梨火疫病菌与梨腐烂病菌对生长和致病的相互影响  

Influences of Interactions Between Erwinia amylovora and Valsa pyri on Growth and Pathogenicity

作　　者：陈春桥 孙丽英[2] 盛强 韩剑[1] 傅本重 罗明[1] CHEN Chunqiao;SUN Liying;SHENG Qiang;HAN Jian;FU Benzhong;LUO Ming(Key Laboratory of Detection and Prevention and Control of Agricultural and Forestry Pests,Key Laboratory of Prevention and Control of Invasive Organisms in Agroforestry in Northwest Desert Oasis,Ministry of Agriculture and Ministry of Agriculture and Rural Affairs,College of Agriculture,Xinjiang Agricultural University,Urumqi 830052,China;School of Plant Protection,Northwest Agroforestry and Science and Technology University,Yangling,Shaanxi 712100,China;Research Institute of Agricultural Science of Bayingolin Mongolian Autonomous Prefecture,Korla,Xinjiang 841003,China)

机构地区：[1]新疆农业大学农学院,农林有害生物检测与防控重点实验室,农业农村部西北荒漠绿洲农林外来入侵生物防控重点实验室,乌鲁木齐830052 [2]西北农林科技大学植物保护学院,陕西杨凌712100 [3]新疆巴音郭楞蒙古自治州农业科学研究院,新疆库尔勒841003

出　　处：《园艺学报》2024年第11期2668-2684,共17页Acta Horticulturae Sinica

基　　金：新疆维吾尔自治区自然科学基金重点项目(2021D01D12);国家重点研发计划项目(2021YFD1400200)。

摘　　要：梨火疫病和梨腐烂病是当前严重危害库尔勒香梨生产的两大病害,在田间常混合发生,加重了危害程度和防治难度。为了明确梨火疫病病原细菌Erwinia amylovora(E.a)和梨腐烂病病原真菌Valsa pyri(V.p)之间的相互作用,探讨复合侵染机制,将梨火疫病菌E.a001菌株(梨腐烂病菌V.pKRL菌株)与V.pKRL(E.a001)的发酵滤液共培养,研究其互作对其生长和致病力的影响。结果表明,与发酵滤液共培养能显著提高两种菌体的生长速率,E.a001活菌数显著高于对照,生物膜形成量是对照的2.2倍,V.pKRL菌丝生物量是对照的1.46倍,分生孢子萌发率提高14.9%。两种发酵滤液共培养均能降低培养液的pH值,而E.a001与梨黑斑病菌(Alternaria alternata)发酵滤液,V.pKRL与梨花枯病菌(Pseudomonas syringae)和梨锈水病菌(Dyckeya fangzhongda sp.nov)发酵滤液共培养则无促进生长和降低pH等作用。E.a001与V.pKRL发酵滤共培养显著增加了E.a001的胞外多糖和梨火疫毒素产量,hrp基因簇中HrpA、hrpB、hrpD、hrpJ、HrpW、hrpY、hrcJ的相对表达量上调1.53~2.27倍,其中hrpY的上调幅度最大;同样地,V.pKRL与E.a001发酵滤液共培养增加了V.pyri根皮苷降解毒素的合成量,细胞壁降解酶相关基因PG、β-Gal、PME和α-Af相对表达量上调1.64~1.91倍,其中PG的上调幅度最大。通过对E.a001和V.pKRL单菌接种、同位点和异位点复合接种,比较病原菌的致病力。结果显示,在库尔勒香梨枝条、离体叶片和果实上均表现出同位点复合接种处理的致病力最强,显症时间短,病斑扩展速度、病斑面积、V.pKRL的产孢数均大于单菌接种、异位点复合接种。本研究结果表明,梨火疫病菌和梨腐烂病菌能相互促进生长,增加毒素产生水平和上调主要致病基因表达量,复合侵染增强了致病力,二者存在着特定的协同互作关系。Fire blight and pear Valsa canker,two prominent diseases,currently inflict substantial damage on the production of Korla fragrant pear(Pyrus sinkiangensis).Their often co-occurrence in the field,exacerbating the severity of the diseases and complicating control efforts.In order to clarify the interaction between the fire blight pathogen bacterium(Erwinia amylovora,E.a)and the pear Valsa canker pathogen fungus(Valsa pyri,V.p),and to explore the complex infection mechanisms of these pathogens,the present study was conducted to investigate the effects of pathogen interactions on the growth and pathogenicity of E.a and V.p by using E.a strain E.a001 and V.p strain V.pKRL fermentation filtrates co-culture.The results showed that co-culture of E.a001 with V.pKRL fermentation filtrates significantly enhanced the growth rate of E.a001,with a higher viable cell count compared to the control,and a 2.2-fold increase in biofilm formation compared to the control.Co-culture of V.pKRL with E.a001 frmentation filtrates resulted in a 1.46-fold increase in V.pKRL mycelial biomass,and a 14.9%increase in conidial germination rate compared to the control.Additionally,both co-culture of E.a001 with V.pKRL and V.pKRL with E.a001 fermentation filtrates reduced the pH of the culture medium,whereas co-culture of E.a001 with the reference strains of Alternaria alternata,and V.pKRL with Pseudomonas syringae and Dyckeya fangzhongda sp.nov did not exhibit growth promotion or pH reduction characteristics.It was found that co-culture of E.a001+V.pKRL fermentation filtrate increased the extracellular polysaccharide and pear fire blight toxin production of E.a001.The relative expression of HrpA,hrpB,hrpD,hrpJ,HrpW,hrpY and hrcJ in the hrp gene cluster was up-regulated by 1.53 to 2.27-fold,with the greatest up-regulation of the hrpY gene.Similarly,E.a001 fermentation filtrate increased the synthesis of V.pKRL phlorizin degradation toxins,and the relative expressions of cell wall degradation-related enzyme genes,PG,β-Gal,PME andα-Af were up-regul

关 键 词：梨 梨火疫病菌 梨腐烂病菌 复合侵染 细菌—真菌互作 致病力 

分 类 号：S661.2[农业科学—果树学]