Inheritance of the four-seeded-pod trait in a soybean mutant and marker-assisted selection for this trait

A high seeds‐per‐pod value is a crucial component of soybean seed yield, but reliable information is lacking on the inheritance and early selection for the four‐seeded pod (4SP) trait. The inheritance of 4SP was followed in crosses originating from an EMS‐derived mutant line (E182, 15% 4SP) with its parental cultivar, ‘Ludou No. 4’ (no 4SP), and the efficiencies of both a molecular and morphological marker selection were determined. The plants of two F₂ populations (with E182 as one of the parents) showed a segregation ratio of 3 : 1 (low to high SP values), indicating a single recessive locus; this mode of inheritance was confirmed by subsequent analysis of the F_{2 : 3} families. Among four microsatellite markers linked with the 4SP trait, Sat_107 was the closest to the 4SP locus (3.2 ± 1.11 cM). Both the molecular marker Sat_107 and the morphological marker, narrow leaflet (NL) associated with the 4SP locus were effective in selecting the 4SP trait, although with different efficiencies. The molecular marker was efficient in selecting soybean progenies from the cross in which one parent was the E182 mutant line because it was tightly linked to the mutated 4SP locus. In the other cross, with 4SP not derived from E182, the efficiency was reduced in comparison with the morphological marker.