Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 4

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  genotypic diversity
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Combined morphological and molecular techniques were used to characterize variation in Elymus repens. We studied the morphological variability of E. repens in relation to the degree of its genetic differentiation, in order to unravel the causes of conspicuous intraspecific morphological variation. Four populations of E. repens from different habitats were analyzed for 35 morphological characters, and their genetic differentiation was assessed by Amplified Fragment Length Polymorphism (AFLP). Four pairs of selective primers were used to detect a total of 279 AFLP bands, of which 104 (37.28%) were polymorphic between populations. Cluster analysis based on AFLP fingerprint data showed that individuals were arranged in population-specific groups. The analyses of variance (ANOVA and AMOVA) indicated significant morphological and genetic differentiation among populations (P<0.01). This study revealed low levels of AFLP variation, which suggests that conspicuous morphological variation of E. repens is caused by plasticity. E. repens is an evolutionarily young species, of hybrid origin, in which microevolutionary processes continue. This study showed that common analysis of genetic diversity and morphology is a powerful tool in low-level taxonomy.
In this study, a total of 54 Vibrio alginolyticus strains were analyzed. The isolates were recovered from different compartments of the Ruditapes decussatus hatchery in the National Institute of Marine Sciences and Technologies, Monastir, Tunisia. All isolates were biochemically identified (API 20E and API ZYM strips), characterized by amplification of the Hsp-40 gene polymerase chain reaction (PCR) and analyzed by enterobacterial repetitive intergenic consensus (ERIC)-based genotyping to evaluate genetic relationship between the isolated strains. We also looked for the presence of ten V. cholera virulence genes (toxRS, toxR, toxT, toxS, tcpP, tcpA, ace, vpi, zot and ctxA) in the genomes of Vibrio isolates. The antibiotics susceptibility, exoenzymes production and in vitro cytotoxic activitiy against HeLa cell line were also carried out for all tested bacteria. Most of V. alginolyticus isolates showed significant antimicrobial resistance rates to at least ten antibacterial agents. For most isolates, the minimum inhibitory concentration (MIC) data showed that tetracyclin and streptomycin were the most effective antibiotics. Construction of the phylogenetic dendogram showed that studied isolates were in general genetically heterogeneous; however some Vibrio strains were present in different structures of the R. decussatus hatchery. The V. cholerae virulence genes investigation showed a wild distribution of toxS (49/54), toxR (45/54) and toxT (22/54) genes among V. alginolyticus strains isolated from the R. decussatus rearing system. Cytotoxic effects of several Vibrio extracellular products (28/54) were also observed on HeLa cells.
Blue honeysuckle due to the high health benefits of its fruit, early ripening (before the first strawberries cultivars) and high frost resistance of both plants and flowers has gained the great popularity both in cultivation and breeding. The implementation of the breeding program of new cultivars requires the knowledge of the characteristics that determine its direction in the selected material. Therefore, in this study the evaluation of the phenological phases, yield, fruit weight, number of seeds per fruit and pollen viability in the cultivars and breeding clones of this species was made. The tested cultivars and clones had different levels of the analysed qualities except the pollen viability which was high but did not differ significantly within the genotypes. The evaluation of such characteristics as yield potential and fruit weight indicates that cultivars ‘Warszawa’, ‘Wojtek’ and T2 clone which had higher values of these characteristics as compared to other genotypes are possible to be used in breeding programme. Obtainment of the forms with early fruit ripening can be realised through the use of the selected Russian cultivars. The objective of this study was also to characterise the blue honeysuckle germplasms using RAPD markers and to assess their genetic similarity. The analysed primers produced 61 fragments out of which 57 (93.44%) were polymorphic. The genetic similarity matrix was made on the basis of RAPD markers. The mean genetic similarity was calculated at 0.56. The presented study confirms that the use of RAPD markers is a practical and effective method to evaluate the genetic similarity of blue honeysuckle genotypes and to establish genetic relationships between these genotypes.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.