Effect of canopy temperature on the stripe rust resistance of wheat

Abstract

Stripe rust of wheat (Triticum aestivum), caused by Puccinia striiformis f. sp. tritici, is highly affected by temperature, but the role of crop canopy temperature in stripe rust resistance is poorly understood. Five wheat varieties, which have different canopy temperatures and are susceptible to P. striiformis f. sp. tritici at the seedling stage, were investigated for resistance to stripe rust at the adult-plant stage in greenhouse and field experiments. In the greenhouse tests, all five varieties were resistant to stripe rust at the adult-plant stage. At the grain-filling stage in the 2007-2010 field experiments at two locations, the two varieties (NR 9405 and 9430) with higher canopy temperatures had lower disease index and smaller area under the disease progress curve values than the three varieties (Shaan 229, RB 6 and Xiaoyan 6) with lower canopy temperatures. The results indicated that the five tested wheat varieties had similar resistance reactions to stripe rust at the adult-plant stage in the greenhouse experiment, but showed different levels of resistance under natural infection conditions in the field. The negative correlation between canopy temperature and disease index during the grain-filling stage was significant. Thus, high wheat canopy temperatures provide unfavourable conditions for the development of stripe rust. This study is helpful for further developing an ecological approach for reducing stripe rust damage.