Impact of Mapped SSR Markers on the Genetic Diversity of Apricot (<Emphasis Type="Italic">Prunus armeniaca</Emphasis> L.) in Tunisia

The impact of mapped microsatellites on the study of genetic diversity of Tunisian apricot accessions was assessed. The genetic variability of 47 traditional apricot cultivars originating from several areas in Tunisia was investigated with 32 polymorphic microsatellite loci selected for their location throughout the eight linkage groups of Prunus genome. The higher polymorphism and greater transportability of these markers among Prunus species were proved by the expected heterozygosity (He = 0.56) and Shannon’s index of diversity (I = 1.05), indicating that Tunisian apricot germplasm maintained a substantial level of genetic diversity. According to their geographical origin, the genetic differentiation among groups (north, center, and south; Fst = 0.04) was lower, while the gene flow among groups was consequent (Nm = 4.79), attesting a narrow genetic background of apricot in the country. Both unweighted pair-group method with arithmetic mean dendrogram, based on Nei’s genetic distances and factorial correspondence analysis, separated northern cultivars from central and southern cultivars, revealing the same molecular basis of apricot material in the Center and the South of Tunisia. These results revealed the efficiency of mapped markers for genetic variability measurements compared to randomly ones, however, no advantage was observed considering the genetic relationships among studied accessions.     

Genetic diversity in apricot revealed by AFLP markers: species and cultivar comparisons

The genetic diversity of apricot ( Prunus armeniaca; 2n = 16) was studied using AFLP markers. Forty seven apricot cultivars were selected from the following geographic regions: Europe, North America, North Africa, Turkey, Iran and China. Five EcoRI- MseI AFLP primer combinations revealed 416 legible bands, of which 379 were polymorphic markers. A similarity matrix was prepared using the simple matching coefficient of similarity. A UPGMA dendrogram demonstrated a gradient of decreasing genetic diversity of varieties from the former USSR to Southern Europe. This is coherent with the historical dissemination of apricot from its center of origin in Asia. The American cultivars were intermediate demonstrating a different genetic base than the European and/or Mediterranean cultivars. Euclidean distances from the first ten Factorial Component Analysis coordinate axes were used to generate a tree using the Ward algorithm. The results of these analyses were evaluated based on the known geographic origins and agronomic characteristics of the cultivars studied. Four cultivar groups were identified: Diversification, Geographically Adaptable, Continental Europe and Mediterranean Basin. To evaluate the relationship of the common apricot with some closely related species, one or two accessions of the following related species or sub-species from within the section Armeniaca were included in the analysis: Prunus armeniaca var. ansu, Prunus mume, Prunus brigantiaca, Prunus dasycarpa, and Prunus holosericea. A Neighbour Joining dendrogram was made using the similarity matrix. The P. holosericea accession fell well within the cultivar group, thus supporting its classification as a variant of P. armeniaca. The P. armeniaca var. ansu accession was sister to the common apricot cluster with a bootstrap value of 96%. P. mume was farther removed. P. brigantiaca was the most-distant from the common apricots. P. dasycarpa was intermediate between P. brigantiaca and P. mume, in accord with its plum-apricot hybrid origin. The results have a direct application for the selection of new breeding progenitors.     

Grafting versus seed propagated apricot populations: two main gene pools in Tunisia evidenced by SSR markers and model-based Bayesian clustering

Apricot was introduced into the Mediterranean Basin from China and Asian mountains through the Middle-East and the Central Europe. Traditionally present in Tunisia, we were interested in accessing the origin of apricot species in the country, and in particular in the number and the location of its introductions. A set of 82 representative apricot accessions including 49 grafted cultivars and 33 seed propagated ‘Bargougs’ were genotyped using 24 microsatellite loci revealing a total of 135 alleles. The model-based Bayesian clustering analysis using both Structure and InStruct programs as well as the multivariate method revealed five distinct genetic clusters. The genetic differentiation among clusters showed that cluster 1, with only four cultivars, was the most differentiated from the four remaining genetic clusters, which constituted the largest part of the studied germplasm. According to their geographic origin, the five identified groups (north, centre, south, Gafsa oasis and other oases groups) enclosed a similar variation within group, with a low level of differentiation. Overall results highlighted the distinction of two apricot gene pools in Tunisia related to the different mode of propagation of the cultivars: grafted and seed propagated apricot, which enclosed a narrow genetic basis. Our findings support the assumption that grafting and seed propagated apricots shared the same origin.     

