Survival of wheat curl mites on different sources of resistance in wheat

Wheat (Triticum aestivum L.) yield is limited by wheat streak mosaic virus which is vectored by the wheat curl mite (WCM) Aceria tosicheilla (Keifer). Host resistance to WCM has reduced losses. This study was conducted to eva luate the effectiveness of resistance in wheat to WCM collected from variou s locations in the Great Plains. Collections of WCM from Montana, Nebraska, South Dakota, Texas, Alberta, Canada, and eight locations in Kansas were c ompared for their ability to survive and reproduce in the greenhouse on sev en lines of wheat and wheat relatives previously identified as resistant. T he lines and their sources of resistance were: AC PGR16635 (Aegilops tausch ii Coss., Cmc1), PI525452 (Thinopyrum ponticum (Podp.) Liu and Wang, Cmc2), KS96WGRC40 (Ae. tauschii and Secale cereale L.), TA920 (Triticum timopheev ii (Zhuk.) Zhuk spp. armenidcum), PI 475772 (S. cereale), 'TAM 107' (S. cer eale), PI 222655 (T. aestivum). KS96WGRC40 and TA920 were the only entries that were resistant to all WCM collections. Other sources of resistance wer e effective against WCMs from some but not all locations. PI 222655 was res istant to WCMs from Nebraska and central Kansas but not to mites from most other locations. WCMs that were virulent to TAM 107 generally were also vir ulent to PIs 222655 and 475772 but avirulent to Cmc2. The WCMs from western Kansas, where TAM 107 is widely grown, were generally more virulent to tha t cultivar than WCM from central Kansas where the hectarage of TAM 107 is s maller. WCMs collected at different times or locations may vary in their re sponses to different sources of resistance; therefore, testing mites for th eir response to resistance genes advanced in breeding programs may be neede d before resistant cultivars are deployed in the field.