Comparative Genetics of Flowering Time Control in Legume

We are using a comparative approach to explore the genetic network controlling flowering time and inflorescence development in temperate legumes. Our approach includes analysis of flowering control mechanisms using induced mutants in pea (Pisum sativum) and barrel medic (Medicago truncatula), and characterization of natural variation in pea and other legume crop species including lentil (Lens culinaris) and chickpea (Cicer arietinum). We have performed comparative phylogenetic analyses of many of the major flowering gene families in legumes, and examined the expression patterns of key genes, including members of the FT family of florigen genes. A candidate gene approach has enabled the cloning of a number of flowering time loci, including several that have a role in the circadian clock and photoperiod response, and others that directly affect the action of FT genes. Examples of each of these will be presented. Our results outline the extent to which features of flowering time control may be widely conserved and which may be unique to temperate legumes. A better understanding of flowering genes in legume crops will be valuable in breeding for new environments and accessing diversity present in wild crop relatives.