Adaptability and stability of conventional early maturity soybeans in 15 different environments in Brazil
The success of a plant breeding program depends on its ability to develop and release new cultivars with superior performance and capability to withstand biotic and/or abiotic stresses. We evaluated the genotype by environment interaction for grain yield in conventional early maturity soybean genotypes, grown in 15 environments (municipalties) distributed in five Brazilian states, to determine adaptability and stability of the genotypes. The experiments were carried out in the 2009/2010, 2010/2011, 2011/2012, 2012/2013 and 2013/2014 growing seasons. Twenty-eight soybean genotypes of early maturity were evaluated, among them 23 lines developed by the soybean breeding program of the Federal University of Uberlândia-UFU and five checks: M-SOY 6101, M-SOY 8001, Emgopa 316, UFUS Guarani, and UFUS Riqueza. The genotype and environment interaction was significant at 1% probability level by the F test, showing differential behavior among genotypes according to environment. The coefficient of genotypic determination was 79.44%, indicating that genetic variation was superior to environmental influences. The methods Annicchiarico and Lin and Binns modified by Carneiro were similar in the classification of the genotypes that stood out for the broad and specific adaptation to favorable and unfavorable environments; Wricke, Eberhart and Russel and AMMI methods identified UFU 21 and UFU 22 lines as the most stable, both presenting grain yields greater than 3,800 kg.ha-1. UFU 06 line obtained an average of grain yield greater than 4,000 kg.ha-1 and showed wide adaptation by the Annicchiarico, Lin and Binns method, modified by Carneiro, and the Centroid method.