Isolation and identification of viruses causing sugar beet Mosaic symptoms in Karaj

Document Type : Scientific-Extension

Authors

1 Plant Pests and Diseases Research Div., Iran

2 University of Tehran, Coll. of Agr. Iran

3 Sugar beet seed institute, Iran

Abstract

Two different viruses were isolated from sugar beet growing areas in Karaj, which caused mosaic symptoms. Collected samples were classified in two different groups. The host range of the first group was confined to some species in Chenopodiaceae and Amaranthaceae families. The sap of infected plants reacted positively with Beet Mosaic Virus antisera in ouchterlony double-diffusion test. Electron microscopy of infected plant’s sap revealed filamentous particles measured roughly 720-740 nm long.
Thermal inactivation point was 55oc for 10 min., dilution end point 10-3 and longevity in vitro was two days. This virus was transmitted by green peach aphid (Myzus persicae) in non-persistent manner with 53.3 efficiency.
Isolats in the second group caused necrotic local lesion in Vigna unguiculata, vicia faba and Chenopodium amaranticolor and became systemic in cucurbitaceaous and solonaceaous hosts. The infected sap of this virus reacted positively with Cucumber Mosaic Virus (type-Strein) antiserum. Upon electron microscopy, the isometric particles of the virus were measured 30nm. in diameter. Thermal inactivation point of this virus was 60 oc for 10min, dilution end point 10-4 and longevity in vitro was one day under greenhouse conditions. This virus was transmitted by the green peach aphid in non-persistent manner with 11.7 percent efficiency.

Keywords