GENES FOR VERNALIZATION RESPONSE IN HOMOEOLOGOUS GROUP 5 OF TRITICUM AESTIVUM

The altered vernalization response of normal Chinese Spring caused by the three individually-substituted chromosomes of homoeologous group 5 of Hope in Chinese Spring was found to be controlled by a single gene on each chromosome. The alleles on chromosomes 5A and 5B of Hope are dominant to those on their respective homologues in Chinese Spring for lowered vernalization response, while that on Hope 5D is dominant to that on Chinese Spring 5D for increased vernalization response. The possibility has been discussed of the vernalization response locus on Hope 5D bearing a null allele or an allele with very little involvement in the vernalization process, in which case the strong vernalization response exhibited by Chinese Spring/Hope 5D could merely be a function of genes promoting vernalization response in the rest of the Chinese Spring genotype.