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1.
The genetic diversity of the genus Dendrobium is not well known and the phylogenetic relationship of Dendrobium species are mainly determined by studies of the comparative vegetative anatomy and plant systematics. In the present study, we used the technique of inter-simple sequence repeats (ISSRs) to evaluate genetic diversity and phylogenetic relationship among 31 Dendrobium species from Yunnan region of China. In total, 2368 bands were amplified by 17 ISSR primers, resulting from 278 ISSR loci with 100% polymorphism at genus level. Thirty-one species were unequivocally distinguished based on ISSR fingerprinting. Species-specific ISSR markers were identified in nine of 31 tested Dendrobium species. Unweighted pair-group mean analysis (UPGMA) showed that 31 Dendrobium species were grouped into six clusters, indicating the genus was polyphyletic with several well-supported lineages. The high polymorphism and reliable amplification across species demonstrated the utility of ISSR marker for species diagnosis and genetic diversity study of the genus Dendrobium.  相似文献   

2.
In this study, the genetic diversity of 50 individuals of rocket, Eruca vesicaria, from five accessions, four of them wild type collected from different parts of Spain and one commercial, were evaluated using morphological, agronomical and inter simple sequence repeat DNA (ISSR) data. Molecular analysis was carried out using the ISSR technique with 20 primers. Out of these 20 primers, nine were polymorphic, producing a total of 395 DNA bands, 247 of which were polymorphic among the accessions. A dendrogram drawn on the basis of a similarity matrix using the UPGMA algorithm revealed that the 50 samples of rocket plants could be classified into three major clusters at a Nei's genetic distance of 0.36. The experiment shows that molecular markers such as ISSR are a good instrument for distinguishing and selecting rocket accessions to group different wild populations. In general, a high variation was observed for most of the 16 morphological and 6 agronomical traits showing significant differences. Some morphological traits such as leaf length, petiole length and lamina width explained 69.1% of the whole variation observed in the populations, and some agronomical traits such as leaf area, nitrate and chlorophyll contents accounted for 65.7%, but the clusters generated by means of agronomical and morphological variables were less evident than when ISSR markers used. Some accessions showed good qualities, such as small leaves, high chlorophyll content, late-flowering or low nitrate content. All these parameters, together with the high degree of genetic homogeneity found, could make the local accessions good candidates for a future breeding programme.  相似文献   

3.
Field performance and molecular diversification of lemon selections   总被引：1，自引：1，他引：0  
Lemon (Citrus limon (L.) Burm. f.) is one of the most important Citrus fruit for Turkey because of its great amount of production and export. It has been cultivated for a long time in Turkey, and therefore variations for agronomical traits are likely among cultivated lemons due to bud mutations and, hybridizations. The objectives of this study were to determine variations for some selected agronomical traits and genetic markers among 12 new lemons derived from selections. Tree growth, yield, fruit quality, and molecular diversification of these clones were determined. After four years of evaluation, ‘Kutdiken’ M-51 indicated the highest canopy volume. For yield per tree, the best clone was ‘Kutdiken’ M-51. After five years of evaluation, ‘Kibris’ M-54 had the highest fruit weight and acidity. ‘Italian Memeli’ M-56 contained the lowest seed number and the highest total soluble solids. Molecular analysis, as assessed with 22 random amplification of polymorphic DNA (RAPD) and 11 inter simple sequence repeats (ISSR) primers, indicated that seven of twelve clones were separated with RAPD markers, whereas four were distinguished with ISSR markers. Combined analysis of RAPD and ISSR data detected that similarity values among the lemons clones were between 0.97 and 1.00. It can be concluded that variations in orchards are abundant and mainly due to mutations.  相似文献   

