GENETIC DIVERSITY AS ASSESSED BY MOLECULAR MARKERS AND MORPHOLOGICAL TRAITS IN EGYPTIAN OKRA GERMPLASM

Abstract

Twenty nine okra accessions (Abelmoschus esculentus L.) collected from different locations, were morphologically characterized. Significant differences were observed between some accessions for all quantitative characters studied while variations were detected and described for the qualitative characters. Forty two ISSR primers and five AFLP combinations were used to determine the level of polymorphism, molecular fingerprinting, identification of unique markers, and the estimation of genetic distances for the 29 okra accessions. The ISSR primers amplified 508 fragments of which 415 were polymorphic. The number of positive and negative unique markers were 103 and were useful in identifying 24 genotypes out of the 29 accessions. Moreover, five AFLP primer combinations yielded 449 amplicons, the total number of polymorphic amplicons was 439. Genetic similarity matrices estimated from ISSR and AFLP data, depicted similarity coefficient ranged from 0.68 – 0.90 and 0.51-0.82, respectively. The highest similarity coefficient was between accessions collected from the same governorate, Generally, the constructed dendrograms based on ISSR and AFLP data, exhibited a tendency to cluster accessions in groups according to their geographical locations. In conclusion, additional okra germplasm needs to be collected from other locations and characterized to ensure the representation of most of the genetic diversity in Egyptian okra germplasm is conserved ex situ.