广西火龙果茎腐病病原菌的鉴定及生防菌筛选  

Identification of the Stem Rot Pathogen of Pitaya in Guangxi and Screening of Its Biocontrol Bacteria

作　　者：李政 李林利 苏姗珊 尹月 申乃坤 张红岩 姜明国 LI Zheng;LI Linli;SU Shanshan;YIN Yue;SHEN Naikun;ZHANG Hongyan;JIANG Mingguo(School of Marine Sciences and Biotechnology,Guangxi Minzu University/Guangxi Key Laboratory of Polysaccharide Materials and Modification,Nanning,Guangxi 530008,China)

机构地区：[1]广西民族大学海洋与生物技术学院/广西多糖材料与改性重点实验室,广西南宁530008

出　　处：《热带作物学报》2024年第10期2162-2170,共9页Chinese Journal of Tropical Crops

基　　金：广西科技重点研发计划项目(No.AB21196019,No.AB21220020);大学生创新创业计划项目(No.S202210608164)。

摘　　要：为了明确广西火龙果茎腐病的病原菌,并对该病害实施微生物防治,采用组织分离法分离病原菌,依据柯赫氏法则,经离体试验验证其致病性,结合形态学和多基因序列分析鉴定病原物种类,再运用平板对峙法筛选火龙果内生菌中的生防菌。结果表明:在火龙果腐烂茎蔓分离到假可可毛色二孢菌(Lasiodiplodia pseudotheobromae)和新暗色柱节孢(Neoscytalidium dimidiatum)2种病原菌,其中假可可毛色二孢菌为国内首次报道可引起火龙果茎腐病;以假可可毛色二孢菌PY6为供试靶标菌,从34株火龙果内生菌中筛选到1株防治效果最好的枯草芽胞杆菌(Bacillussubtilis)L3-4,该菌株能使PY6的菌丝缠绕、断裂;L3-4无菌发酵滤液、100℃处理后的无菌发酵液均有抑菌效果,防效分别可达到72.08%和71.16%;但不产生抑制PY6菌株生长的挥发性化合物;此外,拮抗菌株L3-4对葡萄座腔菌、假禾谷镰刀菌、尖孢镰刀菌和新暗色柱节孢菌均有抑制效果,抑菌率可分别达77.65%、73.13%、64.07%和62.01%。本研究明确了广西火龙果茎腐病的病原菌,筛选出的生防细菌可作为防治火龙果茎腐病的候选菌株,为火龙果茎腐病的诊断与生物防治提供理论依据。The pathogen of pitaya stem rot in Guangxi was isolated by the tissue separation method and the microbial control of the disease was selected.According to Koch’s rule,the pathogenicity was verified by in vitro experiments,and the pathogenic species were identified by the morphological and multi-gene sequence analysis.Then,the biocontrol bacteria were screened by the plate confrontation method.The results showed that two pathogenic fungi,Lasiodiplodia pseudotheobromae and Neoscytalidium dimidiatum,were isolated from the decayed stems of pitaya,of which L.pseudotheobromae was the first reported to cause pitaya stem rot in China.Taking L.pseudotheobromae PY6 as the target pathogen,Bacillus subtilis L3-4 with the best control effect was obtained from 34 strains of pitaya endophytes screened,which could make the mycelium of PY6 entangled and broken.The sterile fermentation filtrate and the sterile fermentation broth after 100℃treatment had antibacterial effect,and the prevention effect could reach 72.08%and 71.16%,respectively.But it did not produce volatile compounds that inhibited the growth of PY6 strain.In addition,strain L3-4 exhibited inhibition to Botryosphaeria dothidea,Fusarium pseudograminearum,F.oxysporum and N.dimidiatum with inhibition rate 77.65%,73.13%,64.07%and 62.01%,respectively.This study clarified the pathogenic pathogen responsible for pitaya stem rot in Guangxi.The screened biocontrol bacteria could be used as candidate strain for controlling pitaya stem rot.The result would provide a theoretical basis for diagnosing and biologically controlling pitaya stem rot.

关 键 词：火龙果 茎腐病 病原菌 假可可毛色二孢菌 拮抗细菌 

分 类 号：S436.67[农业科学—农业昆虫与害虫防治] S476[农业科学—植物保护]