Disease and pest resistance of endophyte infected and non-infected drunken horse grass

Abstract

The naturally occurring mutualistic symbiosis of Neotyphodium gansuense and drunken horse grass (Achnatherum inebrians) was studied previously in China. In this paper, new data on the interactions of endophyte, host and pathogenic fungi, mite and insect pests are presented. Fungal diseases and pests were examined when test plants were grown in pots in a climate chamber or in the field. There were usually no significant (P>0.05) differences in the levels of powdery mildew infection (caused by Blumeria graminis) under climate chamber conditions; the only exception was that E+ plants had significantly less powdery mildew infection at 50% soil water holding capacity (WHC) than at 30% WHC. There was no significant difference (P<0.05) in the levels of infection of E- and E+ plants with leaf spot disease, caused by Bipolaris sorokiniana, under field conditions. Regardless of whether grown under growth chamber or field conditions, densities of the mite Tetranychus cinnabarinus on E+ grass were significantly (P<0.05) lower than that on E- grass. Densities of the bird-cherry-oat aphid (Rhopalosiphum padi) on E+ grass were significantly (P<0.05) lower than that on E- grass. Keywords: Neotyphodium gansuense, Achnatherum inebrians, diseases, pests, resistance, endophytes