Thesis
Genetic variation in Bromus tectorum (L.) (Poaceae) in the Eastern Mediterranean region
Washington State University
Master of Science (MS), Washington State University
2007
Handle:
https://hdl.handle.net/2376/102902
Abstract
Bromus tectorum L. (cheatgrass) has spread from its native Eurasian range to North and South America and Australia in the past 200 years. An understanding of the level and genetic structure of populations in the native and introduced ranges is important for understanding the invasion history of cheatgrass and as an aid in its eventual control. The grass's genetic structure was analyzed in 51 populations from Cyprus, Greece (including Crete and Santorini), and Turkey using starch gel electrophoresis. The results were compared to populations in North America and elsewhere in Eurasia. The mean number of alleles and percent polymorphic loci is higher in populations in the Eastern Mediterranean region compared to either North American or other Eurasia populations, so far reported. On average, populations in the Eastern Mediterranean region have higher total genetic diversity than other Eurasian populations but lower total genetic diversity compared to populations in Canada and the Western United States. Genetic variation is distributed equally within and among populations in Eastern Mediterranean populations (GST = 0.520), in contrast to the predominantly among population variation in other Eurasian populations (GST = 0.754). No heterozygotes were detected in any of the populations. Five novel alleles were detected at the Mdh-2, Me, Pgm-2, Tpi-1, and 6Pgd-1 loci and forty-one multilocus genotypes were detected overall. Thirty-one of these multilocus genotypes have only been detected in this region. The high level of genetic diversity in the Eastern Mediterranean region suggests this area is either close to the origin of the species or has served as a broad conduit for genotypes across the native range, or both. B. tectorum may have spread from the Asia through the Eastern Mediterranean region to Western Europe, and then carried in commerce onward to new ranges.
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Details
- Title
- Genetic variation in Bromus tectorum (L.) (Poaceae) in the Eastern Mediterranean region
- Creators
- Heather Lynn Lindon
- Contributors
- Richard Norton Mack (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Sciences, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525065401842
- Language
- English
- Resource Type
- Thesis