Multigeneration index in the within‐progenies bulk method for breeding of self‐pollinated plants

Abstract

This study proposes a strategy for improving the bulk method within progenies in self‐pollinated plants. The proposal focuses on the use of a multigeneration index, which considers the whole information across generations and the covariance among successive generations with a view toward identification of the best progenies. The results of the simulation and analysis of field data from common bean (Phaseolus vulgaris L.) were concordant and showed that the estimates of the accuracies were near 85% using the multigeneration index and 70% for the traditional methodology based on comparisons among progeny means of the generation F3:6 or of the last generation evaluated. Another advantage of the index is mitigation of the effect of the genotype × environment interaction, because it considers all the generations of assessment, thus involving interaction of the progenies with the sowing times. When selection is performed using only the information from the last generation assessed, performance of the progenies is inflated by this interaction. The efficiency of the strategy proposed leads to a 12% gain in relation to that which is normally used. This gain is considerable and equivalent in most cases to that which would be obtained through one additional selection cycle. It should be highlighted that this increase is obtained without any additional cost on experimentation, but simply through changing the procedure of identification of the best progenies after successive generations.