Biological control effect of compounded bacillus on wilt disease of Bambusa pervariabilis × Dendrocalamopsis daii

ObjectiveIn order to provide a theoretical basis for the development of stable, efficient and cheap compounded bacillus, the biological effects of single and compounded bacillus on wilt disease of bamboo (Bambusa pervariabilis × Dendrocalamopsis daii) were comparatively analyzed in this work.

MethodThe fermentation filtrates of Bacillus amyloliquefaciens daii B01-2, Bacillus subtilis B23-1 and their compounded bacillus were prepared, and the influences of fermentation products of bacillus on mycelial growth, spore germination of Fusarium oxysporum and indexes of resistance physiology of Bambusa pervariabilis × Dendrocalamopsis daii were measured using the methods of mycelial growth rate, spore germinate and pot experiments, respectively.

ResultThe inhibiting effect of compounded bacillus was better than those of single ones did. The colony diameter of fungal pathogen and spore germination rate treated by compounded bacillus were 1.9 cm and 8.8%, and those from treatments of B01-2 and B23-1 were 3.4 cm, 4.1 cm and 17.8%, 31.0%, respectively. Pot experiments displayed that the incidences of wilt disease treated by fermentation filtrates of bacillus were lower than control. The incidence of wilt disease from compounded bacillus (50%) was lower than both of B01-2 (60%) and B23-1 (60%). The control effect of compounded bacillus on wilt disease reached 81.5%, which was higher than those of single ones, i.e., B01-2 (70.4%) and B23-1 (63.0%).The determination of leaf physiological indexes showed that all treatments could induce the activities of defense enzymes (POD, PPO and PAL) to decrease the decomposition of chlorophyll, and to reduce the generation of MDA, resulting in the increase of disease resistance and plant immune abilities. Moreover, the compounded bacillus had higher influences on the physiological indexes compared with single bacillus.

ConclusionIn summary, compounded bacillus had a strong antagonistic activity, which could effectively prevent and control the wilt disease of Bambusa pervariabilis × Dendrocalamopsis daii in pot experiments, showing a good potential application prospect.