Interação genótipo x ambiente no melhoramento genético da batata-doce

Abstract

Sweet potatoes are considered a versatile food with high nutritional content and wide adaptability to different environments. Therefore, it is possible to select genotypes with different agronomic abilities and adapted to different growing environments. Thus, the objective of this study was to evaluate the effects of the genotype x environment (GxE) interaction on the characteristics of sweet potato genotypes suitable for human consumption. The experiments were conducted in two growing seasons, at the Technology Development and Transfer Center (CDTT-UFLA), located in the municipality of Ijaci-MG. The winter experiment was conducted from April to October 2019, while in the summer the experiment took place between October 2019 and April 2020. Each experiment was installed in the design derived from a partially balanced triple lattice, with three replications. Verified through statistical analysis of mixed models, via the LRT test (Likelihood Ratio Test) for all studied characteristics, 100 elite sweet potato genotypes were used as treatments, including the commercial cultivars Brazlândia Roxa, Princesa, Uruguaiana, BRS as controls. Amélia and Beauregard, in addition to three pre-evaluated genotypes (UFVJM-57, UFVJM-58 and UFVJM-61). As quantitative characters, total root productivity (PTR), commercial root productivity (PCR) and dry mass productivity of commercial roots (PMSRC) were evaluated. Regarding qualitative characteristics, root grouping (AG), commercial standard (PC), general shape (FG) and insect resistance (RI) were evaluated. The data obtained were analyzed using mixed statistical models (REML/BLUP), ranking the BLUP estimates to identify the 10 best genotypes for each characteristic studied. There were high heritability values in the broad sense (h_G^2) for the characteristics, total root productivity (71.44%), commercial root productivity (65.45%), dry mass productivity of commercial roots (65 .98%) and root grouping (65.94%). In relation to total root productivity, the best yields were in the winter season with an average productivity of 47.99 t ha1 and 36.76 t ha1 in summer. Considering the summer and winter seasons together, productivity was 42.38 t ha1. The productivity of commercial roots showed considerable gains in the winter season (25.97 t ha1), being 28.5% higher than that observed in the summer (18.55 t ha1). The genotypes 2018-72-1418, 2018-19-464, 2018-28-556, 2018-72- 1376, 2018-19-455 and the commercial cultivar Brazlândia Roxa, are indicated in the selection because they have adaptability for the two seasons evaluated.