Date of Award

Spring 2012

Project Type


Program or Major

Plant Biology

Degree Name

Master of Science

First Advisor

Thomas M Davis


Sex determination is of interest to plant breeders who transfer useful genes from wild relatives to the cultivated strawberry. The potential roles in sex determination of seven candidate genes, which included five SUPERMAN genes, the AGAMOUS gene, and the ACS-7 gene, were studied by re-introducing them into diploid strawberry as overexpression and RNAi constructs by Agrobacterium-mediated transformation. All of the transgenic calli expressed the GFP fluorescence marker. Among regenerated plants, some AGAMOUS-silenced plants transiently displayed a petalloid stamen or a vestigial petal phenotype, pointing to the AGAMOUS gene as negative regulator of A- and B-class genes according to the widely utilized "ABC Model" of flower development. ASC-7 over-expression and RNAi plants had slower growth rate, which may influence flower development, and the RNAi-transformants did not flower during the study period. Failure to regenerate from callus occurred with over-expression constructs of FRASUP1, FRASUP3, FRASUP4, FRASUP5, and AGAMOUS and FRASUP3 RNAi construct.