黑曲霉菌株Y-1对盾壳霉重寄生的影响.docVIP

  黑曲霉菌株 Y-1 对盾壳霉重寄生的影响# 杨丹，李兴鹏，张静，杨龙，李国庆** （湖北省作物病害监测与安全控制重点实验室，华中农业大学） 5 10 15 20 25 30 35 40 摘要：重寄生真菌盾壳霉（Coniothyrium minitans）是核盘菌（Sclerotinia sclerotiorum）的一 种重要生防菌。盾壳霉通过寄生核盘菌菌核，减少初侵染来源，从而达到防治核盘菌的目的。 盾壳霉在田间自然土壤中寄生致腐核盘菌菌核可能受菌核围细菌的抑制。从核盘菌菌核围土 壤中分离到黑曲霉（Aspergillus niger）菌株 Y-1，该菌能分泌大量有机酸，而酸性环境不利 于菌核围细菌的生长。本文评估了黑曲霉 Y-1 对盾壳霉寄生核盘菌菌核的影响。平板拮抗试 验结果表明：黑曲霉 Y-1 PDB 摇培滤液对核盘菌菌核围细菌有显著的抑制作用，黑曲霉 Y-1 产生大量草酸形成的酸性环境是抑制菌核围细菌生长的主要原因。而低浓度（1%, v/v）的 黑曲霉发酵滤液对盾壳霉的孢子萌发没有显著影响。室内砂皿寄生菌核试验表明：黑曲霉 Y-1 对核盘菌菌核有弱寄生能力，对盾壳霉寄生核盘菌菌核没有影响。田间盆栽试验结果表 明：黑曲霉 Y-1 对盾壳霉田间寄生菌核有一定的促进作用。黑曲霉 Y-1 促进盾壳霉寄生核 盘菌菌核的机制可能是黑曲霉与盾壳霉在生态功能上具有互补性，即利用黑曲霉分泌的有机 酸来抑制菌核围细菌，解除菌核围细菌对盾壳霉重寄生的抑制作用，从而提高盾壳霉的生防 效果。 关键词：黑曲霉；核盘菌；盾壳霉；生物防治 中图分类号：S432.1 Effect of Aspergillus niger Strain Y-1 on Infection of Sclerotia of Sclerotinia sclerotiorum by Coniothyrium minitans YANG Dan, Li Xingpeng, ZHANG Jing, YANG Long, LI Guoqing (The Key Laboratory of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, 430070) Abstract: The mycoparasite Coniothyrium minitans is a promising biocontrol agent of Sclerotinia sclerotiorum. It can infect sclerotia of S. sclerotiorum in soil. Our previous study showed that sclerosphere bacteria can suppress infection of sclerotia by C. minitans. Strain Y-1 of Aspergillus niger isolated from sclerosphere of S. sclerotiorum was able to secrete large amount of organic acids, which can suppress the growth of sclerosphere bacteria. The objective of this study was to evaluate the effect of A. niger strain Y-1 on infection of sclerotia by C. minitans. Results showed that A. niger strain Y-1 is an antagonist inhibitory to sclerosphere bacteria. Meanwhile, no negative effects of A. niger strain Y-1 on conidial germination of C. minitans was observed. Furthermore, A. niger strain Y-1 could weakly parasitize sclerotia. It could assist C. minitans to infect and degrade sclerotia of S. sclerotiorum. Simultaneous application of A. niger strain Y-1 and C. minitans significantly reduced the number of apothecia