Prince, Linda .
Genetic Fingerprinting of the rare yellowcress Nasturtium gambelii on Vandenberg Air Force Base, Santa Barbara County, California, USA.
Gambelís yellowcress (Nasturtium gambelii) is a scrambling, perennial mustard currently restricted to an area approximately 5 m √ó 10 m along the San Antonio Creek on Vandenberg Air Force Base in northern Santa Barbara County. Nasturtium gambelii is listed federally as endangered and state listed as threatened in California. Threats include genetic swamping from the closely related, introduced crop species N. officinale. Genetic fingerprinting using fluorescent inter-simple sequence repeats (ISSR) was conducted to test the hypothesis of genetic swamping and to identify the number of distinct genotypes. These data will be used to best maximize the genetic diversity of potential progeny from future propagation and crossing efforts. Five samples from Oso Flaco Lake (putative hybrids) share 5 bands with the N. officinale sample that were not found in any Vandenberg (putatively pure) samples. Two additional bands are present in N. officinale and most Oso Flaco samples, thus hypotheses of introgression of the Oso Flaco population cannot be rejected. Although the Oso Flaco material appears to be introgressed, the majority of bands detected were of N. gambelii. Analysis of 65 polymorphic bands identified 15 genotypes including one very common genotype, 11 rare genotypes, and 3 infrequent genotypes at Vandenberg. Two of the genotypes share a single band with N. officinale thus should not be used for generation of plants for propagation since they may be introgressed with N. officinale. Future studies should take advantage of polymorphic microsatellite markers that would allow more sophisticated analysis of genetic diversity and gene flow.
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1 - Rancho Santa Ana Botanic Garden, 1500 North College Avenue, Claremont, California, 91711-3157, USA
Presentation Type: Oral Paper:Papers for Topics
Location: 551A/Convention Center
Date: Wednesday, August 4th, 2010
Time: 8:00 AM