Pathogenicity Differentiation Of Cotton Verticillium Dahliae In Xinjiang And Rapid Detection Technology

Xinjiang is the largest agricultural province in China, and cotton is the most important crop there. The quality of cotton planted in Xinjiang is superexcellent because of the unique climatic condition. In recent years, cotton production has become the supporting part of agricultural production in Xinjiang. But with the fast expansion of planting area, the Verticillium wilt and Fusarium wilt seriously decrease the cotton's yield. At present, we have controlled the Fusarium wilt of cotton by planting resistant cultivars. But for cotton Verticillium wilt, which caused by V.dahliae and significantly reduced the cotton yield, has been observed in most planting cotton region of the whole province and become the main barrier of sustainable cotton production in Xinjiang. Because cotton Verticillium wilt is an increasing problem, so it is necessary to study this pathogen. Firstly, we should isolate V.dahliae from infected cotton at the major cotton regions in Xinjiang and determine the virulence of these isolates. Secondly, we need to develop a rapid, effective and exact method to detect the V.dahliae pathotype including defoliating and non-defoliating pathotypes. Thirdly, we should determine the genetic relatedness of isolates of V.dahliae from different regions. By these works, we should not only provide foundation to plant quarantine but also give direction to make corrective strategy for resistance breeding and cultivars distributing.Several methods including biology characteristics study, identification host test, VCG test, esterase isoenzyme test and specific primer PCR test were used to detect the V.dahliae pathotype, and increase understanding of the biology, pathogenicity and genetic relatedness of V.dahliae from cotton in Xinjiang. The main results were:1.Through strain's culture characters and the temperature test, it was showed that the colony colors of strains have two main types, including gray/black and white/sandy beige, most of them were gray/black, which amount to 87.5%. Broken was produced by some strains. All strains can produce microsclerotia. All strains growed better at 25℃. At 30℃, the growth of all strains was obviously inhibited. Particularly, most of strains cannot grow at 33℃.