www.tjprc.org editor@tjprc.org IDENTIFICATION OF NOVEL SEX-SPECIFIC PCR-BASED MARKERS TO DISTINGUISH THE GENDERS IN EGYPTIAN DATE PALM TREES SAMI S. ADAWY 1 , JIMING JIANG 2 & MOHAMED A. M. ATIA 3* 1,3 Department of Genome Mapping, Agricultural Genetic Engineering Research Institute (AGERI), ARC, Giza, Egypt 2 Department of Horticulture, University of Wisconsin-Madison, Madison, USA * Corresponding author: matia@ageri.sci.eg ABSTRACT Date palm (Phoenix dactylifera L, 2n=36) is outstanding for the economic value of its different parts and its socio-economic significance in agro-systems of arid zones. Date palm trees are propagated either from seed or vegetative off shoots. Propagation with seeds is unsuitable for commercial production because half of the progeny are males and to date there is no way to distinguish the sex in date palm plants at an early stage of development. During the past decade, there have been numerous attempts to use molecular markers to discriminate among male and female trees in date palm. Here, we employed an effective approach to develop sex-specific PCR-based markers to distinguish the genders in Egyptian date palm. A set of 23 SCoT and 122 RAPD primers were applied against five superior Egyptian date palm cultivars to identify any sex-specific markers. Two SCoT (SCoT36 and SCoT41) and four RAPD primers (OP-A11, OP-M11, OP-O07 and OP-S07) exhibited differential fragments/bands between males and females (Two male-associated markers and five female-associated markers). To verify these results, the PCR reactions were repeated at least three times by different professional hands and by using different commercial reagents (Promega, Ferments and Takara). Then, these differential bands were extracted, cloned to pGEM-T Easy Vector System and transformed into DH5-alpha E. coli competent cells for subsequent sequencing analysis. The BLAST analysis results indicated that SCoT36 revealed high degree of similarity with mitochondrial rpl2 gene in date palm while, SCoT41 revealed high degree of similarity with putative DEIH-box RNA/DNA helicase gene (Os01g0767700) in Oryza sativa Japonica. On the other hand, the BLAST analysis of (OP-A11, OP-O07 and OP-S07) revealed no significant similarity to any well-defined sequences or protein on databases. While, they showed very low similarity with the date palm published sequences which give high probability that this sequences may be a novel or non-sequenced parts of the date palm genome. Meanwhile, OP-M11 exhibited high degree of similarity with the date palm genome (cultivar Deglet Noor, fosmid 9B12) and partial similarity with both putative glucuronoxylan glucuronosyltransferase protein ( Triticumurartu) and Exostosin- like family protein (Oryza sativa). These results represent the first case-study focusing on the applications of SCoT technique as a gene targeting marker in sex-determination in date palm. Moreover, indicate that these promising primers should be helpful in rapidly distinguishing between male and female trees in date palm at earliest stages. KEYWORDS: Date Palm, Sex-Determination, SCoT, RAPD, Molecular Markers INTRODUCTION Date palm (Phoenix dactylifera L.) is a dioecious perennial tree with a great socio-economic importance especially in the Middle East, North Africa and to a small extent in California and Mexico. The date palm trees are cultivated not only for their valuable fruits (dates), but also for producing fuel, fiber and as shelter for ground crops. International Journal of Agricultural Science and Research (IJASR) ISSN(P): 2250-0057; ISSN(E): 2321-0087 Vol. 4, Issue 5, Oct 2014, 45-54 © TJPRC Pvt. Ltd.