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United States Department of Agriculture

Agricultural Research Service


Location: Poisonous Plant Research

2013 Annual Report

1a. Objectives (from AD-416):
The objectives of this research are to: 1) Evaluate and determine the adverse effects of locoweed on cattle production in New Mexico; 2) Evaluate and develop new tools for diagnostics; 3) Determine the role of a newly identified endophyte (Undifilum) in swainsonine production and locoweed growth and longevity; 4) Better understand the rangeland ecology where locoweeds dominate and evaluate methods of control (biological and chemical); and 5) Develop integrated management approaches to improve utilization of rangelands where locoweed grows.

1b. Approach (from AD-416):
This is a coordinated research approach between the USDA-ARS-Poisonous Plant Research Lab, Logan, UT and the Rangeland Research Group and College of Agriculture and Home Economics at New Mexico State University in Las Cruces, NM. The proposed joint research will include methods to: 1) better understand the ecology of locoweeds in this region which includes the Southern High Plains and Canadian Pecos Valleys of West Texas and eastern New Mexico; 2) understand more fully the biological characteristics of the locoweeds which includes the role of a newly discovered endophyte (Undifilum) in toxin (swainsonine) production within the plant and plant hardiness; 3) develop sound methods to understand the biology of the endophyte and employ molecular tools to determine if it can be supressed; 4) reduce the toxic effects in cattle and improve rangeland utilization through grazing strategies; 5) better evaluate locoweed's effects on early reproduction in cow calf operations; 6) identify biomarkers for improved diagnostics and prognosis of locoweed poisoning; and 7) develop a holistic management program to reduce livestock losses and improve the economic stability in this region.

3. Progress Report:
Locoweeds, Oxytropis and Astragalus species containing swainsonine, cause large economic losses to livestock producers in north eastern New Mexico and south eastern Colorado. The production of swainsonine and subsequent toxicity of locoweeds is due to the vertically transmitted endophyte, Undifilum. Swainsonine is only found in Astragalus and Oxytropis species that contain the fungal endophyte, Undifilum, thus explaining why some populations are toxic while others are not. Research is ongoing between scientists at the PPRL and NMSU to characterize the swainsonine biosynthetic pathway in the endophyte. Funds have been pooled between the two groups to sequence the genome of Undifilum oxytropis. Novel swainsonine producing endophytes are being characterized in other locoweed species and other plants that are reported to contain swainsonine. A novel species of Undifilum has been isolated from the swainsonine containing plant Swainsona canescens from Australia.

4. Accomplishments

Last Modified: 06/24/2017
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