Estratégia de análise espacial de experimentos em blocos incompletos no melhoramento do feijoeiro

Abstract

The common bean of the carioca commercial group is the most produced and consumed in Brazil. Due to its importance, the Federal University of Lavras has been conducting a recurrent selection program for carioca beans, which is in its eighteenth cycle. Successful results have been observed throughout these cycles, such as the recommendation of various cultivars. The development of superior bean lines involves the evaluation of these lines under varied environmental conditions through experiments with different numbers of treatments, replications, and experimental designs. Approaches such as mixed models and spatial analyses have assisted in the analysis of data from these experiments and, consequently, in increasing the accuracy of selection in bean breeding. Therefore, the objective of this study was to verify the effect of include spatial information from experimental plots in incomplete block designs on the accuracy of selecting carioca bean lines. In addition, an alternative for selecting carioca bean lines was proposed through comparison with reference checks. A set of 500 carioca bean lines from the eighteenth cycle of recurrent selection at UFLA were evaluated, along with six checks, in augmented block design for productivity, grain appearance, and plant architecture. 250 lines were selected to be re-evaluated with the checks for the same traits. This experiment was conducted in a square lattice design. The evaluation data of the lines were subjected to individual and joint variance/deviance analyses with and without the incorporation of spatial information from the plots. The selection of the best lines was based on the comparison of these lines with the best checks evaluated in each season. Models including spatial information were more precise and accurate. Through the estimates of adjusted means for the lines in these models and their comparison with the checks, 52 lines with high productivity and commercial grain quality were selected.