Abstract Detail

Ericaceae: Systematics, Ecology and Evolution

Huang, Yi [1], Morrison, Glen R [2], Saavedra, Natalie [3], Wahlert, Gregory [4], Stoughton, Thomas [5], Parker, V. T. [6], Keeley, John [7], Vasey, Michael [8], Sanders, Andrew [9], Litt, Amy [10].

Applying environmental and genetic data to evaluate subspecies differentiation in Eastwood’s manzanita (Arctostaphylos glandulosa Eastw., Ericaceae).

Arctostaphylos glandulosa is a widespread shrub species in the California chaparral community, a habitat type that is gradually decreasing in its extent due to human activities. This species is widely distributed across diverse habitats and plays essential ecological roles in the chaparral, such as rapidly recovering the vegetation in fired-disturbed areas via resprouting, and providing food for pollinators and fruit-eating animals. Ten subspecies are currently recognized, two of which, A. glandulosa subsp. gabrielensis and A. glandulosa subsp. crassifolia, are considered rare and/or endangered. Morphologically, these ten subspecies are distinguished based on the presence or absence of glandular hairs, the length and density of hairs, fusion of seeds in the fruit, and leaf color. However, individuals with intermediate phenotypes or characteristics of multiple subspecies are frequently encountered, making subspecies assignment extremely difficult. Our preliminary double digest restriction-site associated DNA sequencing (ddRAD-Seq) analyses suggest that these subspecies are not genetically distinct. However, it remains possible that specific single nucleotide polymorphisms (SNPs) correlated with environmental variation are able to distinguish these subspecies as a result of local environmental adaptation. Here, we collected SNP data for 138 individuals collected at 21 localities in Southern California. Using the analysis package LMFF, we then identified SNPs that were strongly associated with environmental variables such as temperature, precipitation, solar radiation, soil pH, and nitrogen content, which are thought to be important factors in determining the distribution of Arctostaphylos species. We also used principal component analysis and STRUCTURE to test the distinction of these subspecies, including one rare and one federally listed endangered taxon, based on environment-associated SNP data. These data will not only advance the knowledge of taxonomic boundaries within this subspecies complex, but also benefit their conservation by providing insight into their local adaptation and possible evolutionary trajectory in the context of predicted future climate change.

1 - 920 Via Cartago Apt 9, Riverside, CA, 92507, United States
2 - University of California, Riverside, Botany and Plant Sciences, 900 University Ave, Riverside, CA, 92521
3 - 24548 Covington Way, Moreno Valley, CA, 92557, United States
4 - 2351 Valleywood Dr, San Bruno, CA, 94066, United States
5 - 2211 Shenandoah Lane, Glendora, CA, 91741, United States
6 - San Francisco State University, Biology, 1600 Holloway Avenue, Department Of Biology, San Francisco, CA, 94132, United States
7 - U.S Geological Survey
8 - San Francisco State University
9 - UCR Herbarium
10 - UC Riverside, Botany and Plant Science

Keywords:
ddRAD-seq
subspecies
Landscape genetics.

Presentation Type: Colloquium Presentations
Session: CO06, Ericaceae: Systematics, Ecology and Evolution
Location: Tucson D/Starr Pass
Date: Tuesday, July 30th, 2019
Time: 9:15 AM
Number: CO06006
Abstract ID:581
Candidate for Awards:Ecological Section Best Graduate Student Paper,Margaret Menzel Award,George R. Cooley Award