Efficacy and mechanism of control of wheat stripe rust by diversifying cultivars in mix-planting.

【Objective】 To provide a theoretical basis for the use of mix-planting as an ecological control method for wheat stripe rust,the control efficacy and mechanism of wheat stripe rust by diversifying cultivars in mix-planting were studied. 【Method】 Six mono-cultivars treatments and nine mix-cultivars treatments were designed and disease incidence,foci numbers and yield per plot were investigated. Furthmore,TP-M13-SSR technique was employed to detect population genetic diversity of P. striiformis f. sp. tritici in natural infested wheat in mono-cultivar and mix-cultivar plots. 【Result】 The foci numbers and development of disease at seedling stage were obviously inhibited on mix-cultivar plots compared to mono-cultivar plots. The disease index was significantly decreased during spring epidemical stage on mix-cultivar plots. The mixture planting of resistant and susceptible cultivars showed better efficacy in disease control and more reduction of yield losses. The relative control efficacy was 73.27% and yield increase rate was 13.26%,on the average,compared to mono-cultivar planting. Cultivar numbers in mix-cultivar planting did not showed the obvious effect on disease control and yield production. Population genetic diversity of P. striiformis f. sp. tritici was higher in mix-planting than that in mono-planting. 【Conclusion】 The mix-cultivar planting showed higher control effect on wheat stripe rust and more reduction of yield losses than mono-cultivar planting. The mix-cultivar planting could be used as one of the ecological measures to prevent and control disease.