Dissertation
STUDY ON FLOWER BIOLOGY AND POLLINIZER PERFORMANCE OF APPLE IN WASHINGTON STATE
Washington State University
Doctor of Philosophy (PhD), Washington State University
01/2021
DOI:
https://doi.org/10.7273/000002445
Handle:
https://hdl.handle.net/2376/122177
Abstract
Washington State is one of the major apple-growing regions in the United States. Notably, apple pollination-related research has been eliciting increasing interest recently. The present research was designed to address multiple aspects of pollination, including the evaluation of in vitro pollen tube growth performance, assessment of flower morphology, investigation of pistil biology of four domestic apple cultivars, and determination of the photosynthetic performance and vegetative growth of selected crabapple cultivars. First, this research identified novel metrics that can be used to characterize pollen donors based on their in vitro pollen tube length measurements. The performance of new pollen donors was classified using the “decision tree” methodology or by predicting their position onto a factor map of an apple reference pool of cultivars created in this study. Both methods yielded similar results. Second, the effective pollination periods and their limiting factor were determined for ‘Golden Delicious’, ‘Olsentwo Gala’, ‘Rubinstar’, and ‘WA 38’ under natural field conditions. The effective pollination periods for apical spur flowers ranged from 1.4 to 5.6, days depending on the cultivar and year. While pollen tube growth and ovule longevity seemed equally important in limiting effective pollination periods, stigmatic receptivity did not turn out to be a limiting factor. Third, the flower morphologies of selected crabapple and domesticated apple cultivars were compared to determine the cultivars’ variability. Overall, the domestic cultivars showed slightly greater pollen quantities based on the optical density readings. However, the pollen quality based on the in vitro germination rate of the varieties investigated in the present study did not differ between the crabapple and domestic apple cultivars. The results of this study contribute to the ongoing research efforts aimed at evaluating new potential pollinizers for apple orchards and optimizing pollination for apple varieties with commercial relevance.
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Details
- Title
- STUDY ON FLOWER BIOLOGY AND POLLINIZER PERFORMANCE OF APPLE IN WASHINGTON STATE
- Creators
- Stefan Roeder
- Contributors
- Stefano Musacchi (Advisor)Katherine M. Evans (Committee Member)Sara Serra (Committee Member)David R. Rudell (Committee Member)Todd Einhorn (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Horticulture, Department of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 215
- Identifiers
- 99900606855001842
- Language
- English
- Resource Type
- Dissertation