Unravelling genetic diversity and cultivar parentage in the Danish apple gene bank collection

Characterization of apple germplasm is important for conservation management and breeding strategies. A set of 448 Malus domestica accessions, primarily of local Danish origin, were genotyped using 15 microsatellite markers. Ploidy levels were determined by flow cytometry. Special emphasis was given to pedigree reconstruction, cultivar fingerprinting and genetic clustering. A reference set of cultivars, mostly from other European countries, together with a private nursery collection and a small set of Malus sieversii, Malus sylvestris and small-fruited, ornamental Malus cultivars, was also included. The microsatellite markers amplified 17–30 alleles per loci with an average degree of heterozygosity at 0.78. We identified 104 (23%) duplicate genotypes including colour sports. We could infer first-degree relationships for many cultivars with previously unknown parentages. STRUCTURE analysis provided no evidence for a genetic structure but allowed us to present a putative genetic assembly that was consistent with both PCA analysis and parental affiliation. The Danish cultivar collection contains 10% duplicate genotypes including colour sports and 22% triploids. Many unique accessions and considerable genetic diversity make the collection a valuable resource within the European apple germplasm. The findings presented shed new light on the origin of Danish apple cultivars. The fingerprints can be used for cultivar identification and future management of apple genetic resources. In addition, future genome-wide association studies and breeding programmes may benefit from the findings concerning genetic clustering and diversity of cultivars.     

Simple sequence repeat (SSR) analysis for assessment of genetic variability in apricot germplasm

Thirty SSR primer combinations, developed from peach SSR-enriched genomic libraries and BAC libraries of peach [ Prunus persica (L.) Batsch.], were tested for cross amplification with 74 apricot ( Prunus armeniaca L.) germplasm accessions. Twelve primer pairs amplified 14 polymorphic SSR loci useful for discriminating most apricot cultivars, as well as for investigating patterns of variation in apricot germplasm. Levels of polymorphism were higher than the levels described using other codominant marker systems (i.e., isozymes, RFLP markers). Overall, 107 alleles were identified, and all but 11 accessions were unambiguously discriminated. Genetic differentiation of native germplasm into traditional ecogeographical groups was low, with a high level of genetic identity (> 0.75) between the groups. However, neighbor joining cluster analysis of marker distances between cultivars reflected the complex history of apricot domestication, producing groupings not evidently based on the geographical origin of the cultivars. Distant positioning of Chinese cultivars on UPGMA and neighbor joining dendrograms supports the authors' consideration of Chinese apricots as subspecies, Prunus armeniaca var. ansu Maxim., rather than a separate species.     

DNA fingerprinting of jute germplasm by RAPD

The genotype characteristic of cultivars was investigated, along with varieties of both of the jute species, Corchorus olitorius and Corchorus capsularis, in the germplasm collection at the Bangladesh Jute Research Institute (BJRI). DNA fingerprinting was generated for 9 different varieties and 12 accessions of jute cultivars by using random amplified polymorphic DNA (RAPD). A total of 29 arbitrary oligonucleotide primers were screened. Seven primers gave polymorphism within the varieties, and 6 primers detected polymorphism within the accessions that were tested. A dendrogram was engendered from these data, and this gave a distinct clustering of the cultivated species of jute. Therefore, we generated RAPD markers, which are species-specific. These primers can distinguish between C. olitorius and C. capsularis. From the dendrogram that we generated between the various members of these two species, we found the existing genetic classification that agrees with our molecular marking data. A different dendrogram showed that jute accessions could be clustered into three groups. These data will be invaluable in the conservation and utilization of the genetic pool in the germplasm collection.     

