The Interactions Of Verticillium Dah Liae In Hubei Province With Varieties Of Cotton

Verticillium dahliae is one kind of fungal soil-borne diseases in the world spreading all over the cotton production areas, so it is called "cotton cancer". Hubei Province, as one of the main production areas of cotton in Yangtze River, is one of six major cotton-producing provinces, and cotton is the province's biggest economic crops besides the main grain crops. But in recent years, due to the climate instability and neglecting of seed transporting quarantine and other factors, the effects on yield and quality of cotton production in Hubei Province occurred due to Verticillium wilt is increasing year by year showing a variety of disease symptoms in the field type. To do this, finding out the interaction rules between different Verticillium dahliae from different areas of Hubei and different kinds of varieties is important for the control of cotton Verticillium wilt.In order to find out the law of interaction between Verticillium wilt bacteria in Hubei Province with varieties of Cotton,32 representative strains from different regions of Hubei province and 4 different cotton varieties and their plant strains with different resistance to pathotypes were selected to do this research. Secondly, this study mainly based on nutrient water floating nursery seedling technology, and some research have been done about the strengthened seedling, mainly to identify the most effective combination of Mepiquat Chloride concentration. The main results are as follows:(1) According to the pathogenic changes represented on the interactions of the five non-defoliating pathotypes 1cd11-b,1cd3-2,1cd21-b,ve10 and ve5 with cotton varieties of Zhongmiansuo 8 and Jimian 11, the non-defoliating pathotypes could be divided into three types. Typeâ… , the pathotype that performance resistance on Zhongmiansuo 8, and sensitivity on Jimian 11, represented by non-defoliating pathotype 1cd11-b. Typeâ…¡, the pathotype that performance sensitivity on Zhongmiansuo 8, and resistance on Jimian 11, represented by non-defoliating pathotype 1cd3-2. Typeâ…¢, the pathotypes that performance resistance both on Zhongmiansuo 8 and Jimian 11, including pathotypes 1cd21-b, ve10 and ve5. The interaction results between these three types of pathotype with t Zhongmiansuo 8-3 and Jimian 11-5, which seleced from the cross-strain lines of different kinds of varieties, further confirmed that classification and proved the resistance differentiation between non-defoliating pathotypes and cotton varieties.(2) According to the pathogenic changes represented on the interactions of the 27 defoliating pathotypes with cotton varieties of Zhongmiansuo 8, Yumian 21, Yinrui 361 and Jimian 11, the defoliating pathotypes could be divided into five types. Typeâ… , the pathotypes that performance sensitivity on all of the four kinds of varieties, represented by pathotype 1cd3-33, 1cd3-1 and most pathotypes gathered from Caidian. Typeâ…¡, the pathotype that performance resistance on Yinrui 361, and sensitivity on the other three kinds of varieties, represented by pathotype lhnw-1. Typeâ…¢, the pathotype that performance resistance on Yinrui 361 and Yumian 21, and sensitivity on Zhongmiansuo 8 and Jimian 11, represented by pathotype 4tm-52R1. Typeâ…£, the pathotype that performance resistance on all these four kinds of varieties, represented by 1cd3-29. Typeâ…¤, the pathotype that performance tolerance on Yinrui 361 and Jimian 11, and sensitivity on Yumian 21 and Zhongmiansuo 8, represented by pathotype 1cd3-38.(3) The variety purity could be improved since the adoption of cross-plant, and the disease index of cross-strain line generally change too large or too small indicating that resistance and sensitivity differentiation is apparent. Different strains of the same differential host have obvious different resistance and sensitivity performance on the same pathotype, indicating that there exists great difference on the purity of the differential host.(4) Seed soaking and hydroponics treatment after germination seedlings using Mepiquat Chloride could achieve the effect of strengthening the seedlings. In this research, seed soaking and hydroponics treatments with different concentration of Mepiquat Chloride could find the different effect during the time of cotyledon, one leaf and two leaves. The results showed that only treat on the soaking time processing could cause dwarfism but the seedlings still shin, and soaking and hydroponics treatment with 200ppm has a positive effect, having higher fresh weight, shorter length of each section, which is conducive to the late growth.