Multiple categories of resistance to wheat curl mite (Acari: Eriophyidae) expressed in accessions of Aegilops tauschii.

The wheat curl mite, Aceria tosichella Keifer, is an important pest in the western plains of the United States as well as in most major wheat-growing regions of the world. This mite is a vector of the economically important diseases wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV), and High Plains virus (HPV). This study looked at seven accessions of Aegilops tauschii (Coss) Schmal to determine if they exhibit antibiosis, tolerance, and/or antixenosis to the wheat curl mite using 'Jagger', a known wheat curl mite-susceptible variety, and OK05312, a known wheat curl mite-resistant variety, as controls. Four of the seven tested accessions showed antibiotic effects on the population growth of wheat curl mite, as demonstrated by low number of wheat curl mite adults and nymphs at the end of the experiment. Three accessions and the commercial wheat variety Jagger showed some level of tolerance to wheat curl mite infestations, as demonstrated by a significantly reduced percentage proportional tissue dry weight and by tolerance index values. Four accessions demonstrated a strong antixenotic effect on the wheat curl mite, as demonstrated by significantly reduced numbers of mite adults at the end of the experiment. This study also established an effective method for determining antixenosis to the wheat curl mite in wheat that can be used for future experiments. All accessions demonstrated at least one type of plant resistance that could provide a genetic source for control of the wheat curl mite that may have the potential to be transferred into commercial wheat varieties.