Inheritance of Flowering Habit in Russian Dandelion

Abstract

Russian dandelion [Taraxacum kok-saghyz (TKS)] is a latex-producing, temperate species that has the potential to be grown as a source of natural rubber in North America. Flowering habit varies within the species; winter-type plants require a cold period or vernalization to flower, whereas spring-type plants flower without this treatment. Because flowering habit is correlated with rubber yield, understanding the genetic factors governing the trait would be useful for breeding. The objective of this research was to determine the inheritance of vernalization requirement in TKS. Winter-type and spring-type plants were intercrossed to create the F1, F2, and backcross generations and progeny segregation ratios were analyzed. A genetic model with three major genes is proposed, where a dominant allele at locus A, in combination with homozygous recessive alleles at either or both of two loci, B and C, confers winter type, whereas spring type is conferred by homozygous recessive alleles at A, regardless of genotype at B or C, or dominant alleles at A, B, and C.