A Research On Soil Transmission Medium Of Rice Stripe Virus

Rice stripe virus (rice stripe) from the rice stripe virus (rice stripe virus, RSV) causes is currently in wide distribution of rice production, the occurrence of heavy, large damage important virus disease. In recent years, rice production in China pose a serious threat and huge economic losses known as the rice "cancer". Southern region of China in 1963 occurred in the 20th century,90 in Jiangsu and the outbreak of disaster from happening again, now have spread to the entire Yangtze River rice, Plant Protection Station of Jiangsu Province, according to statistics, only 42 of the province in 2004 County, stripe disease, affecting an area of 1.57 million hm, rice accounted for 79% of the total cultivation area, crops area 5200 hm2, rice production has risen to one of the most important diseases.Since the rice stripe in China has been reported, academics generally agreed that rice stripe virus by the planthopper (Laodelphaxstriatellu) is an insect-borne disease transmission, the transmission of the disease are all concentrated On the small brown planthopper. However, efficient high-strength pesticides and insecticidal measures year after year does not seem to curb the trend of the disease in recent years.We note that rice stripe disease is not only have the trend of increasing year by year but also has some soil-borne diseases similar characteristics from the experimental fields of rice-wheat crop rotation for many years. In order to determine whether the rice stripe virus disease has the existence of soil-borne method except the Laodelphaxstriatellu sucking in virus transmission. We isolated and purified morphological characteristics of strains, from successive years of rice stripe disease by high incidence in the soil pool of Nanjing Agricultural University. We examined all of these strains by PCR primers in RSV-CP gene, it was discovered that a bacterial strain can be able to amplified single and clear 990bp±the specific bands, which is same to amplified from RNA of diseased rice leaves with the incidence of RT-PCR products, while the remaining strains are all no corresponding PCR product. This strain was sent to two different commercial sequencing companies naming bacterial 16S-rRNA sequencing, the consequences of two companies were all the Chryseobacterium aquaticum sp. nov.100% homology, so we determine the strain Chryseobacterium aquatic genus Chryseobacterium.We carry on 6 times rice seedlings root inoculated aquatic Chryseobacterium tests, using pot root inoculation method, which contain 5 rice stripe virus disease susceptible varietise (Nipponbare,R109,Wuyugeng) and one rice stripe virus disease resistance varietise (IR36).We are daily observations after inoculation the Chryseobacterium aquaticum. After root inoculating with this bacterial liquid, the results showed that three susceptible rice cultivars in all 5 individual experiments appeared typical symptoms of rice stripe and the incidences of disease plant 4 weeks after inoculating was 12.5-35.9%, the time of onset lasing for 12 days. In contrast, the incidences of disease plant in non-inoculation control was only 1.4-9.3%. The different rice stripe virus disease susceptible varietise is not much fluctuation at different times.Rice stripe virus disease resistance varietise IR36 whether or not inoculated is not diseased. This indicates that the Chryseobacterium can really induce rice stripe virus-induced disease by the method of root inoculating, and the resistant variety also showed good resistance by the method of root inoculating about its resistance of stripe disease gene.In order to determine whether the vaccination of aquatic Chryseobacterium strains are stripe virus disease, we teste all the plants carrying out by RT-PCR, to determine whether there is the strain stripe virus. The results showed that the incidence of all inoculated plants not only have the same symptoms with the natural field strains disease, but also its diseased leaves using the RSV virus CP gene primers can be extended out a single clear bands of 990bp±and using the RSV virus SP gene primers can be extended out of 500bp±bands, these bands were sequenced by the outgoing commercial company, and it is the corresponding stripe virus sequence. And non-inoculated control without the typical leaf curl symptoms of heart after inoculation individual plants can be expanded unless the outside with the rest can not be exzamed. Tanaka incidence obtained from different parts of the leaves of plants to detect the carriers of the virus, but not all the situations can be detected in leaves and tillers infected in different situations are also different. As a result, we guess this maybe the mass poisoning caused by different media. Thus initially determined, rice stripe disease resistance is also a soil-borne disease, the pathogenic virus of the mediator is aquatic Chryseobacterium. RSV immune serum with colloidal gold labeling the bacteria samples. In the cell can clearly see the presence of gold particles.The results of RSV antibody in the aquatic Chryseobacterium also indicates the presence of soil transmission.