Effect Of Verticillum Dahliae On Root Growth And Development And Photosynthesis In Leaves In Cotton Seedling Of Different Resistant Cultivars

Cotton is an important economic crops in China even the whole world, as a widely-spread diseasein cotton, Verticillium wilt caused huge losses to the production of cotton．The research about the effectof Verticillum dahliae on root growth and development in Cotton seedling of different resistant cultivarshave important practical significance in the study of cotton resistance mechanism on disease, strainidentification, breeding disease-resistant varieties of cotton．As a typical vascular disease, Verticillium wilt of cotton (Verticillium dahliae Kleb．) infectedplants from root．Study on root system is mainly concentrated on the fibrous root system of plants, atlow temperature, freezing, nutrition element stress factors．There is less study Researchthe interactionbetween Verticillium Wilt and root. In this paper,we could make it clear that the differences in rootvarieties with different resistance to V． dahliae, as well as the effect of Verticillium dahliaeKleb．infection on root growth and development through the infection of cotton varieties with differentresistance of root physiological and ecological index of Verticillium dahliae．The the work, three different cotton cultivars---the resistant cultivar(Zhongzhi4)、tolerantcultivar(Lumian21) and susceptible cultivar(Jimian11) in the vermiculite culture of greenhouse werechosen to be the experimental materials．Study on the differences of root growth in seedling of different resistant cotton varieties in the3cotton varieties, the experiment measured the length of taproot、the number of first lateral root，startedto sample from20days to45days at an interval of5days．The research showed that, there aredifferences in root growth in seedling of different resistant varieties in cotton seedling disease resistantvarieties in4and resistance to disease, early variety Lumian21main root length, lateral root numberlevel was not significantly different, same disease varieties Jimian11significantly, far higher than theJimian11．The difference of root morphology、root vitality after inoculation with Verticillium dahliae wereinvestigated in seedling among the resistant cultivar(Zhongzhi4)、tolerant cultivar(Lumian21) andsusceptible cultivar(Jimian11) after inoculated with. The result showed that the length of taprootincreased higher、the number of first lateral roots and root vitality for the resistant cultivar andsusceptible cultivar were higher than the susceptible cultivar.The length of taproot and root vitalityincreased,the number of first lateral root decreased in all cultivars after inoculating with Verticilliumdahliae.The extent in Jimian11changed maximal, Zhongzhi4changed minimum. The extent inLumian21changed fall in between Jimian11and Zhongzhi4.In the study of on effect of leaves chlorophyll parameters infected with Verticillium dahliae ofdifferent cotton cultivars in seedling. The values of SPAD and Fv/Fm increased in all cultivars afterinoculating with Verticillium dahliae. The extent in Jimian11changed maximal, Zhongzhi4changedminimum. The extent in Lumian21changed fall in between Jimian11and Zhongzhi4. Study of effect of Verticillum dahliae on root growth and development and photosynthesis inleaves in cotton seedling of different resistant cultivars can help us to understand Verticillum dahliaesystemic infection of cotton. To provide a theoretical basis for the identification of disease-resistantvarieties in cotton breeding．...