2024 Poster Session
Varsalona, Vincent, P.
- Reinhardt University, 7300 Reinhardt College Cir, Waleska, GA 30183
- Virginia Chapter of the American Chestnut Foundation, 900 Natural Resources Dr. Charlottesville
Abstract
The American Chestnut Foundation is working to breed a chestnut population resistant to the chestnut blight fungus (Cryphonectria parasitica) and the soil-borne pathogen, Phytophthora cinnamomi, by crossing American chestnut (Castanea dentata) with the resistant Chinese chestnut (Castanea mollissima) through controlled pollination. Current practice is to cover female flowers when styles emerge and pollinate those flowers 10-14 days later. Chestnuts exhibit a flowering phenology called duodichogamy where male catkins emerge, followed by female flowers (burs), and a second flush of staminate flowers occurs on the bisexual catkin. (Stout, 1928). Long thought to be characteristic of male fitness, Pauly et al. suggest that duodichogamy has evolved mostly for female fitness (2023). Furthermore, styles of female flowers in European chestnut (C. sativa) are each receptive at varying times for an interval of two days. (Valdiviesso, 1999) If styles in the female flowers of C. dentata are receptive at differing times and a second staminate inflorescence is beneficial to female fitness, then pollination could be performed over a longer period than two weeks and double pollination could yield more nuts at harvest. This study aims to optimize controlled pollination in chestnut by i) performing pollen treatments across a range of 5-24 days after bagging female flowers and ii) applying double pollination treatments at 10 and 15 days after bagging to test if individuals that receive two pollen treatments bear more nuts. The results of this study will be collected at harvest in the