparison to the non-cultivated germplasm. The calculated coefficients were used to construct a dendrogram using the unweighted pair group of arithmetic means (UPGMA) algorithm, which grouped the genotypes/cultivars into two major and three smaller clusters. The study is the first comprehensive analysis of the genetic diversity of G. arboreum germplasm and identifies cultivars that will be useful in extending the genetic diversity of cultivated varieties and future genome mapping projects.  相似文献   

9.
The genetic diversity of taro (Colocasia esculenta (L.) Schott.) accessions growing naturally in Andaman Islands was analysed using morphological and DNA markers. Twenty one representative samples of C. esculenta from different parts of Islands in addition to three commercial varieties as reference genotypes were used in study. About 63% phenotypic variation was observed in C. esculenta A total number of 491 amplified fragments were obtained of which 347 showed polymorphic banding patterns. The accessions were grouped into two major clusters with both RAPD and ISSR markers with 56 and 57% diversity, respectively. The reference genotypes were grouped into one group and island population in other cluster. Both marker systems divided population into two sub clusters and showed correlation with morphological parameters. The diversity pattern observed in present study showed rich genetic diversity of C. esculenta in Andaman Islands provided simple strategy for reducing repeatability of taro germplasm in gene banks. The study also suggested pre-evaluation of germplasm using molecular and morphological markers to enhance efficiency of exploration trips.  相似文献   

10.
This study characterized the genetic diversity of 18 Tunisian fig cultivars using random amplified polymorphic DNA (RAPD) and inter simple sequence repeats (ISSR). Both random and ISSR primers tested generated a total of 116 RAPD and 47 ISSR markers. Considerable genetic variation was observed among fig cultivars sampled from two regional Tunisian collections with an average diversity of 4.57. RAPD and ISSR banding patterns and genetic distances values reflected the high level of diversity among the collections and lower variability between the two collections. The correlation between the RAPD and ISSR similarity matrices computed for the 153 pairwise comparisons among the 18 varieties was lower and significant. An analysis of molecular variance showed that 92% of the total genetic diversity resided within collections, whereas only 8% between collections. The results indicated that in the local fig germ plasm the information provided by RAPD and ISSR is not analogous, most likely as a consequence of the fact that the two classes of markers explore, at least in part, different portions of the genome.  相似文献   

11.
Dioscorea trifida L. (Dioscoreaceae) is among the economically most important cultivated Amerindian yam species, whose origin and domestication are still unresolved issues. In order to estimate the genetic diversity maintained by traditional farmers in Brazil, 53 accessions of D. trifida from 11 municipalities in the states of São Paulo, Santa Catarina, Mato Grosso and Amazonas were characterized on the basis of eight Simple Sequence Repeats (SSR) and 16 Inter Simple Sequence Repeats (ISSR) markers. The level of polymorphism among the accessions was high, 95 % for SSR and 75.8 % for ISSR. The SSR marker showed higher discrimination power among accessions compared to ISSR, with D parameter values of 0.79 and 0.44, respectively. Although SSR and ISSR markers led to dendrograms with different topologies, both separated the accessions into three main groups: I—Ubatuba-SP; II—Iguape-SP and Santa Catarina; and III—Mato Grosso. The accessions from Amazonas State were classified in group II with SSR and in a separate group with ISSR. Bayesian and principal coordinate analyzes conducted with both molecular markers corroborated the classification into three main groups. Higher variation was found within groups in the AMOVA analysis for both markers (66.5 and 60.6 % for ISSR and SSR, respectively), and higher Shannon diversity index was found for group II with SSR. Significant but low correlations were found between genetic and geographic distances (r = 0.08; p = 0.0007 for SSR and r = 0.16; p = 0.0002 for ISSR). Therefore, results from both markers showed a slight spatially structured genetic diversity in D. trifida accessions maintained by small traditional farmers in Brazil.  相似文献   

12.
Nineteen fig varieties and lines from Europe and Asia have been fingerprinted by ISSR, RAPD, and SSR markers, respectively, using 13, 19, and 13 primer combinations. All primers produced 258 loci, with the highest number of loci (119) generated by RAPD (R p: 48.42). Clustering analysis was applied to the three marker datasets to elucidate the genetic structure and relationships among these varieties. Mean genetic similarities were 0.787, 0.717, and 0.749, respectively, as determined using ISSR, RAPD, and SSR. Each marker system produced incompletely separated clusters, although a weak binding group based on race type appeared in the combined dataset. Comparisons of coefficients revealed no correlation between different similarity matrices; congruence was observed between similarity matrices and co-phenetic matrices in all markers. Analysis of molecular variance (AMOVA) showed that most of the total polymorphism was attributable to within-group variance (ISSRs + RAPDs, 97.41%; SSRs, 90.18%). These results suggest that the genetic diversity of this fig population is low and that multiple marker utilization is critical to estimate the relatedness of figs at the variety level. Additionally, it was presumed that ‘Houraihi’, the oldest variety in Japan, was disseminated independently of other foreign varieties in the 17th century or before then.  相似文献   

