Graduation Year


Graduation Month


Document Type


Degree Name

Bachelor of Science

School or Department

Biological Sciences, Division of


Biology – Genetics and Evolution

Faculty Mentor Department

Biological Sciences, Division of

Faculty Mentor

Lila Fishman

Faculty Reader(s)

Lila Fishman


Monkeyflower, genetics, stigma closure, carotenoids

Subject Categories

Evolution | Genetics



The interactions between pollinators and flowers have long been a driving force for the evolution of many physical floral traits. Traits such as flower shape, size, color, and smell are just some of these traits that evolve because of these interactions. This evolution does not only occur in the more obvious morphological floral traits, however, but also in more subtle traits like touch sensitive stigma closure. 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. Corolla carotenoid is also a trait that demonstrates large variation between species. Some present deep or pale yellows, reds, pinks, purples, and oranges. This is due to adaptation in conjunction with pollinator preferences. 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 as well as two loci related to carotenogenesis. To assess which loci could be responsible for these traits, plants were grown in a randomized array until the first flower opened. At this point, stigma closure speed and corolla color (along with several other traits) were 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.

Honors College Research Project


GLI Capstone Project




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