Detection Technology Of Apple Virus Disease In Gansu Province

In recent years, the areas of apple planting were expanding in Gansu Province, the appleindustry has become the main way of economic development of the main apple planting areas, butapple virus disease causing serious harm to the apple industry. To clear the kinds, occurrence anddistribution of Gansu apple virus, The study surveyed the incidence and the type of symptomsabout Apple mosaic virus and Apple scar skin viroid of two main non latent virus though fieldinvestigation in Gansu Province. Apple mosaic virus infected by DS-ELISA detection method ofGansu Province and the host range of the Apple mosaic virus virus was determined by mechanicalinoculation method. The host tissue lesions by Apple mosaic virus were observed though electronmicroscopy. Apple scar skin viroid, Apple chlorotic leaf spot virus, Apple stem grooving virus andApple stem pitting virus were detected by RT-PCR. The results were summarized as follows:1. Investigated the incidence and symptoms type of Apple mosaic disease in Jingning County,Zhuanglang County, Lanzhou City in2013. The results showed that the average of3area incidencerate was19%. The Lanzhou city average incidence rate was11.7%, The Jingning County averageincidence rate was24.6%, The Zhuanglang County average incidence rate was25.2%.Theincidence of severe trees over the age of10, Fuji serious disease than the Starkrimson. Symptomstypes were divided into8categories that are streak type, mottled typeⅠ, mottled typeⅡ, ring spot,mosaic type, edge type, batocera type and net spot; In2013September,the Apple scar skin viroidwere investigated in Apple planting area of Lanzhou City, the results show that Lanzhou city Applescar skin viroid general occurs, the average incidence rate was6.3%, the main symptoms of rustfruit, flower face type and rust fruit-flower face mixed type, the flower face type was divided intothree grades according to the scab area.2. In Jingning County, Zhuanglang County, Lanzhou City of Gansu Province,84samples werecollected with has mosaic symptoms and no symptoms of apple leaves, detected Apple mosaicvirus by DS-ELISA method, the results showed that the total positive rate was78.57%, three areawith an average infection rate were84.38%,81.25%and65%. The mosaic symptoms sampleinfection rate were reaching100%,87.5%,80%. The non mosaic symptoms sample infection ratewere reaching68.75%,75%and50%. It was choosed19host plants of9families to detect the hostrange of Apple mosaic virus, The biological measurement results showed that kidney bean,nightshade and celery have no obvious symptoms, other host plants show mosaic、dry spots、chlorotic spots、shrinkage and other symptoms. DS-ELISA detection of host infested found,tobacco, beans, black nightshade, sunflower and celery showed negative, the other14kinds of hostplant were Apple mosaic virus positive, while the ordinary tobacco and sunflower have obvious symptoms, DS-ELISA test results were negative.3. Select apple leaves with green and yellow mosaic symptoms and normal parts of apple leaftissue of slices ultrathin electron microscopy observation, the result shows that virus particles in adecentralized linear accumulated in the cytoplasm, The number of chloroplast decreased, andchloroplasts left from cell wall and owed ferritin.4. Application of RT-PCR technique were used to examine the main apple virus,The summershoots and winter buds were selected to extract total RNA of apple plant tissues, The total RNA ofsummer shoots18S,28S was clearly,5S was light, OD230/260and OD230/260at about1.9, RNAintegrity mentioned better. The total RNA of winter bud18S,28S shoots also was clearly, OD230/260and OD230/260at about1.8, but can be used for further reverse transcription and amplification ofPCR. We select8pairs of primers were used in PCR amplification, the primers XG2, TL2, JG2,JD1had better detected of Apple scar skin viroid,Apple chlorotic leaf spot virus, Apple stemgrooving virus and Apple stem pitting virus. The application of this system was tested on8samplesof field, the results show that, the Apple scar skin viroid carried rate was25%, the Apple chloroticleaf spot virus carried rate was87.5%, the Apple stem grooving virus carried rate was62.5%, theApple stem pitting virus carried rate was50%, The mixed infection rate of latter three virus was37.5%.