Study On AFLP And RGA Molecular Markers Linked To Verticillium Wilt Resistance Gene In Upland Cotton

Cotton is the most important source for living materials and textile industry. Stable yield is more valuable to keep the whole countrie's society security and stability. Verticillium wilt is one of the two most important diseases of cotton, and it has been epidemic all over the world for many years. It also spreads in China cotton planting areas and causes serious yield lossing.Applying cotton resistance varieties is the most efficient way to defence Verticillium wilt. But there are some big difficulties, such as, the complexity of the resistance mechanism, the lack of resistance variety in upland cotton and none resistance gene clones was obtained. Along with the development of moden biology science, especially the progress of the molecular marker technology, more and more scientists attempt to identify the resistance genes by these methods, and want to discover the genetic diversity of cotton community, find the way of cotton resistance breeding. To look for the molecular markers tightly linked with resistance genes and set up systems of molecular marker assisted selection (MAS), they would accelerate cotton resistance breeding.Resistance of some upland cotton varieties were identified by noting the state of Verticillium wilt in fields, and the identity of resistance representation was observed comparing results of 2003 and 2004 in this experience. Studied the state of resistant/susceptible separation in F2 population of Za23 and Za25, it was proved that the law of upland cotton resistance against Verticillium wilt was complex. The state of Verticillium wilt was dynamic and volatile, and it's a synthesized representation of diversified factors. The rate of resistant/susceptible was deviated from 3:1, and it's suggested that there would be more than one resistance genes were working. DNA polymorphism of the near isogenic lines and F2 segregating population of intercross cotton varieties with/without Verticillium wilt resistance genes were analyzed using AFLP method and RGA makers technology. A total of 54 random primer pairs were screened to identify the AFLP markers linked to Verticillium wilt resistance genes. Three polymorphic DNA fragments with the molecular weight of...