Inheritance of tolerance to metribuzin in durum wheat

The inheritance of tolerance to the herbicide metribuzin was studied in two durum wheat cultivars, one of which, 'Anton', is resistant and one, 'Nita' , susceptible. Parents, F-1, F-2 and F-3 of the crosses 'Anton' x 'Nita' an d 'Nita' x 'Anton' were tested for herbicide response. The character evalua ted was the increase in weight of plants treated with the herbicide. As the re were no significant differences between progenies of reciprocal crosses, cytoplasm was not involved in tolerance. Tolerance was semi-dominant with means values of F-1, F-2 and F-3 progenies in the range of mid-parent. The heritability of this trait estimated by regression of the average of progen y F-3 in their parent F-2 had a value of 0.23 +/- 0.063 and a value of 0.52 +/- 0.150 estimated by the relation V-G/V-P for full-sib F-2 families.