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The co-occurrence of hybrids and parental species in similar ecological niches poses a question on the role of traits additivity and overdispersion (emergence of new traits) in microevolutionary processes. We analysed genetic polymorphism of Bromus benekenii, B. ramosus and the spontaneous hybrid B. benekenii × B. ramosus in sympatric and allopatric parts of the species distribution in Europe, based on non-coding regions of the taxon genomes (ISSR genetic fingerprinting). We tested 68 individuals in 7 populations, including a hybrid population in N France. Altogether 233 polymorphic ISSR bands (loci) were obtained. We found that the parent species were genetically distinct and the hybrids had an additive pattern of ISSR bands found in the putative parental species (NMDS, STRUCTURE); however, there was evidence of introgression towards B. ramosus (NEWHYBRIDS, UPGMA classifications, Nei's D genetic distance). Bromus benekenii had 72, B. ramosus 21 and the hybrids 9 private bands (genetic overdispersion), probably resulting from the rearranged genomes. Based on its low genetic divergence index DW, the hybrid population seems to be at a young age. We argue that in the face of anthropogenic landscape transformations favouring secondary contacts, the hybrids may competitively replace the parental species in sympatric areas.
Species of Gleditsia show considerable morphological variability that makes them difficult to distinguish using either vegetative or floral characters. Honeylocusts, especially the thornless cultivars, are popular ornamental, shade, street, attractive landscape trees. In this study the ISSR technique was used to evaluate the range of genetic variability between seven genotypes of Gleditsia cultivated in Polish dendrological collections [Gleditsia caspica Desf., Gleditsia japonica Miq., Gleditsia japonica Miq. var. korainensis (= G. korainensis Nakai), Gleditsia triacanthos L., Gleditsia triacanthos L. (bulk), Gleditsia triacanthos f. inermis (L.) Zabel (bulk). Forty ISSR primers were tested and 18 were selected for their ability to produce clear and reproducible patterns of multiple bands.A total of 177 loci of 260-2600 bp were amplified, of which 89 (50%) were polymorphic, 14 (8%) monomorphic and 74 (42%) were accession-specific. Accession-specific ISSR loci were obtained for all of the seven accessions tested. A dendrogram generated using the UPGMA, based on a similarity measure of total character difference, showed that the Gleditsia accessions were clustered into two main groups (‘a’ and ‘b’). The first grup –‘a’– included: Gleditsia triacanthos L., Gleditsia triacanthos L. (bulk) and Gleditsia triacanthos f. inermis (L.) Zabel (similarity 0.61–0.75), the second –‘b’– included 2 species: Gleditsia japonica and Gleditsia japonica var. korainensis (similarity 0.43). Analysis of the phylogenetic similarity dendrogram has shown wide range of diversity between studied accessions. The clustering pattern obtained in our experiment was in agreement with the data based on morphological, allozyme and ITS analysis.
Inter-simple sequence repeat (ISSR) amplification was used to analyze polymorphism of microsatellite sequences in the lilacs genom and to evaluate genetic diversity among seven lilacs species (Syringa × prestoniae McKelvey., S. reflexa K.C. Schneid., S. villosa Vahl, S. × chinensis Willd., S. meyeri K.C.Schneid., S. vulgaris L.and S. reticulata (Blume) var. amurensis (Rupr.)). The plant material was originated from the collection of Dendrological Garden in Przelewice.A total of 30 primers, containing different simple sequence repeat motifs were tested for amplification.Out of the 30 primers only 13 gave interpretable banding patterns in all lilacs species.A total of 182 ISSR fragments were generated with 13 primers of which 109 (60%) were polymorphic and 57 (31.2%) species-specific. ISSR–PCR with genomic DNAs of the showed lilacs yielded DNA fragmets ranging form 2200 to 123 bp in size.Species-specific ISSR fragments were detected for each lilacs accessions.UPGMA cluster analysis was used to construct a dendrogram and to estimate the genetic distances between lilacs species.The ISSR-based phylogeny was generally consistent with Syringa taxonomy based on morphological and phenological evidence.
This communication reports detection of somaclonal variation among tissue culture-raised plants of Amorphophallus rivieri Durieu, an economically important crop in China, with high content of glucomannan in its corms. A population of regenerated plants was obtained from a single donor plant of A. rivieri via corm organogenesis, and 28 plants were randomly selected as a representative sample and subjected to analysis of somaclonal variation using inter-simple sequence repeat (ISSR) markers. Of the 26 ISSR primers screened, 13 gave distinct and reproducible band patterns, yielding 131 bands with an average of 10.1 bands per primer. Ten primers were polymorphic and generated 16 polymorphic bands with 12.2% mean polymorphism. Based on the ISSR data from the regenerated plants and the donor plant, Jaccard's similarity coefficients were calculated; they ranged from 0.961 to 1.000 with a mean of 0.982. A dendrogram was constructed using the unweighted pair group method with arithmetic mean (UPGMA); it showed that a majority of regenerated plants (including the donor plant) clustered closely, with a mean similarity coefficient of 0.987. Low somaclonal variation observed in the regenerated plants indicates that rapid propagation of A. rivieri via corm organogenesis is a practicable method with a low risk of genetic instability.
