陕西玉米病毒病及流行因素研究

STUDY ON MAIZE VIRUS DISEASE AND THEIR EPIDEMIOLOGICAL FACTORS IN SHAANXI PROVINCE

研究结果表明:陕西玉米病毒病毒原主要有玉米矮花叶病毒B 株系(M DMV-B)、玉米粗缩病毒(M RDV)和大麦黄矮病毒(BYDV)。用血清鉴定 225 份病株样品中,MDMV-B、M RDV 和 BYDV侵染分别占40% 、23% 、4.5% 。MDMV-B和MRDV 复合侵染占23.5% 。在田间自然条件下,M DMV-B主要通过玉米蚜和禾谷缢管蚜以非持久性传播,MRDV 则由灰飞虱以持久传播。M DMV-B、MRDV和BYDV 的粒子大小分别为 735～755 nm ×17 nm 、70～75 nm 和23～30 nm 。随着玉米生育成熟,侵染逐渐降低,为害亦趋减轻。研究认为,玉米品种、播种期、播量、田间传毒介体数量及发生早晚和地膜覆盖等是影响玉米病毒病流行的主要因素。

The mainly maize virus diseases in Shaanxi were identified as maize dwarf mosaic virus strain B(MDMV B),maize rough dwarf virus(MRDV)and barley yellow dwarf virus(BYDV). Results from serological analysis of 225 diseased plants in maize field showed that frequencies of MDMV B,MRDV,BYDV and MDMV plus MRDV were 40%,23%,4.5% and 23.5%,respectively. MDMV B was transmitted by aphids in non persistent manner,but MRDV was transmitted by Laodelphax striatellus in persistent manner. Virus particles were 735-755 nm×17 nm(MDMV B),70-75 nm(MRDV)and 23-30 nm(BYDV).MDMV B virus could form wheel inclusion bodies in cytoplasm of phloem. The infection rate of viruses decreased gradually as maize plants developed. Results showed that maize varieties(lines),planting date,planting weight,number and appearance date of transmissible vectors in the field and the plastic covering were important factors of disease epidemic.