Ex situ conservation of underutilised fruit tree species: establishment of a core collection for Ficus carica L. using microsatellite markers (SSRs)

Ex situ germ plasm collections of woody crops are necessary to ensure the optimal use of plant genetic resources. The fig tree (Ficus carica L.) germ plasm bank, consisting of 229 accessions, is located in Centro de Investigación ‘La Orden’. Despite great progress in conservation, ex situ collections face size and organization problems. Core collections obtained from structured samples of bigger collections are a useful tool to improve germ plasm management. In this work, we used simple sequence repeat (SSR) markers to establish a core collection in this underutilised Mediterranean fruit tree species. Four approaches have been carried out (random sampling, maximization, simulated annealing and stepwise clustering) to determine the best method to develop a core collection in this woody plant. The genetic diversity obtained with each subset was compared with that of the complete collection. It was found that the most efficient way to achieve the maximum diversity was the maximization strategy, which, with 30 accessions, recovers all the SSR alleles and does not show significant differences in allele frequency distribution in any of the loci or in the variability parameters (H _O, H _E) between the whole and core collections. Thus, this core collection, a representative of most fig diversity conserved in the germ plasm bank, could be used as a basis for plant material exchange among researchers and breeders.     

The origin of cultivated <Emphasis Type="Italic">Coffea arabica</Emphasis> L. varieties revealed by AFLP and SSR markers

Molecular markers were used to assess polymorphism between and within the genetic bases of coffee (i.e. Typica and Bourbon) spread from Yemen since the early 18th century that have given rise to most arabica cultivars grown world-wide. Eleven Coffea arabica accessions derived from the disseminated bases were evaluated by amplified fragment length polymorphism (AFLP) using 37 primer combinations and simple-sequence repeats (SSRs) produced by six microsatellites. Four cultivars growing in Yemen and 11 subspontaneous accessions collected in the primary centre of diversity of the species were included in the study in order to define their relationship with the accessions derived from the genetic bases of cultivars. One hundred and seven AFLP markers were used to calculate genetic distances and construct a dendrogram. The accessions derived from the disseminated bases were grouped separately, according to their genetic origin, and were distinguished from the subspontaneous accessions. The Yemen cultivars were classified with the Typica-derived accessions. Except for one AFLP marker, all AFLP and SSR markers present in the cultivated accessions were also detected in the subspontaneous accessions. Polymorphism among the subspontaneous accessions was much higher than among the cultivated accessions. It was very low within the genetic bases, confirming the historical documentation on their dissemination. The results enabled a discussion of the genetic diversity reductions that successively occurred during the dissemination of C. arabica from its primary centre of diversity.     

Genetic analysis of Spanish melon (<Emphasis Type="Italic">Cucumis melo</Emphasis> L.) germplasm using a standardized molecular-marker array and geographically diverse reference accessions

