PERFORMANCE OF MAIZE CROSSES OBTAINED BY IRRADIATION AND SELECTION

Abstract

The induction of mutations has been used to increase the genetic variation and to improve agronomic traits. In the last 15 years, 1019 varieties derived from mutations have been released. In this work we evaluated tropical composite mutant lines (CLMT) crossed with composite lines F₁S₁ (CLF) obtained from subtropical hybrids, in order to select useful germplasm for maize breeding in the subtropical region of México. Results showed that the mutant materials achieved a higher dominance variance (_σ²_D =5.4) for ear yield than the non mutant materials. ‘CLMT- 27 x CML-311’, ‘(LMT-6)S₄-bk-1-7-1p-9p x CML-176’ and ‘(LMT-6)S₄-bk-1-7-1p-8p x NC-300’ derived from mutant materials, yielded 13.7, 10.8 and 10.0 t ha^-1, respectively, and were statistically equal (P ≤ 0.05) than the commercial hybrid ‘Pioneer 30G40’ which yielded 13.7 and 11.2 t ha^-1 in two experiments. Composite ‘CLMT-27’, ‘CLMT-3’ and ‘CLMT-9’ had an average GCA for yield of 11.2, 9.7 and 9.1 t ha^-1, respectively, so they could be included in maize breeding programs.