禾长蠕孢菌稗草专化型固体发酵产孢培养基及其工艺条件的研究

The Medium and Culture Conditions of Helminthosporium gramineum Rabenh. f. sp. echinochaloae with Solid State Fermentation

禾长蠕孢菌稗草专化型(Helminthosporium gramineum Rabenh. f. sp. echinochloae,HGE)是一株稗草生防潜力菌,为了获得该生防菌大量孢子用于田间试验,本文研究了其固体发酵产孢最佳培养基配方及其培养条件。通过试验筛选确定了固体发酵培养基所需碳源及其浓度、氮源及其浓度以及底物基质,适合HGE菌孢子生产的培养基最佳组合为:以珍珠岩为底物基质,在其中添加4%米粉、1%豆粕粉、0.2%Na3PO4.12H2O、0.1%MgSO4.7H2O。同时确定了适合HGE菌孢子生产的培养条件:培养基最适含水量为40%,最佳接菌量为8%菌悬液,25℃静置培养11 d,培养期间用黑光灯12 h循环光照。按优化后培养条件放大培养HGE菌,获得最高产孢量可以达到1.5×107孢子·克-1干物质。温室生测结果显示优化条件生产的HGE菌孢子对稗草防效可达80%以上。

Helminthosporium gramineum Rabenh f. sp. echinochloae （HGE） is a potential biocontrol agent for bamyardgrass control in rice field. Authors optimized the medium and culture conditions in a solid state fermentation system for mass production ofHGE conidia. Investigation on carbon source, nitrogen source and solid substrate indicated that a medium consisted of 4% rice flour, 1% soybean meal, 0.2% Na3PO4·12H2O, 0.1% MgSO4·7H2O and pedite was better for high yield of condia. 40% medium moisture, 8% inoculum concentration, 25℃ and 11 d incubation were good for the conidial production. By the medium and culture conditions, the maximum conidial yield was 1.5×107 conidia.g-1 dry material. Pot bioassay in the greenhouse gave rise to 80% control efficacy against barnyardgrass after treatment with HGE conidia at 0.6 g-m-2.