花椒树腐朽病病原菌鉴定及其生防菌剂筛选

Identification on Pathogens of Zanthoxylum bungeanum Decay Disease and Screening of Its Biocontrol Fungicides

旨在探明甘肃省永靖县三塬镇花椒树腐朽病病原菌种类及其生物学特性,筛选出对其抑菌率较高的生物农药。通过田间调查、病样采集及组织分离培养、形态观察和分子生物学等方法,明确了花椒树腐朽病发生情况,对病原菌进行鉴定,测定4种生物农药和2种化学农药对病原菌的抑菌活性。结果表明,该病害田间发病率为77.50%,病情指数为29.00,病害枯斑面积最大可达240cm2;从病斑上分离纯化获得3株菌,其中Z1菌株、腐皮镰刀菌(Fusarium solani Mart.)、链格孢(Alternaria alternata)的分离频率分别为80%、20%和25%;对优势菌分离菌Z1致病性测定表明:有伤接种病斑分离物和裂褶菌子实体均发病,且症状相同;经形态学特征和rDNA-ITS序列分析将Z1鉴定为裂褶菌(Schizphylhls commune Fr.),GenBank序列号为MT251888.1;裂褶菌生长的最适温度、相对湿度、pH和培养基分别为30℃、70%、pH7、花椒枝条煎汁葡萄糖琼脂培养基;菌丝比孢子侵染寄主快,25d可完成一个侵染循环;筛选出3种对S.commune活性较高的生物农药:6%寡糖链蛋白、哈茨木霉和深绿木霉,它们的抑菌率与80%嘧霉胺、30%氟菌唑在推荐使用浓度下的抑菌率相当。

In order to ascertain the pathogen species and biological characteristics of the pathogen ofZanthoxyl um bungeanum decay in Sanyuan town of Yongjing in Gansu province,the biological pesticides with high inhibition rate were screened out.Through field investigation,collection of diseasesamples,tissue isolation culture,morphological observation and molecular biology,the occurrence ofZanthoxyl um bungeanum decay was clarified,the pathogens were identified,and the biological characteristics of the pathogen and the inhibition activities of four biological pesticides and two chemicalpesticides against the pathogen were determined.The results showed that the disease incidence ratewas 77.50%.and the disease index was 29.00,the maximum diseased spots area could reach 240cm^(2).Three strains of them were obtained from the diseased spot by the pathogen separation and puri-fication,and the isolation frequency of Z1 strain,Fusarium solani Mart.and Alternaria alternatawere 80%,20%and 25%,respectively.The pathogenicity test of dominant strain Z1 showed thatboth the inoculated diseased spots isolated and Schiz ph ylhls com m une Fr.fruiting body had the samesymptoms.Z1 was identified as S.commune by morphological characteristics and rDNA-ITS sequenceanalysis,and the GenBank sequence number was MT251888.1.The findings also revealed that the optimum temperature,relative humidity,and pH for the growth of S.commune were 30℃70%,pH 7,respectively,while the best medium was the dextrose agar with decoction of Zanthoxylumbungeanum branches.The infection rate of mycelium was faster than that of spores,and an infectioncycle could be completed within 25 days.In addition,three biological pesticides with high activity toS.commune were also screened out,namely 6%oligosaccharide chain protein,Trichoderma harzianum and Trichoderma atroviride.Meanwhile,their inhibition rate was equivalent to that of the chemical pesticides 80%pyrimethanil and 30%triflumizole at recommended concentration.