Abstract:

The aim is to clarify the biocontrol application effect of Bacillus altitudinis, and lay a foundation for the development and application. Two B. altitudinis strains of JYW21 and JYW26 with good controlling effects against rice blast were preliminarily screened through enzyme and antagonistic activity to Magnaporthe oryzae. In this experiment, their biocontrol effects against rice blast were verified in different conditions (in leaf blades, greenhouse and field tests). At the same time, the growth promotion effect of rice was determined by seed germination, potting and field tests. The control effects of B. altitudinis were at least 96% in leaf blades and 79% in greenhouse respectively, and the control effects were 55% against leaf blast and 70% against panicle blast in field experiments. At the same time, it had a higher biocontrol effect on rice sheath blight and rice smut disease. The experimental results also showed that B. altitudinisJYW21 and JYW26 played a good role in rice seeds germination, plant growth, which could increase the germination rate of rice by 6.27% and 6.81%, seedling height by 12.91% and 14.91%, seedling fresh weight by 21.43% and 28.57%, plant height by 24.67%and 18.67%, fresh weight by 64.04% and 61.79%, root length by 30.96% and 27.94%, and root weight by 24.71% and 25.88% in greenhouse, respectively. Under field conditions, B. altitudiniss JYW21 and JYW26 increased rice tillering number by 20.59% and 15.27%, panicle weight by 19.55% and 3.53%, thousand seed weight by 4.77% and 1.25%, respectively. These results showed that the two strains of B. altitudinis could not only be used to control rice blast and other fungal diseases, but also could promote the growth and production of rice. It was also found that the two strains of B. altitudinis could increase the content of chlorophyll in rice leaves, which might be one of the reasons for promoting the growth of rice.

Key words: Bacillus altitudinis, rice blast, bio-control, growth promoting, chlorophyll