Dissertation
Identifying the Genetic Mechanism of Ethylene-Inducible Fruit Abscission in Sweet Cherry
Washington State University
Doctor of Philosophy (PhD), Washington State University
05/2017
DOI:
https://doi.org/10.7273/000005562
Abstract
Sweet cherry (Prunus avium, L.) belongs to the Amygdaloideae subfamily in the Rosaceae family and is related to Peach (Prunus persica, L.) which presents a classical example of climacteric ripening along with members in other sub-families such as Apple (Malus x domestica Borkh). While the fruit ripening process in sweet cherry is non-climacteric, a novel response to ethylene has been observed in a subset of cultivars, e.g., 'Bing', where a pre-harvest canopy-wide application of exogenous ethylene results in the formation of a distinct pedicel-fruit abscission zone. This decreases the force required to separate fruit from pedicel, presenting the possibility of harvesting the fruit mechanically. Some cultivars, e.g., 'Chelan', maintain a high pedicel fruit retention force, while the abscission zone in 'Skeena' develops without exogenous ethylene. This natural spectrum of phenotypes for ethylene-inducible abscission zone formation presents an interesting forward genetics model to unravel the underlying molecular mechanism. This is critical for a perennial crops species where reverse genetics approaches are not feasible due to the lack of genetic resources available in annual model system crops. Understanding the causal molecular and genetic underpinnings of the inducible abscission zone formation offers the potential to expand the basic knowledge of ethylene's role in a non-climacteric fruit crop. Practical applications from this work include precision in timing the application of chemicals that induce abscission zone formation in other non-climacteric horticultural crops to enable mechanical harvesting, efficiently manage labor and enhance safety. My research used a genomics approach to refine limited genomic data for the 'Stella' genotype by resequencing five additional genotypes: 'Bing', 'Kimberly', 'Glory', 'Staccato' and 'Sweetheart'. Genes involved in ethylene inducible fruit abscission were then characterized using a developmental time-course transcriptomic approach. The results are presented in the following chapters. Chapter 1: A international collaboration established the reference genome for sweet cherry and outlines the rationale for strategies used. Chapter 2: Multiple approaches to identify polymorphisms in genomic data were evaluated. Chapter 3: The results of the developmental time course, genotypic, and tissue specific transcriptome analysis that enabled the identification of co-expressed sequences during ethylene-induced abscission are described.; This is an abstract.
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Details
- Title
- Identifying the Genetic Mechanism of Ethylene-Inducible Fruit Abscission in Sweet Cherry
- Creators
- Benjamin Richard Kilian
- Contributors
- Amit Dhingra (Chair)Anantharaman Kalyanaraman (Committee Member) - Washington State University, Electrical Engineering and Computer Science, School ofHelmut Kirchhoff (Committee Member) - Washington State University, Biological Chemistry, Institute ofMatthew David Whiting (Committee Member) - Washington State University, Horticulture, Department of
- Awarding Institution
- Washington State University
- Academic Unit
- Program in Molecular Plant Sciences
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 145
- Identifiers
- 99901054231701842
- Language
- English
- Resource Type
- Dissertation