Association of an ectoparasitic nematode - Helicotylenchus microcephalus, with poor growth of Cymbidium hybrids in Sikkim.

摘要

During a survey of growers nurseries at Rai Gaon, Pakyong, East Sikkim, India, in 2007-08, several hybrids of Cymbidium were pale and stunted, and their roots showed distortions, irregular swellings, fluffiness and severe necrosis. The affected plants exhibited twisting and bending of leaves. The same symptoms also occurred in other orchid nurseries at Rumtek, Dickling and Assam Lingzey in east Sikkim, an at Ravangla, Namchi and Berring in South Sikkim. The incidence of the disease at the different locations ranged from 1.14 to 2.75%. H. microcephalus was isolated from the roots of the affected plants. The association of H. microcephalus with Cymbidium hybrids is possibly the first report from India.