Factor analysis and environmental stratification in the assessment of grain sorghum adaptability and stability

Abstract

The environmental stratification studies are crucial when releasing hybrids for different growing regions. An outstanding performance of a genotype in one environment does not qualify it for indication to all environments, due the occurrence of GxE interaction. Environmental stratification aim the breeders to form groups of environments that minimize GxE interaction. The purpose of this work was to evaluate the use of factor analysis in preliminary environmental stratification assisting at the recommendation of grain sorghum cultivars. Twenty-five hybrids were evaluated, using a randomized block design, in 12 locations during the 2015/16 season. Initially, the individual analysis of the experiments was carried out and later the joint analysis, aiming to examine the existence of G×E interaction. The means of the hybrids in the individual analyses were used to obtain the correlation matrix between pairs of environments. The factorization of this matrix was also carried out via factor analysis in order to group together the environments that most correlated with respect to the hybrids performance. Thus, differential performance between hybrids was observed through individual analyses for all the environments, with the exception of Sete Lagoas and Teresina. The joint analysis revealed the existence of a significant G×E interaction, that is, a differential behavior of the hybrids in relation to the evaluated environments. Based on the criterion of the analysis of the proportion of explained variance, it was found that six factors captured an accumulated variation of 86.29%, and the average communality observed was of 0.86. Considering the geographic and edaphoclimatic variables in the cultivation period, a pattern was not observed among the grouped places, but it is noteworthy that the grouping of places is a function of the performance of the evaluated genotypes, which can be similar even under different conditions. Given the results presented, factor analysis proved to be a tool with potential to perform environmental stratification and assist in the recommendation of grain sorghum cultivars for different regions.

Breeding Sorghum for Grain, Forage and Bioenergy in Brazil

“…The implications of GE interaction in sorghum are widely reported in the literature (Diatta et al, 2021;Ribeiro et al, 2021;Wagaw et al, 2020;Mare et al, 2017;Souza et al, 2013).…”

“…Due to their stability, the male-sterility ms3 and ms7 alleles have been extensively used (Aruna et al, 2021), being the male-sterility conditioned to homozygous recessive genotypes. In a recent book by Embrapa, the use of genetic male-sterility in sorghum is discussed in detail (Oliveira et al, 2021). Aruna et al (2021) mentioned that it is necessary to create a base population before Revista Brasileira de Milho e Sorgo, v.21, e1275, 2022 DOI: https://doi.org/10.18512/rbms2022v21e1275 selecting.…”

“…The panicles of male-sterile F 2 plants (msms) are identified during flowering and then harvested separately for use in new backcrosses or the first recombination. To obtain the first generation of recombination of the recurrent selection, an equal amount of seeds from male-sterile F 2 panicles is mixed, and the same procedure is performed to obtain the second and third generation of recombination (Oliveira et al, 2021)…”

Phenotypic stability and adaptability of sweet sorghum genotypes evaluated in different Brazilian regions

“…Besides having rapid growth, high sugar accumulation, and biomass production potential, sweet sorghum has wider adaptability (Souza, Parrella, Souza, & Parrella, 2016;Silva et al, 2017;Appiah-Nkansah et al, 2019;Leite et al, 2019). Besides, it is can be grown with less irrigation and rainfall and purchased inputs compared to sugarcane (Ribeiro, Salvador, Oliveira, & Menezes, 2021). The sugar content in the juice extracted from sweet sorghum varies from 16 -23% Brix.…”