Identification Of Potato Resistance To Blight Caused By Fusarium Oxysporum

Potato blight is a soil-born disease caused by Fusarium oxysporum.In recent years, it has take place in many potato planting areas in Inner Mongolia, and endanger become more seriously. It lead to the potato production fall down, affected the quality of potato become seriously, directly result in the economic decline.So the study which identification of potato resistance to blight caused by Fusarium oxysporum was better to prevention and control this plant disease establish the rationale to research.The research of the study as follows.1Laboratory inoculation were conducted to evaluate the resistance of potato to blight caused by Fusarium oxysporum. In results, none of potato cultivars selected was immune.2potato cultivars with moderate resistance were identified, accounting for10.53%,10potato cultivars showed moderate susceptible level, accounting for52.63%,and7potato cultivars showed higher susceptible level, accounting for36.84%by inoculated with virus-free potato seedling in test tube.2Field trials were also conducted for evaluating the resistance of20potato cultivars by inoculating with Fusarium oxysporum. In results,9potato cultivars showed resistant level, accounting for45%,11cultivars of potato showed susceptible level, accounting for55%.3The toxin of Fusarium oxysporum can caused the same pathogenicity as pathogen., but it pathogenicity weaker than pathogen.It has different pathogenicity in potato cultivars,that it to say,potato cultivars has different resistance to the toxin. The toxin can inhibition Virus-free potato seedling stem growth, At the equal concentration of toxin, higher susceptible level potato cultivars inhibition is overtop than higher resistant level.the same variety, as the concentration of toxin increased, the Virus-free potato seedling stem growth inhibition gradually to strengthen.4Defense enzyme activity experiment result indicated that did not inoculation Fusarium oxysporum dispose, the POD、PPO、SOD activity in potato of resistance cultivar are all overtop than the susceptible one. After inoculation Fusarium oxysporum, higher susceptible level and higher susceptible potato variety POD、 PPO、SOD and PAL activity all increased, and go up to peak in different times, but the resistant potato variety peak is higher than the susceptible one. the several enzyme activity is positive correlation with potato variety diseased resistance.5Host range test show that Fusarium oxysporum host has cotton, sugar b eet,chili, cabbage, flax. Fusarium rricinctum host has cotton, eggplant, melon, fl ax. Fusarium solani host has tomato. The carrier and showing symptoms blight crops for flax. Not the host has wheat, oat. sunflower, oilseed rape, alfalfa, s ovbean.