玉米矮花叶病侵染导致玉米对大、小斑病抗性丧失的研究

A Study on loss of Disease Resistance to Helimnthosporium turcicum Pass and Helminthosporium maydis of Corn Infected by maize Dwarf Mosaic Virus

河北省为玉米大、小斑病混合发生区，近年来玉米矮花叶病发病逐年加重。通过对河北省玉米生产上的１１份主栽玉米杂交种和１１份骨干玉米自交系对大、小斑病和矮花叶病的单独接种和复合接合鉴定结果看出，被玉米矮花叶病侵染的玉米对大、小斑病的抗性严重丧失，病级一般加重２～３级，病指增高４０％以上，由抗病品种变成了感病品种，所以选育种植抗大、小斑病的玉米品种时，必须同时兼抗玉米矮花叶病。

The two diseases catlsed by H. turcicum Pass. and H.maydis are mainlyones in corn production of Hebei Province. In recent years,a disease caused by maizedwarf mosaic virus (MDMV)has been increasing gradually. This paper reported the experimental results of single and multiple inoculations of H. turcicum Pass. and H. maydison 11 main hybrids and 11 inbred lines of corn with MDMV infection. The resultsshowed that MDMV illfection caused the disease resistance loss; 2￣3 disease grade increasing;and more than 40% disease index increasing of H. turcicum Pass. and H. maydis. So we Suggest that the resistance to MDMV should be considered when carrying outselective breeding of H. turcicum pass.and H. maydis.