Oral Presentations
The Genetic Basis of Touch-Sensitive Stigma Closure in Monkeyflowers
Presentation Type
Presentation
Faculty Mentor’s Full Name
Lila Fishman
Faculty Mentor’s Department
Division of Biological Sciences
Abstract / Artist's Statement
The interactions between pollinators and flowers have long been a driving force for the evolution of many physical floral traits. In hundreds of Lamiales species, the bilobed stigma, the organ that receives pollen from pollinators, closes rapidly upon touch. Theory and experiments show that this novel dynamic reproductive trait increases pollen export and seed fertilization in animal-pollinated flowers. The rapid touch-sensitive stigma closure trait has been observed across the monkeyflower genus (Mimulus), but stigma closure is also lost in several self-pollinating species. Previous QTL mapping in interspecific hybrids of the yellow monkeyflower M. guttatus with selfer M. nasutus has identified four loci responsible for the loss of closure in M. nasutus. To assess whether the same loci are responsible for rare non-closer plants in M. guttatus, plants were grown in a randomized array until the first flower opened. At this point, stigma closure speed (along with several other traits) was recorded. Plants in this grow out were from typical non-closing line IM709, a fast-closing line IM767, and hundreds of F2 hybrid crosses of the parents. Subsequent DNA collection and further analysis will allow us to make genomic comparisons between the parental lines and the F2s and to observe a correlation between their phenotypes and genotypes. This investigation into the genetic source of the stigma closure trait not only helps to understand the genetic basis of such a novel reproductive plant phenotype but could also lead to exploration into this trait’s mechanics and other touch-sensitive plant phenotypes.
Category
Life Sciences
The Genetic Basis of Touch-Sensitive Stigma Closure in Monkeyflowers
UC 331
The interactions between pollinators and flowers have long been a driving force for the evolution of many physical floral traits. In hundreds of Lamiales species, the bilobed stigma, the organ that receives pollen from pollinators, closes rapidly upon touch. Theory and experiments show that this novel dynamic reproductive trait increases pollen export and seed fertilization in animal-pollinated flowers. The rapid touch-sensitive stigma closure trait has been observed across the monkeyflower genus (Mimulus), but stigma closure is also lost in several self-pollinating species. Previous QTL mapping in interspecific hybrids of the yellow monkeyflower M. guttatus with selfer M. nasutus has identified four loci responsible for the loss of closure in M. nasutus. To assess whether the same loci are responsible for rare non-closer plants in M. guttatus, plants were grown in a randomized array until the first flower opened. At this point, stigma closure speed (along with several other traits) was recorded. Plants in this grow out were from typical non-closing line IM709, a fast-closing line IM767, and hundreds of F2 hybrid crosses of the parents. Subsequent DNA collection and further analysis will allow us to make genomic comparisons between the parental lines and the F2s and to observe a correlation between their phenotypes and genotypes. This investigation into the genetic source of the stigma closure trait not only helps to understand the genetic basis of such a novel reproductive plant phenotype but could also lead to exploration into this trait’s mechanics and other touch-sensitive plant phenotypes.