Explore variability of local peach genetic resources for efficient breeding programs

Abstract

Fruits of local peach strains, grown under Dakahlia governorate for a long time ago, are characterize with special taste and aroma, compared with other peach cultivars, and appear in the markets yearly from mide-June to mid-September, the period when the fruits of most early and mid-season peach cultivars disappear. Local peach trees were sexually propagated, so different strains were produced. Such strains are greatly differed in growth habits, maturity date, and yield and fruit characteristics within the same orchard. Those strains have locally common names known to farmers. Since traditional methods, based on morphological and phenological characters are time consuming, blurred by environmental influences and frequently lake resolving power needed to undoubtedly identify individual genotype, the present study aimed to detect genetic variability and explore local peach genetic resources, where genetic aspects are powerful tools in the improvement of the crop and development of molecular markers, as an efficient short cut and cost-effective tool for evaluation, could assist selection and breeding programs. Electrophoretic protein banding patterns and two enzyme profiles; peroxidase and Polyphenol Oxidase, randomly amplified polymorphic DNA-PCR (RAPD-PCR) and inter simple sequence repeat-PCR (ISSR-PCR) were used to assess the genetic diversity of five selected, on basis of growth habits and flowering attitudes, Sultani peach seedy individuals. One RAPD primer; D07, and two ISSR primers; HB10 and HB12, were tested. Based on the results of overall markers (biochemical and molecular), only two (No. 1 and 5) of the five selected individuals were genetically identical to each other. Only one protein band was unique in one of the five selected individuals (No. 4), while one peroxidase isozyme was not detectable only in the second individual. Polyphenol Oxidase exhibited four monomorphic bands across the five selected individuals. All primers were successfully used as fingerprinting tool. One specific fragment was detected to discriminate the fourth individual