Identification And Comprehensive Evaluation Of 32 Watermel Germplasm Resources And Varieties Resistance To Fusarium Wilt

Fusarium wilt is a worldwide funguses disease of watermelon caused by special Fusarium oxysporum.f.sp.niveum. Due to constantly expansion of watermelon cropping in recent years, continuous cropping obstacles of watermelon happened normally, especially Fusarium wilt, which had become one of the main factors that limit the watermelon production. Screening resistant varieties is the basic method to prevent and control watermelon continuous cropping obstacles. So the purpose of this study was to explore the resistance of 32 watermelon materials against fusarium wilt; Combined with quality index, to select high-resistance and good-quality watermelon germplasm resources and varieties.So as to provide evidence of fusarium wilt prevention and control in the future.The research was to identify the 32 germplasm resources and varieties resistance to fusarium wilt with inoculating artificially at seeding stage by root soak method. Observed and counted the number of incidence and diseased plants at all levels, calculated incidence,disease index and divided the level of resistance; Identified and evaluated their resistance to fusarium wilt. At the same time, identified the the fusarium wilt resistance at 5-year continuous cropping land to further evaluate their resistance to fusarium wilt. Measured the rhizosphere soil pH 、 leaf MDA, SOD, PAL of 32 kinds of watermelon materials on the foundation of the studies above. The main results obtained as follows:1. The results of incidence of fusarium wilt disease showed that 11 kinds of materials were high resistance(HR,0%~20%) to fusarium wilt; 11 kinds of materials were medium resistance(MR,21%~21%), 7 kinds of materials were light resistance(SR,51%~80%); 3kinds of materials were(S,81%~100%). The results about incidence of fusarium wilt in five-year continuous cropping area showed that 12 kinds of materials were high resistance(HR, 0%~20%) against fusarium wilt; 11 kinds of materials were medium resistance(MR,21%~21%); 7 kinds of light resistance(SR,51%~80%); 2 kinds of materials were susceptible(S,81%~100%). The evaluation results during seeding stage and in successive cropping area were basically same, except particular difference.2. Combined with quality index and selected 10 kinds of high-resistance and good-quality materials, Xinong No.8, Nong Ke Da No.6, Hong Guanlong, Ling Longwang,Jingxin No.3,Zhong 10 Haikang, Y-1(female),F09, Jingfu-5, M08.3.The rhizosphere soil pH and the resistance of fusarium wilt in watermelon were negatively correlated; the content of leaf MDA and the resistance of fusarium wilt in watermelon were negatively correlated; leaf PAL activity and leaf SOD activity were positively correlated with watermelon fusarium wilt disease resistance. There was no significant correlation between the resistance and quality of watermelon fusarium wilt.