Adaptability and stability of transgenic soybean lines and cultivars in the Brazilian macroregion 3 assessed by using parametric and nonparametric methods

This study aimed to evaluate the adaptability and stability of 20 soybean genotypes, ten of which were lines of Monsoy Ltd breeding program, whereas the other 10 genotypes were commercially used cultivars. The experiments were carried out in the agricultural years of 2005/2006 and 2006/2007, in Brazil, specifically in the soybean microregions 301, 302 and 303 (part of Minas Gerais, Goias and Sao Paulo states). A randomized complete block design was used for all genotypes in each location, with three repetitions. Individual and joint analyses were done considering genotype yield in the different locations. Subsequently, genotypic adaptability and stability were evaluated by the methods of Eberhart and Russel (1966), Lin and Binns modified by Carneiro, Annicchiarico and Centroid. All methods presented partial coherence on classifying the best genotypes and allowed the identification of the transgenic lines L1 and L4, and the cultivars M-SOY 8199 RR, M-SOY 8045 RR, and Valiosa RR as the most promising ones to be grown in the microregion 3 because they have shown both stability and wide adaptation combined with outstanding grain yield. Lines L1 and L4, both with superior grain yield than the controls M-SOY 8199 RR and Valiosa RR, were classified as those with adaptability and stability to favorable environments. On the other hand, the lines L3, L10 and the cultivars M-SOY 8064, M-SOY 7908, and M-SOY 8045 RR were the most stable and productive genotypes for unfavorable environments.