INTER SIMPLE SEQUENCE REPEAT (ISSR) AND START CODON TARGETED POLYMORPHISM (SCoT) AS DISCRIMINATION TECHNIQUES BETWEEN CERTAIN APPLE AND PEAR CULTIVARS.

Abstract

Rosaceae is a large family in the plant regality, includes 3200 species in 115 genera such as Malus and Pyrus to which belong Malus domestica Borkh. fruits (apples) and Pyrus communis L. fruits (pears). Apples and pears have a wide variety of active constituents like anthocyanins, flavonoids, sterols, and tannins. P. communis and M. domestica fruits exhibit good antioxidant, antihyperglycemic, and chemopreventive activities. Botanists prefer to keep apple and pear under genus Pyrus but recently, American authors keep them distinct, apple under genus Malus and pear under genus Pyrus. Hybrids were developed to produce cultivars adapted to Egypt warm weather, so there is a large similarity between the different pear and apple cultivars which requires accurate and rapid techniques for their differentiation. The genetic discrimination between apple cultivars, Anna (1), Volus (2), Dorset golden

(3) and pear cultivars, Le-Conte (4), MKM (5) and Flordahome (6) were carried out using start codon targeted and inter simple sequence repeat techniques with ten decamer primers, five for each technique. All primers gave bands with all cultivars with total 49 bands, 26 with ISSR and 23 with SCoT techniques, respectively with 27, 19 and 3 monomorphic, polymorphic and unique bands, respectively. According to combined dendrogram and similarity matrix, apple and pear cultivars grouped into two main groups, one contains the apple cultivars and the other contains pear cultivars with similarity coefficient 0.76-0.92. As a result, we can use ISSR and SCoT techniques for differentiation between apple and pear cultivars which have large morphological similarity.