Submitted to: American Journal of Plant Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/26/2020
Publication Date: 6/29/2020
Citation: Mornhinweg, D.W., Puterka, G.J., Armstrong, J.S. 2020. Resistance in barley (Hordeum vulgare L.) to new invasive aphid, Hedgehog grain aphid (Sipha maydis, Passerini) (Hemiptera: Aphididae). American Journal of Plant Sciences. 11:869-879. https://doi.org/10.4236/ajps.2020.116063.
Interpretive Summary: The hedgehog grain aphid is a new invasive pest found on and infesting cereal grains within the U.S. After screening 6 known resistant barley's, we found 2 lines (00BX 11-115 and Post 90) that had previously been found resistant to greenbug, and now discovered to also resistant to the hedgehog grain aphid. We identified the expression of resistance by statistically comparing damage ratings, the significantly lower intrinsic rates of increase, and other factors.
Technical Abstract: Sipha maydis Passerini (Hemiptera: Aphididae) is a pest of cereals in many regions of the world and was identified as an invasive pest of the US in 2007. Regional surveys from 2015 – 2017 revealed this pest was broadly distributed throughout many of the western Great Plains states where it is a potential threat to cereal production. The common name hedgehog grain aphid, HGA, has been associated with Sipha maydis in the U.S. Cross-resistance where a plant resistant to one aphid species is also resistant to another species is known to occur. Six barleys were evaluated for cross-resistance to HGA: Russian wheat aphid, RWA, resistant germplasms STARS 9301B and STARS 9577B and cultivar 'Mesa'; greenbug, GB, resistant germplasm STARS 1051B and cultivar 'Post 90'; and RWA and GB resistant experimental line 00BX 11-115. Cultivars 'Morex' and 'Schuyler' were susceptible controls. Antixenosis was measured 5 days after infestation by HGA. Seedling damage ratings and reductions in seedling growth were recorded after 17 days of infestation. Intrinsic rate of increase, rm, of HGA was determined by following the development of newborn aphids to adulthood and reproduction. 00BX 11-115 and Post 90 had significantly greater antixenosis (fewer aphids/seedling), significantly lower plant damage ratings, and significantly lower intrinsic rates of increase than other entries. Differences in seedling growth were not significant. 00BX 11-115 and Post 90 were the only entries with the Rsg1 greenbug resistance gene. Rsg1 greenbug resistance confers cross-resistance to HGA in the seedling stage.