Study on Cotton Infected by Mixtures of Different Pathotypes of Verticillium dahliae

It is first reported that the morphological character of variant is useful in studying the infection complex of different verticillium strains. A plant invaded by different pathotypes of Verticillium dahliae at the same time could be verified by reisolating the pathogen from infected plant which roots had been immersed in mixed conidia suspension of strains with different morphological characters. Reisolating results and vegetative compatibility test showed that the quantity of mixed infection was 1/15 to 1/3 of total infected plants. Author considered that this is a handy method to investigate the distribution and interaction of the plant pathogenic strains with different virulence in the same host. Furthermore, paper made a suggestion that it is suitable to use the single spore strains for virulence test and the character of morphological variant is advantageous for investigation of the cross protection in verticillium wilt disease of cotton.