INHERITANCE OF BRANCHED RACEME AND CAULIFLOWER CHARACTERS IN ALFALFA

Abstract

The inheritance of the branched raceme character in alfalfa (Medicago saliva L.) was studied. In the segregation of inflorescence types, the cauliflower type with vestigial flowers appeared in the segregating population together with the branched raceme and normal types. According to the inheritance patterns observed in F2, F3, F4 and test cross, it was postulated that a single recessive tetrasomically inherited gene is responsible for both types of inflorescence; the genotypes for branched raceme and cauliflower types were designated as simplex (Aaaa) and nulliplex (aaaa), respectively. Various segregation ratios obtained in the progenies from inter-crossings and backcrossings were explained consistently due to the possible combination of the genotypes used for the parents. Test crossings between cauliflower and normal types also demonstrated the simple tetrasomic inheritance in F2 populations under random chromosome assortment. It was determined that the branched raceme character used for the experiments possesses the heterozygous simplex genotype (Aaaa).