Topics on the genetics of maize yield stability
Cleso Antônio Patto Pacheco, Manoel Xavier dos Santos, Cosme Damião Cruz, Paulo Evaristo de Oliveira Guimarães, Sidney Netto Parentoni and Elto Eugênio Gomes e Gama
Diallel experiments were carried out in several environments to investigate the genetic control of maize yield stability. The analyses used the methodology developed by Pacheco (1997) which is useful when the genotype x environment interaction is significant and the genetic effects are not consistent across environments. The 28 population diallel assessed in ten environments allowed the following conclusions: a) dominance deviations were the main cause of yield instability; b) populations selected under environmental stress conditions, such as Saracura, produced more stable intervarietal hybrids through a reduction in the deviations from regression due to specific combining ability; c) selection for yield followed by selection for stability would increase the breeding program efficiency if the initial populations had high General and Specific Combining Abilities, broad adaptability and regression deviations close to zero.