Grant: Discovery Grants Program - Individual

Plants exhibit an incredibly diverse array of reproductive systems. Plants are normally immobile organismsand are usually hermaphrodites (an individual is both male and female). To reproduce, they often exploit animals as a means of transferring pollen (analogous to sperm)to achieve fertilization resulting in fruit and seed production. Different plant species have adopted a variety of strategies or systems to regulate the way in which they mate. Some of these systems involve the prevention or avoidance of self-fertilization which can have negative consequences for seed production, fruit production and the quality/health of their offspring. We investigate one such system that prevents self-fertilization (distyly). Among the most interesting of these systems preventing self-fertilization is distyly. Distylous plants come in two forms, yet both are hermaphrodites. They possess an unknown set of genes that prevent self-fertilization, as well as genes that cause differences in the structure of their flowers. These structural differences are also important in regulating the amount and precision of transfer of pollen to stigmas (the female reproductive organ that receives pollen). Distyly occurs in some crop plants (e.g. buckwheat), and in species related to crop plants. For example, there aredistylous specieswithin thepassionflower family, although passion flowers are not distylous.A number of ornamentals are distylous(e.g. primroses, forsythia). The genes determining distyly are entirely unknown. We willidentify the genes determining this system for species in the genus Turnera , which are members ofthe passion flower family (although they are not passion flowers). The discovery of such genes represents a significant goal in the fields of plant genetics, reproductionand development. The work will resolvea number of outstanding questionsthat have arisen duringthe long history of studyof this intriguing reproductive system (in fact, Charles Darwin published a book largely devoted to this breeding system). The discovery of these genes could also be of value in agriculture, given their capacity to regulate mating patterns, and fruit and seed yields.