Genetic relationships among 125 Spanish melon (Cucumis melo L.) accessions from a Spanish germplasm collection were assessed using a standard molecular-marker array consisting of 34 random amplified polymorphic DNA (RAPD) markers bands (19 primers) and 72 reference accessions drawn from previous studies. The reference accession array consisted of a broad range [Japanese (19) Crete (17), African (15), and USA and Europe (US/EU, 21)] of horticultural groupings (Group Cantalupensis, Group Conomon, Group Inodorus, Group Flexuosus, and Group Chito), and of melon market classes (e.g., Charentais, U.S. Western and European Shipper types, Ogen, and Galia, Honeydew, and Casaba). Spanish melon accessions (largely Casaba, Group Inodorus) were genetically distinct from the reference accessions and other Group Inodorus melons of different origins. Most African accessions showed common genetic affinities, and grouped with the Group Chito and the Group Conomon accessions examined. Those accession groupings were distinct from all other accessions belonging to Group Cantalupensis, Flexuosus, and Inodorus accessions originating from Crete, Japan, Europe, and the U.S. Genetic diversity was highest in accessions of African origin and lowest in accessions of Spanish origin. Additional RAPD markers (49 primers, 141 bands) and 22 selected agronomic traits (quantitative and qualitative) were then used to assess the genetic diversity among Spanish accessions. While cluster analysis using fruit characteristics grouped accessions into cultivars, RAPD-based genetic-distance estimate did not provide consistent accession groupings either by cultivar or geographic origin. While the highest level of polymorphism was detected among melons originating from the central region of Spain, and in the Rochet cultivar, accessions from the Andalucía region and Green cultivars were comparatively less diverse. These results indicate that the Spanish melon accessions could be used to broaden the genetic base of local and foreign Casaba germplasm, to enhance the genetic diversity of U.S and European commercial melon germplasm, and to delineate collection strategies for acquisition of additional Spanish landraces.Communicated by C. MöllersMention of trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the USDA and does not imply its approval to the exclusion of other products that may be suitable.     

Analysis of genetic diversity among persimmon cultivars using microsatellite markers

In the Mediterranean area, the production of persimmon (Diospyros kaki Thumb) [2n = 6x = 90] has increased recently as an alternative to the major fruit crops. In Spain, production relies almost exclusively on the cultivar “Rojo Brillante” which accounts for 83% of the crop. A crop based on a monovarietal culture implies several commercial risks that can compromise the future of the crop. Although the species was introduced in Europe very recently, it is well adapted to the climate of southern Europe. However, the recent introduction from Japan, the mistakes on the identity of varieties in the collections due to a bad translation of variety names from Japanese, and the lack of genetic characterization of many varieties have caused difficulties for effective management of the available genetic resources. The present paper was aimed at exploring the genetic diversity among different persimmon cultivars, including those collected in the European survey as well as Japanese cultivars. Seventy-one persimmon cultivars coming from two European collections that included accessions from Japan, Italy, and Spain were analyzed using 19 polymorphic microsatellite markers. A total of 206 alleles were obtained, with a mean value of 10.8 alleles per locus. A neighbor joining dendrogram and a principal coordinate analysis arranged the cultivars according to their genetic relationships. Analysis of molecular variance revealed significant genetic variability between and within groups, 73.3% and 85.2% for astringent-type and country origin, respectively. The simple sequence repeat markers classified the persimmon cultivars according to their genetic relationship.     

New insights into the history of domesticated and wild apricots and its contribution to Plum pox virus resistance

Studying domesticated species and their wild relatives allows understanding of the mechanisms of population divergence and adaptation, and identifying valuable genetic resources. Apricot is an important fruit in the Northern hemisphere, where it is threatened by the Plum pox virus (PPV), causing the sharka disease. The histories of apricot domestication and of its resistance to sharka are however still poorly understood. We used 18 microsatellite markers to genotype a collection of 230 wild trees from Central Asia and 142 cultivated apricots as representatives of the worldwide cultivated apricot germplasm; we also performed experimental PPV inoculation tests. The genetic markers revealed highest levels of diversity in Central Asian and Chinese wild and cultivated apricots, confirming an origin in this region. In cultivated apricots, Chinese accessions were differentiated from more Western accessions, while cultivated apricots were differentiated from wild apricots. An approximate Bayesian approach indicated that apricots likely underwent two independent domestication events, with bottlenecks, from the same wild population. Central Asian native apricots exhibited genetic subdivision and high frequency of resistance to sharka. Altogether, our results contribute to the understanding of the domestication history of cultivated apricot and point to valuable genetic diversity in the extant genetic resources of wild apricots.     

Assessment of genetic variation and differentiation of hop genotypes by microsatellite and AFLP markers.

