Defense Date

2009

Document Type

Thesis

Degree Name

Master of Science

Department

Biology

First Advisor

Rodney Dyer

Abstract

Studies of gene flow in natural plant populations often focus on either historical or abiotic dispersal methods (e.g. wind, water, gravity), but there is little information available on contemporary, animal-mediated pollen dispersal patterns. Emerging molecular laboratory techniques allow unprecedented insights into spatial patterns of pollen-mediated gene flow. However, to date, technical challenges have limited their widespread application. The genome of a pollen grain can be amplified via whole genome amplification (WGA) prior to traditional amplification via polymerase chain reaction (PCR) to prevent the stochastic effects associated with low copy number amplification. Even still, WGA can suffer from low success rates or poor repeatability. The present study examined the extent to which WGA can be used to aid in understanding insect-mediated pollen flow in Cornus florida (flowering dogwood) within Virginia Commonwealth University’s Inger and Walter Rice Center for Environmental Life Sciences. Initial amplification of DNA isolated from frozen grains was successful, until the pollen had been stored longer than 120 days at -20ºC. After this time point, the PCR targets failed to amplify. The percent success of downstream PCR amplification on fresh pollen grains varied from 20% to 100%, with an average of 62% success. The addition of a common molecular crowder, polyethylene glycol, produced consistent amplification, regardless of input DNA concentration and eliminated the need for triplicate samples. Successful pollination and subsequent reproduction of flowering plants has a substantial ecological and agricultural importance that warrants increased understanding into how insects move pollen across the landscape. Determining the haploid profiles of a single pollen grain will allow scientists to elucidate dispersal patterns of pollen grains and track the movement and efficiency of biotic pollinators.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

July 2009

Included in

Biology Commons

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