Theme 12: Forage Breeding and Genetics
Description
Genotype x environment (GE) interactions limit the effectiveness of selection when selection is based only on mean yields. The objective of this study was to evaluate the amount of GE interaction for vetch forage yield in some environments of Southern Italy, and to analyze some stability parameters that can be useful in the selection of genotypes adapted to Mediterranean environmental conditions. Eleven vetch genotypes were grown in a total of 16 environments in Southern Italy. The combined analysis of variance for forage yield showed that the environment, genotype and GE interaction terms were significant at 0.01 level, suggesting a broad range of genotype diversity and environmental variation. Production stability for yield was measured by computing five stability parameters: (i) mean forage yield, (ii) the regression coefficients of the yields of a genotype on to mean yields of the 16 environments (b), (iii) the deviations from regression mean square (sdi2), (iv) the determination coefficient (r2), and (v) the ranking indices (R1 and R2) of genotypes productivity. Phenotypic correlations between forage yield and stability parameters were also calculated. More than 90% of yield variability of single vetch genotype is due to the linear regression. The mean forage yield and the adaptability (b) and stability (sd2 and r2 ) parameters showed a significant variability. No significant correlation was observed between yield and adaptability and stability parameters, whereas the correlation between r2 and sd2 parameters was highly significant (r = – 0,978**). Three genotypes, useful for Mediterranean environments, were selected.
Included in
Genotype-Environment Interaction for Forage Yield of Vetch (Vicia sativa L.) in Mediterranean Environments
Genotype x environment (GE) interactions limit the effectiveness of selection when selection is based only on mean yields. The objective of this study was to evaluate the amount of GE interaction for vetch forage yield in some environments of Southern Italy, and to analyze some stability parameters that can be useful in the selection of genotypes adapted to Mediterranean environmental conditions. Eleven vetch genotypes were grown in a total of 16 environments in Southern Italy. The combined analysis of variance for forage yield showed that the environment, genotype and GE interaction terms were significant at 0.01 level, suggesting a broad range of genotype diversity and environmental variation. Production stability for yield was measured by computing five stability parameters: (i) mean forage yield, (ii) the regression coefficients of the yields of a genotype on to mean yields of the 16 environments (b), (iii) the deviations from regression mean square (sdi2), (iv) the determination coefficient (r2), and (v) the ranking indices (R1 and R2) of genotypes productivity. Phenotypic correlations between forage yield and stability parameters were also calculated. More than 90% of yield variability of single vetch genotype is due to the linear regression. The mean forage yield and the adaptability (b) and stability (sd2 and r2 ) parameters showed a significant variability. No significant correlation was observed between yield and adaptability and stability parameters, whereas the correlation between r2 and sd2 parameters was highly significant (r = – 0,978**). Three genotypes, useful for Mediterranean environments, were selected.