Microsatellites have many desirable marker properties and have been increasingly used in crop plants in genetic diversity studies. Here we report on the characterisation of microsatellite markers and on their use for the determination of genetic identities and the assessment of genetic variability among accessions from a germplasm collection of hop. Thirty-two polymorphic alleles were found in the 55 diploid genotypes, with an average number of eight alleles (3.4 effective alleles) for four microsatellite loci. Calculated polymorphic information content values classified three loci as informative markers and two loci as suitable for mapping. The average observed heterozygosity was 0.7 and the common probability of identical genotypes was 3.271 x 10(-4). An additional locus, amplified by one primer pair, was confirmed by segregation analysis of two crosses. The locus discovered was heterozygous, with a null allele in the segregating population. The same range of alleles was detected in nine triploid and five tetraploid hop genotypes. Cultivar heterozygosity varied among all 69 accessions, with only one cultivar being homozygous at four loci. Microsatellite allele polymorphisms distinguished 81% of all genotypes; the same allelic profile was found mainly in clonally selected cultivars. Cultivar-specific alleles were found in some genotypes, as well as a specific distribution of alleles in geographically distinct hop germplasms. The genetic relationship among 41 hop accessions was compared on the basis of microsatellite and AFLP polymorphisms. Genetic similarity dendrograms showed low correlation between the two marker systems. The microsatellite dendrogram grouped genetically related accessions reasonably well, while the AFLP dendrogram showed good clustering of closely related accessions and, additionally, separated two geographically distinct hop germplasms. The results of microsatellite and AFLP analysis are discussed from the point of view of the applicability of the two marker systems for different aspects of germplasm evaluation.     

Molecular genetic diversity and association mapping of nut and kernel traits in Slovenian hazelnut (<Emphasis Type="Italic">Corylus avellana</Emphasis>) germplasm

European hazelnut (Corylus avellana L.), cultivated in several areas of the world including Europe, Anatolia, and the USA, is an economically important nut crop due to its high mineral, oleic acid, amino acid, and phenolic compound content and pleasant flavor. This study examined molecular genetic diversity and population structure of 54 wild accessions and 48 cultivars from the Slovenian national hazelnut collection using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Eleven AFLP primer combinations and 49 SSR markers yielded 532 and 504 polymorphic fragments, respectively. As expected for a wind-pollinated, self-incompatible species, levels of genetic diversity were high with cultivars and wild accessions having mean dissimilarity values of 0.50 and 0.60, respectively. In general, cultivars and wild accessions clustered separately in dendrogram, principal coordinate, and population structure analyses with regional clustering of the wild material. The accessions were also characterized for ten nut and seven kernel traits and some wild accessions were shown to have breeding potential. Morphological principal component analysis showed distinct clustering of cultivars and wild accessions. An association mapping panel composed of 64 hazelnut cultivars and wild accessions had considerable variation for the nut and kernel quality traits. Morphological and molecular data were associated to identify markers controlling the traits. In all, 49 SSR markers were significantly associated with nut and kernel traits [P < 0.0001 and LD value (r ²) = 0.15–0.50]. This work is the first use of association mapping in hazelnut and has identified molecular markers associated with important quality parameters in this important nut crop.     

Genetic variation and covariation in a population of tetraploid Dactylis L. accessions

Summary Efficient utilization of divergent germ plasm sources in breeding cultivated Dactylis glomerata L. ssp. glomerata Domin depends on knowledge of quantitative variation within and among accessions. This study was undertaken to quantify variation and covariation for forage yield, maturity, disease reaction, and ground cover within a population of tetraploid Dactylis accessions. Variation was observed among families within the population for each variable. Most genetic variation (73%–93% of the family sums of squares) was within country sources or within accessions. Thus, country boundaries, which are traditionally important factors used in defining limits of plant exploration expeditions, have limited expected use in targeting future exploration for specific sources of high yield, disease resistance, or ground cover. Maturity was the exception to this; late-maturing accessions were identified as originating exclusively from the USSR. Some relationships among traits, such as that for yield and disease reaction, differed for accessions and cultivars. Several accessions and families within accessions were identified to have performance superior to most or all cultivars included in this study. Existing germ plasm from several countries was identified to have potential in breeding orchardgrass, while that from other countries appeared to have little or no potential in supplying germ plasm for hay production in humid-temperate environments.     

