IN VITRO MUTAGENESIS OF THREE CULTIVARS OF POTATO BY SODIUM AZIDE

In vitro of three potato cultivars (Arnova, Provento and Emma) were mutated with sodium azide (NaN3) at a concentration of 1mM for different periods of time (0, 5, 10, 15, 30) minutes. The optimum mutagenic dose was determined and the effect of sodium azide was studied on the phenotypic traits of vegetative (plant height, number of shoots, number of leaves and nodes) and root systems (number and height of roots) and compared with non-mutagenic plants (control treatment). The cultures were incubated at 25 ± 2 °C and 16 h day-1 illumination. Mutated and non-mutated plants of the three cultivars were transferred to the greenhouse and data were taken on the number of minitubers, diameter and their weight after 90 days of planting. Random Amplified Polymorphic DNA (RAPD) technique was applied to detect genetic variations using 6 random primers (A8, A10, C8, C15, H16 and S12).The results showed that the percentage of mortality (LD50%) of stem cuttings of the cultivars (Arnova, Provento and Emma) was 30 minutes for mutation with sodium azide at 1 mM concentration The results also showed the significant deference between the cultivars in their response to the mutation with sodium azide at different periods of time in the phenotypic traits of vegetative and root system. The six primers distinguished a number of bands with different molecular weights in mutated plants and their absence in non-mutated plants within the same cultivar. C15 primer was distinguished 3 bands in mutagenic plants of Arnova cultivar and 5 bands of Provento cultivar. While the primers A8 and S12 distinguished only one band with a molecular weight of 1000 base pair in the mutated of Arnova and Provento, as well as the primer A10 distinguished one band in the cultivar Provento and two bands in the cultivar Emma.