Rice donggro globular virus (RTSV).

Classification status:

Poku orientalis baculovirus belongs to Poku orientalis baculovirus, cauliflower mosaic virus family.

Rice donggru globular virus belongs to dwarf virus genus, associated virus family.

The codes of ICTV are 00.015.0.04.001(rtbv) and 00.065.0.02.004(RTSV) respectively.

Virus Synonyms: Rice Leaf Yellowing Virus) =RTSV, Rice Huaika Virus) =RTSV, Rice Mentek Virus) =RTSV, Rice Bunken Virus = RTBV, Rice Yellow Leaf Virus.

Virus purification: the diseased leaves of RTSV were ground with 0.0 1m EDTA (pH 8.0), and the homogenate was incubated in a water bath at 40℃ for 1h to clarify the mixed solution, and the mixture was purified with 7%PEG(6000), 0.2mol/LNaCl,1%tritonx-/. Centrifuge at 40000(r/min) for 40min and 10000(r/min) 10min(Beckman, RT-65) respectively, and use 10% ~ 50% sucrose density gradient (0.0/kloc-0 The virus band was collected, diluted with 0.0 1 mol/L EDTA (pH 8.0), centrifuged at 40,000 (r/min) for 40 minutes, and the precipitate was resuspended with 0.0 1 mol/L phosphate buffer (pH 7.4),10000 (r It is difficult to separate and purify RTBV and RTSV from the disease strains of rice mushroom. Omura et al. (1983) separated RTBV three times by sucrose density gradient centrifugation, and then precipitated RTSV with antiserum of Japanese rice dwarf virus (RTSV).

Physical and chemical characteristics of virus:

① Virus particles: RTV has two kinds of particles-spherical (RTSV) and rod-shaped (RTBV). RTBV particles are rod-shaped, with smooth ends, parallel sides and no coating, and the size is110 ~ 400 nm * 30 ~ 35 nm. RTBV has sedimentation component, and the buoyancy density in cesium chloride is 1.3 12g/cm3, and A260/A280 is1.1(hibino, 1990). RTSV particles are spherical, with a diameter of 30 ~ 35 nm and no coating. The sedimentation coefficient of RTSV is 175 5s (Galvez, 1968), and the buoyancy density in cesium chloride is 1.55 1g/cm3, and A260/A280 is 1.75 (hibino,/.

② Nucleic acid: RTBV is single-molecule open-loop double-stranded DNA(dsDNA) with a length of 8.3kb, and RTSV is single-molecule linear single-stranded RNA(ssRNA) with a length of about 12kb and a molecular weight of 3.7* 106u.

③ protein: RTBV has four open reading frames, which are coded as 24, 12, 19 and 46ku protein respectively. RTSV coat protein consists of three peptides with molecular weights of 22.9, 22.3 and 36ku.

Response: It's very confusing. According to the symptom response of RTV in FK 135, it can be divided into S strain and M strain (Rivera &: Ou, 1967), plus a T strain (Galvez et al., 1970). In India, according to the symptom response of Taichung 1 (TN 1), there are four strains (Shastry et al.,1972; Anjaneyulu & John, 1972). According to the comparative study of four rice lines between China and the Philippines in Donggulu, the infected lines were isolated by serological method, and then RTBV was divided into RTBV- 1 and RTBV-2, and RTSV was divided into RTV-1,RTSV-2 and RTV.