Genetic Diversity and Identity of Chinese Loquat Cultivars/Accessions (<Emphasis Type="Italic">Eriobotrya japonica</Emphasis>) Using Apple SSR Markers

Loquat (Eriobotrya japonica) is an underutilized fruit crop that originated in China and for which only a small number of molecular markers are available. This number can be increased by identifying apple SSRs that are transferable to loquat cultivars/accessions to provide new insight into the level of genetic diversity within loquat and synteny with apple. We evaluated 71 apple SSR markers distributed across 17 linkage groups, and identified 39 SSRs transferable to loquat. Testing 54 loquat accessions, from Japan, Spain, four provinces in China, and two wild species gave a total of 155 different alleles with a mean value of 3.38 per locus. The mean effective number of alleles was 2.21, and the mean observed heterozygosity was 0.47. These values indicate a high degree of genetic diversity in the set of Chinese loquat accessions analyzed. Unweighted pair-group method analysis based on simple matching coefficent clustered the accessions into two groups, cultivated and wild loquat. The cultivated loquat can be subdivided into three subgroups which generally reflect their geographic origin in China. The Spanish cultivars clustered with those of the Jiangsu and Zhejiang provinces. A core set of five SSR markers could distinguish most accessions.     

Evaluation of Genetic Diversity in Chinese Wild Apple Species Along with Apple Cultivars Using SSR Markers

China, one of the primary centers of genetic diversity for the genus Malus, is very rich in wild apple germplasm. In this study, genetic diversity in 29 Malus accessions, including 12 accessions from 7 Chinese Malus species, 4 Chinese landraces, and 13 introduced apple cultivars, was assessed using a set of 19 single-locus simple sequence repeat (SSR) markers distributed across all 17 linkage groups of the apple genome. The number of alleles detected at each locus ranged from 2 to 11, with an average of 5.3 per SSR marker. In some accessions, 16 unique alleles were identified. Ten out of these 16 unique alleles (62.5%) were detected exclusively in wild species, indicating that these Chinese wild apple species have considerable genetic diversity and can be used in breeding programs to increase the genetic diversity of apple cultivars. Using 19 SSRs, an unweighted pair-group method with arithmetic average cluster analysis was conducted, and the resulting dendrogram revealed that all cultivars, except for E??peMeBckoe, were clustered together in the same group. The Russian cultivar E??peMeBckoe was closely related to the Chinese crabapple Baihaitang (M. prunifolia), with a high similarity coefficient value of 0.94. Of the two M. sieversii accessions used, one accession showed a close relationship to apple cultivars, while the other accession was closely related to wild apple species, suggesting the presence of a wider genetic diversity in Chinese M. sieversii species. The influence of SSR marker selection on genetic diversity analysis in this Malus collection was also discussed.     

Genetic diversity in Arabidopsis thaliana L. Heynh. investigated by cleaved amplified polymorphic sequence (CAPS) and inter-simple sequence repeat (ISSR) markers

In this study, we investigated genetic diversity among 37 accessions in Arabidopsis thaliana from Eurasia, North Africa and North America using morphological traits and two polymerase chain reaction (PCR)-based marker systems: cleaved amplified polymorphic sequences (CAPS) and inter-simple sequence repeats (ISSR). Cluster analysis based on genetic similarities calculated from CAPS data grouped the accessions roughly according to their geographical origin: one large group contained accessions from Western, Northern and Southern Europe as well as North Africa, a second group consisted of Eastern European and Asian continental accessions. North American accessions were interspersed into these groups. Contrary to the CAPS analysis, the dendrogram obtained from the ISSR data did not reflect the geographical origin of the accessions, and the calculated genetic distances did not match the CAPS results. This could be attributable to an uneven genomic distribution of ISSR markers as substantiated by a database search for ISSR binding sites in A. thaliana genomic DNA sequence files, or to the ISSR's different mode of evolution. We recommend CAPS markers for diversity analysis in A. thaliana because a careful selection of markers can ascertain an even representation of the entire genome.     

