Establishment Of DNA Fingerprinting On Physiological Races Of Tomato Leaf Mold

Tomato leaf mold disease have become the main disease which threatens tomato's production,and also the physiological races of Fulvia fulva cook differentiate rapidly.In order to breeding the resistance of tomato leaf mold ,it is important to monitor the variation of predominant physiological races of it. It is importmant to find out a quickly and simple way which does not influenced by the environment to identify the physiological races.In the experiment ,DNA fingerprinting on eight physiological races of Fulvia fulva cook was established by SSR and AFLP.Then the dendrogram of eight physiological races was established to cluster analysis.Forty-two pathogen strains of Fulvia fulva cook collected were identified by host.The result of forty-two pathogen strain identified by DNA fingerprinting was to see if it was the same to the identified result of host. The main results were as fo11ows:1. DNA fingerprinting on eight physiological races of Fulvia fulva cook was established by SSR.Two hundred and nineteen SSR bands were amplified with three SSR primer and twenty-two were polymorphic bands.The rate of polymorphism bands was10.04%.The fingerprinting of three primer can distinguish all the eight physiological races.The AFLP was fail to amplify bands,so it can not be used to establish DNA fingerprinting.2. The result based on the cluster analysis indicated that DNA polymorphism in fungue population was high.The similarity coefficient between physiological race 1.2.4 and 1.3 was 0.86,which was the maxmum., and it between physiological race 2.3 and the others was 0.53 ,which was the minimum.On the similarity coefficient of 0.53,the eight physiological races can be divided into two microbial population .3. The forty-two physiological races of tomato leaf mold which collected from the eastern three provinces in 2009 were identified by the host plant.The result showed that eight different physiological races 1.2, 1.2.3, 1.2.3.4,1.2.4, 1.3 ,1.3.4 ,1.4 and 2.3 were examined among the collected forty-two pathogen strains. The predominant physiological race was 1.2.3.4 and the rate of it was 30.95%.Then was physiological races 1.2.3 and the rate of it was 16.67%.the new physiological races was no found.4. Using three pairs of SSR primers M69, M80, M91 to amplify the forty-two pathogen strains which was identified by host plant.SSR fingerprintings of them were obtained. Compared with the DNA fingerprinting of eight physiological races which were known.The primer M69 and M80 in the physiological races identification reaults agreed well with results of conventional identification of host plant.Because of the forty-one pathogen strain was different,the identification reaults of primer M91 was 97.62% same to the conventional identification of host plant.The research demonstrates that DNA fingerprinting which is a quick and accurare new method, can be used in identification on physiological races of Fulvia fulva cook .