13.
Randomly amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) and a semi-random PCR system were used to analyze the genetic diversity of 16 Italian common bean landraces and their relationship to four commercial cultivars. Of the primers tested, 8 ISSR, 6 RAPD and 7 semi-random primers produced polymorphic and reproducible DNA fragments. A higher proportion of polymorphic bands were observed using ISSR (85%) and semi-random (90%) primers than RAPD (69%) method. The combination of any two semi-random markers allowed the identification of all 20 bean genotypes. In contrast ISSR (except for primer (CAC)3GC) and RAPD markers appeared to be less informative as more than two markers were necessary to achieve the same diagnostic level. Moreover, 7 ISSR, 2 RAPD and 8 semi-random exclusive bands were identified as putative population-specific markers. Semi-random and ISSR derived dendrograms showed similar tendencies in terms of genetic relatedness, whereas clustering of genotypes within groups was not similar when compared with the RAPD technique. Despite the different ability to resolve genetic variation among the investigated landraces, two major clusters with less than 60% (ISSR) and 40% (RAPD and semi-random) genetic similarity were formed with all three marker systems. The two groups were correlated with the phaseolin patterns and seed size of the landraces. The analysis showed that the cultivar ȁ8Lingua di Fuocoȁ9 and most of the landraces (13 out of 16) collected in Italy belong to the Andean gene pool, whereas only the three populations from Pratomagno belong to the Middle American gene pool.  相似文献   

14.
The present study was performed to investigate genetic diversity of Kenyan landraces of the white-flowered gourd (Lagenaria siceraria), which exhibits tremendous morphological variation. RAPD analyses were performed on 53 landraces of the cultivated species L. siceraria and 42 accessions of three wild species (40 L. sphaerica, 1 L. abyssinica, and 1 L. breviflora). A total of 432 polymorphic bands were detected using 54 primers. The four species were clearly differentiated from one another. Intra-specific variations were investigated with L. siceraria and its wild relative L. sphaerica. Landraces of the cultivated species collected from different ethnic communities or regions were differentiated. Morphological variations were not associated with RAPD variations. Bitter landraces collected in Maasai communities showed two specific RAPD bands. In the wild species, accessions collected from the eastern and western sides of the Great Rift Valley were genetically differentiated from each other. In both species, genetic and geographical distance matrices computed among all pairs of accessions were significantly correlated, implying that the observed geographical variation can be explained by the 'Isolation by distance model'. Progeny plants derived from a common mother in L. siceraria showed a low level of segregation in RAPD pattern, suggesting that collected landraces are cultivated, maintaining their inherent traits although they are monoecious and insect-pollinated, whereas the wild relative L. sphaerica showed a higher level of segregation. The morphological diversity observed among landraces of L. siceraria is the result of human selection and their genetic identities are maintained by inbreeding probably resulting from frequent self-pollination.  相似文献   

15.
A total of 561 amplified fragment length polymorphism (AFLP) loci were generated and used to study the genetic diversity of wild and cultivated genotypes of pigeonpea. Out of 561 marker loci, 558 were polymorphic with an average of 76.12 bands. Analysis of molecular variation (AMOVA) revealed significant strong population structure when genotypes were structured according to continent of origin (FST = 0.22) also when structured into cultivated and wild genotypes (FST = 0.16). Maximum polymorphic loci were observed in cultivated species C. cajan (352) which is due to more number of genotypes used while, a minimum number of 45 polymorphic bands were obtained in C. acutifolius. Highest (0.291) average gene diversity was recorded in species C. mollis and lowest (0.079) average gene diversity was recorded in C. acutifolius. The 33 genotypes grouped into 14 clusters at 26% Jaccard’s similarity coefficients. Clustering analysis revealed most cultivated genotypes grouped into one major cluster while, the wild genotypes grouped into many clusters at 26% Jaccard’s similarity revealing greater diversity within wild species as compared to cultivated genotypes. From among the various cultivated genotypes studied, four genotypes BRG 3, ICP 7035, TTB 7 and ICP 8863 were molecularly and morphologically diverse and were used as parental genotypes to study nature of inheritance and to identify markers linked to sterility mosaic disease.  相似文献   

