Diallel analysis for grain yield and mineral absorption rate of soybeans grown in acid Brazilian Savannah soil

High available aluminium and low levels of calcium below the ploughed zone of the soil are limiting factors for agricultural sustainability in the Bra zilian Cerrados (Savannahs). The mineral stresses compound with dry spells effect by preventing deep root growth of cultivated plants and causes yield instability. The mode of inheritance for grain yield and mineral absorptio n ratio of a diallel cross in soybeans [Glycine max (L.) Merrill] grown in high and low Al areas was identified. Differences among the genotypes for g rain yield were more evident in the high Al, by grouping tolerant and non-t olerant genotypes for their respective arrays in the hybrids. A large propo rtion of genetic variance was additive for grain yield and mineral absorpti on ratio in both environments. High heritability values suggest that soybea ns can be improved by crosses among Al-tolerant genotypes, using modified p edigree, early generation and recurrent selection schemes.