Abstracts Category : Other

Broadening the Genetic Base of Papaya via Intergeneric Hybridization with Wild Relatives

by Gregory Hoover

M.S. University of Hawaii at Manoa 2016. Pre-breeding of papaya by hybridizing it with wild relatives could yield new traits of value to papaya production, both for agricultural (e.g. disease resistance) and consumer oriented (e.g. flavor components) traits. Hybrids between papaya and its closest major relatives, the Vasconcellea, ultimately result in sterile progeny. Here, inducing tetraploidy is proposed as a method of overcoming that sterility. Crosses were made between papaya and several Vasconcellea species by utilizing embryo rescue techniques. These hybrids were then treated with a mitotic inhibitor, oryzalin, to produce plants with tetraploid tissues. Thus far, flowering has occurred in interspecific hybrids, resulting in the production of larger, yet well formed, pollen grains.