IDENTIFICATION AND CHARACTERIZATION OF MUTANTS INDUCED BY GAMMA RADIATION IN WINTER WHEAT (Triticum aestivum L.)

Mutation breeding is one of the breeding methods used successfully in durum wheat for selecting lines with increased agronomic values. This study was carried out to determine gamma rays effect and interaction between gamma-rays and the genotype of treated variety of winter wheat in mutations induction. We used physical mutagens: gamma-rays in doses 100, 150, 200, 250 Gy. Seeds of eight winter wheat varieties were exposed with gamma-rays. Insensitive and most sensitive for mutagen actions varieties have been developed. Thirty-six different types mutated traits were observed. Among them there were seven valuable for breeding process. Mutations rate was waved from 0,4 to 30 %. Medium dose of gamma rays (100 Gy) is recommended for winter wheat mutation breeding and high dose (200 Gy) for obtaining genetic-value mutants (parent components for crossbreeding with some valuable traits like as semi-dwarf, early-heading and other). For high-productivity lines were identified. Positive desirable mutants will be selected and be incorporated in future breeding programs. We have shown that varieties obtained by gamma radiation are less sensitive to this mutagen. Their re-exposure is inappropriate by same mutagen. However, the varieties which obtained by field hybridization or treatment by mutagens of another nature (chemical agents, temperature) indicate a higher level of mutation rate and variability of traits.