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United States Department of Agriculture

Agricultural Research Service

Title: Correlation of An Endophytic Fungus (Alternaria SPP.) with the Presence of Swainsonine in Lambert Locoweed (Oxytropis Lambertii)

Authors
item Gardner, Dale
item Romero, J - NEW MEXICO STATE UNIV.
item Ralphs, Michael
item Creamer, R - NEW MEXICO STATE UNIV.

Submitted to: Poisonous Plants Symposium Proceedings
Publication Type: Book / Chapter
Publication Acceptance Date: May 20, 2003
Publication Date: November 1, 2003
Citation: Gardner, D.R., Romero, J., Ralphs, M.H., Creamer, R. 2003. Correlation of an endophytic fungus (alternaria spp.) with the presence of swainsonine in lambert locoweed (oxytropis lambertii). Poisonous Plants Symposium Proceedings.

Interpretive Summary: Locoweed poisoning is the most widespread poisonous plant problem in the western United States. Oxytropis lambertii or Lambert locoweed is one of the Oxytropis species known to contain the locoweed toxin swainsonine and is geographically spread throughout eight different western states. The locoweed toxin is believed to be a result of secondary plant biosynthesis, but recent investigations have identified a new endophytic fungus (Alternaria spp.) within locoweed that may also produce swainsonine. Sixteen individual populations of Lambert locoweed were sampled and analyzed for swainsonine and tested for the presence of absence of the endophytic fungus. Swainsonine was detected in five of the 16 collection sites with an average toxin level ranging fro 0.008% (day weight) to 0.054%. The endophytic fungus was also cultured from the same five O. lambertii populations that were found to contain swainsonine. A strong correlation between swainsonine content and the presence of a new Alternaria endophytic fungus was therefore established in Oxytropis lambertii.

Technical Abstract: Locoweed poisoning is the most widespread poisonous plant problem in the western United States. Oxytropis lambertii or Lambert locoweed is one of the Oxytropis species known to contain the locoweed toxin swainsonine and is geographically spread throughout eight different western states. The locoweed toxin is believed to be a result of secondary plant biosynthesis, but recent investigations have identified a new endophytic fungus (Alternaria spp.) within locoweed that may also produce swainsonine. Sixteen individual populations of Lambert locoweed were sampled and analyzed for swainsonine and tested for the presence of absence of the endophytic fungus. Swainsonine was detected in five of the 16 collection sites with an average toxin level ranging fro 0.008% (day weight) to 0.054%. The endophytic fungus was also cultured from the same five O. lambertii populations that were found to contain swainsonine. A strong correlation between swainsonine content and the presence of a new Alternaria endophytic fungus was therefore established in Oxytropis lambertii.

Last Modified: 10/22/2014
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