Abstract Detail



Biogeography

Lambert, Joshua [1], Sinn, Brandon [2], Barrett, Craig [1].

Genetic variation and hybridization in southwestern Rhus ovata and R. integrifolia (Anacardiaceae) using plastid and nuclear markers.

Rhus integrifolia and R. ovata are sister species native to Southern California and the Baja California Peninsula comprising major structural components of coastal sage scrub and chaparral communities, respectively. Rhus ovata is also found in a similar, disjunct community (interior chaparral) in Arizona with the Sonoran and Mojave deserts separating them from Californian populations. Both have been shown in earlier studies to hybridize, often displaying intermediate morphological characteristics. This goals of this study are to answer questions of: 1) basic evolution regarding how natural selection and gene flow interact to determine species boundaries and; 2) how genetic variation is distributed over the geographic range of this species complex; and 3) how ecological niches influence morpho-genetic distinctness and hybridization. We sampled approximately 70 individuals from 13 localities in AZ and CA for R. integrifolia and R. ovata. PCR primers for the plastid spacer regions ndhC-trnV and rpl16-rps3, and nuclear regions ITS and RPB2 amplify consistently among accessions. Preliminary results based on plastid markers suggest that populations are polymorphic for plastid haplotypes. There is support for a western R. ovata clade (all AZ accessions and one accession from Orange Co., CA), but a basal polytomy is observed among accessions of R. integrifolia and individuals of R. ovata and putative hybrids from a population in Ventura Co., CA, suggesting some detectable level of gene flow. Additional plastid and nuclear data, along with population genetic analyses, will help resolve patterns of variation across the geographic range of this complex.


1 - West Virginia University, Biology, 53 campus dr, Morgantown, WV, 26506, US
2 - West Virginia University, Biology, Life Sciences Building, 53 Campus Drive, Morgantown, WV, 26506, United States

Keywords:
lemonadeberry
chaparral
disjunct populations
Hybridization
Introgression
gene flow
Natural Selection.

Presentation Type: Poster
Number: PBG007
Abstract ID:617
Candidate for Awards:None


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