Genetic Diversity Of Fusarium Graminearum From Wheat In Shaanxi Province

Fusarium head blight is one of the most serious wheat diseases in the wheat which cauesed a large of wheat yield lost. Fusarium graminearum is the main pathogen of this disease. The Gibberella zeae is the the sexual zeae. Wheat is the main crop in Shaanxi province and Fusarium head blight is the main disease which not only reduced the wheat yield severely but also caused the bad quality of wheat, and the trend of this disease becomed heavier year by year. In recent years, there are many reports about studying genetic diversity for using morphology, cytology, isozyme and DNA technology. There are also some reports of studying genetic diversity of wheat Fusarium graminearum. But there are not reports about genetic diversity of Fusarium graminearum from wheat in Shaanxi Province. We used AFLP to study genetic diversity of Fusarium graminearum from different wheat areas in Shaanxi Province which in order to reveal the origin of the disease, trace the path of the transmission and know the relationship of different strains to make the foundation of preventing the Fusarium head blight. The main research results are follows:1. We separated 534 single spore strains from wheat which collected from 19 regions of Shaanxi in the year 2008. We selected 162 strains from the 534 strains using the morphological and molecular biology technology to identify which type they are. The results showed that the 162 strains are all Fusarium graminearum. We also used the specific primers (16F/Fg16R) to amplificate with the PCR on experiment, the results showed that there are two types of Fusarium graminearum in Shaanxi Province which separately divided into type 1 and type 5, which with 117 strains are type 1 which occuppied 72.22% of the entire group, 54 strains are type 5 which occuppied 27.78% of the entire group.2.162 strains collected from 19 regions of Shaanxi were amplified by AFLP with four pairs of primers (EcoR I and Mse I). The results showed that each primer amplified different number of fragments between 100-750 bp, with the least 6 and the most 20. The cluster analysis suggested that the F. graminearum species complex from Shaanxi province could be classified into group A and group B. There were obvious relationship between group differentiation and geographic location. The group A was mainly distributed in the middle region and the group B was in the south region of Shaanxi. The ecological environments and varieties of wheat in these two areas might be the main cause of this division. However, the relationship between strains and geographic location was complicated. Some strains had a certain relationship to the geographic location but some not. The further research for the relationship between strains and geographic location is needed.