Mechanical Transmission, Purification, and Some Properties of Whitefly-Borne Mung Bean Yellow Mosaic Virus in Thailand. Y. Honda, Institute for Plant Virus Research, Tsukuba Science City, Yatabe, Ibaraki 305, Japan. M. Iwaki, and Y. Saito, Institute for Plant Virus Research, Tsukuba Science City, Yatabe, Ibaraki 305, Japan, and P. Thongmeearkom, K. Kittisak, and N. Deema, Division of Plant Pathology and Microbiology, Department of Agriculture, Bangkhen, Bangkok 9, Thailand. Plant Dis. 67:801-804. Accepted for publication 27 December 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-801.

The whitefly-borne mung bean yellow mosaic virus (MYMV) in Thailand was transmitted by mechanical inoculation. Among the several buffers used in attempted transmissions, 0.1 M potassium or sodium phosphate, pH 7.8, gave the highest transmission rates. The optimal incubation temperatures for symptom expression ranged from 25 to 30 C in the growth chamber or 30 C in the daytime and 20 C at night in the greenhouse. Host range of MYMV was limited to seven plant species in the family Leguminosae. Determinations of the stability of the virus in plant sap gave the following results: thermal inactivation point of 40–50 C for 10 min, dilution end point of 10^-2–10^-3, and longevity in vitro of 1–2 days at 20 C. Purified virus preparations had an ultraviolet light absorption spectrum typical of that of nucleoprotein with a A₂₆₀/A₂₈₀ value of about 1.3–1.4. Purified preparations and leaf-dip samples contained geminate particles of about 18 × 30 nm. Infectivity was associated with the presence of purified virus particles.

Keyword(s): geminivirus.