Genetic variability in some economic traits of a sweet basil (Ocimum bassillicum L.) cultivar affected by gamma irradiation

The present study aimed to induce mutation in a sweet basil (Ocimum basilicum L.) cultivar , 
a medicinal plant, for improving its economic characters .To achieve this purpose , the seeds 
were exposed to different doses (5, 10, 15 Kr) of gamma irradiation. Irradiated and non
irradiated seeds were cultivated during the two successive seasons 2010 and 2011. The 
experiment was designed as randomized complete blocks with 4 treatments and 5 replicates. 
Vegetative characters and chemical composition of essential oil in treated plants were studied. In 
addition, RAPD-PCR and protein banding profiles using SDS-PAGE were performed for 
characterization of the irradiated types. The results indicated that 10 and 15 Kr doses had a 
highly significant impact on essential oil percent, number of branches per plant and plant height 
in first and second cuts in both seasons compared with control. RAPD -PCR revealed that all 
primers were polymorphic producing 92 polymorphic bands in total. Protein banding profile 
demonstrated a conserved band (100 KDa) was present at10Kr in both seasons and a deviated 
band with high molecular mass (180 KDa) was induced at the same dose. Our results indicated 
that10 and 15 Kr doses could be useful to produce superior chemical composition and biomass 
yield in sweet basil plant. In addition, RAPD and protein analysis could help identifying genetic 
variation among irradiated types.