Abstract
In this study we identified two grapevine cultivars (Thompson and Superior) from two different locations in Egypt (El-Behera and El-Minia Governorates) which are characterized by widely different environmental conditions. Fruit quality and RAPD markers were used to examine the impact of environmental conditions on these cultivars. The study was conducted in two growing seasons at the two locations. Environmental condition caused significant differences in cluster weight, berry diameter, Size of 100 berries, juice volume, TSS, cluster and berries number of both cultivars. Meanwhile, there were no significant differences between regions for cluster length and width, berry length, weight of 100 berries. Ten RAPD primers produced clear and reproducible amplification patterns were selected and used to study the impact of environmental conditions on genetic structure of the grapevine cultivars. A total of 241 DNA fragments amplified from the tested cultivars with an average of 24.1 bands per and high level of polymorphism (183 bands, 76%). High similarity (Si = 0.60) and lower genetic distance (Gd = 0.511) were observed between Superior cultivar collected from El-Behera and El-Minia. Thompson collected from El-Behera and El-Minia showed longest genetic distance (Gd = 0.844) and lowest similarity (Si = 0.43). Long genetic distances ranged from 0.713 to 0.844 were observed between the other combinations of Superior and Thompson plants of the two locations. The UPGMA cluster analysis grouped the two grapevine cultivars in two separated clusters according to their genetic background. The present study revealed Superior and Thompson grapes grown in El-Behera and El-Minia possessed considerable genetic differences in addition to the differences exist between the two cultivars. Since these cultivars are established in El-Behera and El-Minia for a long time, these genetic differences between grape plants may be due to the two variegated environments and environmental changes.