Study On Detection Methods Of Pathogenic Differentiation Of Cotton-wilt Fusarium In Xinjiang

In this paper, adopting traditional methods (identification host, vegetative compatibility) and modern biological methods (isozyme, molecular marker), pathogenic differentiation of Fusarium oxysporum f. sp. Vasinfectum in Xinjiang are comprehensive detected. The whole tested 42 strains identified belong to race 7 and one vegetative compatibility group, which can compatible with standard strain of race 7. Race 7 is still dominant race in Fusarium oxysporum f. sp. Vasinfectum in Xinjiang, and they exist further different pathotype ( strong,middle,weak) .The strains of race 7 are distributed by planting area of Xinjiang and the strains with strong virulence are distributed by the north of Xinjiang. In this study, race 3 and race 8 are not found, which compared with the experiment (the detection of races of cotton-wilt Fusarium in Xinjiang) by teacher Zhang li,Li guo-ying in our university and previous research, the population components of cotton-wilt Fusarium have not changed yet.The study of electrophoresis of the soluble protein, esterase and peroxidase isozyme on all tested FOV strains shows that there has distant difference among different races, the race 3,7,8 have their own characteristic bands, Most of the tested strains have 1 or more characteristic bands of the standard race 7, which most of the tested strains may identify race7. This result is identical to the result of identification host .So it shows that technology of electrophoresis of isozyme can be of consult value in identification of physiologic races of cotton-wilt Fusarium.In this paper, the advantage and disadvantage of these detection methods are compared. Due to detection of races of the tested strains of cotton-wilt Fusarium and pathogenicity of strains,we still adopt the main method of identification host, plus the auxiliary methods of VCG, isozyme and molecular marker technology.The results of pathogenicity of the strains with different virulence by subculture show that they tend to weaken their virulence, compared with the other tow pathotype, the stains with strong virulence are obvious. At the same time, the tentative studies show that Fusarium oxysporum f. sp. Vasinfectum colonized in different tissues of cotton display some difference on pathogenicity, colonization stability and protein level.