4.
Rosa L. taxa are dominantly used for horticulture, food, medicinal, ornamental and aesthetic purposes. Rosa is represented with approximately 200 wild species in the world. The number of natural Rosa species in Turkey is reported as about 31. Rosa species are widely distributed in all regions in Turkey. In this study, RAPD and ISSR markers were applied to assess genetic diversity and genetic relationships among 27 species of Rosa. The UPGMA cluster was constructed using a combination of data from RAPD and ISSR markers. The dendrogram revealed two main clusters. Each cluster was divided into subgroups. This investigation showed that genetic distance was relatively significant among the species. As the results of the study close genetic relationships were found between evolutionary relations, morphplogical properties, and phytogeographical distributions of the Rosa species, The results also propose that RAPD and ISSR markers are useful tools for indicating genetic relationships among Rosa genotypes.  相似文献   

5.
True-to-type clonal fidelity is one of the most important pre-requisites in micropropagation of crop species. Genetic fidelity of in vitro raised 45 plants of gerbera (Gerbera jamesonii Bolus) derived from three different explants, viz., capitulum, leaf and shoot tips, was assessed by 32 ISSR markers, for their genetic stability. Out of 32 ISSR markers, 15 markers produced clear, distinct and scorable bands with an average of 5.47 bands per marker. The markers designed from AG motif amplified more number of bands. The markers anchored at 3′ ends produced high number of consistent bands than unanchored markers. Fifteen ISSR markers generated a total of 3773 bands, out of which 3770 were monomorphic among all the clones. The Jaccard's similarity coefficient revealed that out of 45 clones derived from different explants, 44 were grouped into a single large cluster alongwith the mother plant with a similarity coefficient value of 1.00, whereas one clone (C38) remained ungrouped. The clones derived from capitulum and shoot tip explants did not show any genetic variation, whereas, one of the leaf-derived clones exhibited some degree of variation.  相似文献   

6.
Genetic diversity and relatedness of 23 yardlong bean (Vigna unguiculata spp. sesquipedalis) accessions and 7 accessions of a hybrid between cowpea (V. unguiculata spp. unguiculata) and yardlong bean (dwarf yardlong bean) in Thailand were estimated using morphological characters, simple sequence repeat (SSR) and inter-simple sequence repeat (ISSR) markers. In addition, two mungbean (Vignaradiata (L.) Wilczek) and two blackgram (Vigna mungo (L.) Hepper) accessions were also used as outgroup species for molecular analysis. Five morphological characters were diverse among most accessions. However, five groups of 2–3 accessions could not be distinguished from one another based on these morphological characters alone. Unweighted pair-group arithmetic average (UPGMA) analysis of these characters separated these 30 accessions into 2 major groups; the yardlong bean group and the dwarf yardlong bean group. Eleven of the sixteen SSR primers yielded clear SSRs, ten of which were polymorphic (90.91% polymorphism), detecting a total of 54 alleles with an average of 4.91 alleles per locus. These 10 polymorphic SSR markers successfully distinguished 28 yardlong bean and dwarf yardlong bean accessions. The polymorphic information content (PIC) among genotypes varied from 0.251 to 0.752 with an average of 0.597. Among the 16 ISSR primers used, a total of 312 ISSR fragments were amplified for these three Vigna species, revealing the polymorphism percentage of 91.03%. The average ISSR PIC value (0.197) with the range of 0.137–0.276 was lower than that of SSR. Nevertheless, the average marker index of this multilocus marker was 3.495, which was higher than that of SSR (0.669), owing to the differences in the effective multiplex ratio. In addition, Mantel test cophenetic correlation coefficient was higher for ISSR (0.566) than that of SSR (0.198). These results indicated higher efficiency of ISSR for estimating the levels of genetic diversity and relationships among yardlong beans and dwarf yardlong beans in this study. Pair-wise coefficients of SSR- and ISSR-based genetic similarity among all yardlong bean and dwarf yardlong bean accessions averaged 0.87 and 0.91, respectively, suggesting a narrow genetic base that emphasizes the need to broaden genetic diversity to ensure continued breeding success. Clustering of genotypes within groups was not similar when SSR and ISSR derived dendrograms from UPGMA analysis were compared. It appeared that ISSR was the most effective marker system in determining the genetic variability and relationships among yardlong bean and dwarf yardlong bean accessions and differentiating three Vigna species. In addition, ISSR was also most useful for variety identification since all 30 yardlong beans and dwarf yardlong bean accessions can be effectively distinguished by only four ISSR primers with the highest PIC values.  相似文献   

