WDC31: Locoweed and its Fungal Endophyte: Impact, Ecology, and Management
(Multistate Research Project)
Status: Inactive/Terminating
WDC31: Locoweed and its Fungal Endophyte: Impact, Ecology, and Management
Duration: 06/01/2014 to 09/30/2015
Administrative Advisor(s):
NIFA Reps:
Non-Technical Summary
Statement of Issues and Justification
Statement of Issue and Justification:
Locoweeds are the most widespread group of poisonous plants in the western United States. Consumption of toxic species within the plant genera of Astragalus and Oxytropis, within the Fabaceae, cause locoism, to grazing animals. Locoism is caused by consumption of the indolizidine alkaloid swainsonine, an alpha-mannosidase inhibitor. Locoism symptoms include reproductive problems, cellular vacuolization, neurological damage, and lack of coordination. Livestock poisoning from locoweeds causes major economic losses in the western U.S. While the magnitude of economic loss depends on the degree of intoxication, losses from locoweed due to poor animal health, low reproductive performance, increased death and reduced weight can cause reductions in cattle prices from 10% to 85% . In New Mexico in 1985, over 10% of the cow/calf and 40% of the cow stocker operations reported losses of over $20 million from locoism.
Fungal endophytes of locoweeds of the genus Undifilum produce swainsonine and are thus responsible for the disease symptoms. The endophytes are seed transmitted and generaly do not cause disease to their plant host. The ecological relationship between the endophytes and locoweeds has not been established. However, plants grown without the endophytes are non-toxic high quality forage.
Effective management of locoweeds and locoism has been difficult to implement and costly. Recommendations include restricting access to pastures for grazing in the spring, supplementing cattle feed, so that they dont graze on locoweeds, spraying herbicides during locoweed flowering, and using insects for biocontrol. Behaviour modification of cattle and horses shows promise as a management option, although large scale feasbility has not been determined. .An effective, sustainable management program is needed for this difficult problem. A better understanding of the endophytic fungi and how they produce swainsoine and how they interact with their plant hosts is important toward any long term manangement solution.
We propose establishment of a development committee to organize a regional project to study locoweeds and their fungal endophytes. Locoweeds and locoism is a problem over a larger area and the researchers that address the problem are spread over several states. A multistate project will improve communication and research efficiency. This committee will meet to discuss, assess, and prioritize research into topics such as locoweed genetics, endophyte genetics, plant and fungal ecology, and disease detection and management. The committee will coordinate planning of the regional project, including who will work together, what specific topics will be studied, how the group will be structured, and how the group will coordinate research to provide preliminary information needed to secure grant funding.
Related, Current and Previous Work
Objectives
-
1. Assemble a group which will include university, government, extension, and industry-based individuals to assess the current status of locoweeds, locoism, and fungal endophytes of locoweeds and set priorities for research.