Abstract Detail

Ericaceae: Systematics, Ecology and Evolution

Huang, Yi [1], Morrison, Glen [2], Sanders, Andrew [1], Saavedra, Natalie [3], Burge, Dylan [4], Parker, Thomas [5], Keeley, John [6], Litt, Amy [7].

Genetic Variation and habitat differentiation in a group of taxonomically difficult plants: Arctostaphylos glandulosa (Ericaceae).

Manzanitas (Arctostaphylos Adans., Ericaceae) are among the most outstanding chaparral species in Southern California, with distinguishing red twisting branches, simple evergreen leaves, and clusters of urn-shaped flowers. They are a group of recently-radiated plants, diversified around 1.5 million years ago. A recent study using ITS sequence data found low levels of genetic diversity within this genus. Hybridization, polyploidy, and phenotypic plasticity make species delimitation difficult in this genus because they introduce individuals with intermediate phenotypes and/or genotypes, and incongruence in the diversification of morphology and genetics. Arctostaphylos glandulosa is one of the most problematical species in this genus. It is divided into 10 subspecies including both widely distributed and restricted ones. Morphologically, these subspecies are distinguished based on 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 are commonly found in the field, making subspecific assignment difficult or impossible. Furthermore, herbarium records and observations in the field show more than one subspecies intermingled in some locations, which is against the expectation of geographic isolation needed for subspecies. Two subspecies, A. glandulosa subsp. gabrielensis and A. glandulosa subsp. crassifolia have narrow distributions and are considered rare in the California Native Plant Society Inventory of Rare and Endangered Plants. A. glandulosa subsp. crassifolia is also recognized as endangered by US government. Here, we use Restriction-site Associated DNA sequencing (RAD-seq) to generate SNPs and test whether these subspecies, especially these two rare ones, are genetically distinct. We also apply the MaxEnt program to identify environmental factors that define the restricted distribution of these two rare taxa. These results enhance the understanding on subspecies classification within A. glandulosa and can be used to inform conservation strategies for the two rare subspecies.

1 - University of California, Riverside, Botany and Plant Science, 900 University Ave, Batchelor Hall, Riverside, California, 92521, USA
2 - University Of California Riverside, Botany And Plant Sciences, 900 University Ave, Riverside, CA, 92521, United States
3 - 24548 Covington Way, Moreno Valley, CA, 92557, United States
4 - 13411 Bean Flat Road, Chico, CA, 95928, United States
5 - Cal State San Fransisco, 1600 Holloway Ave, San Francisco , CA, 94132, USA
6 - USGS Western Ecological Research Center, Sequoia Kings Cayon Field Station, 47050 Generals Hwy, Three Rivers, California, 93271
7 - University Of California Riverside, Botany Dept, 900 University Ave, Riverside, CA, 92521, United States

Keywords:
radiation
RAD-seq
Species Distribution Modelling
subspecies
manzanitas.

Presentation Type: Colloquium Presentations
Session: C07b, Ericaceae: Systematics, Ecology, and Evolution Part 2
Location: 114/Mayo Civic Center
Date: Tuesday, July 24th, 2018
Time: 4:45 PM
Number: C07b013
Abstract ID:397
Candidate for Awards:None