7.
Improvement of fruit traits is an important objective in current mulberry breeding programs. In this study, 93 mulberry accessions of diverse origin were genotyped using 15 ISSR markers to identify marker–trait associations with fruit traits. Fifteen ISSR primers generated a total of 104 amplification products, of which 94 were polymorphic, revealing 90.38% polymorphism; the mean PIC value was 0.2698. UPGMA cluster analysis showed clear genetic relationships between the 93 mulberry cultivars, and the major clusters were related to known pedigree relationships and their ecotype. The mean r2 value for all intra-chromosomal loci pairs was 0.0210. Marker–trait associations were investigated using the unified mixed-model approach, considering both population structure (Q) and kinship (K). In total, 24 marker–trait associations (p < 0.01) were identified using different ISSR markers. The results suggest that association mapping in mulberry is a viable alternative to quantitative trait loci mapping, and detection of associations between markers and mulberry fruit traits will also provide important information for marker-assisted breeding.  相似文献   

8.
Bermudagrass (Cynodon dactylon L.) is an important warm-season turfgrass. Although it is widely distributed in China, studies on the genetic variation and relationship among the large-scale indigenous bermudagrass were relatively insufficient, especially at molecular level. The purpose of this study was to assess the molecular variation and relationship among one commercial cultivar ‘Tift3’ and 95 wild bermudagrass accessions collected from 11 provinces in China by ISSR marker technique. The results indicated that 29 ISSR primers generated a total of 248 bands among which 242 (97.6%) were polymorphic bands. The genetic similarity coefficients among accessions ranged from 0.51 to 0.97 with an average of 0.74. All accessions could be clustered into 11 groups with UPGMA method. Accessions from the same or adjacent regions generally were clustered into the same group or subgroups. A few accessions, however, were greatly different from the majority of all accessions. The results suggested that ISSR marker is an effective tool for the study of genetic variation in Chinese natural bermudagrass.  相似文献   

9.
Summary

Genetic variation and resulting variable groupings in tea (Camellia sinensis) and its wild Camelia relatives were assessed using Random Amplified Polymorphic DNA (RAPD) and Amplified Fragment Length Polymorphic (AFLP) markers. Numerous polymorphic bands were generated, of which 266 unambiguous ones were scored. The highest level of polymorphism as determined by the expected heterozygosity (Hav) was detected with AFLPs. Three major groups were recognized in the germplasm based on the parsimony method of cluster analysis. Two of the groups corresponded to varieties assamica and sinensis while the third group consisted of a heterogeneous mix of tea cultivars and related wild species. The Taiwan yamacha, unique tea cultivars grown predominantly in the highlands of Taiwan for the production of pan fired semi-fermented (Oolong and Pouchong) tea clustered in this group. Analysis of phenotypic diversity based on the generated RAPD and AFLP profiles revealed that population diversity (H), decreased in the order; Wild Camellia >India > China > Kenya > Sri-lanka > Vietnam > Japan > Taiwan. Analysis of molecular variance (AMOVA) revealed that most variation resided among individuals within populations (72%). Calculation of genetic distances and nested AMOVA further revealed a significant degree of structuring among the populations based on the country of origin.  相似文献   

