G.J.B.A.H.S.,Vol.4(1):117-128 (January-March, 2015) ISSN: 2319 – 5584 117 GENETIC DIVERSITY AS ASSESSED BY MOLECULAR MARKERS AND MORPHOLOGICAL TRAITS IN EGYPTIAN OKRA GERMPLASM Rania A.A. Younis 1* , S. M. K. Hassan 2 & H. A. El Itriby 3 1 Genetics Department, Faculty of Agriculture, Ain Shams University, Cairo ,Egypt. 2 National Gene Bank, Cairo, Egypt. 3 Director, National Gene Bank, Cairo, Egypt. *Corresponding Author 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. Key words: Okra, ISSR, AFLP, genetic distance. INTRODUCTION The cultivated okra (Abelmoschus esculentus L.) commonly known as ‘Lady’s fingers’, ‘Gumbo’, and ’Bamia ’, belongs to the family Malvaceae. The crop is a native of Africa and is still found growing wild around the River Nile as well as in Ethiopia, in tropical and sub-tropical areas (Kochhar, 1986). It can grow all year round, but in Egypt it's production is mainly during the summer season. Okra was previously included in the genus Hibiscus. Later, it was designated to Abelmoschus. Although about 50 species have been described, eight of them are most widely accepted (IBPGR, 1991).Contradicting evidence exists on the geographical origin of A. esculentus. One putative ancestor (A. tuberculatus) is native to Uttar Pradesh in North India, suggesting that A. esculentus originated in India. The other evidence is based on the plants cultivation in ancient times, and the presence of another putative ancestor ( A. ficulneus) in East Africa, suggesting northern Egypt and Ethiopia as the geographical origin of A.esculentus. The major producers of okra are India, Costa Rica, Nigeria and Ghana (NARP, 1993). Conservation and management of germplasm in gene banks require morphological characterization and descriptors are vital tools in that respect (Rubenstein and Heisey, 2003). Also, molecular markers have proven to be powerful tools in the assessment of genetic variation and in the elucidation of genetic relationships within and between species (Omonhinmin and Osawaru, 2005; Chakravarthi and Naravaneni, 2006). In addition they can be used to identify unique genotypes and markers that are associated or linked to important agronomic traits. Therefore, the application of molecular marker techniques such as RAPD, ISSR, SSR, and AFLP and the proper documentation of useful polymorphism between accessions constitute an important role in enhancing germplasm utilization. Since okra has been considered a minor crop, attention has not been paid to the collection and conservation of okra germplasm and likewise to its genetic improvement either at the national level or in the international research programs. Similarly studies using molecular markers in okra are lagging behind the other major crops (Martinello et al. 2001; Aladele et al. 2008; Saifullah and Rabbani, 2009; Kaur et al. 2013). Therefore, the objectives of this study were to conduct morphological characterization of 29 okra accessions conserved at the National Gene Bank of Egypt, the estimation of the genetic variation and genetic relationships among these accessions using ISSR and AFLP marker systems techniques, and to develop genetic profiles for these accessions. MATERIALS AND METHODS Materials This study was carried out on 29 okra accessions (Table 1) collected from different locations in Egypt during 2004 through 2006 and conserved in the National Gene Bank (NGB), Agricultural Research Centre (ARC).