关键词: 生物炭, 玉米, 立枯丝核菌, 纹枯病, 生理指标, 抗病性

Abstract: In order to clarify the effect of adding biochar in soil on maize sheath blight resistance,and to reveal the physiological mechanism of biochar increasing disease resistance, by adding 0 (B0), 1%(B1),5% (B5),9% (B9) biochar to indoor potted soil,two-point inoculation of Rhizoctonia solani was carried out using the leaf sheath toothpick embedding method and leaf insect needle fixing method to study the disease incidence of maize seedlings and changes in physiological indicators.The results showed that the disease incidence of maize plants with biochar added was milder than that of maize with no biochar.Compared with non-inoculated plants,the plant height,root length,plant fresh weight,root fresh weight,plant dry weight and root dry weight of B0,B1,B5,and B9 treated plants were decreased by 13.8%—18.6%, 9.3%—40.2%, 22.2%—28.3%, 20.4%—38.2%, 30.8%—43.3%, 25.9%—41.2%,and the decrease of B1 treatment was lower.At the same time,the MDA content and relative conductivity in the inoculated plants showed an increasing trend with the extension of the inoculation time.At 72 h,B0—B9 treatment increased by 77.1%—119.1% and 106.0%—165.7% compared with 0 h,and the increase value was relatively smaller in B1 treatment.Compared with 0 h after inoculation,the production rate of superoxide anion in maize treated after 72 h of B0—B9 increased by 43.2%—69.1%,and the content of H₂O₂ increased by 30.2%—53.1%.The activities of SOD,POD,CAT,and APX increased significantly,the SOD activities of B0,B5,and B9 treatments increased by 19.9%—34.5% at 48 h after inoculation, the activities of POD, CAT, and APX at 72 h after inoculation respectively increased by 21.8%—126.0%,13.7%—60.3%,and 112.9%—223.2% in B0—B9 treatments.In summary,the addition of biochar to the soil could alleviate the adverse effect of Rhizoctonia solani infection on the phenotypic traits of maize seedlings,enhance the activity of antioxidant enzymes,and reduce membrane lipid peroxidation damage.Thus,the resistance of maize seedlings to sheath blight was strengthened,and the addition of 1% biochar increased the resistance of maize seedling best.

Key words: Biochar, Maize, Rhizoctonia solani, Sheath blight, Physiological parameters, Disease resistance