Analysis Of Genome And Identification Of Pepper Mild Mottle Virus

Pepper mild mottle virus was a kind of Tobamovirus, mainly was parasitic on Capsicum fructescens and Capsicum annuum, and gave rise to reduction in production and quality. As for its serious damages to the economy of peppers, based on biological method, RT-PCR and ELISA method, this study had identified this virus effectively. We also obtained the whole-genome sequence of this virus and studied three purified kinds of polysaccharide of Phellinus baumii impacted on the inoculation and proliferation of this virus.1Pepper mild mottle virus was inoculated mechanically to tobacco leaves, which showed symptoms of mottle, faded green, wrinkle, curl, and necrotic spot, respectively after a span of incubation. Expected fragments were obtained with two pairs of special primers of Pepper mild mottle virus by RT-PCR, and confirmed as fragments of Pepper mild mottle virus by sequencing. Otherwise this virus was identified as Pepper mild mottle virus with DAS-ELISA reagent kit of AGDIA successfully.2System of extracted RNA was established with dried leaves of pepper and tobacco. Namely pepper or tobacco leaves were dried at65℃, and then the total RNA of dried leaves could be extracted with CTAB effectively. Obtained stripes of RNA were clear without any trailing. Parts of genome fragments of Pepper mild mottle virus with length of above2000bp could be amplified effectively with the total RNA as temples.3The whole genome sequence of a Chinese isolate of Pepper mild mottle virus was obtained by RT-PCR with length of6294bp,63bp nucleotides less than isolates of PMMOV in GenBank. The isolate in this study had a closer relationship with Japanese isolate and a farther relationship with isolate which can break out L3resistant gene of pepper. So it was speculated that this virus could not break out L3resistant gene of pepper.4Polysaccharide of Phellinus baumii was purified with ion exchange chromatography, and was divided into three ingredients, renamed as PIP30-I, PIP60-I, PIP80-I, respectively. Pepper mild mottle virus was inoculated to tobacco leaves, then effect of polysaccharide of Phellinus baumii on inoculation and proliferation of PMMOV was detected using DAS-ELISA. The result was that PIP80-I, PIP30-I had the effect of inactivation to the virus, no inhibition or treatment effect. Polysaccharide of PIP60-I had no inactivation, inhibition or treatment effect.