Cymbidium mosaic disease (Cymbidiumm)

1. Harm: orchid mosaic disease is found in most orchid producing areas all over the world. It is particularly common in the United States and Japan. It is common in Shanghai, Xiamen, Fuzhou, Guangzhou, Chengdu, Shenzhen and other places in China. Jian Cymbidium mosaic virus infection alone had little effect on orchid growth, but combined infection with other viruses could produce symptoms such as necrosis, poor plant growth and so on. The disease can harm many kinds of orchid plants, such as Cartland, Jian orchid, Dendrobium, vanilla, crane orchid, Magnolia, Magnolia and so on, and form mosaic or necrotic spots. Inoculate plants such as Jiangnan, Cassia, Datura, Chenopodium amaranth, apricot and other plants to form local necrotic spots or chlorotic spots.

2. Symptoms: cause mosaic or necrosis on the new leaves of orchids, or chlorotic stripes on the veins of orchids, and local necrosis on Cartland's inoculated leaves. If co-infected with ORSV, the bud can produce brown necrosis and Dendrobium can produce mosaic.

3. Pathogen: Cymbidium mosaic virus (CyMV) is linear, 475nmX12nm, nucleic acid RNA content is 6%, nucleocapsid is helical, sedimentation coefficient is 144s, lethal temperature is 65-70 ℃, dilution end point is 5X10*10*10*10*10, in vitro preservation period at room temperature is 7-30 days.

4. the regularity of the disease: the juice is transmitted, and the peach aphid can transmit virus. The virus was preserved for a long time in diseased leaf sap and lost its pathogenicity in some orchid varieties for 2 months. Some diseased orchid plants will suffer from disease for life, and new buds will also be infected with viruses. if healthy and disease-free seedlings are planted in mud pots or soil that have been planted with poisonous orchids, the plants are prone to disease.

5. Prevention and control methods:

(1) for some valuable virus-free orchids, they must be isolated from the orchid production base.

(2) in gardening operations such as ramets and turning pots, fingers and tools have to be re-sterilized every time they are planted.

(3) washing roots cannot be washed in the same container, and running water should be used to wash roots.

(4) the media such as peat, moss and gravel used for orchid culture should be disinfected. (Liu Zhongjian)