摘要
为了解香蕉灰纹病便于指导该病害的防治工作,本研究采用组织分离法从海南香蕉主产区的香蕉病叶上分离病原物,通过致病性测定、形态学观察结合真菌核糖体RNA基因内转录间隔区(rDNA-ITS)序列及其系统发育树分析等方法对其进行鉴定,并探讨了培养基、温度、pH、碳源、氮源、光照与通气条件对菌丝生长的影响。结果表明,实验室获得的6株分离株回接3 d后,发病部位表现轮纹病斑,周围有黄晕,与自然发病香蕉叶片的病状相符;6株致病菌菌落均呈灰白色,圆形,边缘不整齐,有轮纹,分生孢子倒卵形,双胞;6株致病菌的rDNA-ITS序列均为575 bp(代表菌株CATAS-CM01 GenBank登录号为MN960387),与GenBank中的香蕉暗双胞菌Neocordana musae模式菌株的相应片段相似性达99.28%~99.65%,且与N.musae模式菌株在系统发育树上聚为同一分支,遗传距离最近。结合形态特征及分子鉴定,确认获得的6株病原菌均为香蕉暗双胞菌Neocordana musae。病原菌最适生长培养基是马铃薯葡萄糖琼脂培养基(PDA)和燕麦片琼脂培养基(OA);生长适宜温度为25~30℃,最适生长温度为30℃;适宜pH为5~7,最适pH为6;最适碳源是乳糖;最适氮源是酵母膏;全光照条件下,病原菌菌丝生长最快;连续振荡培养条件下,菌丝干质量最大;菌丝致死条件为60℃,10 min。
An attempt was made to have a good understanding of Cordana leaf spot of banana in Hainnan province for prevention and control.Fungi were isolated through routine tissue separation and identified based on pathogenicity test,morphological characteristics,analysis of fungal rDNA-ITS sequence and phylogeny.The isolated fungi were cultured to observe their mycelial growth on different mediums under different conditions of temperature,pH,carbon source,nitrogen source,light and ventilation.The results showed that necrotic spots with concentric rings surrounded by a bright yellow halo were observed on the infected leaves three days after inoculation,which was similar to the symptoms and signs on the leaves infected in the field.The colonies of the six strains of the fungi were grayish-white,and circular with concentric rings and irregular edge.The conidia of the six strains were obovate with single septum.The rDNA-ITS sequence length of the six strains was 575 bp(representing the accession number of strain CATAS-CM01:MN960387),which shared 100%sequence similarity to each other among the fungi isolated and 99.28%-99.65%sequence similarity to those of Neocordana musae ex-types in Genbank.Phylogenetic analysis showed that CATAS-CM01 was gathered on the same branch of several sequences of N.musae.Based on the morphological characteristics and analysis of ITS sequence and phylogenetic relationship the six pathogenic strains were identified as Neocordana musae.The analysis of the biological characteristics of the fungi isolated showed that the optimal culture media,temperature and pH for its mycelia growth were PDA and OA,30℃and 6,respectively.The optimal C-source and N-source for the mycelia growth of the fungi were lactobiose and yeast extract,respectively.Successive light and shaking were favorable for the growth of mycelia.The lethal temperature for the mycelia growth was 60℃for 10 min.
作者
扶艳萍
漆艳香
谢艺贤
彭军
曾凡云
张欣
FU Yanping;QI Yanxiang;XIE Yixian;PENG Jun;ZENG Fanyun;ZHANG Xin(College of Plant Science and Technology,Huazhong Agricultural University,Wuhan,430070,china;Environment and Plant Protection Institute,Chinese Academy of Tropical Agricultural Sciences/Ministry of Agriculture and Rural Affairs Key Laboratory of Integrated Pest Management on Tropical Crops,Haikou,Hainan 571101,china)
出处
《热带生物学报》
2021年第1期63-71,共9页
Journal of Tropical Biology
基金
2019年海南省基础与应用基础研究计划(自然科学领域)高层次人才项目(2019RC278)
现代农业产业技术体系建设专项(CARS-31-07)。
关键词
香蕉灰纹病
病原鉴定
暗双孢
生物学特性
Cordana leaf spot of banana
pathogenic identification
Neocordana musae
biological characteristics
