A new pratylenchid nematode, Hoplotylus japonicus n. sp. (Tylenchina: Pratylenchidae) from the rhizosphere of Japanese maple, Acer palmatum (Thumb.)

Abstract

Summary During quarantine inspections, a new species of Hoplotylus was detected from the rhizosphere of the Japanese maple, Acer palmatum, imported into China from Japan. Hoplotylus japonicus n. sp. is characterised by a stout 431-602 μm long body, well-developed 20.0-24.5 μm long stylet with tulip-shaped knobs having rounded sides in lateral view and a rounded anterior margin, excretory pore located slightly posterior to the hemizonid, usually empty, spermatheca, conical tail with a spike-like projection, which is distally smooth on the dorsal side, and males not found. It was morphologically compared with four currently known species of the genus, viz., H. femina, H. montanus, H. silvaticus, and H. sjacobi. In molecular phylogenetic analyses using 18S, 28S and internal transcribed spacer (ITS) ribosomal DNA sequences, the new species formed a clade with the only currently sequenced species of the genus, H. femina, in all phylogenies. This is the second species of the genus characterised by molecular data and the second species recovered from Japan.