Structural pattern and genetic diversity in blueberry ( Vaccinium ) clones and cultivars using EST-PCR and microsatellite markers

The blueberry ( Vaccinium L. section Cyanococcus Rydb.) is a health promoting and economically important small fruit crop. Structured genetic diversity and relatedness were studied in 63 blueberry wild clones and cultivars , using eleven EST-PCR and nine microsatellite markers. Markers were found to be polymorphic and detected 249 alleles with mean polymorphic information content of 0.80 for EST-PCR; and 164 alleles with mean polymorphic information content of 0.77 for microsatellite markers. The average resolving power was 4.6 for EST-PCR and 2.6 for microsatellite markers. The average values of expected and observed heterozygosity, inbreeding coefficient and Shannon’s index were higher for the EST-PCR markers than those of microsatellites. Multivariate clustering analyses using neighbor joining and principal coordinate analyses formed five groups and clustered the genotypes according to their place of origin that were also confirmed by STRUCTURE analysis and analysis of molecular variance. While 33% of variation was found among the geographic groups, the variation among the communities within the groups was 23% and among genotypes within the communities was 44%, in combined analysis. The availability of high genetic diversity among the wild clones will contribute significantly in germplasm management and their utilization in the current blueberry improvement program.