ARS | Publication request: FIELD EVALUATION OF WILD BARLEY AGAINST RUSSIAN WHEAT APHID.

Submitted to: Arthropod Management Tests
Publication Type: Other
Publication Acceptance Date: December 2, 1998
Publication Date: N/A

Interpretive Summary: Plant and microbial germplasm stored in seed repositories of the USDA- Agricultural Research Service and other organizations may be a valuable source of new materials for insect management applications. Indeed, research has shown that insect pest resistance in forage and turf grasses from USDA-ARS seed repositories is associated with the presence of microbes (called endophytic fungi) in these grasses. The basis of this resistance is specific chemicals produced by endophyte-infected grasses. This paper describes field resistance of endophyte-infected wild barley accessions from the USDA-ARS small grains collections in Aberdeen, Idaho to Russian wheat aphid. This field research confirms results from earlier laboratory studies and strengthens the hypothesis that wild barley harbors novel microbes for use in developing a new control method for pest aphids.

Technical Abstract: A field experiment compared densities of Russian wheat aphid on 11 accessions of wild barley. Seven accessions produced plants free of fungal endophytes in the genus Neotyphodium and these supported significantly more aphids than did four accessions with endophyte-infected plants. Only plants from endophyte-free accessions exhibited Russian wheat aphid-induced dfeeding damage. These results support laboratory research that linked Russian wheat aphid resistance in wild barley to the presence of fungal endophytes.