Detection and description of Ditylenchus israelensis n. sp. (Nematoda: Anguinidae) from bulbs of the Persian buttercup (Ranunculus asiaticus L.)

摘要

The present study describes a new Ditylenchus species, isolated from the bulbs of the Persian buttercup (Ranunculus asiaticus L.) imported from Israel at the Ningbo plant quarantine lab, Ningbo, P.R. China. Ditylenchus israelensis n. sp. is an amphimictic species; females have six incisures in the lateral field, a long and slim body, a delicate, short stylet (7-8 & mu;m) with small and rounded knobs, excretory pore in the anterior region of the basal pharyngeal bulb, posteriorly located vulva (V = 78.6-83.1), a short PUS (15.0-24.0 & mu;m), and a long conical tail with a pointed terminus. Males are similar to females in general morphology and have 14.0-18.0 & mu;m long spicules. The new species was also characterised molecularly using 18S, ITS and D2-D3 expansion segments of 28S rDNA genes. Our phylogenetic analyses showed its independent position among available Ditylenchus species and a close phylogenetic affinity with D. valveus. Several Ditylenchus species are regulated pests; their detection in a given sample can implement quarantine measures. However, to our knowledge D. israelensis n. sp. did not cause any damage to the R. asiaticus bulbs. In addition, future studies regarding fecundity and host association may shed some light on the pathogenic potential of D. israelensis n. sp.