Thesis
PHYSIO-ANATOMICAL AND ULTRASTRUCTURAL PERSPECTIVE OF RED BLOTCH --A RELATIVELY NEW VIRUS DISEASE OF GRAPEVINE (Vitis vinifera L.)
Washington State University
Master of Science (MS), Washington State University
01/2022
DOI:
https://doi.org/10.7273/000004534
Handle:
https://hdl.handle.net/2376/125027
Abstract
Red Blotch disease caused by Grapevine red blotch virus (GRBV) is a serious concern to grape growers and winemakers on the West Coast, including California, Oregon, and Washington. One crucial characteristic of all viruses, including Red Blotch, is the intimate association with cell components and anomalous structures following infection. Therefore, the objectives of this study were to investigate the fruit quality attributes and ultrastructure of various tissues and document the relationship between ultrastructural cytopathology and GRBV infection in ‘Pinot Noir’ employing various microscopy techniques from two vineyard locations in the Rogue Valley and Willamette AVAs in Oregon. The infected vines visually exhibited typical interveinal red blotches in the leaves with red-colored veins with flat leaf blade margins at the onset of berry ripening. The infected vines developed millerandage (large and small berries), with significantly lower fresh berry weight. Also, the infection significantly altered the primary and secondary metabolites desired for fermentation and the final composition of wine. Given that post-veraison berry development and ripening relies on phloem influx, the altered metabolism was indicative of a disruption of the phloem pathway. Transmission electron microscopy revealed that the sieve plates in the leaves and petiole were plugged with P protein, thereby inhibiting exporting of photosynthates out of the leaf. Consequently, there was a massive accumulation of starch granules in the chloroplast, which reflects depressed translocation. However, this did not affect the primary leaf anatomical organization in the infected vines. The starch accumulation grotesquely altered the chloroplast ultrastructure ranging from degradation of grana and stroma lamellae to complete dismantling of the chloroplasts, which corresponded to an increase in plastoglobuli and tannins in the cytoplasm. This study demonstrated that the normal metabolism of the grapevines relies on the structural integrity of the plant’s tissues.
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Details
- Title
- PHYSIO-ANATOMICAL AND ULTRASTRUCTURAL PERSPECTIVE OF RED BLOTCH --A RELATIVELY NEW VIRUS DISEASE OF GRAPEVINE (Vitis vinifera L.)
- Creators
- Bailey Hallwachs
- Contributors
- Bhaskar Bondada (Advisor)Linda Chalker-Scott (Committee Member)Hanu Pappu (Committee Member)Sadanand Dhekney (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Horticulture, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Number of pages
- 160
- Identifiers
- 99900882928301842
- Language
- English
- Resource Type
- Thesis