Recent Topics Posters
Beardsley, Paul , Steingraeber, David , Suni, Sevan .
Unexpected patterns of neutral genetic diversity within the uniquely reproducing asexual rare plant Mimulus gemmiparus (Phrymaceae).
Mimulus gemmiparus (Phrymaceae) reproduces asexually via unique structures classified as bulbils. Produced from proximal meristems of each leaf axils, bulbils are functionally analogous to seeds, even containing morphological analogues to cotyledons and a seed coat. Though individuals are observed to flower, they have never been observed to set seed in nature. Additionally, M. gemmiparus is rare and endemic to Colorado. Eight populations have been described historically, but only six are currently thought to be extant. Both its asexual reproduction and rarity led us to expect low levels of genetic diversity within M. gemmiparus. We also expected most of the diversity to be apportioned among populations. However, analysis of 213 AFLP fragments from a total of 60 individuals representing all six extant populations indicate levels of diversity typical of outcrossing plants and considerably higher than those reported in AFLP studies of other rare plant species. Surprisingly, AMOVA analyses revealed that 63% of the diversity was apportioned within populations and 37% among populations. Neighbor-Joining cluster analyses suggest genetic differentiation amongst three broad geographical areas, and that populations mostly form mostly natural groups, with varying levels of diversity. We speculate that the high levels of diversity are caused by high rates of mutation accumulation, influenced by the annual life history of this asexual plant.
1 - Colorado State University, Department of Biology, Fort Collins, Colorado, 80523-1878, U.S.A.
2 - Colorado College, Biology, 14 E Cache La Poudre Street, Colorado Springs, Colorado, 80903
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM