Some hosts and properties of narcissus latent virus, a carlavirus commonly infecting narcissus and bulbous iris

Narcissus latent virus (NLV) is common in many cultivars of narcissus and bulbous iris, but was detected in only one of nineteen cultivars of nerine. It induced symptoms in some narcissus cultivars, but inconspicuous infection in bulbous iris and nerine. NLV was not seed-borne in narcissus or Nicotiana clevelandii but was transmitted readily by aphids (Acyrthosiphon pisum, Aphis gossypii and Myzus persicae) in the non-persistent manner and by sap-inoculation to twelve of fifty-three species from three of sixteen families. Sap from N. clevelandii was infective after dilution to io^-3 but not io*, after 10 min at 65 but not 70 ^oC or after 3–4 days at 20 ^oC or 16–32 days at 2 ^oC. Purified virus preparations were obtained from infected N. clevelandii by clarification of buffered leaf extracts with diethyl ether and carbon tetrachloride, followed by one or two cycles of differential centrifugation and molecular permeation chromatography. NLV has filamentous particles c. i3times65onm which sediment as a single component (i^o_{20, w}= 156S). They contain c. 5% nucleic acid and a single polypeptide of mol. wt 32·6 × 10³. The biological and physical properties of NLV place it in the carlavirus group; it is serologically related to lily symptomless virus, but not to fourteen other authentic carlaviruses. NLV has the cryptogram */*:*/(5):E/E:S/Ve/Ap.