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Genetic diversity in six species of Passiflora spp. using RAPD

Abstract:

RAPD markers were used to study the genetic diversity in the Passiflora germplasm bank of INIA-CENIAP in Venezuela. Six genotypes were molecularly characterized: one cultivated species and five wild type species, collected in diverse regions of the country. DNA extraction was performed according to the modified CIAT method. Sixty 10-mer RAPD primers were used and generated 763 polymorphic discriminating bands revealing high levels of diversity among the studied species. A cluster analysis was made using the Ward linkage method (Dice distance for non standardized data). A cophenetic correlation of 0.858 was found and all the species were associated into three discriminating groups. Group I separated P. edulis f flavicarpa from the wild type Passiflora with a statistical significant difference. Group II was formed by P. foetida and P. maliformis, and group III was conformed by P. subpeltata, P. cincinnata and P. giberti. These last two groups contained the wild type Passiflora, and they differed in more than 82% from P. edulis. Each species had its specific molecular patterns. The analysis showed differences among the six species indicating high genetic diversity based on the presence of distinct band patterns. Variability encountered in the genera could be probably due to being allogamic, autoincompatible species and amenable to intercross.