16.
Little is known about the genetic diversity of pale flax (Linum bienne Mill.), the wild progenitor of cultivated flax (L. usitatissimum L.), and ex situ germplasm of pale flax was scarce. Effort was made to collect 34 pale flax accessions and five landrace accessions of cultivated flax in Turkey. The inter simple sequence repeat (ISSR) technique was applied to characterize this set of flax germplasm, along with one Turkish cultivar, one Russian cultivar, five winter and four dehiscent type accessions of cultivated flax. Twenty-four ISSR primer pairs detected a total of 311 DNA fragments, of which 298 bands were polymorphic across 493 flax samples (roughly 10 samples per accession). These polymorphic bands had frequencies ranging from 0.002 to 0.998 and averaging 0.38. Accession-specific ISSR variation (Fst values) ranged from 0.469 to 0.514 and averaged 0.493. There was 49.3% ISSR variation resided among these 50 accessions, 35.9% harbored among landrace, winter, dehiscent types of cultivated flax and pale flax, and 38.2% present among 34 pale flax accessions. Pale flax displayed more ISSR variation than landraces and dehiscent type, but less than winter type, of cultivated flax. Clustering 493 individual plants revealed that these assayed plants were largely grouped according to their plant types and that pale flax was genetically more close to the dehiscent type, followed by the winter type and landrace, of cultivated flax. Pale flax collected within the geographic range of 180 km displayed a significant spatial genetic autocorrelation. Genetic distances among the pale flax accessions were significantly associated with their geographic distances and elevation differences. These findings are significant for understanding flax domestication and its primary gene pool.  相似文献   

17.
Substantial progress was made in the last decade in understanding the diversity in Dioscorea species. However, most of the studies so far concentrated in the ‘yam belt in Africa’. We present a genetic diversity and structure analysis among commercial and local varieties of water yam (Dioscorea alata L.) in Brazil using microsatellite and morphological markers. Twelve microsatellite primers were used to generate DNA profiles of 72 local varieties and 17 commercial accessions of water yam collected in four different regions in Brazil. Also, four morphological traits were evaluated on individual plants under field conditions. The morphological characterization showed considerable diversity. High polymorphism was found with 100 % polymorphism observed for 11 primers and a discriminating power value of 0.92, on average. We did not observe a strong population structure among sampling regions, while most of the genetic diversity was concentrated within regions (95.9 %). Analysis of the relationship between accessions did not clearly separate the local and commercial genotypes. However, the molecular analyses of D. alata showed high intraspecific diversity in local accessions from different regions in Brazil, with the highest Shannon index value (H′ = 0.41) for the Southeast region. These results confirmed an admixture of accessions in all sampling regions, consistent with the lack of a significant correlation between geographic and genetic distances, suggesting that farmers exchanged water yam materials extensively. The genetic diversity can be explained by the result of a continuous exchange of accessions by farmers throughout Brazil.  相似文献   

18.
Sesame (Sesamum indicum L.) is a traditional oil crop cultivated throughout South East Asia. To estimate the genetic diversity of this crop in parts at the region, 22 sesame accessions collected in Vietnam and Cambodia were analyzed using 10 RAPD markers. The 10 primers generated 107 amplification products of which 88 were polymorphic fragments (83%). Genetic diversity of all populations was Ht = 0.34 when estimated by Nei’s genetic diversity and species diversity was H′sp = 0.513 when estimated by Shannon diversity index. Genetic distance ranged from 0.03 to 0.43, with a mean genetic distance of 0.23. The unweighted pair group method with arithmetic averages (UPGMA) cluster analysis for the 22 accessions divided the material in four groups. The dendrogram revealed a clear division among the sesame accessions based on their geographical region. Interestingly, some geographically distant accessions clustered in the same group, which might indicate the human factor involved in the spreading of sesame varieties. The high level of polymorphism shown suggests that RAPD techniques can also be useful for the selection of parents in sesame (Sesamum indicum L.) breeding program and for cultivar differentiation.  相似文献   

19.
Summary Genetic diversity and patterns of geographic variation among collections of Paspalum scrobiculatum (kodo millet) and P. polystachyum were studied using molecular markers generated through the random amplified polymorphic DNA (RAPD) method. A high level of polymorphism in RAPD markers was observed among the individual accessions, demonstrating the high genetic diversity of the crop. The markers obtained from the RAPD method were analyzed with the cluster analysis, principal coordinates and minimum spanning tree methods. Three major groups were resolved, one representing the African accessions, and two for the Indian accessions. The accessions of the north African kodo millet and P. polystachyum (considered conspecific with P. scrobiculatum) were quite distinct. The Australian kodo millet showed higher affinity to the African types. The study demonstrated that the RAPD technique can be applied to resolving degrees and patterns of genetic variation at the population and species levels, identifying cultivars, and defining gene pools of this crop.  相似文献   

20.
In order to evaluate the genetic diversity in Lathyrus genus, the Inter Simple Sequence Repeats method (ISSR) was exploited in five populations. These consisted of two cultivated species belonging to section Lathyrus (L. sativus L. and L. cicera L.) and a wild one belonging to the section Clymenum (L. ochrus DC.). Two 3′anchored ISSR primers and two unanchored ones, generated a total of 60 useful polymorphic DNA bands. Our data provide evidence of high molecular polymorphism at the intra- and the inter-specific levels showing that both wild and cultivated forms constitute an important pool of diversity. Moreover, among the generated DNA bands, a 500 bp band, totally absent in the banding patterns of the section Clymenum, appears to be a molecular marker of section Lathyrus. Results provided for lineage and suggest recent origin of these species that might have evolved from a common ancestor producing both L. ochrus species and the two other species L. sativus and L. cicera. These relationships support previous studies based on morphological variation and molecular analysis.  相似文献   

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