摘要
为筛选对蓝莓根腐病有良好防效的生防真菌资源,通过组织分离法和平板对峙法从蓝莓组织中分离筛选蓝莓根腐病病原菌——尖镰孢菌Fusarium oxysporum的拮抗真菌,对拮抗效果较好的菌株进行形态学和分子生物学鉴定,并采用平皿培养法和液相色谱-质谱联用法测定拮抗菌株代谢产物的抑菌活性及其成分,观察其重寄生现象,测定其胞外水解酶活性以及室内盆栽防效。结果显示,分离筛选到2株菌株G18和MG6对蓝莓根腐病病原菌有较好的拮抗作用,对病原菌菌丝生长的抑制率分别为60.24%和62.65%;结合形态学特征和核糖体转录间隔区(internal transcribed spacer,ITS)序列分析,最终将菌株MG6鉴定为球孢瓶束霉Ascodesmis sphaerospora;菌株G18和MG6的发酵代谢物对蓝莓根腐病病原菌的抑制率分别为39.85%和42.86%,挥发性代谢物对其抑制率分别为21.39%和18.50%;从2株菌株发酵液中检测到了芥酸酰胺、邻苯二甲酸二丁酯和α-姜黄烯等13种已知具有抑菌活性的物质;同时发现2株菌株均可以分泌β-1,3-葡聚糖酶、纤维素酶和蛋白酶等水解酶;显微观察发现2株菌株均使病原菌菌丝出现明显的溶解、裂解等现象;菌株G18和MG6对蓝莓根腐病的防效明显,分别为65.33%和61.33%;接种菌株G18和MG6后蓝莓幼苗根中过氧化氢酶(catalase,CAT)活性最高,较清水对照组分别显著提高了1.01倍和1.02倍,接种菌株MG6后蓝莓过氧化物酶(peroxidase,POD)活性最高,在根和叶中的POD活性较清水对照组分别显著提高了1.10倍和1.09倍,先接种菌株G18后接种病原菌的蓝莓中超氧化物歧化酶(superoxide dismutase,SOD)活性最高,在根和叶中分别达559.61 U/g和422.68 U/g;接种菌株G18和MG6后蓝莓幼苗的叶绿素含量分别为1.036 mg/g和1.038 mg/g,均高于清水对照组。表明菌株MG6和G18是具有较好应用前景的蓝莓根腐病生防资源。
To screen effective biocontrol fungi against blueberry root rot caused by Fusarium oxysporum,fungi strains were isolated from the blueberry tissue with tissue separation method,and screened with confrontation assay.The two strains G18 and MG6 obtained from screening showed a strong antagonistic ability against blueberry root rot,with inhibition rates of 60.24%and 62.65%,respectively.According to their morphological characteristics and internal transcribed spacer(ITS)sequence analysis,MG6 was identified as Ascodesmis sphaerospora.The inhibition rates of fermentation metabolites of strain G18 and MG6 against F.oxysporum were 39.85%and 42.86%,respectively,and the inhibition rates of their volatile metabolites were 21.39%and 18.50%,respectively.Thirteen known antimicrobial metabolites,including erucamide,dibutyl phthalate and alpha-curcumene,were detected in the fermentation broth of the two antagonistic strains by high-performance liquid chromatography-mass spectrometry(HPLC-MS).The results of hydrolase activity test showed that the two strains could secreteβ-1,3-glucanase,cellulase and protease.Microscopic observation showed obvious disintegration and fracture for the hyphae of pathogen treated with the two biocontrol strains.The results of pot experiments in greenhouse indicated that G18 and MG6 could control blueberry root rot,with efficacies of 65.33%and61.33%,respectively.Extracellular hydrolase activity assay showed that treatment with both G18 and MG6 significantly increased the activity of catalase(CAT)in the roots of blueberry seedlings by 1.01and 1.02 times,respectively.The activity of peroxidase(POD)in the seedlings inoculated with MG6was the highest,and the activity in root and leaf significantly increased 1.10 and 1.09 times.The activity of superoxide dismutase(SOD)in roots and leaves inoculated with both G28 and F.oxysporum were559.61 U/g and 422.68 U/g,respectively.The chlorophyll contents of seedlings treated with G18 or MG6 were 1.036 mg/g and 1.038 mg/g,respectively,which were higher than those of the control group.In total,the results indicated that G18 and MG6 strains have great potential for the biocontrol of blueberry root rot.
作者
张富美
尚晓静
李思
侯瑞
Zhang Fumei;Shang Xiaojing;Li Si;Hou Rui(College of Forestry,Guizhou University,Guiyang 550025,Guizhou Province,China;Hezhang County Forestry Bureau,Bijie 553200,Guizhou Province,China)
出处
《植物保护学报》
CAS
CSCD
北大核心
2022年第6期1673-1684,共12页
Journal of Plant Protection
基金
国家自然科学基金(32260651)
贵州省科技计划项目(黔科合支撑[2017]2567,黔科合平台人才[2018]5781)。
关键词
蓝莓根腐病
球孢瓶束霉
裂褶菌
鉴定
生防机制
防效
blueberry root rot
Ascodesmis sphaerospora
Schizophyllum commune
identification
biocontrol mechanisms
control effect
