Use of pollen traits for early detection of induced micromutations in wheat

Two pre-release wheat varieties, namely, OW 32-3 and OW 13-1, were treated with two doses each of ethylmethane sulphonate (EMS) and sodium azide(SA) and the effectiveness of the mutagenic treatments for induction of micromutations was assessed in M₁ using two pollen traits, namely, pollen sterility and size. The presumptive mutants showing only pollen sterility were classified as Type I, those showing only pollen size variation were termed Type II, and those showing both pollen sterility and size variation were called Type III. The Type II mutations occurred in greater frequency in the EMS treatments of both the varieties. Between the varieties, OW 13-1 had more of Type II mutations with lower doses of both the mutagens. EMS wasmore effective than SA in inducing useful micromutations, while OW 13-1 showed better response than OW 32-3 for such mutations.