摘要
本研究通过大蜡螟Galleria mellonella虫饵法从新疆胡杨林采集的土样中分离得到1株昆虫病原真菌,编号为XJ-2。在PDA培养基上,菌株XJ-2菌落正面颜色随生长由白变为黄色或黄褐色,培养7 d,菌落直径约为70 mm。菌丝有隔,分生孢子梗由一根直立的菌丝形成,菌丝顶端膨大呈球状,分生孢子透明光滑,圆形,直径为2~3μm,在小梗上形成链状的孢子串。菌株的核糖体DNA ITS1-ITS4区间序列为582 bp(登录号:PQ013057),与溜曲霉Aspergillus tamarii CBS 104.13^(T)(AF004929)相似度达97%。基于形态学和rDNA-ITS鉴定,确定菌株XJ-2为Aspergillus tamarii。采用喷雾接种法测定了菌株XJ-2孢子悬液对大蜡螟、亚洲玉米螟Ostrinia furnacalis和马铃薯甲虫Leptinotarsa decemlineata的致死率和致死中时,结果显示,菌株XJ-2对大蜡螟、亚洲玉米螟和马铃薯甲虫均具有较强的致病力,存在明显的剂量依赖效应。1×10^(8)个/mL,孢子悬浮液处理后7 d,大蜡螟、亚洲玉米螟和马铃薯甲虫累计校正死亡率和LT_(50)分别为93.83%和4.20 d、91.67%和4.74 d及50.00%和6.60 d。培养试验表明,A.tamarii XJ-2在萨氏葡萄糖+酵母粉琼脂培养基上的利用最好,其7 d平均生长速率为12.29 mm/d、产孢量9.75×10^(9)个/cm^(2)和孢子萌发率89.89%;以果糖为碳源、牛肉膏为氮源的培养基获得最高产孢量和孢子萌发率,分别为1.39×10^(9)个/cm^(2)和52.81%、1.75×10^(9)个/cm^(2)和62.61%;最适pH为7.0,温度为30℃,其生长速率分别为13.00 mm/d和10.33 mm/d。综上,该菌株最适培养基为萨氏葡萄糖+酵母粉琼脂培养基,最适碳氮源为果糖和牛肉膏,pH 7.0和温度为30℃时生长最好。溜曲霉A.tamarii XJ-2具有良好的生防潜力及开发应用前景。
A strain of entomopathogenic fungus,designated Aspergillus tamarii XJ-2,was isolated from poplar forest soil in Xinjiang using the Galleria mellonella insect bait method.This study aimed to determine its taxonomic status,pathogenicity and optimal culture conditions,providing basic data for its potential application in pest biological control.Strain XJ-2 was identified based on morphological characteristics and rDNA-ITS sequence analysis.The results showed that after seven days on PDA medium,the colony diameter reached 70 mm,with the colony color transitioning from white to yellow or yellowish brown over time.Microscopic examination revealed septate mycelia,erect conidiophores with terminal spherical vesicles,and smooth,transparent,round conidia(2-3μm in diameter)forming chain-like spore strings.The rDNA-ITS sequence(582 bp,GenBank accession no.PQ013057)exhibited 97%similarity with Aspergillus tamarii CBS 104.13^(T)(AF004929).Based on morphological and molecular identification,strain XJ-2 was confirmed as A.tamarii.Pathogenicity tests using spray inoculation demonstrated strong virulence against G.mellonella,Ostrinia furnacalis and Leptinotarsa decemlineata,showing a dose-dependent effect.After seven days of treatment,the cumulative corrected mortality rates and LT_(50)values were as follows:G.mellonella,93.83%,LT_(50)=4.20 d;O.furnacalis,91.67%,LT_(50)=4.74 d,and L.decemlineata,50.00%,LT_(50)=6.60 d.Culture optimization experiments showed that A.tamarii XJ-2 exhibited the best growth on Sabouraud glucose+yeast extract agar medium,with an average growth rate of 12.29 mm/d,spore production of 9.75×10^(9)spores/cm^(2)and spore germination rate of 89.89%.The optimal carbon and nitrogen sources for sporulation and germination were fructose and beef extract,yielding a spore production of 1.39×10^(9)spores/cm^(2)(52.81%germination rate)and 1.75×10^(9)spores/cm^(2)(62.61%germination rate),respectively.The most favorable growth conditions were pH 7.0 and 30℃,with a growth rate of 13.00 mm/d and 10.33 mm/d.In conclusion,A.tamarii XJ-2 exhibits promising biocontrol potential,with optimal growth in Sabouraud glucose+yeast extract agar medium,fructose and beef extract as ideal carbon and nitrogen sources,and pH 7.0 at 30℃as the most suitable conditions.This strain holds great potential for biological pest control applications.
作者
董玉琦
王小武
詹发强
马雪茹
吐尔逊·阿合买提
付开赟
贾尊尊
罗明
郭文超
丁新华
DONG Yuqi;WANG Xiaowu;ZHAN Faqiang;MA Xueru;TUERSUN·Ahmat;FU Kaiyun;JIA Zunzun;LUO Ming;GUO Wenchao;DING Xinhua(College of Agronomy,Xinjiang Agricultural University,Urumqi 830052,China;Institute of Plant Protection,Xinjiang Uygur Autonomous Region Academy of Agricultural Sciences,Xinjiang Key Laboratory of Agricultural Biosecurity,Urumqi 830091,China;Institute of Microbiology Application,Xinjiang Uygur Autonomous Region Academy of Agricultural Sciences,Urumqi 830091,China)
出处
《植物保护》
北大核心
2025年第3期166-181,共16页
Plant Protection
基金
天山英才-科技领军人才项目
新疆维吾尔自治区重大科技专项(2023A02006)。
关键词
溜曲霉
分离鉴定
致病性
培养条件
Aspergillus tamarii
separation and identification
pathogenicity
cultivation conditions
