California State University, Northridge WordmarkOviatt Library WordmarkOviatt Library Catalog Wordmark
Author Zung, Lisa L., author.
Title Genetic variation and gene flow in pentachaeta lyonii (asteraceae) at seven sites in Southern California / by Lisa L. Zung.
Published [Northridge, California] : California State University, Northridge, 2012.
 Electronic Book  QH51 .Z95 2012 Z86eb    ONLINE
Description 1 online resource (vi, 25 pages) : maps, color.
Content Type still image
Format online resource
File Characteristics text file PDF
Thesis M.S. California State University, Northridge 2012.
Bibliography Includes bibliographical references (pages 17-22).
Summary The reduction of suitable habitat due to urbanization is an increasing threat to many native plant populations. As a result, plant populations that were once continuous have become fragmented into smaller isolated populations. These resulting small populations face reduced gene flow and increased genetic drift, decreasing genetic variability. Populations with reduced genetic variability are more susceptible to disease and environmental change. Southern California is a region where the encroachment of urban development has taken a heavy toll on native plant populations. In particular, Pentachaeta lyonii, a native federally listed endangered plant that was once found in many parts of Los Angeles County and southeastern Ventura County now persists in a few locations in the Santa Monica Mountains and Simi Hills. The objective of this study was to determine the population structure and estimate gene flow between seven sites where P. lyonii occurred. To accomplish this, DNA was extracted from whole plants collected at each site, and the nuclear genetic markers internal transcribed spacer 1 and 2 (ITS1 and ITS2) were amplified and sequenced for each sample. The resulting sequences were then compared using an analysis of molecular variance (AMOVA), and used to estimate levels of gene flow. A high level of genetic variation was found among sites (90.82%) with very little variation found within them (9.18%). Gene flow was highly restricted (estimated Nem = 0.03) and there was a high level of genetic differentiation (FST = 0.91 and GST = 0.89) clustering sites into what seems to be larger northern and southern groups. Because only one set of nuclear molecular markers was assessed, and within these the sequence divergence was less than 1%, additional genetic analyses should be undertaken to verify this difference before developing restoration plans that would involve moving seeds and/or pollen from one area to another. Until more is known about the population genetics of P. lyonii, conservation of its habitat should be a priority.
Note Description based on online resource; title from PDF title page (viewed on August 27, 2012).
Subject Compositae -- Genetic aspects.
Local Subject Dissertations, Academic -- CSUN -- Biology.
OCLC number 849988262