Adaptabilidade e estabilidade de cultivares de sorgo sacarino

Abstract

The study of adaptability and stability of genotypes is essential in the final program of plant breeding for correct indications of genotypes suitable for growing regions. This study aimed to analyze the adaptability and stability of 25 cultivars of sweet sorghum, 24 varíeties and one hybrid. The experiments were carried out in six environments, three in the state of Minas Gerais, in Sete Lagoas, Nova Porteirinha and Jaíba, and in the cities of Sinop - MT, Pelotas - RS and Goiânia - GO, in a randomized block designed with three replications. The plots consisted of four rows of 5 m spacing of 0.70 m, with a population of 125.000 plants ha”. Only the two central lines were evaluated. We evaluated the production of green mass (GMP) of the plot, converted to tons per hectare, and total soluble solids (TSS) in the pulp by a digital refractometer with reading in degrees Brix. Analyses were performed individually and as a group. As the genotype x environment interaction was significant, we proceeded to the analyses of adaptability and stability, using the methods of Wricke e Weber (1986), Eberhart and Russell (1966), Annicchiarico (1992) and Lin and Binns (1988). In determining the adaptability and yield stability of sweet sorghum cultivars, the methods of Eberhart and Russel] (1966); Annicchiarico (1992) and Lin and Binns (1988) show in this study that results are similar but are different from those obtained with the methodology proposed by Wricke e Weber (1986), which prioritizes genotypes with high stability, but low adaptation, which is undesirable. It was possible to identify stable and more adapted genotypes of sorghum to the characteristics evaluated. Genotypes CMSXS634 and CMSXS646 and presented themselves as the most adapted and stable to PMV. and Brix, at the same time. The first one is more adapted to favorable environments and the second one to unfavorable environments.