Race And Virulence Frequency Of Puccinia Triticina In China In 2013

Six hundred and thirty-five samples of Puccinia triticina were collected in China in 2013. Three hundred and forty-five single-uredinial isolates were derived from the collection samples, and were described to 86 physiological races. The most common physiological races were THTT(24.6%), THTS(14.5%), PHTT(7.5%), THSS(5.2%), PHTS(2.9%), THKT(2.9%).The physiological races were analysed base on the wheat areas. There were twenty-one physiological races among 92 isolates of P. triticina in the Xinjiang winter-spring wheat area, the most common physiological races were THTT(50.0%) and THTS(15.2%). Seven physiological races were found among 7 isolates of P. triticina in the Southern spring wheat area. In the Northern winter wheat area, sixteen physiological races were found among 32 isolates of P. triticina, and the most common physiological races were THTS(15.6%), PHTT(15.6%), THTT(12.5%). Fifty-four physiological races were identified from 145 isolates of P. triticina in the Huang-Huai winter wheat area, and THTS(13.8%), THTT(11.0%), THSS(10.3%), PHTT(9.7%) were the four most common physiological races. Fifteen physiological races were found among 25 isolates of P. triticina in the middle and lower reaches of Yangtze River winter wheat area, the most common physiological races were THTT(32.0%) and THTS(12.0%). Twenty physiological races were identified from 44 isolates of P. triticina in the Southwest spring wheat area, the most common physiological races were THTT(25.0%), THTS(18.2%), PHTS(11.4%). THTT and THTS were the most common physiological races in all wheat areas except for the Northern spring wheat area. PHTT was found in all wheat areas, and the most common physiological races in the Northern winter wheat area and Huang-Huai winter wheat area. THSS and PHTS were found in all wheat areas except for Xinjiang winter-spring wheat area and the Northern spring wheat area, and the most common physiological races in the Huang-Huai winter wheat area and the Southwest spring wheat area. There were the unique type of physiological races in all wheat areas.The composition of physiological races were analysed base on the provinces. There were many physiological races in every province. The populations of P. triticina were varied bunch. There were the unique type of physiological races in all provinces except for Sichuan,Guizhou and Anhui. The most common physiological races were found in all provinces except for Inner Mongolia and Zhejiang. Types of the most common physiological races and ratios of the races were different in all the provincesThe resistance genes Lr9、Lr19、Lr24、Lr38、Lr39、Lr42、Lr47 were the effective resistance genes, and Lr1、 Lr2a、Lr2c、Lr3、Lr16、 Lr26、 Lr3ka、 Lr11、Lr17、Lr21、Lr B、Lr10、 Lr14a、 Lr2b、 Lr3bg、 Lr14b、Lr29、Lr32、Lr33、 Lr33+34、 Lr25、Lr37、Lr50 had almost losed the resistance for wheat leaf rust in China.The genetic distance and genetic identity were calculated by using software NTSYS2.10. The results showed that the virulence similarity is high between populations of P. triticina and the genetic relationship is close. Cluster analysis of different populations based on virulence characteristics of P. triticina using the software MEGA6. The results showed that the populations of P. triticina from the geographical proximity maybe clustering together or not; and the populations of P. triticina from the geographically remote maybe clustering together. So the virulence of P. triticina with geographical origin has some relevance, but not perfectly correlated. The results indicated that the P. triticina can spread over long distance by air,leading to exchange between populations.