|Budget Amount *help
¥6,100,000 (Direct Cost: ¥6,100,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥5,600,000 (Direct Cost: ¥5,600,000)
1. The occurrence of luteoviruses in Japan
In Japan, 11 luteoviruses were confirmed to distributed in the fields from Hokkaido to Okinawa as follows,barley yellow dwarfvirus(BYDV),beet western yellows virus(BWYV),carrot red leaf virus, grapevine ajinashika virus, leek uellows virus, milk-vetch dwarf cirus(MVDV),potato leafroll virus, soybean dwarf virus(SDV),strawverry mild yellow edge virus,tobacco necrotic dwart virus and a luteovirus from green peper.
2. Comparative studies of luteoviruses
Among the viruses mentioned above, 4 viruses such as BYDV,BWYV,SDV and MVDV were used to conduct some comparative studies.
(1)BYDV--Two strains,BYDV805 and BYDV-F85,were isolated from the barley plants. Both strains were transmitted in a circulative manner by Rhopalosiphum padi and Sitobion avenae. r padi, however,transmitted the virus more efficiently then S. avenae. Serological and physicochemical properties of the virus were determined. Cytopathic changes of the infected plants were also examined by an electron microscope.
(2)BWYV--A strain was isolated from the spinach plants showing yellow-dwarf symptoms. This virus was transmitted in a circulative manner by Myzus persicae. Serological and physicochemical properties of the virus were determined. Cytopathic changes of the infected plants were also examined.
(3)SDV--This virus was transmitted by Aulocothum solani. Cytopathic changes of the infected plants with both strains, SDV-Y were compared.
(4)MVDV-- A strain was isolated from the broad bean plants showing yellow-dwarf symptoms. This virus was transmitted in a circulative manner by Aphis cracivora. Small spherical particles (c. 18 nm in diameter) were found in the purified preparations. Same particles were restricted to the phloem cells. No dsRNA (RF) was detected on PAGE. MVDV might be a novel virus group.