格木寄生线虫中国新记录种——卡勒萨隐皮孢囊线虫Cryphodera kalesari

First record of Cryphodera kalesari parasitizing Erythrophleum fordii in China

在对广东省主要珍贵树种上的线虫进行调查时从格木Erythrophleum fordii上分离到一种隐皮孢囊线虫,经形态特征观察和测量数据分析,将其鉴定为卡勒萨隐皮孢囊线虫Cryphodera kalesari。其诊断特征为:雌虫椭圆形至近球形,头部具有1个唇盘和2~3个唇环,口针长33.6~37.8μm,阴门唇突出,阴门与肛门之间区域凹陷,肛阴距为42~72μm;2龄幼虫头部具1个明显的唇盘和3个唇后环纹,口针长24.8~29.5μm,口针基部球前缘凹陷,侧区3条侧线,尾长圆锥形,长38~53.5μm,尾末端细圆,透明尾长17.1~25.1μm,侧尾腺孔位于肛门后2~5环;雄虫未发现。本研究首次获得了卡勒萨隐皮孢囊线虫的rDNA(LSU D2D3和ITS)序列,为此线虫的鉴定提供了可靠的分子数据。本研究还分析了卡勒萨隐皮孢囊线虫与本属其他种类的系统进化关系。卡勒萨隐皮孢囊线虫为中国的地理新记录种。格木为隐皮孢囊线虫的新寄主。

A species of cystoid nematode parasitizing Erythrophleum fordii was isolated during the survey of plant nematodes associated with precious trees in Guangdong province.Detailed morphological study confirmed the cystoid nematode as Cryphodera kalesari.The nematode was characterized by oval to near round females with 2-3 lip annuli and one distinct labial disc,a stylet of 33.6-37.8μm in length,a protruding vulval lip,concave vulva-anus profile,a vulva-anus distance of 42-72μm.Second-stage juveniles possessed 3 lip annuli and one labial disc,a stylet of 24.8-29.5μm in length with concave knobs and 3 lines at the lateral field,an elongate-conoid tail,38-53.5μm long,with a narrow rounded tip,hyaline tail region of 17.1-25.1μm long,phasmids with a lens-like structure located 2-5 annuli posterior to the anus.Male was absent.LSU rDNA D2D3 segment and rDNA-ITS fragment were amplified and sequenced,which provided molecular information for rapid and accurate detection of the cystoid nematode in the future.Moreover,the phylogenetic relationship of C.kalesari and other Cryphodera species was analyzed.C.kalesari was reported for the first time from China.Erythrophleum fordii is a new reported host plant of C.kalesari.