Periódicos Brasileiros em Medicina Veterinária e Zootecnia

Soybean genotypes selection with resistance to White Mold and agronomic performance from moderately resistant parents

Polloni-Barros, Lorraine CristinaHamawaki, Osvaldo ToshiyukiPolloni, LorenaBarros, Heber Leão SilvaMorais, Tâmara Prado deHamawaki, Raphael LemesHamawaki, Cristiane Divina LemesJuliatti, Fernando CezarNogueira, Ana Paula Oliveira

ABSTRACT: White Mold (WM) is a yieldlimiting disease found in soybean. However, up to now no cultivars have been genetically resistant to this disease. Given this context, the present study aimed to develop superior soybean lines with resistance to WM, while maintaining other desirable agronomic traits. Two early maturing soybean cultivars (i.e., EMGOPA 316 and MG/BR 46Conquista), moderately resistant to WM were used for biparental crosses from which the analyzed population was derived. Therefore, we assessed the resistance to WM in early generation testing of this population. Additionally, we determined the agronomic traits, genetic parameters and selection gains. From 348 F2 genotypes, 35 transgressive genotypes moderately resistant to WM were identified, amongst which 22 genotypes showed desirable agronomic traits for early cycle and grain yield. Moreover, 69 lines were selected as the most promising genotypes for each agronomic trait (i.e. based on the number of days to flowering and maturity, plant height at flowering and maturity, number of nodes on main stem at flowering and maturity, number of pods, grain yield, etc.). Among these selected lines, ten progenies emerged as the superior genotypes for grain yield and early cycle. All together, these results demonstrated that the cross between EMGOPA 316 × MG/BR 46 (Conquista) revealed promising progenies with moderate resistance to WM and/or desirable agronomic traits. Thus, these lines could be used as future resources for breeding efforts aimed at improving resistance to WM.

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