Ultastructural Characteristics of Necrosis and Stunt Disease in Red Pepper by the Mixed Infections of Tobacco mosaic virus or Pepper mild mottle virus and Pepper mottle virus.

The commercial cultivars of red pepper were screened against Tobacco mosaic virus (TMV), Pepper mild mottle virus (PMMoV) and Pepper mottle virus (PepMoV) by seedling test. Tn single infection of TMV or PMMoV, mosaic symptom was produced on the cultivars of 'Cheongyang'and 'Wangshilgun'. However, in cultivars of 'Manilla'and 'Bugang', symptoms were not occurred. In single infection of PepMoV, symptoms of mottle and malformation were produced on the tested cultivars of 'Manilla', 'Bugang', 'Cheongyang'and 'Wangshilgun' In the cultivars of 'Cheongyang'and 'Wangshilgun', synergistic symptoms of stunt and lethal death were induced by mixed infections in the two combinations of TMV+PepMoV and PMMoV+PepMoV. However, in cultivars of 'Manilla'and 'Bugang', synergistic symptom was not occurred as mottle which was milder than that of single infection. Cells were single infected with TMV and PMMoV the cultivars of 'Cheongyang'and 'Wangshilgun', respectively, had typical ultrastructures of tobamovirus as the stacked-band structure and multiple spiral aggregate (SA). Ultrastructures of cell and tissues infected with PepMoV on the cultivars of 'Cheongyang', 'Wangshilgun', 'Manilla'and 'Bugang', the potyvirus inclusions of pinwhills, scrolls, lamminated aggregates and amorphous inclusion were observed. Infected cells with a combination of TMV+PepMoV and PMMoV+PepMoV, the virus particles and inclusions of the two different viruses were found only mixed infection in the same cytoplasm and the amounts of viruses in mixed infections were abundant than in single infection. The angled-layer aggregates (ALA) was observed in the cells infected mixedly with TMV and PepMoV