Graduate Studies


First Advisor

Mark Lagrimini

Date of this Version

Spring 4-18-2019


A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Agronomy, Under the Supervision of Professor Mark Lagrimini. Lincoln, Nebraska: May 2019

Copyright 2019 Alexandra Therese Cote Rader


Characterization of three flower timing mutants in processing tomato varieties both individually and in combination across genetic backgrounds and in various growing conditions allowed for evaluation of these mutations and their acceptability for introduction into new hybrid material. These observational and quantitative trials revealed dw1 in both heterozygous and homozygous states, and TMF in the homozygous state increased earliness. Dw1 conferred distinctive plant phenotype characteristics, including reduced plant size and vegetative regrowth. TMF provided a less extreme decrease in overall plant maturity when compared to dw1, but overall created a hybrid phenotypically similar to the original hybrid across backgrounds. SFT, conversely, is a mutation that creates a late flowering phenotype with single flower inflorescences and increased vegetative growth. When in combination, either dw1-SFT or TMF TMF-SFT the earliness and lateness roughly balanced out to return to the original hybrids’ maturity. Overall, two successes from a commercial point of view arose from the study – first, dw1-SFT and TMF TMF-SFT combinations in some backgrounds created an increase in yield. Second, TMF TMF and dw1 dw1 in some backgrounds created equivalent yields to the original hybrid but mature early enough to create hybrids competitive in the “Early” processing tomato class. Overall, dw1, TMF, and SFT open the door to unique combinations of genetics using proven commercial backgrounds and novel mutants that may provide maturity, or yield shifts for the positive within the processing tomato industry, but further evaluation would be needed to ensure phenotypic, yield and fruit characteristics meet or exceed industry standards.

Advisor: Mark Lagrimini