Mechanism of transmission of tobacco streak virus by Scirtothrips dorsalis, Frankliniella schultzei and Megalurothrips usitatus in groundnut, Arachis hypogaea L.

摘要

Peanut stem necrosis disease (PSND) was first reported in groundnut in the 2000 rainy season in Anantapur district of Andhra Pradesh. The disease affected nearly 225,000 ha and the crop losses were estimated to exceed Rs. 3 billion (Reddy et al., 2002). Tobacco streak virus (TSV) was identified as the causal agent of PSND, The pollen-assisted TSV transmission process has been studied in detail in other host plants, Nicotiana Clevelandii, Chenopodium amaranticolor, Lycopersicon esculentum and Cucumissativus by Sdoodee and Teakle, 1987 and Greber et al., 1991. The TSV transmission occurs when thrips carrying pollen from TSV infected plants on their bodies, land on host-plants and cause them to dislodge on leaves and while feeding on host plants woundboth leaf tissue and infected pollen to facilitate virus infection of the plants. After identification of the causal agent of PSND in India, TSV transmission studies were initiated, Adults of all the three thrips species [(Frankliniella schultzei (Trybom), Scirtothrips dorsalis Hood and Megalurothrips usitatus (Bagnall)] were experimentally proved to transmit TSV in groundnut, sunflower and cowpea in the presence of pollen from TSV infected parthenium, sunflower or marigold plants (Prasada Rao et al.,2003). Further studies were needed to study the.-role of nymphs of thrips in virus transmission and possibility of disease spread from the infected plants in the field. This paper summarises the results obtained from experiments designed to further study virus-vector-pollen-host relationships in groundnut.