IDENTIFICATION AND GENETIC SIMILARITY ANALYSIS OF DATE PALM (Phoenix dactylifera L.) COLLECTED FROM DIFFER- ENT REGIONS IN SIWA OASIS USING MORPHOLOGICALLY TRAITS AND MOLECULAR MARKERS.

Abstract

Date palm (Phoenix dactylifera L., 2n = 36) is a fruit tree mainly cultivated in arid regions in the Middle East, where it has been domesticated for at least 5,000 years and is believed to have originated in Mesopotamia. Date palm (Phoenix dactylifera L) is the major factor of oasis environmental and economic stability (Zehdi et al., 2004). The major date producers in the world are located in the Middle East and North Africa (Rania et al., 2008).
In Egypt, date palm is an important crop where the total number of fruitful female palm is about 10 million palm trees according to the statistics of the Central Administrations of Horticultural, Ministry of Agriculture (Rania et al., 2008). This crop is of a great socioeconomic importance in oases. The oasis of Siwa located in Egypt’s western desert is about 600 km away from Alexandria and 300 km South-West from Matrouh (Mediterranean coast) and about 65 km east from the Libyan borders. Siwa oasis is a natural isolated depression in the western desert of Egypt. However, little is known about the genetic characterization of Date palm cultivars. The date palm cultivation takes about 40% of all cultivated area.
The pollen of the date palm has been found to exert a direct influence on the size, shape and color of the seed and also, on the size of the fruit, on the speed of development of the fruit and on the time of ripening of the fruit. This direct influence of the male parent on the development of the date fruit is precise and definite and varies with the particular male used to fertilize the female flowers. Each male is exerting approximately the same effect on fruit of all varieties and exerting the same effect in different years. Therefore, it is important to select and identify superior male in term of fertilization (Walter, 1928).
Recently, study of genetic diversity for plant crops is the process by which variation among individuals or groups of individuals is analyzed by a specific genetically method or a combination of such methods. The most important measurements are data obtained by DNA based marker data that detect and monitor identification of different genomes. Many new markers can be identified in the same region using inter Simple Sequence Repeat (ISSR) markers linked to genes of interest. Furthermore, ISSR is informative about many loci and are suitable to discriminate closely related genotype variants and lastly, ISSR markers constitute discrete markers suitable in the DNA fingerprinting (Gupta and Varshney, 2000).
The objectives of this study were designed to the determine morphological traits among nine date palm cultivars and six male trees grow in Siwa oasis and develop molecular fingerprints based RAPD and ISSR analysis. Moreover, through the obtained data, determine genetic relationships among these cultivars by applying morphological and molecular analysis.