You are here
agInnovation Research Center | Plant Pathology
agInnovation Research Center | Plant Pathology
Plant pathology research at UOG
Western Pacific Tropical Research Center plant pathologists are engaged in research of the diseases of traditional Pacific island plant crops as well as other plants cultivated in the islands. Given Guam's unique environment and endemic plant species, much of our lab's work is on pathogens unique to Guam.
The Plant Pathology Lab utilizes a combination of classical microbial culturing techniques and molecular diagnostics to identify pathogens.
Why it's important
Ecological and agricultural needs in Guam guide the scientific study of plant diseases. Guam’s tropical environment supports several diverse ecosystems with many uncommon and unique native plant species. These plant species provide habitats and nutrition for higher organisms, such as the Marianas fruit bat and the endangered Mariana eight-spot butterfly. Similarly, these same plants are utilized in local CHamoru diets and traditional healing practices.
As a regional transport hub, international movement of cargo in and out of Guam exposes the island and region to foreign plant disease. Non-native agricultural crops and a robust ornamental plant trade contribute to the island’s plant diversity but also carry additional biosecurity risks.
Plant diseases are caused by pathogens (biotic) and environmental conditions (abiotic). Plant pathogens threaten many native species, yet they remain largely unidentified and undocumented.
Sustainability of the island’s flora requires a higher understanding of the pests and diseases that threaten their health. Rapid identification of these pathogens creates better informed actions on quarantine and eradication.
Past impacts
Work in the Plant Pathology Lab under previous faculty researchers Dr. Andrea Blas and Dr. Robert Schlub has resulted in:
- the development of improved varieties of papaya targeted for Guam's environment and consumer preferences
- identifying the Ageratum yellow vein virus, which was causing local farmers to lose their whole tomato crops
- a deeper understanding of brown root rot in the trees of Guam's limestone forests
- the identification and promotion of cucumber cultivars resistant to Anthracnose disease
Papaya
The Plant Pathology Lab has recently isolated and identified two Erwinia different species that are the causal agent of mushy canker on papaya. Ongoing work will identify virulence factors and the role of cell-cell communication in these pathogens. Additional work looks at the role of mollusk vectors in the spread of the pathogens.
Funding source: Hatch
Hot Pepper
Cycads
Cycas micronesica, the endemic Guam cycad tree, was once Guam’s most common tree but is now endangered due to human development/habitat reduction and an assault of various foreign pests and diseases. Considerable effort at the University of Guam is invested in nursery propagation for future out-planting. Microscopic observation has identified two novel foliar pathogens. Ongoing work focuses on getting pathogens into culture, completing Koch’s postulates, and completing DNA sequence analysis for identification. Future work will survey for diseases in wild cycad populations and identify best management practices to reduce negative impacts on the plants’ growth.
Funding source: None
Publications
Title | Publication | Date |
---|---|---|
First report of Erwinia papayae associated with Papaya Mushy Canker Disease in Guam | Plant Disease | September 2024 |
Pathology Lab identifies an anthracnose-causing pathogen on pepper plants | National Land Grant Impact Database | 2024 |
Pathology study pinpoints cause of mushy canker in Guam’s papaya plants | National Land Grant Impact Database | 2024 |
(On-air interview) How a deadly disease discovered on Guam papaya plants could impact Hawai'i | Hawai'i Public Radio | August 2024 |
Diseases of local importance: Citrus greening, banana bunch top disease, and tinangaja disease of coconut | May 2016 | |
Banana Bunchy Top Disease: Managing Bunchy Top Disease in your field or home garden | May 2016 | |
Citrus greening (Huanglongbing): A field guide to identification of citrus greening in Guam | May 2016 |
Last updated: August 2023
RESEARCHER:
Glenn Dulla, Ph.D.
ALS Bldg., Room 217
Phone: (671) 735-2140
Email: dullag@triton.uog.edu