复合微生物菌剂对水稻稻瘟病的生防效应

Biocontrol effect of a composite microbial agent on rice blast

摘要:

【背景】单一生防菌剂存在生防效果不够稳定、持效性差等不足，研究不同功能微生物的协同增效作用，开发复合微生物菌剂是控制植物病害的有效途径之一。【目的】探究不同功能微生物组合后对水稻稻瘟病的生防效应，开发高效生防水稻稻瘟病的复合微生物菌剂。【方法】将多株高效拮抗稻瘟病菌的链霉菌和细菌进行两两组合后与助剂复配，通过盆栽和大田试验，研究了复合微生物菌剂对水稻稻瘟病的生防效应。【结果】链霉菌Ahn75和解淀粉芽孢杆菌CWJ2菌株组合效果最好，与助剂复配后对水稻叶瘟和穗颈瘟的盆栽防效分别达到65.07%和63.00%，显著高于单一菌株Ahn75、CWJ2和其他菌剂组合的生物防效。同时，该复合菌剂能有效促进水稻植株生长，盆栽分蘖数和株高与对照相比分别提高93.33%和9.83%。而且，田间小区试验的结果也表明，该复合微生物菌剂的使用可以有效降低稻瘟病的发病，防效最高可达52.16%，与农药三环唑的防效（52.97%）相当。此外，菌株Ahn75和CWJ2分别对14种和16种稻瘟病病原菌生理小种的抑菌率超过50%，表明（Ahn75+CWJ2）复合菌剂对水稻稻瘟病具有广谱抗性。【结论】复合微生物菌剂（Ahn75+CWJ2）在防治水稻稻瘟病方面具有较高的潜能，可用于生物农药的开发与应用。

关键词:复合微生物菌剂;水稻稻瘟病;生防效应;助剂

Abstract:

[Background] Single biocontrol agents have unstable and poor lasting biocontrol effects. It is one of the effective ways to control plant diseases to develop composite microbial agents for biocontrol by studying the synergistic effect of different functional microorganisms. [Objective] To explore the biocontrol effects of different functional microbial combinations on rice blast, and develop an efficient composite microbial agent. [Methods] The biocontrol effects of Streptomyces combined with bacteria on rice blast were studied by pot and field experiments. [Results] The combination of Streptomyces Ahn75 and Bacillus amyloliquefaciens CWJ2 had the best effect, which, combined with adjuvants, showed the potting control effects of 65.07% and 63.00% on rice blast in the leaves and panicles, respectively. The combination had significantly higher biocontrol effect than the single strain Ahn75 or CWJ2 and other combinations. Moreover, this composite microbial agent can promote the growth of rice plants, increasing the number of tillers and plant height in pots by 93.33% and 9.83%, respectively. Similarly, the results of field experiments showed that this composite microbial agent reduced the incidence of rice blast, with the maximum control effect of 52.16%, which was comparable to that (52.97%) of tricyclazole. In addition, the inhibition rates of Ahn75 and CWJ2 against 14 and 16 races of Magnaporthe oryzae were higher than 50%, indicating that the composite microbial agent possessed broad-spectrum resistance to rice blast. [Conclusion] The composite microbial agent (Ahn75+CWJ2) has a promising prospect in the control of rice blast and can be used in the development and application of biopesticides.

Key words:composite microbial agent;rice blast;biocontrol effect;adjuvant