oa Molecular Diversity In Date Palm Using Inter Simple Sequence Repeat (Issr) Markers

Total of 47 Date palm samples representing 15 cultivars from two germplasm collections (Rodat Alfaras Germplasm field and Germplasm field of Qatar University Experimental farm) were collected to study the genetic diversity among and within date palm cultivars grown in Qatar. 29 samples representing 11 varieties were collected from Rodat Alfaras Farm. Eighteen samples including six varieties were collected from Qatar University Experimental Farm. DNAs were extracted from fresh leaves by using commercial DNeasy Plant System Kit (Qiagen, Inc., Valencia, CA) Total of 18 (Inter Simple Sequence Repeat) ISSR single primers were used to amplify DNA fragments using genomic DNA of the 47 samples. First screening was done to test the ability of these primers to amplify clear bands using Date palm genomic DNA. All 18 ISSR primers successfully produced clear bands in the first screening. Then, each primer was used separately to genotype the whole set of 47 Date palm samples. Total of 4794 bands were generated using 12 ISSR primers for the 47 Date palm samples. On average, each primer generated 400 bands. The Number of amplified bands varied from cultivar to cultivar and differed from area to area for the same cultivar. The highest number of bands was obtained using Primers 2, 5 and 12 for the 17 cultivars over all locations (470 bands), while the lowest number of bands were obtained by Primers 1, 7 and 8 where they produced only 329 bands. However, variation within each individual cultivar as number of polymorphic fragments was considerably smaller than the inter-specific variation among the studied cultivars. Markers were scored for the presence and absence of the corresponding band among the different cultivars grown in different locations. Data were subjected to cluster analysis. A similarity matrix was constructed and the similarity values were used for cluster analysis.