The Exploration For Maize Dwarf Mosaic Virus Disease

Maize dwarf mosaic, caused by maize dwarf mosaic potyvirus (MDMV), is the most important widespread viral disease of maize in the world. It has caused serious epidemics in the northern China as well as most other maize and sorghum growing regions. It can cause up to 100% yield losses. The greatest losses occur with susceptible varieties when the infection occurs during early growth stages.Maize dwarf mosaic virus consists of several strains of which A and B are best characterized. Serological tests and studies on the host range have revealed the existence of MDMV-B, in China. In 1994, The nucleotide acid sequence of MDMV-B CP was reported, too.The virus is transmitted by many species of aphids, including Schizaphis graminum., Rhopalosiphum padi, Rhopalosiphum maidis, Macrosiphum avenae, and Myzus persicae. In addition, maize seed transmits MDMV, too.In 1997 and 1998, 45 sample of maize dwarf mosaic virus from Gansu, Shanxi, Shannxi, Beijing, Ningxia, Hainan, Henan, and Liaoning province were detected by dot-ELISA, biological method, and indirect-ELISA. The results showed that 27 sample was MDMV B strains and 3 samples were similar to MDMV A strains. In addition, CP Sequence of MDMV in China were compared with MDMV-A, B, O, KS1, and SCMV-SC and SCMV-JG strains CP sequence from internet in the world. The homologous is 72.0%, 80%, 61.5%, 60.9%, 80.6% and 60.0% respectively. The results showed that MDMV-B strain in China is different from MDMV-B in the world.The result showed that MDMV is not transmitted by maize pollen through dot-ELISA and reverse transcription and polymerase chain reaction (RT-PCR) technology.Seedborne virus is very important not only for primary infection, but also for long distance transmission. This paper is the first report on the detection of MDMV in maize seed (inbred Mo17 and Ye107) by RT-PCR technology. The results showed that the virus was found in albumen and seed capsule, but not in embryo. The causation of the embryo was not infected by MDMV was discussed.The control techniques are to extend resistance varieties. There are many resistance varieties in China, for example, Tangyu5, Yedan12, Huangzao4, Tangkang5, Zhongdan8, Huobai, Bao10, et al.