Abstract

REBOLLOZA HERNANDEZ, Hermes et al. Estimation of genetic parameters and selection of S₁ lines in a segregating population of tropical maize. Rev. Mex. Cienc. Agríc [online]. 2016, vol.7, n.8, pp.1893-1904. ISSN 2007-0934.

In Mexico 7.5 million hectares of corn are grown, with an average grain yield of 3.2 t ha-1, a strategy to increase yield is the use of improved varieties. The objectives of this study were 1) estimate genetic parameters in a segregating population of tropical maize; 2) select S1lines based on grain yield and earliness; and 3) determine the phenotypic and genetic correlation between traits. The germplasm under study consisted of 193 segregating S1 lines, parents and a control, S1 lines come from the F2 population from crossing Ac7643 x B-39. The lines were evaluated under irrigation using an alpha lattice design with two replications during the spring-summer 2013 and autumn-winter 2013/2014 cycle, in Ayala, Morelos. The variables recorded were days to male (FM) and female silking (FF), floral synchrony (SF), plant height (AP) and cob (AM) and grain yield (RG). The results indicate that the coefficient of additive genetic variation for RG was 17% and for FM 4%; heritability for the same traits was 0.42 and 0.80, respectively. The expected genetic gain for RG was 0.143 t ha-1 and for FM -0.62 d. The LUM-80 line turned with positive transgressive inheritance in RG. Phenotypic and genetic correlations between RG and the rest of the traits were low. The high degree of genetic variability present in the segregating population allows continuing with the breeding program.

Keywords : genetic gain; heritability; transgressive inheritance.