Publication Date: 2019.
Swainsonine has been identified as the toxin in legumes belonging to the genera Astragalus and Oxytropis throughout the world including China, North America, and South America. Several South American Astragalus species have been reported to contain swainsonine; however, data is lacking to support the presence of a fungal symbiont in South American Astragalus species as has been shown for North American and Chinese Astragalus and Oxytropis species. The objective of this study was to investigate several South American species that have been reported to contain swainsonine for the presence of the fungal symbiont using culturing and PCR. Swainsonine was detected in field collections of A. pehuenches, A. illinii and A. chamissonis but not A. moyanoi, which is consistent with reports of toxicity regarding these species. The symbiont Alternaria section Undifilum was detected by PCR in all three species that contained swainsonine but not in A. moyanoi. A fungal symbiont was isolated from seeds of Astragalus pehuenches and A. illinii. The isolated symbiont from both respective species produced swainsonine in vitro, and was demonstrated to belong to the genus Alternaria section Undifilum by analysis of the nuclear ribosomal DNA. It is highly likely that Alternaria section Undifilum isolates will be associated with other South American Astragalus species that are reported to contain swainsonine.
Estación Experimental Agropecuaria Bariloche
Author affiliation: Martinez, Agustin. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área Producción Animal. Grupo Sanidad Animal; Argentina
Author affiliation: Robles, Carlos Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área Producción Animal. Grupo Sanidad Animal; Argentina
Author affiliation: Roper, Jessie M. USDA. ARS Poisonous Plant Research; Estados Unidos
Author affiliation: Gardner, Dale R. USDA. ARS Poisonous Plant Research; Estados Unidos
Author affiliation: Neyaz, Marwah S. New Mexico State University. Department of Entomology, Plant Pathology and Weed Science; Mexico
Author affiliation: Joelson, Natalia Zoe. Universidad Nacional del Comahue; Argentina
Author affiliation: Cook, Daniel. USDA. ARS Poisonous Plant Research; Estados Unidos
Repository: INTA Digital (INTA). Instituto Nacional de Tecnología Agropecuaria