Fungal Diseases Of Oat In Gansu Provience

Fungi carried of four varieties of oat seed were tested, and oat fungal diseases were classified, which collected from Gansu province, and the pathogenic fungi were identified. The pathogenicity of major pathogenic fungi was determined. Antagonism of 6 growth-promoting bacteria strains to 9 pathogenic fungi was tested as well. The results obtained as follows:1. In four varieties of oat, the percentage of fungi carried by Baiyan No.7 was the maximum (30.7%) and the Denmark 444 was the minimum (6.2%). For the quantity of bacterial isolated on seed surface, Baiyan No.7 was the maximum (2.6×10~5cfu/g), and the minimum was Dingyou No.2 (1.2×10~3cfu/g). And the quantity of bacterial isolated from seed interior, Baiyan No.7 was the maximum (9.5×10~4cfu/g), and the minimum is Dingyou No.6 (3×10~2cfu/g). For the quantity of fungal isolated on seed surface, Dingyou No.2 was the maximum (2000cfu/g), and the minimum was Denmark 444 (89cfu/g). The maximum quantity of fungal isolated from seed interior was Denmark 444 (141cfu/g), and minimum was Dingyou No.2 (2.3cfu/g).2. From the four species of oat seeds, 6 generas and 21 species of fungi were isolated and identified. Among those fungi species, there were 6 species of Penicillium, 3 of Alternaria, 4 of Fusarium, 3 of Aspergillus, 2 of Mucor and 3 of Rhizopus.3. Twenty nine specimens of fungal disease from Lanzhou, DingXi, Tongwei and Tianzhu of Gansu Province were collected. From these specimens, 17 species of pathogenic fungi were identified, among these species Ustilago can cause 2 kinds of diseases, and 1 kind of disease caused by Colletotrichum, 4 caused by Puccinia, 1 caused by Trichothecium, 4 caused by Rhizoctonia, 1 caused by Alternaria, 2 caused by Fusarium and 2 caused by Helminthosporiume.4. Nine species of pathogenic fungi include 2 kinds of Fusarium, 1 kind of Helminthosporium sp., 4 kinds of Rhizoctonia sp., 1 kind of Trichothecium sp. and 1 kind of Alternaria sp.. All this 9 pathogenic fungi can decline the germination percentage of oat seeds and cause diseases in oat seeding stage, and the latent period of pathogenesis is 15d to 27d. The rate of incidence of a disease under the treatment by vaccinating fungi on seed is 38.7% to 79.5% and under the treatment by vaccinating fungi on leaf, the rate is 8.5% to 25.3%. The disease index under the treatment by vaccinating fungi on seed is 35.7% to 74.6% and under the treatment by vaccinating fungi on leaf, the index is 8.3% to 24%. These two treatments both can reduce the height of oat.5. The antagonism of 6 kinds of growth-promoting bacteria to 9 kinds of the major pathogenic fungi was in varying degrees. Among these species, the antagonism of LHS11 to Rhizoctonia sp3 was the strongest, the suppression ratio is 100%, in the second place, and the suppression ratio of the antagonism of Jm170 to Rhizoctonia solani was 84.1%. Keyword: Oat; fungal diseases; pathogenic fungi;pathogenicity; antagonism; percentage of...