苦皮藤内生真菌中杀虫杀菌活性物质的初步研究

Preliminary study on the insecticidical and fungicidical components of endophytic fungus in Celastrus angulatus

对杀虫植物苦皮藤植株中的内生真菌进行了研究。从苦皮藤根中和侧枝中分别分离得到24株和15株内生真菌,其中表皮层10株,韧皮部27株,木质部2株。对分离出的菌株进行液体培养,并对其发酵产物进行了杀虫和杀菌活性测定。以生物活性追踪为指导,对杀虫和杀菌成分分别进行了制备薄层分离和柱层析分离。生物活性测定结果表明,只有1B菌株菌丝体的丙酮粗提物对3龄粘虫有毒杀作用,在500μg/mL浓度处理下,24h后的死亡率为85.3%;在500μg/mL浓度处理下,1L,2B和5J3个菌株的发酵液和菌丝体粗提物对番茄灰霉病菌、小麦赤霉病菌、苹果炭疽病菌和玉米小斑病菌表现出了不同程度的抑制菌丝生长活性;其菌丝体粗提物对番茄灰霉病菌、玉米小斑病菌和烟草赤星病菌有明显的抑制孢子萌发作用,在盆栽试验中,对小麦白粉病和黄瓜霜霉病的盆栽防效均在50%以上;从1B菌株中分离到1个杀虫化合物1B-4;从1L菌株中分离出3个杀菌化合物1L-3,1L-6和1L-8,其中1L-6杀菌活性最高。

Taking PDA as separating culture medium,24 and 15 strains of endophytic fungi were separated from the roots and twigs of Celastrus angulatus,respectively.In these strains,10,27 and 2 strains were separated from the epidermis,phloem and xylem of the plant,respectively.The insecticidal and fungicidal activities of their fermentation products were examined,and the active ingredients were sepreated by p-TLC and HPLC.The results of insecticidical bioassay indicated that only the acetone extract of 1B strain mycelium exhibited poisonous activity,and had a mortality of 85.3% against the 3rd instar larvae of Mythimna separata at the concentration of 500 μg/mL.By means of mycelium growth rate,the acetone extracts of mycelium of 1L,2B,and 5J strains had a certain degree fungicidical activity against Botrytis cinerea,Gibberella zeae,Phytophthora capsici,Glomerella eingulata,Bipolaris maydis,Alternaria alternata at the concentration of 500 μg/mL,and exhibited moderate activity against Botrytis cinerea,Bipolaris maydis,Alternaria alternata in the test of spore germination.The results of pot test indicated that the acetone extracts of 1L,2B and 5J strain exhibited more than 50% of protective and therapeutic efficacy against Blumeria graminis disease and Pseudoperonospora cubensis disease at the concentration of 500 μg/mL.An insecticidical component 1B-4,three fungicidical components 1L-3,1L-6 and 1L-8 were isolated from the acetone extracts of the mycelium of 1B and 1L strain by bioassay-guided separation.