Title

Assessing the contribution of horticultural genotypes to invasive populations of Berberis thunbergii DC.

Date of Completion

January 2008

Keywords

Agriculture, Horticulture

Degree

Ph.D.

Abstract

This work assessed the contribution of the horticultural genotype, B. thunbergii var. atropurpurea, to feral populations of Berberis thunbergii. I compared germination, growth and survival in five natural environments (full sun, edge of woods, moist woods, dry woods, pine woods) of Berberis thunbergii and its ornamental form, B. t. var. atropurpurea , to determine whether these two forms have a similar ability to naturalize. B. thunbergii and B. t. var. atropurpurea had similar germination rates however survival rate was significantly greater for B. thunbergii. Amplified fragment length polymorphism molecular markers were used to determine whether genetic contributions from B. thunbergii var. atropurpurea are found in naturalized populations of B. thunbergii in southern New England. B. thunbergii var. atropurpurea had minimal genetic influence on feral populations in southern New England. However, a single landscape specimen of B. thunbergii var. atropurpurea, established for many decades, had a significant impact on its surrounding feral population. ^