The Resistance Of Strawberry (Fragria Ananassa Duch) Inoculated With VAM To The Major Root Pathogens

Both Glomus mosseae (G.M) and Glomus versiforume are endogeneticly symbiotic fungi, which form Vesicular - Arbuscular Mycorrhizae (VAM) in their hosts. Several trials were carried out on testing the function of promoting growth of the two VAMs to strawberry seedlings and the resistance of strawberry seedlings treated with G.M, G.V and G.M+G.V to Verticillium dahlias Kelb (v), Fusarium oxysporum Schlecht (f) and Rhizoctonia solani Kuhn(r), and observing the physiological changes in strawberry seedling treated with VAM.The function of promoting growth of G.M, G.V and G.M+G.V to strawberry seedlings and the resistance of strawberry seedlings treated by G.M, G.V and G.M+G.V to v, f, r, r+f, r+f+v were studied in lab. The result showed that G.M expressed the strongest promoting growth to strawberry seedlings. Comparing with the control for plant height, diameter of stem, root length, fresh weight and dry weight of canopy, fresh weight and dry weight of root etc, the treatment of G.M was the strongest; G.V also showed the function of promoting growth but weaker than G.M; G.M+G.V showed no obviously promoting function. Among the VAMs, the strawberry seedlings treated by G.V showed the strongest resistance to r and f; the strawberry treated by G.M showed the strongest resistance to v; the strawberry seedlings treated by G.M+G.V showed the strongest resistance to r+f; the strawberry seedlings treated by G.V and G.M showed obviously stronger resistance to r+f+v than control. Additionally, after the strawberry seedlings were treated by G.M+G.V for 10, 20, 30 days, the resistance to r+f was also studied in lab. The result showed that after being treated by G.M+G.V for 20 days the strawberry seedlings showed the strongest resistance to r+f.The state of growth and development of strawberry seedlings treated by G.M, G.V and G.M+G.V after being transplanted in different soil was studied. Results showed that the strawberry seedlings treated by G.V and transplanted in the soil that had planted strawberry for one year showed the most for the fresh weight of canopy and the lest disease index.The changes of the deoxidizing activities of TTC, the activities of SOD, POD in the roots of the strawberry seedlings treated by G.M, G.V, G.M+G.V and in the roots of the strawberry seedlings treated by VAM fungi and pathogens. Results showed that after being treated for 60d the strawberry seedlings treated by G.M showed the strongest deoxidizing activity of TTC, then was the strawberry seedlings treated by G.V. The strawberry seedlings treated by G.M+G.V showed the lowest deoxidizing activity of TTC. After being inoculated with f, v and r 8 days, the strawberry seedlings treated by G.V and f and those treated by G.V and r showed strongerdeoxidizing activity of TTC than the strawberry seedlings treated by other VAMs and r, f.After the strawberry seedlings treated by VAM fungi for 31, 32, 34 days, the activities of SOD and POD showed no obvious change between each time. As the result of each day as concerned, the activity of SOD was lowest While the strawberry seedling treated by G.M: After the strawberry seedlings were treated by G.M, G.V, G.M+G.V for 30 days, and then was inoculated with r, f, v, from 31 to 34 days the activity of SOD increased and the activity of POD decreased. For each day the concerned, the activity of SOD in the root of the strawberry seedlings treated by G.V and r, f is lower than those treated by other VAMs and r, f. The activity of POD was higher than those treated by other VAMs and r, f. The activity of SOD in the root of the strawberry seedlings treated by G.V and v was lower than those treated by other VAMs and v. The activity of POD was higher than those treated by other VAMs and v.After the strawberry seedlings treated by G.M, G.V, G.M+G.V for 30 days, the strawberry seedlings were inoculated with r, f, v, 20 days later the number of vesicular per centimeter of each treatment showed no significant differentce (p=0.05).