Relative genetic potential of brachytic maize (Zea mays L.) varieties as breeding populations.

Six brachytic maize (Zea mays L.) varietis were evaluated in diallel cross. The six varieties, the fifteen intervarietal hybrids and two checks were evaluated in a randomized block design with six replications at one locations. The statistical-genetical analyses were performed according to the model proposed by Gardner and Eberhart (1966). Relative to the mid-parent, average heterosis was 0.8596 t/ha (17.09%), ranging from 0.150 t/ha (2.46%) to 2.221 t/ha (49.25%). The results showed that the varieties are genetically different both in terms of performance and heterotic potential. Significant specific heterosis was observed for plant height and ear height, which can be explained by the genetic diversity of the varieties with respect to the modifier genescontaining some degree of dominance. The Piranao VD-1 and Piranao VF-1 varieties showed outstanding yielding ability both per se and in crossing. The hybrid between these two varieties showed the highest yielding ability of all diallel crosses. The heterosis level of this particular cross (13.79%) provided evidence of the presence of genetic diversity between the parental varieties, and these varieties are recommended for use in medium-term program involving inbred line hybrids as well as in long-term programs of reciprocal recurrent selection

Interação genótipos x localidades, em híbridos crípticos de milho S1 x S1, nas regiões Sudeste e Nordeste brasileiras.

Estudou-se a interação genótipos x localidades em 104 híbridos crípticos de milho, na segunda geração de intercruzamentos, em duas regiões brasileiras: Sudeste e Nordeste