崔凌霄 杨成德 魏立娟 薛莉 张俊莲

摘要

对甘肃省定西市安定区的马铃薯疮痂病病原进行了分离、鉴定和生物学特性研究。结果表明，菌株5T-1具有较强致病性，菌落表面呈灰色，有金属光泽，平均直径为4.68 mm，可产生黄褐色素，孢子圆形或圆柱形，孢子丝松散，革兰氏染色呈阳性。5T-1的16S rDNA序列与加利利链霉菌Streptomyces galilaeus菌株的相似度为99%，结合形态特征将菌株5T-1鉴定为Streptomyces galilaeus，为甘肃省新报道病原菌。菌株5T-1生长最适温度为30℃，最适光照条件为全黑暗，最适pH为8.5，最佳碳源和氮源分别为肌醇和天冬氨酸。该研究结果为甘肃省马铃薯疮痂病诊断和综合防治提供了依据。

关键词

马铃薯疮痂病; 病原; 16S rDNA序列分析; 鉴定; 生物学特性

中图分类号：

S 435.32

文献标识码： A

DOI： 10.16688/j.zwbh.2018109

Isolation， identification and biological characterization of Streptomyces galilaeus，

a new pathogen of potato scab in Dingxi City， Gansu Province

CUI Lingxiao YANG Chengde WEI Lijuan XUE Li ZHANG Junlian2

（1. Laboratory of Biocontrol Engineering of Crop Pests and Diseases in Gansu Province， College of

Plant Protection， Gansu Agricultural University， Lanzhou 730070， China; 2. Gansu Key Lab of

Crop Improvement & Germplasm Enhancement， Lanzhou 730070， China）

Abstract

The pathogen of potato scab from Anding District of Dingxi City in Gansu Province was isolated and identified， and its biological characteristics were also determined. The results showed that the strain 5T-1 was highly pathogenic. The colony was gray with a metallic luster and the average diameter of 4.68 mm， which could produce yellow brown pigment. The spores were round or cylindrical and spores silk was loose. Gram staining is positive. The similarity of 16S rDNA sequence of 5T-1 to that of Streptomyces galilaeus was 99%. Combining with the morphological characteristics， the strain 5T-1 was identified as S.galilaeus. It is a newly reported pathogen in Gansu Province. The optimal temperature for strain growth was 30℃. The optimal illumination conditions were darkness and the optimal pH value was 8.5. The best carbon source and nitrogen source were inositol and aspartic acid， respectively. The results provide a basis for the diagnosis and integrated control of potato scab in Gansu Province.

Key words

potato scab; pathogen; 16S rDNA sequence analysis; identification; biological characteristics

马铃薯为继玉米、小麦和水稻之后的世界第四大粮食作物[1]，分布广，种植便捷，产量高，是备受人们喜爱的经济作物之一。甘肃省是国内马铃薯种植大省，尤其定西马铃薯更是世界闻名。但是，随着种植面积扩大，重茬严重，致土传病害严重发生，特别是马铃薯疮痂病近年来成为甘肃省定西市薯块主要病害之一。马铃薯疮痂病在世界各地马铃薯种植区普遍发生[2]，其在薯块上形成褐色木栓化病斑，发病严重时，病斑成片，严重影响薯块品质和商品性。据报道，引起马铃薯疮痂病的病原为链霉菌，国内外报道的种主要有Streptomyces scabies、S.acidiscabies、S.turgidiscabies、S.europaeiscabiei、S.bobili、S.reticuliscabiei和S.griseus等[2-6]，其中S.scabies发现最早，分布最广。我国不同省份报道的疮痂链霉菌存在差异，内蒙古自治区有S.scabies、S.galilaeus和S.bobili[7]，甘肅省有S.scabies和S.griseus[8]，黑龙江省有S.scabies、S.turgidiscabies和S.acidiscabies[9]。……