明尼苏达大尾线虫中国新记录种报道

The First Report on Trophurus minnesotensisin China

在2011年采自贵州省湄潭县烟草Nicotiana tabacum Linn.根围土样中,分离到大尾线虫属群体,通过系统的形态学观测,鉴定为明尼苏达大尾线虫Trophurus minnesotensis(Caveness,1958)Caveness,1959,为中国新记录种。其主要的鉴别特征是虫体中等长度,角质层环纹不显著,侧线4条。唇区圆锥形,连续光滑,头骨架中度骨化。口针细弱,长15.0～16.8μm,口针基部球向后倾斜。中食道球梭形,中食道球到头端的距离占整个食道长的53%,食道腺梨形,不覆盖肠。排泄孔紧靠神经环后面。阴门横裂,位于虫体57.8%～60.9%处,阴道长,占阴门处体宽的3/5,单卵巢,后阴子宫囊短。尾长为29.6(25.5～37.2)μm,c'=1.6～2.0,圆柱形,尾端具膨大的透明区,光滑。雄虫尾交合伞末端膨大,包至尾端,与尾端基本垂直。交合刺弓形,引带短,简单。新记录种的近缘种是瓦勒特大尾线虫T.vultus和雕刻大尾线虫T.sculptus。新记录种与前者的主要区别是:新记录种尾端光滑,圆柱形;瓦勒特大尾线虫尾端有环纹,棒状。新记录种与后者的主要区别是:新记录种尾圆柱形,后阴子宫囊短;雕刻大尾线虫尾棒状,后阴子宫囊长。

A soil nematode population was collected and separated from the rhizosphere soil of tobacco（Nicotiana tabacum Linn.）collected in Meitan county,Guizhou province in 2011.Based on the morphological characteristics,Trophurus minnesotensis（Caveness,1958） Caveness,1959-a new record species for China was identified.The new record species is characterized by body middle with the body length,cuticle annulation inconspicuous.Lateral fields marked by 4 lines.Lip region conoid,continuous,smooth and cephalic framework moderately sclerotized.Spear very slender,15.0~16.8μm long.Stylet knobs back-sloped.Metacarpus fusiformis,and distance between metacorpus and head located at esophagus 53% and oesophageal glands pyriform,not overlap intestine.Excretory pore just located behind nerve ring.Vulva transverse,located at anterior body with the V value of 57.8%~60.9%.Vagina extends over about three-fifths of body diameter,one ovary and post-uterine sac short.Tail 29.6（25.5~37.2）μm long with c′ value of 1.6~2.0,cylindroid,with inflated transparent region,smooth.Male tail with broad bursa,surround terminus,and verticality.Spicule arcuate,and gubernaculums short,simple.The new record species is similar to T.vultus and T.sculptus.The new record species differs from T.vultus in the tail smooth and cylindroid（vs.annulate and clavate in T.vultus）.The new record species differs from T.sculptus in the tail cylindroid（vs.clavate in T.sculptus）;length of posterior uterine branch short（vs.long in T.sculptus）