Genetic Variation among and within Okra Ablemoschus esculents L.landraces in Jordan

Genetic variation among and within nineteen okra landraces in addition to one cultivar was estimated based on morphological differences between genotypes in the field. Five landraces, and one cultivar were further analyzed to detect variations among and within landraces at the DNA level using Random Amplified Polymorphic DNA (RAPD) technique. In addition different horticultural and fruit traits were studied such as days to flowering, plant height at flowering, final plant height, immature pod width, immature pod length, mature pod length, immature pod weight, pod per plant, pod yield per plant, seed per pod, stem color, leaf color, leaf petiole color and pod color. Statistical analysis using mean, correlation, standard deviation and coefficient of variability, indicated significant variability either among or within some landraces. The highest morphological variation registered was for the number of pods per plant (50.2%) and the lowest one was for days to flowering (8.3%) this was indicative of the effectiveness of selection also, wide range variability for most quantitative genetic traits. Some okra landraces shared the same color in stems pods and leaves, indicating that common genes controlling these traits. Days to flowering, pod yield per plant, immature pod width and pod color could be used to discriminate between genotypes. Data obtained from arbitrary decamer-oligouncleotide primers have indicated that the RAPD technique could be useful to detect variation among and within landraces. Primer OPA13 were particularly efficient to amplify banding patterns among and within okra landraces. One landrace could be distinguished with caution from other landraces using the presence or absence of a DNA fragment size of 386 bp or 1000 bp when this primer was used. RAPD analysis could be used efficiently for detecting variations among and within landraces and cultivar. Although okra landraces were different morphologically, but at the DNA level variations were not enough to obtain a characteristic DNA polymorphism for each landrace or cultivar. Analysis of additional arbitrary primers in RAPD revealed that different primers could be used in breeding programs. This study initiated molecular characterization for identification and collecting okra of different genetic resources. It lays foundation for breeding programs.