10.
Ten inbred lines of ash gourd [Benincasa hispida (Thunb.) Cogn.] were crossed to produce 45 F1 hybrids (without reciprocal) which were evaluated along with the parents for 20 growth- and yield-related traits, in a replicated field trial. High level of heterosis was observed among the hybrids for most of the traits examined, including yield. These inbred lines were analysed by using 42 RAPD primers those produced 282 DNA marker bands. A total of 130 RAPD markers were obtained with a mean of 3.1 per primer, which in combination discriminated all the inbreds from each other. Pair-wise genetic distance measurements ranged from 0.07 to 0.31, suggesting a wide genetic diversity for these inbreds. These inberds were also analysed with five ISSR primers of which four were informative. Twenty-six ISSR marker bands were generated of which 11 were polymorphic with an average of 2.80 per primers. The percentage of polymorphic bands produced were higher in ISSR markers (>80%) than generated through RAPD markers (46%). Although the results indicated significant positive correlations of genetic distance with hybrid performance and heterosis, the RAPD based genetic distance measures and use of limited ISSR markers in this present study could not effectively predict hybrid performance in this crop. The genetic variation among ash gourd inbred lines examined, herein, defined a marker array (combined ISSR and RAPD) for the development of a standard reference for further genetic analyses, and the selection of potential parents for predicting hybrid performance and heterosis.  相似文献   

11.
A genetic analysis of 38 diverse Indian bitter gourd (Momordicacharantia var. charantia, and var. muricata) accessions was performed using 29 RAPD and 15 ISSR markers. RAPD primers yielded 208 amplicons of which 76 (36.5%) were polymorphic providing an average of 2.6 amplicons per primer. RAPD amplicons per primer ranged from 3 (OPE-19, OPW-09) to 15 (OPW-05), and varied in size from 200 bp to 3000 bp. Fifteen ISSR primers provided a total of 125 bands of which 94 (74.7%) were polymorphic. Polymorphic ISSR markers ranged from 0 (UBC-841) to 12 (UBC-890) providing a mean of 6.3 amplicons per primer that ranged in size from 150 bp to 2700 bp. Nevertheless, the concordance among bitter gourd accession groupings after cluster analysis was relatively high (r = 0.77), indicating that RAPD- and ISSR-based diversity assessments in this germplasm array were generally consistent. The M.charantia var. charantia (domesticated) and var. muricata (wild, free-living) accessions examined were genetically distinct, and these differences provided for the development of strategies for genetic analyses and crop improvement in this species.  相似文献   

12.
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13.
Summary

The high degree of polymorphism of AFLPs provides an efficient system for identification and genome analysis of sweet cherry (Prunus avium) cultivars and selections. The cultivars of sweet cherry have usually been characterized by assessment of phenotypic and pomological traits. AFLP markers were employed to identify 38 sweet cherry accessions and estimate the genetic diversity among this material. Ten of 18 tested primer combinations were informative with up to 80 bands per primer combination. Seven to 33% of the amplfied bands were polymorphic depending upon primer combination. Allcultivars and selections tested could be clearly identified. The objective of this work was to demonstrate the usefulness of molecular markers in revealing the genetic diversity among different sweet cherry genotypes.  相似文献   

14.
Summary

Three different PCR methods [Random Amplified Polymorphic DNA (RAPD), Inter-Simple Sequence Repeats (ISSR), and Directed Amplification of Minisatellite DNA (DAMD)] were used to analyse genetic diversity and parentage among 20 mango cultivars, including 18 landraces and two hybrids (‘Amrapali’ and ‘Mallika’). These hybrids together with a third hybrid (‘Ratna’), and an out-group species (Mangifera sylvatica) were also analysed for parentage. Fifteen, seven and four primers were used to amplify a total of 158, 69 and 59 distinct DNA fragments by RAPD, ISSR and DAMD, respectively. Of these, approx. 85%, 64% and 90% were polymorphic, respectively. Genetic distances between pairs of mango cultivars were measured separately by each method and depicted graphically as a Neighbor Joining (NJ) tree. The three methods revealed different groupings of cultivars and hybrids. A NJ tree based on the cumulative data from all methods correlated well with the parentage of the mango hybrids, and the grouping of cultivars on a regional basis. Genetic markers likely to be associated with important agronomic traits were identified by further analysing the hybrids, with their respective parents, using all three methods. On the basis of the highest number of polymorphic bands observed (90%), DAMD was judged to be the best method with which to analyse mango germplasm.  相似文献   

