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摘要 为了明确交枝顶孢霉Acremonium implicatum CQBBW8的杀螨活性及其生物学特性，采用触杀毒力法检测CQBBW8菌株对柑橘全爪螨的致死率，通过单因素试验测试不同培养基、碳源、氮源、温度、pH及紫外线对CQBBW8菌株生长、产孢及其分生孢子萌发的影响。结果表明，CQBBW8菌株对柑橘全爪螨Panonychus citri （McGregor）的校正致死率为54.42%，LC50为1.2×106个/mL，LT50值为5.175 9 d。最佳生长和产孢培养基分别为PDA和SEA；菌丝生长最适碳源和氮源为甘露醇和蛋白胨，产孢最适碳源和氮源为可溶性淀粉和氯化铵；最适生长温度为25℃，最适产孢和分生孢子萌发温度为30℃；最适生长和产孢pH为6.0，最适萌发pH为7.0；紫外线对菌丝生长影响不明显，对产孢影响较大，紫外线照射时间越长，孢子萌发率越高。综上，CQBBW8菌株对柑橘全爪螨有较强的毒力，对营养需求不高，环境适应性较强，具有开发为杀螨真菌制剂的潜力。
关键词 交枝顶孢霉； 生物学特性； 杀螨活性
中图分类号： S 476.1
文献标识码： A
DOI： 10.3969/j.issn.05291542.2017.02.015
Abstract To explore the acaricidal activity and biological characteristics of Acremonium implicatum CQBBW8， the lethal rate of CQBBW8 strain to Panonychus citri （McGregor） was detected by using contact toxicity method， and the effects of different factors， such as culture medium， carbon source， nitrogen source， temperature， pH， and UV on the hyphal growth， sporulation and spore germination of A. implicatum were tested by using single factor test. The results indicated that the corrected mortality rate of CQBBW8 strain to P.citri was 54.42%； the LC50 was 1.2×106 spores/mL and the LT50 was 5.175 9 d. The optimum growth and sporulation culture medium were PDA and SEA. Mannite and peptone were the best carbon and nitrogen sources for hyphal growth， and soluble starch and ammonium chloride were the best carbon and nitrogen sources for sporulation， respectively. The most suitable culture temperature for hyphal growth was 25℃， and the most suitable temperature for sporulation and spore germination was 30℃. The optimum pH for hyphal growth and sporulation was 6.0， and the optimum pH for spore germination was 7.0. Although UV had no significant effect on fungal growth rate， it had a marked effect on sporulation； the longer the ultraviolet irradiation time， the higher the rate of spore germination. In summary， CQBBW8 strain had a strong toxicity to P.citri， without a high nutritional demand， and its environmental adaptability was strong， with a potential for development of the fungus preparation for killing mites.
Key words Acremonium implicatum； biological characteristic； acaricidal activity
頂孢霉属Acremonium sp.是一类广谱性昆虫病原真菌，能够防治多种农林害虫，如青杨天牛Saperda populnea L.[1]、根结线虫Meloidogyne incognita[25]、杨干象Cryptorrhynchus lapathi （Linnaeus）[6]、六星黑点豹蠹蛾Zeuzera leuconotum Butler[7]、甘蓝蚜Brevicoryne brassicae、菜青虫 Pieris rapae （Linnaeus）、小菜蛾Plutella xylostella和黏虫Mythimna separata （Walker）[89]等等。并且顶孢霉也是一种抑制多种植物病原真菌生长的拮抗真菌[1012]，同时还具有医药价值[1314]，是一种具有开发应用潜力的真菌。2005年宋丽雯等[15]从菜豆蚜Aphis medicaginis Koch虫尸上分离到顶孢霉Acremonium hansfordii Ahy1菌株并且对其营养条件进行了初步研究，该菌株对二斑叶螨 Tetranychus urticae Koch雌成螨有较高的侵染力，且能够延长螨卵的发育历期，降低螨卵孵化率；2012年姜立波等[16]研究发现顶孢霉Ahy1孢子与常用杀螨剂配合使用后对二斑叶螨的致死率提高了60%左右，LT50明显缩短；2013年王婧[17]研究表明顶孢霉与抑制剂对羟基苯甲酸、苯甲酸混用对顶孢霉侵染二斑叶螨有较好的协同作用。