Emmanuel Arnhold

Heredabilidad de la sobrevivencia en 169 familias de maíz-roseta de granos blancos: Un enfoque Bayesiano

M.A. Rodovalho, F. Mora, E.M. Santos, C.A. Scapim, and E. Arnhold. 2008. Survival heritability in 169 families of white grain popcorn: A Bayesian approach. Cien. Inv. Agr. 35(3):303-309. During the genetic evaluation of 169 half-sib families of white grain popcorn (Zea mays), at the beginning of a breeding program conducted in southern Brazil (Cycle I), signifi cant differences in family survival were detected (p < 0.01). Consequently, plant survival was incorporated into the breeding program. The main objective of this study was to examine genetic parameters for plant survival, and their association with other traits of agronomic interest. A Bayesian approach was used for this purpose, implemented by Gibbs sampling (for individual plant selection) and independence chain algorithms (for family selection). The survival (measured as a binary trait) varied from 48 to 100% at the family level. Heritability (h 2 ) was signifi cant and high for this trait, with a posterior mean of h 2 =0.63 and Bayesian credible interval of 0.53-0.74. The genetic gain was 14.5% (selection intensity: 20%). Survival was correlated positively and signifi cantly with grain yield (p < 0.01), indicating that family selection based on survival alone would have a positive effect on yield and vice versa. The Spearman correlation coeffi cient calculated between survival and popping expansion was not signifi cantly different from zero, indicating that selection for family based on popping expansion would not have a signifi cant effect on survival.