Inheritance of supernodulation in soybean and estimation of the genetically effective cell number.

Provided the nature of inheritance is known, the frequency of homozygous mutant plants in individual M2 families (derived from M1 seed) can be used to estimate the genetically effective cell number (GECN). Segregation ratios in M3 families derived from M2 wild-type plants indicated that the supernodulation characters nts382, nts1007 and nts183 are inherited as Mendelian recessives. The nature of inheritance was also known or confirmed to be recessive by crossing the wild type to these and several other mutants derived from the same population of M2 families. Subsequently, using the frequency of mutant plants in individual M2 families, the GECN for soybean was calculated to be approximately two.