Abstract Detail

Genetics Section

Denton, Renee [1], Harding, Ethelynda [2].

Genetic variation in Trifolium bolanderi A. Gray compared with Trifolium longipes Nutt.

Trifolium bolanderi A. Gray (Bolander’s clover) (Fabaceae) is a narrow endemic, restricted to meadows of the central Sierra Nevada of California extending from Yosemite National Park south across the Sierra National Forest to north of the King’s River. It is obligate to wet meadows and occurs only within a narrow elevational band from 2130 m to 2165 m. These montane meadow floristic communities are particularly vulnerable to warming trends. Long-term viability of the T. bolanderi population may depend on the level of genetic heterogeneity. Starch gel electrophoresis was used to elucidate the genetic variation within and among populations of T. bolanderi and to compare and contrast this variation with that of Trifolium longipes. Genetic variation for T. longipes occurs over a much broader spatial scale than the variation for the narrow congener. In this study, the two congeners were evaluated at the same spatial scale, limited to the known geographic range and habitat type of T. bolanderi. Ten montane meadow populations were sampled for both taxa. Sixteen putative loci were resolved by electrophoresing nondenatured plant protein through starch gels under three electrophoretic systems. Mean expected heterozygosity (H_e) within populations of T. bolanderi (0.17) was lower than within populations of T. longipes (0.24) as expected when comparing spatial data for other rare and widespread congeners. Percentage of polymorphic loci (%P) for T. bolanderi (43.13) was also lower than for T. longipes (56.88) at the population level. Interpopulation level heterozygosity for T. bolanderi, 0.20, did not exceed that of T. longipes, 0.29, as expected. Surprisingly high polymorphism was detected for both species. When T. bolanderi populations were clustered based on genetic distance, two major groups emerged each of which were distributed across the geographic range.

1 - Sierra Nevada Research Center, PSW, 2081 E. Sierra Ave., Fresno, California, 93710, USA
2 - California State University Fresno, Department of Biology, 5240 N. Jackson Ave., M/S UC116, Fresno, California, 93740, USA

Keywords:
population genetics
population structure
Fabaceae
genetic diversity
rare taxa
mountain meadows
Trifolium
isozymes
population genetics of clovers
Sierra Nevada Meadows
strach gel electrophoresis
narrow endemics
Allozyme
starch gel electrophoresis.

Presentation Type: Paper
Session: 41-15
Location: Peruvian (Cliff Lodge)
Date: Wednesday, August 4th, 2004
Time: 11:45 AM
Abstract ID:603