The Dose Response and Mutation Induction by Gamma Ray in Vicia Faba Cv. Saraziri

Sufficient genetic variation is an essential source for having a successful breeding program. Mutation is known to be a high throughput technique to induce genetic variation in plants. Irradiation is the most common method of inducing mutations in plants mutation breeding programs leading to the production of mutants with superior genotypes. Faba bean is a crop whose diversity needs to be improved for breeding programs in Iran. Unfortunately, few researches have been carried out on mutagenesis of faba bean.

In the present study, the dose response and effects of gamma irradiation have been investigated by exposing the seeds of Vicia fabacv. Saraziri to doses of 25, 35, 45, 55, 100, and 120 Gray (Gy) in the Lab at the college of Agriculture, Shahid Chamran University of Ahvaz in 2013 to 2015. The implementation of the research was under the guidance and in cooperation with the Atomic Energy Organization of Iran. The experiments were assigned as a completed block design with four replications in both laboratory and the field.

The results of the analysis of the variance indicated that there was no significant difference in germination trait of M0 generation in the seeds at various gamma irradiation doses whereas, germination rate, seedling length, and weight were significantly altered at varied doses (P≤0.05), and further responses of these traits decreased as the dosage increased. Moreover, increasing the irradiation doses caused a delay in flowering, pod setting, and pod ripening period in M2 generation. A linear regression between different characters and gamma doses was detected. Lethal dose, 50% (LD50) for fertility and seed setting, was detected as between 60-65 Gy based on reproductive traits. The principal component analysis revealed information that the first two components within the traits at the different doses were accounted for approximately 71% of the total variance. Using the biplot diagram of the first two components, 320 mutant plants appeared and the superior one within plants was identified as compared to control.

This research is reported the optimum dose of gamma irradiation of 50 to 55 Gy to exert mutation induction in Vicia Faba based on the LD50 of vegetative and reproductive phases. The findings of the current work acquired several promising mutants that might be used as beneficial sources to develop new faba bean cultivars.