How to spread and control barley stripe mosaic virus disease?

Hazard: In the United States, BSMV only causes economic losses in Montana and North Dakota (Carroll. 1983). 1953- 1970, the virus caused losses to barley as high as 30 million dollars, of which 1964 caused the most serious losses, reaching 3 million dollars. Mechanical inoculation of BSMV (Chiko & Berker, 1978) reduced barley production by 24%. At present, the economic losses caused by BSMV in the world (including the United States) are decreasing year by year (Carroll, 1983). It has been found in Harbin, Shandong, Shanghai and Xinjiang in China (Yudeng 1980).

Mode of transmission: the virus is transmitted only by seeds, and barley is generally self-pollinated, so pollen transmission is not important (Slack et al., 1975). However, when using male sterile plants to cultivate barley germplasm, pollen transmission is an important factor in BSNW epidemiology.

Carrier: No natural carrier was found.

Seedling plants: the seedling rate of barley is 90% ~ 100%, that of grey barley is 2%, that of wheat is 2%, that of wheat is 7% ~ 8 1%, that of agropyron cristatum is 22%, and that of oat is 22%. Ryegrass 3% ~ 8%.

Others include Aegilops tauschii, Avena sativa, Milkweed, Bromus brevis, regens, scoparius, Cutandia memphitica, Cynosurus coloratus, Barley, H.spontaneum, Koeleria phleoides, Phalaris canariensis, Pholiurus filiformis, P.incuruus and Poa exilis.

According to Zhang Yueji (1984), the seeds of diseased corn plants may also be toxic. The seed transmission rate of different strains is different (90% ~ 100%) (Timian, 1974), and the seed transmission rate is also affected by plant growth stage and temperature (Singh et al., 1960). The infection rates of pollen and ovule were 10% ~ 35% and17% ~ 66% respectively (Carroll & Mayhew,1976a; ; 1976b). In barley, the seed transmission rate varies with varieties and infection periods. Before jointing, the seed transmission rate of infected people was 83.3%, the booting stage was 69.6%, and the heading stage was only 65,438 0.98% (Li et al., 65,438 0.979). Enzyme-linked immunosorbent assay showed that the seed coat, embryo and bud of toxic seeds were all toxic.

Natural hosts: barley, cultivated barley, common wheat and oats.

Infected plants were inoculated artificially: Gramineae (Jackson&Lane, 198 1), rye, corn, rice, sorghum and millet; ; Dicotyledonous plants: tobacco, beet, spinach, Chenopodium album, Chenopodium album, Chenopodium album, etc. Aegilops divaricata, Aegilops divaricata, Aegilops divaricata, Aegilops divaricata, Aegilops divaricata, Aegilops ovata, Aegilops mirabilis, Aegilops Sharon, Aegilops skrjabini, Aegilops spelt, Aegilops trifoliata, Aegilops obliqua, Agropyron cristatum, Aegilops viridis, Amaranthus retroflexus, Eupatorium odoratum, Avena sativa, Avena sativa, China Avena sativa. Bromus japonicus, Bromus lanceolatus, Bromus villosum, rigens, Bromus sclerosus, Bromus rutaecarpa, Bromus littoralis, Mexican millet, buckwheat, Festuca arundinacea, Poa pratensis, Poa rubra, Gaudi grass, Stipa angustifolia, barley, Boletus brevispike, Boletus hexaspike, Zhu Dinghong, Boletus microphylla, Festuca arundinacea, Rhamnus. Lolium multiflorum, Lolium persicum, Lolium perenne, Leymus pumila, Lolium sclerophyllum, Turanicum aestivum, Senecio sibiricum, Senecio scandens, Euonymus japonicus, tobacco, rice, broomcorn millet, Artemisia capillaris, millet, broomcorn millet, crabgrass, Setaria angustifolia, Setaria viridis, Setaria bicolor, sorghum, spinach, spinach and black spike.

Disease, environment and epidemic: The symptoms of plants vary according to virus strains, host species and environment (McKinney&Greeley, 1965), and high temperature (24 ~ 30℃) aggravates the symptoms (McKinney, 1954). The severity of the disease is related to the sowing date. The earlier the sowing date, the more serious the disease is. Delaying sowing properly can reduce diseases.

Disease control: BSMV is a seed-borne virus, and sowing after virus-free can avoid yield reduction. In Montana and North Dakota of the United States, barley seeds are managed by strict quarantine certificates to prevent virus damage (Carroll, 1963). In Montana, these management include warehouse registration, seed testing, and regular observation in the field to prevent seeds from mixing into epidemic areas. In each seed bin, 200 samples were taken for serum test. Issue quarantine certificates to healthy seeds. In North Dakota, there is a similar management system, but the serum is detected by latex flocculent precipitation method. It is reported that some barley varieties are resistant to some strains of BSMV, but no barley varieties with both economic value and resistance have been found.