Effect of Long Period Cooling Storage on the Nucleic Acid of Harvested Cowpea Seeds (Vigna Sinensis L.) Treated by Gamma Irradiation and Micro Elements

Cowpea seeds (Vigna sinensis L.) were exposed to 40 & 80 Gy gamma radiation, in order to study the effect of long period under cooling storage by using RAPD and ISSR PCR facilities. The obtained results indicated that RAPD protocol gave 65% monomorphic and 56% polymorphic fragments between the samples as compared to storage and nonstorage controls. While, ISSR protocol gave 83% monomorphic and 85% polymorphic fragments. It should be mentioned that other percentages 86% and 91% were found among samples in case of using another primers. The results could be summarized as follow: 1- Primer OP-B01 gave 7 monomorphic and 13 polymorphic fragments (65%). 2- The Primer OP-B02 and Primer OP-B05 gave 4 monomorphic fragments with 14 polymorphic fragments (79%). 3- The Primer HA-98 gave 4 monomorphic fragments with 19 detected polymorphic 83%. 4- The Primer HA-99 and HB-12 gave 3 monomorphic fragments and 17 polymorphic 85 and 86%, respectively. 5- The Primer HB-13 gave 2 monomorphic fragments with 21 detected polymorphic fragments 91%. 6- The primer HA-98 gave 83% while the primer HA-99 gave 85%. The previous results showed some polymorphism differences among the samples, while the primer HB-12 gave 86% and the primer HB-13 91% exhibited high levels of polymorphism. The DNA of stored cowpea seeds which were exposed to 80 Gy in the presence of zinc showed the highest differentiation, while radiation dose 40 Gy treated with zinc or boron, 80 Gy with boron and 40 or 80 Gy treatment alone compared to the two controls (storage and non storage).