Evaluation of Wheat Stripe Rust Resistance in Sichuan Province

Wheat stripe rust,caused by Puccinia striiformis Westend. f. sp. tritici Erikss.( Pst),is one of the most destructive diseases of wheat( Triticum aestivum L.) worldwide. Sichuan province plays an important role in stripe rust epidemic in China. To identify and evaluate wheat stripe rust resistance in Sichuan Province,134 wheat cultivars( lines) were inoculated with seven Pst races at seedling stage and adult stage. The results indicated that the resistance frequencies of wheat cultivars( lines) against seven races CYR31,Su11-7,CYR29,Su11-4,CYR32,CYR33 and V26 were 92. 4%,92. 5%,89. 3%,89. 4%,87. 3%,85. 0% and 82. 8%,respectively. Among 134 materials,76( 56. 0%) performed resistance against all tested races both in seedling and adult stages. The virulence of new pathogenic type V26 of Pst on wheat cultivars( lines) was stronger than the dominant races CYR32 and CYR33. All wheat cultivars( lines) were classified into three types according to analysis of resistance spectrum; 66. 4% of cultivars( lines) showed all-stage resistance,17. 9% were adult-plant resistance,and 15. 7% were susceptible. This indicated that although the overall resistance level of wheat cultivars( lines) in Sichuan Province was very high,the resistance type was simple. Therefore,it is important to identify new resistance genes and enhance resistance gene diversity. Meanwhile,pyramiding breeding of all-stage resistance gene and adult-plant resistance gene could be gradually developed,to achieve durable resistance of wheat cultivars(lines) against stripe rust in Sichuan Province.