Enviado por vivislizzetthh • 18 de Enero de 2014 • 203 Palabras (1 Páginas) • 131 Visitas
In total, 588 alleles were obtained with 48 SSRs on 653 peach accessions, giving an average of 12.25 alleles
per locus. In general, the average value of observed heterozygosity (0.47) was lower than the expected
heterozygosity (0.60). The separate analysis of groups of accessions according to their origin or reproductive
strategies showed greater variability in Oriental cultivars, mainly due to the high level of heterozygosity in Chinese
landraces. Genetic distance analysis clustered the cultivars into two main groups: one included four wild related
Prunus, and the other included most of the Oriental and Occidental landraces and breeding cultivars. STRUCTURE
analysis assigned 469 accessions to three subpopulations: Oriental (234), Occidental (174), and Landraces (61).
Nested STRUCTURE analysis divided the Oriental subpopulation into two different subpopulations:‘Yu Lu’ and
‘Hakuho’. The Occidental breeding subpopulation was also subdivided into nectarine and peach subpopulations.
Linkage disequilibrium (LD) analysis in each of these subpopulations showed that the percentage of linked (r
intra-chromosome comparisons ranged between 14% and 47%. LD decayed faster in Oriental (1,196 Kbp) than in
Occidental (2,687 Kbp) samples. In the‘Yu Lu’ subpopulation there was considerable LD extension while no
variation of LD with physical distance was observed in the landraces. From the first STRUCTURE result, LG1 had the
greatest proportion of alleles in LD within all three subpopulations