【摘要】 本研究对甘肃省玉米茎腐病症状进行了描述,并对病原菌进行了鉴定和生物学特性测定。结果表明,玉米茎腐病发生后导致受害植株黄化,病斑内部坏死或腐烂。病原菌大型分生孢子无色,呈镰刀形,3~5隔,大小为(4.54~11.74)μm×(1.96~4.27)μm;小型分生孢子卵圆形或椭圆形,单胞,大小为(1.25~5.50)μm×(1.25~3.75)μm;菌丝有隔,无色;病原菌ITS基因序列与藤仓镰孢霉菌(Fusarium fujikuroi)(KJ000440.1)的同源性达99%,结合形态学特征,将其鉴定为藤仓镰孢霉菌;该病原菌生长及其孢子萌发的最适温度为25℃;菌丝最适生长pH为8;碳源中菌丝生长以D-半乳糖最好,L-山梨糖最差,孢子萌发以L-山梨糖最好,葡萄糖最差;氮源中菌丝生长以氯化铵最好,碳酸铵最差,孢子萌发以干酪素最好,牛肉膏最差;相对湿度低于90%孢子不萌发。该研究结果为玉米茎腐病的诊断和综合防治提供了依据。更多还原

【Abstract】 In this study,the symptoms of maize stalk rot disease occurring in Gansu Province were documented.The pathogen was identified and its biological characteristics were determined.Affected plants turned yellow and showed internal lesions such as necrosis or rotting.The pathogen’s maxconidia were colorless,sickle shaped,had three to five septa,and the sizes were(4.54~11.74)μm×(1.96~4.27)μm.Minconidia were ovoid or elliptical with single cell,and the sizes were(1.25~5.50)μm×(1.25~3.75)μm.The mycelium was septate and colorless.The ITS gene sequences of the pathogen shared 99% homology with Fusarium fujikuroi(GenBank Accession No.KJ000440.1).The pathogen was identified as F.fujikuroi based on morphological characteristics and ITS sequence analyses.The optimum temperature for mycelium growth and conidial germination was 25℃.The optimum pH for mycelium growth was 8.0.Regarding carbon sources,D-galactose was best for mycelium growth,and L-sorbose was the least favorable.For spore germination,L-sorbose produced the best results,and glucose was the least favorable.Ammonium chloride was the best nitrogen source for mycelium growth and salvolatile was the least favorable.Casein was best for spore germination and beef extract was the least favorable.Spore did not germinate when relative humidity was below 90%.These results provide a basis for the diagnosis and comprehensive control of maize stalk rot disease.更多还原