Analysis Of Related Disease Factors To Maize Head Smut And Screening Of Resistance Cultivars

The experiments that 6 inoculated treatments of 4 maize cultivars with different level of resistance to maize head smut ( Sphacelothea reiliana (Kuhn) Clint. Var. Zeae ), testing of field natural disease incidence for 7 different seedtimes, crop rotation experiment by serving the 4 crops as the former stubble and with the maize cultivars each other were cinducted. The field natural incidence of the disease in 4 major maize planting regions in Jilin province and spring maize in China was investigated. The results showed that in the condition of different quantities of inoculum in soil, the incidence of the disease among the maize cultivars had a regular tendency, which increased with the quantity of inoculum in soil raised, and cultivars with strong resistance were less sensitive to the environment than cultivars with low resistance. Along with the prolonging of the seedtime, the incidence of the maize head smut went down, but the tendency was not obvious. Crop rotation between high resistant cultivar (HR) and resistant cultivar (R), between high resistant cultivar (HR) and susceptible cultivar (S) had a samll impact on the incidence of maize head smut. There was a great effect on the disease rating of maize head smut in crop rotation both between resistant cultivars (R) and high susceptible cultivars (HS), and between susceptible cultivars (S) and high susceptible cultivars (HS). It was largely apparent that the disease rating of hybrid cultivars varied from major maize plant regions in China, accounting for there were different quantities of inoculum in soil among the plant regions, or possessed different pathogenic races, furthermore, the different cultivars had a much great difference in the response to races of maize head smut.Based on the pathogenicity tests for the 50 hybrids and 60 parent inbreds spread mainly in the production and breeding of Jilin province (0.1%), it showed that the hybrids and parent inbreds came from different areas differed obviously in their resistance to maize head smut: Tang Si Ping Tou, Ye 107, and local germplasms are susceptible cultivars to the disease (S~HS), some foreign germplasm, such as Lancast, 78599, and so on, are resistant cultivars (R~HR), There was a decline in the resistance to the disease between Dan 330 and Lu line, for they had been spread for many years. We screened out 42 high resistant cultivars to maize head smut, such as WK 15, WK29, WK 40 and so on, and some inbreds and a group of basic resources, providing further theoretic basis and germplasms for the resistance to maize head smut for the field of breeding.