Ograniczanie wyników

Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 65

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 4 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  genetic analysis
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 4 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Modern technologies and accurate information on genetic diversity and structure are contributing to improve the plant breeding, in particular for all the minor species with a lack of data. Genetic diversity of 139 different Ficus carica L. genotypes collected from Italy and Croatia, and divided into two subgroups: uniferous (only main crop) and biferous (breba and main crop), was investigated using 49 microsatellite markers. A total of 70 alleles were generated, of which 64 (91.4%) showed a polymorphic pattern indicating high level of genetic diversity within the studied collection. The mean heterozygosity over the 64 single locus microsatellites was 0.33 and the expected and observed averaged variance were 16.50 and 184.08, respectively. The 139 fig genotypes formed two clusters in the PCoA analysis, suggesting a division between Italian and Croatian genotypes. Moreover, the fig accessions could be divided into two main clusters based on the STRUCTURE analysis according to the biological type, uniferous or biferous, with partly overlapping varieties. In conclusion, our results demonstrated that molecular markers were able to discriminate among genotypes and useful for the authentication of fig tree varieties (homonymies and synonymies).
The aim of the study was to determine the origin of additional embryos on the basis of marker characters observed in the phenotype of twin pairs of F2 and F3 generations of two hybrid cultivars of tomato (Alonso and Carmello). The marker characters were the presence/absence of the so-called green back, and the type of growth, which can be indeterminate or determinate. Among 112 F2 twins, differences in marker characters were observed in 24 pairs. In the material derived from Alonso, 9 of 18 observed F3 progenies did not show segregation in marker characters. Progenies of Carmello had higher variability; only 12 of 28 progeny groups showed no recombinants. Analysis of the F3 generation enabled further limitation of the sources of additional embryos. Segregation of any marker character excluded the possibility that a particular F2 twin was formed from a haploid cell of the embryo sac after spontaneous doubling of chromosome number.
Analysis of genetic structure of Silesian horses from National Stud. The aim of the study was to analyze the genetic composition of Silesian horses bred in "Książ" National Stud basing on their pedigreesand to try to answer the following question: is the subdivision of Silesian horse population really necessary to prevent local horse breed? As the material 72 pedigrees of brood mares and stallions, born between 1991 and 2009 were used. On average, 93.1% of animals were inbred, there were 96.55% inbred stallions and 90.70% inbred mares. The mean inbreeding coefficient for all horses was 2.3%, for inbred horses it reached 2.5%. There were more inbred mares (39) than stallions (28). All 72 Silesian horses from "Książ" State Stud were related with the average relationship coefficient of 8.5%. The total and effective number of founders were 458 and 163, respectively. The total andeffective number of ancestors were 64 and 22, respectively. Among the founding breeds Thoroughbred horses predominated, the next were Oldenburg and Silesian horses, whereas among ancestors there were much more Silesian horses than Thorougbreds. All in all, the genetic diversity of the Silesian horses from "Książ" National Stud was satisfactory, however its monitoring is required because of both upward inbreeding and 100% related animals. Because the population of Silesian horses is small, less than 2,000 animals and sligtly over 1,000 animals included in conservation programme, the artifical subdivision of this population as proposed in the new breeding programme, which would result in creation of two subpopulations: “old-type” and “new-type” Silesian horses, is not recommended. For maintaining genetic diversity, it could be also possible to carefully import of semen or stallions of similar breeds, i.e. German Alt-Oldenburger horses or German Heavy Warmblood horses. The plan should also include the matings recommended within the population of all available Silesian horses of both types. The authors consider introducing such a program essential. It should be also clearly stated in the plan how large proportion of the Silesian mares population could be each year mated to Thoroughbredstallions. Division into two types implies that some fraction of new-type Silesian horses and their progeny would not be regarded as potential parents of individuals for the conservation programme.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 4 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.