The Research Of Physiological Differentiation Of Sporisorium Reilianum In China

The physiological differentiation of Sporisorium reilianum came from different provinces in China was studied with a combine method of differential hosts and RAPD markers. The result proved that physiological differentiation of S. reilianum was because of genetic differentiation but not phenotype differentiation.Through a great number of field investigations and inoculation identifications in two years, five inbred-lines(Mol7,Huang zao41,Liao1311,Zi330,Hong se bao lie) representing corn blood were defined as differential hosts for physiological differentiation of S. reilianum in China. The five inbred-lines represented different resistant and susceptible level of corn to S. reilianum and were able to recruit the system of differential hosts for physiological differentiation of S. reilianum in China.Pathogens of S. reilianum came from four provinces (Ji lin,Liao ning,Hei long jiang,Inner Mongolia) were divided into three pathogenic types by five differential hosts in the field. Pathogenic type â…  , pathogens of S. reilianum came from Chang chum Ha er bin,Shuang cheng and Tong liao; Pathogenic type â…¡, pathogens of S. reilianum came from Dan dong; Pathogenic type â…¢, pathogens of S. reilianum came from Bai cheng and Tie ling. The incidence rate of pathogenic type â…  was severely and that of pathogenic type â…¢ was lightly.Pathogens of S. reilianum came from six provinces (Ji lin,Liao ning, Hei long jiang, He bei, Shan xi, Inner Mongolia) were divided into six pathogenic groups by ten primers of RAPD (percent agreement 0.42). Group A, pathogens of S. reilianum came from Si ping, Ji lin, liao yuan , Song yuan, Liu he and a part of Chang chun; group B, pathogens of S. reilianum came from Bai cheng , Yan bian, the other part of Chang chun and Inner Mongolia municipality ; group C, pathogens of S. reilianum came from Shan xi province; group D, pathogens of S. reilianum came from Liao ning province.; group E, pathogens of S. reilianum came from He bei province; group F, pathogens of S. reilianum came from Hei long jiang province. GroupA and group B were divided into more subgroup . There was similar percent agreement that pathogen of S. reilianum came from near or same areas according to the test result. Pathogens of S. reilianum came from sorghum could had two pathogenic types because of dissimilar percent agreement.A method of DNA extraction from pathogens of Sporisorium reilianum was invented with freeing little water in mortor and controlling of rubbing time by tests repeatly.