Journal Article Research Support, U.S. Gov't, Non-P.H.S. Research Support, Non-U.S. Gov't maize disease resistance microbiome phyllosphere Blumeria graminis GMW67QNF9C Leucine Triticum aestivum breeding disease ecology effector genome-wide association study heterosis host resistance hybridization introgression leucine-rich repeat receptor kinase pathology powdery mildew quantitative resistance rhizosphere southern leaf blight susceptibility gene wheat