Location: Subtropical Horticulture Research
Project Number: 6038-21000-026-013-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jun 15, 2024
End Date: Jun 14, 2028
Objective:
To improve growers' income in the Southeastern region of the United States, we are working towards developing a sustainable plant production system that can enhance the productivity of avocado, an economically and nutritionally important fruit crop. The avocado industry in Florida has suffered a severe decline in the last two decades due to the impact of laurel wilt disease and the high susceptibility of the crop. Laurel wilt (LW) is a lethal vascular disease caused by the fungus Harringtonia lauricola, first introduced and vectored by the Redbay ambrosia beetle but now spread by multiple locally established ambrosia beetles species. This disease was first reported in the US in 2004, though the pathogen and its primary vector were documented in 2002. Since then, millions of Redbay trees have died, and the disease has spread throughout the Southeastern United States being currently present in twelve states. Once a tree is infected, it rapidly wilts and dies within weeks. Presently, no known cure or cost-effective control method exists. More than 50 species in the Lauraceae family are at risk of contracting the disease, and both commercial and backyard avocado growers are at risk. To sustain the avocado industry, it is essential to provide cost-effective and sustainable management options to the industry.
Approach:
This research collaboration aims to gather preliminary data to create a robust detached plant tissue screening assay for the evaluation of Laurel Wilt (LW) response, under controlled conditions. Current methods (established by the Gazis’ laboratory) to screen avocado seedling material can take up to two years, as the stems of the plants need to reach an appropriate diameter before being inoculated with the pathogen. The development of a detached plant assay will allow for rapid screening and require less resources. Detached assays can be conducted inside a laboratory inside incubators or growth chambers, whereas whole plant assays require more care and the use of air conditioning greenhouses. In addition, clonal material from cultivars growing in other regions could be brought to SHRS or UF-TREC for screening. The second objective of this agreement, screening the current SHRS open pollinated population consisting of 200 progeny plants in pots, will potentially identify sources of tolerance or resistance. If exist, this material will serve as the foundation for developing and delivering avocado cultivars tolerant/resistant to LW to stakeholders and growers in the region and the nation. The collaboration between the USDA-ARS in Miami and TREC scientists will allow for the sharing of resources and expertise. The USDA-ARS, SHRS, has developed a diverse collection of avocado germplasm, including genetic mapping populations and open-pollinated populations. Also, it holds a diverse germplasm collection with more than 150 cultivars. On the other hand, the TREC team has ample experience in screening of avocado germplasm for LW disease response.
Statement of mutual interest: TREC and the SHRS of the U.S. Department of Agriculture's Agricultural Research Service (USDA-ARS) will conduct independent research to characterize the germplasm collection for different desirable traits. TREC and SHRS are collaborating on monitoring and managing various invasive pest/diseases. Achieving the goals of this project will strengthen and enhance the research programs of both entities by increasing their understanding of the variation in host response to the pathogen infection. This research affirms our mutual interest in cooperative research programs and exchanges, benefiting both parties and the people of the United States.
Roles and responsibilities: PI and CO-PI from USDA-ARS, along with a scientist from TREC, will provide guidance and oversight to the study, ensuring that the project's objectives are met. The research results will be shared equally and used for publication. PI and Scientist from TREC will co-lead and share responsibility for generating data and ensuring the research meets high-quality standards.