Subspecies-specific intron length polymorphism markers reveal clear genetic differentiation in common wild rice （Oryza rufipogon L.） in relation to the domestication of cultivated rice （O. sativa L.）

It is generally accepted that Oryza rufipogon is the progenitor of Asian cultivated rice （O. sativa）. However, how the two subspecies of O. sativa （indica and japonica） were domesticated has long been debated. To investigate the genetic differentiation in O. rufipogon in relation to the domestication of O. sativa, we developed 57 subspecies-specific intron length polymorphism （SSILP） markers by comparison between 10 indica cultivars and 10 japonica cultivars and defined a standard indica rice and a standard japonica rice based on these SSILP markers. Using these SSILP markers to genotype 73 O. rufipogon accessions, we found that the indica alleles and japonica alleles of the SSILP markers were predominant in the O. rufipogon accessions, suggesting that SSILPs were highly conserved during the evolution of O. sativa. Cluster analysis based on these markers yielded a dendrogram consisting of two distinct groups： one group （Group I） comprises all the O. rufipogon accesions from tropical （South and Southeast） Asia as well as the standard indica rice; the other group （Group II） comprises all the O. rufipogon accessions from Southern China as well as the standard japonica rice. Further analysis showed that the two groups have significantly higher frequencies of indica alleles and japonica alleles, respectively. These results support the hypothesis that indica rice and japonica rice were domesticated from the O. rufipogon of tropical Asia and from that of Southern China, respectively, and suggest that the indica-japonica differentiation should have formed in O. rufipogon long before the beginning of domestication. Furthermore, with an O. glaberrima accession as an outgroup, it is suggested that the indica-japonica differentiation in O. ruffpogon might occur after its speciation from other AA-genome species.     

Genotyping of Vitis vinifera L. within the Slovak national collection of genetic resources

Microsatellites were used as a very effective tool for genetic diversity analysis and characterization of 51 grapevine (Vitis vinifera L.) accessions from the national collection of genetic resources. Genetic diversity was relatively high, 8.91 alleles were detected per analysed microsatellite locus in average, and fifty-one accessions were distinguished into 45 groups. Distribution of recent Slovak cultivars across the dendrogram accented both their genetic diversity and the effectiveness of the national breeding program in maintaining genetic diversity and generating new genetic variants. Each cultivar was different from the others and twelve of them contained 77.6% of the total genetic diversity of the whole analysed set. Microsatellite patterns were also able to confirm parentage in selected Slovak cultivars. An unusual phenomenon of triallelism was also detected in one of the analysed accessions. The present study has initiated molecular characterization within the national grapevine genetic resource collection and their comparison with well-established international cultivars.     

Molecular characterization and genetic diversity analysis of soybean (Glycine max (L.) Merr.) germplasm accessions in India

Molecular characterization and genetic diversity among 82 soybean accessions was carried out by using 44 simple sequence repeat (SSR) markers. Of the 44 SSR markers used, 40 markers were found polymorphic among 82 soybean accessions. These 40 polymorphic markers produced a total of 119 alleles, of which five were unique alleles and four alleles were rare. The allele number for each SSR locus varied between two to four with an average of 2.97 alleles per marker. Polymorphic information content values of SSRs ranged from 0.101 to 0.742 with an average of 0.477. Jaccard’s similarity coefficient was employed to study the molecular diversity of 82 soybean accessions. The pairwise genetic similarity among 82 soybean accessions varied from 0.28 to 0.90. The dendrogram constructed based on genetic similarities among 82 soybean accessions identified three major clusters. The majority of genotypes including four improved cultivars were grouped in a single subcluster IIIa of cluster III, indicating high genetic resemblance among soybean germplasm collection in India.

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