Inheritance of late flowering in natural variants of soybean cultivars under short‑day conditions

Abstract

The objective of this work was to determine the inheritance of the long juvenile period trait in natural variants of the Doko, BR 9 (Savana), Davis, Embrapa 1 (IAS 5RC), and BR 16 soybean cultivars. Complete diallel crosses were made between the Doko and BR 16 cultivars and their variants. A 3:1 segregation ratio was observed in the F2 populations of the 'Doko' x Doko‑18T, 'Doko' x Doko‑Milionária, 'Davis' x São Carlos, and 'BR 9 (Savana)' x MABR92‑836 (Savanão) crosses, indicating that the long juvenile period trait is controlled by a pair of recessive genes. The difference in late flowering between the Doko cultivar and both of its variants was caused by a recessive spontaneous mutation at the same genetic locus. However, the variants Doko‑18T and Doko‑Milionária are identical mutants that share a pair of genes that control the long juvenile period under short‑day conditions. These mutants can be used in breeding programs to develop cultivars adapted to low‑latitude tropical regions.