Aconitum bucovinense, a high-mountain species endemic to the Eastern and Southern Carpathians, including the Apuseni Mountains, is legally protected and classified in the Polish Red Data Book of Plants. It attains its NW geographical range in two peripheral populations in the Western Bieszczady Mountains (Polish Eastern Carpathians), isolated by a distance of 13.1 km. PCR-ISSR analysis has been used to elucidate the within- and among-populational levels of species genetic diversity. A UPGMA and block clustering showed discreteness of the populations and subpopulations based on ISSR banding pattern. Analysis of Molecular Variance (AMOVA) revealed significant divergence (P = 0.024) of the two marginal populations and highly significant (P < 0.001) differentiation of subpopulations within populations. The theta index calculated for the two marginal populations and the core population in the Carpathians was 0.131 ±0.030 S.D. Most of the population-genetic diversity indices of the mar­ginal populations were not different from those in the core area but the Shannon’s and rarity indices were lower in the marginal populations. It seems that founder effect and subsequent genetic bottleneck resulted in a fine-scale population genetic structure. The marginal populations under study need a relevant recovery program to maintain their genetic diversity.
The ISSR technique was used to determine the genetic similarity between 18 cultivars of sour cherry (Prunus cerasus L.), 24 cultivars of sweet cherry (Prunus avium L.) and 9 types of rootstocks for plants of these species. In reactions where 35 primers were used, 230 polymorphic DNA fragments diversifying the rootstocks were acquired, as well as 144 polymorphic fragments for the cultivars of sour cherry and 98 of sweet cherry. The highest degree of DNA polymorphism was observed in the case of the rootstocks (71.2%). For sour cherry, it was 50.7% and for sweet cherry 39.5%. It was possible to distinguish between types of rootstocks using two primers (827, 841), cultivars of sour cherry using also two primers (825, 841), whereas in order to distinguish the sweet cherry cultivars, three primers had to be used: 830, 841 and 843. Among the cultivars of sweet cherry, the highest genetic similarity was observed between 'Van' and 'Techlovan', 'Regina' and 'Karina', 'Summit' and 'Sam'. In the case of sour cherry, the most similar genetically proved to be 'Debreceni Botormo' and 'Ujfehertoi Furtos' as well as 'Nefris' and 'Safir'. Among the rootstocks, the least disparity demonstrated genotypes of two groups from the GiSeLa and PHL series. Obtained ISSR markers allow the identification of tested genotypes as well as their more accurate characterization. Results of the research may find application in gene banks of Prunus genotypes, and in orchard and nursery practice.
Prunus mume is one of the most popular landscape plants In China and Japan. A successful in vitro propagation system for six cultivars of Prunus mume has been developed by in vitro culture of nodal segments from seedling and mature plants. High multiplication rates (from 2.5 to 5.5) were achieved using modified MS media and WPM basic media supplemented with TDZ, BA, IBA, 2,4-D or NAA at concentrations adjusted for each cultivar. All the studied cultivars could be proliferated efficiently on WPM media supplemented with 2.2 µM TDZ, 2.2 µM BA and 2.5 µM IBA. Shoots were rooted on agar-gelled 1/2 MS or WPM basic media containing 2.5 or 5.0 µM IBA, and plantlets were transferred to pots after they had grown more than 3 roots and at least one root was more than 10 mm long. The effects of TDZ, media composition and different genotypes on shoot multiplication and growth were studied in detail. The genetic fidelity of the micropropagated plants from the ’Xuemei’ cultivar was examined using PCR-ISSR markers, and the results demonstrated complete genetic stability in the cloned plants.
In the paper a comparative analysis of three genetic similarity assessement systems is presented. Genetic similarity of 12 Polish cultivars of Avena sativa L. was established based on RAPD and ISSR molecular markers and pedigree data. Mean cultivar similarity estimation based on ISSR markers was 0.933, and the one derived from RAPD was a little lower 0.912. The mean value of coefficient of parentage (COP) was considerably lower than molecular marker polimorphism-based genetic similarities and amounted to 0.142. The highest and significant correlation coefficient (0.66) was established between genetic similarities calculated from RAPD and ISSR molecular data. Coefficients of correlation between COP matrix and genetic similarity matrices derived from molecular markers were also significant. It allows a conclusion, that each method used in this studies can be apllied separately for genetic similarity assessement.
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