Studied On Lentil Root Rot And β-glucosaminidase Of Fusarium Oxysporum In Dingxi Area

1. Studied on Lentil root rot and Pathogenicity TestLentil root diease samples were obtained from Dingxi of Gansu, and 130 monoconidial Fusarium strains were gained ,they had been identified as 6 species of Fusarium, isolations of F.oxysporum were majority with the rate of 76.9%, F.solani, F.moniliforme, F.acuminatum, F.equiset, F.sambucimum were 9%,7%,3.9%,0.7%,3.08%. The result of Pathogenicity test showed that F.oxysporum had the highest pathogenicity. Inoculated at the different site of stem,the result showed that it was easy to infect by pathogenic Fusarium after lentil germinated 8d,and at the middle and the base of root was more sensitive than that from tip of root and base of stem.2. Studied on disease resistance of several lentil cultivarsSoil-borne fungal diseases were the most important factors, limiting the yield of grain legumes in many countries worldwide. Root rot, caused by Fusarium,is a serious disease of lentil in Dingxi of Gansu Province.The most effective control of this disease was used of resistant varieties. In this paper, 7 cultivars were tested to screen the sources of resistance on root rots. Screening in the growth chamber and the results showed DingxuanⅠindicated that moderately resistance, other cultivars expressed susceptible, None of the cultivars were immune or resistance to the pathogen under growth chamber conditions. And no cultivars was highly susceptible in this experiment.3.β-glucosaminidase activity test of Fusarium oxysporum on lentilFusarium oxysporum 24 producedβ-glucosaminidase when grown on wheat bran and sucrose carbon sources in solid-state fermentation. The initial moisture content of growth medium were 65%, and the maximum enzyme yield 10.14U at 13 day.Using p-Nitrophanyl-β-D-glucosaminide (PNPG) as substrate for testingβ-glucosaminidase activity, the results showed the optimum buffer pH of isozymes was 5.7, maximum activity was obtained at 40℃,and reaction time 12min. Highly sucrose concentration would inhibit the activity ofβ-glucosaminidase4. The relation between pathogenicity andβ-glucosaminidase on Fusarium oxysporum18 strains of Fusarium oxysporum had the different pathogenicity were grown on solid-state fermentation, after 13 days incubate, took smples for test the activity of β-glucosaminidase, the positive correlation between pathogenicity andβ-glucosaminidase was reserved,but the relation between pathogenicity andβ-glucosaminidase was not corresponding,β-glucosaminidase was not only effect caused pathogenicity of fungi.