15.
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16.
Immature fruit of cultivated species of eggplant (Solanum melongena L.) are commonly used as a summer vegetable in India. Rich morphological variation exists among the cultivated species of eggplant in different growing regions of the country. We have characterised 24 breeding lines of Solanum spp., including 20 eggplant cultivars and four wild species of eggplant, based on 13 morphological characters using Mahalonabis D2 statistics. All 24 breeding lines of Solanum spp., including the 20 eggplant cultivars and four wild species, were grouped into four clusters by agglomerative clustering. Cluster II and Cluster IV contained the most accessions (eight each), while Cluster I and Cluster III had four accessions each. The highest inter-cluster (D2) distance (158.33) was observed between Cluster I and Cluster II, followed by Cluster I and Cluster III (108.48), and Cluster II and Cluster IV (102.96), which indicated that accessions in Cluster I and Cluster II were more divergent than those in the other clusters. The highest intra-cluster distance (5.80) was observed in Cluster IV, with eight genotypes, and the lowest intra-cluster distance (2.21) was observed in Cluster II, also with eight genotypes. The intra-cluster distances in all four clusters were lower than the inter-cluster distances, which indicated that genotypes within the same cluster were closely related. Genotypes in Cluster IV had the maximum number of flowers per cluster (3.63), the highest number of fruit per cluster (3.25), and number of fruit per plant (208.63), which revealed that genotypes could be selected from Cluster IV for these characters. The first three principal components (PC1, PC2, and PC3) accounted 73.99% of the total variation among the 24 genotypes. These phenotypic data increase the feasibility of prioritising breeding lines in a crossing programme based on the uniqueness of their desirable morphological traits.  相似文献   

17.
The application and informativeness of RAPD, ISSR, IRAP and REMAP markers to study the genetic diversity and relationship among the Citrus and its relative genotypes were investigated. High levels of polymorphism were observed for all four marker systems. The RAPD technique generated the highest number of polymorphic bands and average number of polymorphic band per assay unit. Average limit of the discriminating power was very close to its actual discriminating power of each marker. The highest and the lowest values of effective number of patterns were obtained from the marker REMAP (5.94) and RAPD (4.48), respectively. Correlation between the genetic similarities matrices were estimated from all four markers using the Mantel matrix correspondence test, and results showed significant correlations among the RAPD, ISSR, IRAP and REMAP similarity matrices. The highest correlations were found comparing RAPD and ISSR markers, whereas RAPD and REMAP (r = 0.143) markers were poorly correlated. To assess the usefulness of the overall information provided by these marker data for establishing phylogenetic relationships and Citrus germplasm classification, cluster analysis was performed. All four techniques, solely or in combination, discriminated the genotypes very efficiently and generated a high similarity in dendrogram topologies, although some differences were observed. The linkage analysis was conducted based on the segregation of 38 RAPD, 13 ISSR, 19 IRAP and 9 REMAP loci in 96 progeny of an intergeneric cross Citrus sinensis and Poncirus trifoliata. Among the 81 studied loci 65 loci distributed on five linkage groups. Comparing the result obtained with RAPD, ISSR, IRAP and REMAP markers in this study, IRAP and REMAP proved to be as a reliable molecular marker for fingerprinting, mapping and diversity study of Citrus and its relatives.  相似文献   

