Genetic diversity of loquat cultivars assessed by AFLP markers.

摘要

The levels of genetic diversity in 34 cultivars loquat (Eriobotrya japonica) were analyzed using amplified fragment length polymorphism (AFLP) markers in order to provide information on parental selection and germplasm resources management. A total of 1091 AFLP bands were generated from eight informative primer combinations, of which 993 (91.0%) were polymorphic bands. An average of 124.1 polymorphic bands was detected for each AFLP primer combination, which ranged from 92 to 148. The average observed number of alleles (Na), effective number of alleles (Ne), Nei's gene diversity (H) and Shannon's information index (I) were 1.95+or-0.22, 1.43+or-0.32, 0.27+or-0.16 and 0.41+or-0.21, respectively, suggesting the cultivars studied exhibit substantial genetic diversity. The mean coefficient of gene differentiation (Gst) among populations was 0.16; 83.9% corresponded to within populations and 16.1% among populations. The mean gene flow estimate was 2.61, indicating adequate gene flow occurs among populations, however the genetic pool is narrow. The mean genetic distance based on Nei and Li's genetic similarity (GS) coefficient values among samples was 0.36, with values ranging from 0.12 to 0.52. AFLP analysis revealed a close genetic relationship of loquat cultivars derived from different planting zones.