Abstract Detail

Conservation Biology

Porter, J. Mark [1], Callaway, Tara [2].

Range-wide Phylogenomics of Opuntia basilaris (Cactaceae).

Opuntia basilarisis a charismatic and characteristic species of the Southwestern Deserts of the US and adjacent Mexico. Within it is included the endangered Bakersfield cactus (O.basilarisvar. treleasei); however, taxon boundaries are poorly understood and remain controversial. We examine genetic diversity of O. basilarisacross its range, using genotype-by-sequencing (GBS) high throughput DNA sequencing. We find considerable diversity among the 37 populations sampled, with average FSTof 0.386. By contrast, heterozygosity HOis somewhat low, averaging 0.0132, but not low enough to infer inbreeding. Of the four varieties currently recognized, vars. basilarisbrachycladalongiareolataand treleasei, each represents vastly different spatial and temporal events. For example, Obasilarisvar. longiareolatais the result of an ancient divergence, while Obasilarisvar. treleasei is consequent to a recent invasion of the San Juaquin Valley. These two varieties are genetically well demarcated; however, varieties basilarisand brachycladado not form genetically cohesive groups. With the exception of var. longiareolata, admixture appears common among the named groups. We show that admixture has occurred across the Tehachapi Mountains of California but the genetic groups on either side have remained distinct.

1 - Rancho Santa Ana Botanic Garden, 1500 N. College Ave., Claremont, CA, 91711, United States
2 - U.S. Fish and Wildlife Service , Central Washington Field Office, 215 Melody Lane, Suite 103 , Wenatchee, WA, 98801, USA


Presentation Type: Oral Paper
Number: 0012
Abstract ID:915
Candidate for Awards:None

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