Fehlberg, Shannon D. .
Distribution of genetic variation in Encelia farinosa (Asteraceae) inferred from universal nuclear markers for the Asteraceae.
Recent advances in bioinformatics, including the availability of whole genome sequences and large numbers of expressed sequence tag (EST) databases, have led to the potential for development of low-copy nuclear markers useful for phylogenetic and population genetic studies in plants. The purpose of this study was to test the utility of several universal nuclear markers recently developed for the Asteraceae for examining population genetic variation and structure in Encelia farinosa (Asteraceae) from the southwestern deserts. Twenty pairs of universal nuclear primers were tested for amplification and ease of direct sequencing across individuals from multiple populations. The primer pairs that yielded the best results were then used to obtain sequences for 210 individuals sampled across 21 populations throughout the range. Results from the genetic and spatial analyses of these low-copy nuclear sequences were then compared to results from the analyses of plastid psbA-trnH and nuclear ITS sequences. Plastid sequences revealed strongly differentiated populations and statistically significant associations between geography and genetic diversity, while nuclear sequences revealed populations characterized by high levels of genetic diversity, a lack of large-scale geographical structuring, and an overall pattern of gene flow and isolation-by-distance. These contrasting genetic structures are likely due to life history characteristics of E. farinosa and differences in the evolution and inheritance of plastid and nuclear markers. Results from this study suggest that universal nuclear markers developed for the Asteraceae will be useful for examining population level variation and structure.
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1 - Desert Botanical Garden, Research, 1201 N. Galvin Pkwy., Phoenix, AZ, 85008, USA
North American deserts
low-copy nuclear gene
Presentation Type: Oral Paper:Papers for Topics
Location: 556A/Convention Center
Date: Tuesday, August 3rd, 2010
Time: 8:00 AM