冀东地区旱黄瓜多主棒孢菌(Corynespora cassiicola)培养性状多样性

The Diversity of Culture Traits of Corynespora cassiicola in Cucumbers in Eastern Hebei Province

为明确旱黄瓜棒孢叶斑病的病菌种类及其菌株培养性状多样性,采用ITS序列测定病原菌种类的基础上,分析了河北省冀东地区旱黄瓜多主棒孢菌的生长速度、培养性状、显微特征、致病力及其营养需求的差异性。根据生长速度将28株旱黄瓜多主棒孢菌分为快、中、慢等3种类型,分离频率分别占25.00%,67.86%和7.14%。菌落颜色分别为墨绿色、灰绿色、灰褐色和灰白色。BB19112508致病力最强,在中农6,新津春4号和娇子8号上黄瓜棒孢叶斑病病情指数分别为57.78,54.07,53.70。BBCL19122506的假隔膜数量变化最大,1~14个;分生孢子的长度和基脐宽度最大,分别为139.17,4.24μm。BB19112508菌丝和分生孢子生长最适营养分别为:PDA,乳糖;硝酸钠。BBCL19122506菌丝和分生孢子生长最适营养分别为:PDA,可溶性淀粉;硝酸钠,硝酸钾。BBCL20052502产孢最适培养基为察氏培养基。旱黄瓜多主棒孢菌培养性状间存在着丰富的多样性,防治时应考虑优势菌株的比例。

The difference in growth rate,traits,microscopic features,pathogenicity and nutritional requirements of C.cassiicola was analyzed with ITS sequence determining the pathogen species to clarify the pathogenic species of cucumber Corynespora cassiicola leaf spot and the diversity of bacterial culture traits.According to the growth speed,28 strains of C.cassiicola were divided into fast,medium and slow types,and the isolation frequencies accounted for 25.00%,67.86%and 7.14%,respectively.Colony colors were dark green,gray-green,gray-brown,and gray-white.BB19112508 had the strongest pathogenicity,and the disease index of cucumber C.cassiicola leaf spot on Zhongnong 6,Xinjinchun 4 and Jiaozi 8 were 57.78,54.07 and 53.70,respectively.BBCL19122506 had the largest variation in the number of false septa,ranging from 1 to 14.The length of conidia and the width of basal umbilicus were the largest,which were 139.17 and 4.24μm,respectively.The optimum nutrients for mycelium and conidia growth of BB19112508 were PDA,lactose and sodium nitrate,respectively;the optimum nutrients for mycelium and conidia growth of BBCL19122506 were PDA,soluble starch and sodium nitrate,potassium nitrate,respectively;The medium was Chapman's medium.There was a rich diversity among the culture traits of C.cassiicola.in cucumbers,and the proportion of dominant strains should be considered in the control.