|Armstrong, John - Scott|
|Mornhinweg, Dolores - Do|
|PAYTON, MARK - Oklahoma State University|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2015
Publication Date: 1/10/2016
Citation: Armstrong, J.S., Mornhinweg, D.W., Payton, M.E., Puterka, G.J. 2016. The discovery of resistant sources of spring barley, Hordeum vulgare ssp. spontaneum, and unique greenbug biotypes. Journal of Economic Entomology. 109(1):434-438.
Interpretive Summary: We evaluated four barley lines from the Wild Barley Diversity Collection (WBDC) for host-plant resistance to several different greenbug biotypes. Three of the lines showed very dominant resistance to the most of the greenbug biotypes tested. We also discovered through using phenotypic assays from host-plant differentials, that we had six new greenbug biotypes collected from Wyoming. This research results in a greater diversity of genes that can be used to prevent greenbug damage to barley, and also identifies potentially damaging greenbug biotypes that had never been previously reported.
Technical Abstract: The genetic sources for host-plant resistance to the greenbug (Schiazphis graminum Ronani) in barley (Hordeum vulgare ssp. spontaneum) are limited in that only two single dominant genes Rsg1 and Rsg2 are available for resistance to greenbug biotypes. We evaluated four new barley lines from the Wild Barley Diversity Collection (WBDC) that previously showed potential for greenbug resistance. Three of those entries WBDC 53, WBDC 117, WBDC 336 exhibited very dominant sources of resistance to older known biotypes B, C, E, F, H, I, and TX1, which also add to the host-plant differentials used separate greenbug biotypes. We also re-evaluated the older set of greenbug biotypes that have been in culture for many years against the known host-plant differentials, and included seven newer greenbug isolates collected from Wyoming to the full complement of small grains differentials. This resulted in the discovery of five new greenbug biotypes WY10MC, WY81, WY10 B, WY12 MC, and WY86. Wyoming isolates WY4 A and WY4 B were identical in their phenotypic profile, and should be combined as a single unique greenbug biotype. These barley trials resulted in finding new sources of host-plant resistance, although more research needs to be conducted on what type of resistance it is, and how it can be used. We also document that the Wheatland, Wyoming area serves as a very conducive place for the development of new greenbug biotypes.