Centrosema mosaic: A new virus disease of Crotalaria SPP. in Papua and New Guinea

Abstract

A study has been made of an undescribed virus disease which has been called Centrosema mosaic. Observations on its occurrence and symptoms, and data on its host range and modes of transmission are presented. The virus occurs naturally in the field on Crotalaria anagyroides H.U.K., C. goreensis Guill. & Perr., C. retusa L., C. mucronata Desv., Calopogonium mucunoides Desv., Centrosema pubescens Benth., and Desmodium distortum (Aubl.) Macbride. The host range appears to be restricted to the Leguminosae, and mainly to Crotalaria spp. The virus is mechanically transmissible, has a thermal inactivation point between 55 and 58°C, a dilution end-point of 1 in 2000, and a longevity in vitro of less than 6 hr. It is transmitted in a non-persistent manner by the aphids Aphis gossypii Glover, Aphis craccivora (Koch), Myzus persicae (Sulz.), and Brachycaudus helichrysi (Kalt.) var. warei (Theob.) and by two species of plant bugs of the genus Nysius. It is readily transmitted by Cuscuta campestris Yuncker, but not by seed or soil.