Dissertation
ASSESSING THE TOLERANCE OF RED RASPBERRY (RUBUS IDAEUS L.) CULTIVARS TO PHYTOPHTHORA. RUBI WITH SATURATED PERIODS AND RELATIONSHIP TO TERPENES COMPOUND
Doctor of Philosophy (PhD), Washington State University
01/2020
Handle:
https://hdl.handle.net/2376/111353
Abstract
ASSESSING THE TOLERANCE OF RED RASPBERRY (RUBUS IDAEUS L.) CULTIVARS TO PHYTOPHTHORA. RUBI WITH SATURATED PERIODS AND RELATIONSHIP TO TERPENES COMPOUNDS.
Abstract
by Khaled M. Mazik Hesaien Sr, Ph.D.
Washington State University
May 2020
Chair: Patrick P. Moore
Soilborne diseases of red raspberry (Rubus idaeus) cause significant damage to production worldwide because susceptible cultivars are widely planted. A sustainable alternative would be growing cultivars with durable disease tolerance or resistance. Developing cultivars with durable resistance and elite fruit quality is difficult and time-consuming. Screening for resistance or tolerance in a greenhouse would be useful for efficiently identifying suitable cultivars or parent materials. The objectives of this project were to: 1) develop reliable tests for raspberry infected with Phytophthora root rot (Phytophthora rubi) to distinguish tolerance or resistance levels; 2) evaluate how saturated soil impacts raspberry and pathogen development, and 3) investigate the potential relationship between root triterpene compounds with tolerance or resistance to P. rubi. Beginning in 2017, tissue culture propagated red raspberry cultivars were subjected to different pathogen concentrations and water saturation periods. Growth and root and shoot symptoms expression were observed. 'Cascade Gold' was found to be very susceptible to P. rubi regardless of the amount of inoculum or water stress. ‘Cascade Bounty’ showed the highest tolerance to P. rubi and it was relatively insensitive to inoculum concentration, although root rot and stunting were observed at the highest inoculum levels with high water stress. Analysis of root terpenes through HPLC-MS showed the tolerant cultivar, ‘Cascade Bounty’, contained four-fold more pomaceic acid than the susceptible ‘Cascade Gold’. Euphasic acid increased with increasing pathogen stress, while corosolic acid declined with increases in pathogen stress. There was no significant difference in triterpene acid compounds when exposed to different saturation levels. It appears that root rot tolerance may be related to the production and type of terpenes in the root. If this is the case, the traits could be a selection criterion for breeding resistance or tolerances to P. rubi.
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Details
- Title
- ASSESSING THE TOLERANCE OF RED RASPBERRY (RUBUS IDAEUS L.) CULTIVARS TO PHYTOPHTHORA. RUBI WITH SATURATED PERIODS AND RELATIONSHIP TO TERPENES COMPOUND
- Creators
- Khaled Mazik Hesaien
- Contributors
- Patrick. P Moore (Advisor)Lisa Wasko DeVetter (Committee Member)David Rudell, (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Horticulture, Department of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 173
- Identifiers
- 99900581612601842
- Language
- English
- Resource Type
- Dissertation