18.
Inter simple sequence repeats (ISSR) polymorphism in Citrus indica Tanaka (Rutaceae), an endemic and threatened wild species, was examined along with three other closely related wild taxa (C. medica L., C. latipes (Swingle) Tanaka, and C. sp. ‘Memang athur’) by analyzing 53 representative accessions sampled from North-east India. Jaccard's similarity values among 53 accessions of Citrus ranged from 0.46 to 0.97 (average = 0.75). Genetic similarity values among all the 34 accessions of C. indica were found in the range of 0.82 to 0.97 with an average of 0.90. Heterozygosity (Ht = 0.123) and Shannon's information index (I = 0.188) values estimated for C. indica revealed significantly low level of genetic variation within the species. UPGMA dendrogram grouped all 53 accessions of Citrus into four major clusters: Cluster I – C. latipes; Cluster II – C. medica; Cluster III – ‘Memang athur’ and Cluster IV – C. indica. The dendrogram placed all the 34 accessions of C. indica in five sub-clusters under Cluster IV. The placement of C. indica accessions in various sub-clusters and groups in the dendrogram was based on molecular differentiation of individual accessions rather than their geographical origin. Very low genetic diversity and destruction of its natural habitat pose serious threat to C. indica even in the Citrus Gene Sanctuary in Nokrek Biosphere Reserve (NBR) in Meghalaya. Low genetic variability, heterozygosity and Shannon's information index in C. medica, C. latipes and ‘Memang athur’ are also concerns that need to be addressed for developing appropriate strategies to conserve the genetic diversity extant in these valuable genetic resources.  相似文献   

19.
In this study, RAPD and ISSR markers were used to investigate the genetic diversity and genetic relationships among different germplasm of Nelumbo including 70 Chinese ornamental cultivars, 7 wild Thai genotypes, 2 Nelumbo lutea genotypes and 8 hybrids of Nelumbo nucifera and N. lutea. High genetic diversities of 96.4% and 91.2% respectively were detected in the Nelumbo accessions using RAPD and ISSR markers. A dendrogram based on both RAPD and ISSR clustering data indicated that: (1) the genotypes of N. nucifera and N. lutea from different geographical origins were clustered into different groups. This indicated significant genetic differentiation attributed to extensive periods of geographical isolation and lack of gene exchange; (2) the Thai wild genotypes were separated from Chinese genotypes. This indicated genetic divergence between germplasm from Southeast Asia and that from China. Geographical location appears to have affected genetic diversity due to adaptation of the plants to the different environments. A new Southeastern Asia Lotus category is suggested as an addition to the current lotus cultivars classification system; (3) data on three morphological traits (namely: plant size, petal shape and flower color), showed that only the data on plant size was consistent with the dendrogram constructed from molecular data. This finding suggests that using data on genetic relationships in combination with morphological characteristics would serve to improve the classification system of lotus cultivars currently in use. The finding of previously unknown germplasm in this study indicated the potential of RAPD and ISSR techniques in identifying and managing lotus resources. Both marker techniques are potentially useful in improving the current strategies in breeding and germplasm conservation to enhance the ornamental and economic value of lotus.  相似文献   

20.
Olive tree is mainly vegetatively propagated; therefore a small level of polymorphism is expected among clones of the same cultivar. In order to access the level of intra-varietal genetic variability within a collection of 120 clones of the Portuguese olive ‘Cobrançosa’ DNA fingerprinting was performed. Ten random amplified polymorphism DNA (RAPD) primers amplified 150 fragments, of which 75 were polymorphic, while 10 inter-simple sequence repeats (ISSR) primers amplified 179 fragments of which 98 were polymorphic. ‘Cobrançosa’ clones were compared and analysed using Jaccard's coefficient with unweighted pair group mathematical averages, using the RAPD data, the ISSR data and both markers simultaneously. The data indicates a wide intra-varietal genetic variability among the clones. It was possible to cluster some clones according to geographical provenance. Analysis of molecular variance revealed greater variation within clones than among different geographical origins. Significant genetic diversity among the ‘Cobrançosa’ olive cultivar, even though the clones came from a limited geographical area, was also detected.  相似文献   

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