Genotypic Value in The Selection of Bean Types
Breeders may use different procedures to identify superior genotypes in preliminary experiments of lines (EPL); the common practice is to observe the field phenotype (known as phenotypic value) from which its obtained statistical means are used to estimate the grain yield. An alternative is to predict the genotypic value by using the linear and unbiased predictor (BLUP). Because of these, the objective of the present study was to identify breeding lines of common bean (Phaseolus vulgaris L.) high in an EPL to be used in tests of the value for cultivation and use (VCU), based on the estimation of phenotypic values and the prediction of the genotypic values. The study was carried out during the 2012-2013 agricultural year (1st and 2nd cycles of cultivation), 34 common bean genotypes: 29 breeding lines and five cultivars (treatments) were sown; the experimental design was randomized blocks with three replicates, from which 11 agronomic traits were evaluated. The results were analyzed with an ANOVA, the F test and the SNK (p≤0.05) for means comparison. The joint analysis included the two evaluated seasons. The procedure used for the prediction of genetic values was BLUP. Joint evaluation of the phenotypic and genotypic values allowed best inferences and precision in the selection of the breeding lines that should be included in trials of VCU. The criterion selection of the higher or lower genotypes must be based on the combination of the results of the values observed in the field (visual assessment), the averages of the values obtained in the trial (phenotypic values) and the estimated genotypic values.