甘肃天祝农牧区燕麦田孢囊线虫调查及种类鉴定

Investigation and Identification of Cyst Nematode in Agricultural and Pastoral Oats Fields in Tianzhu of Gansu Province

为了明确甘肃天祝农牧区燕麦田孢囊线虫的发生情况及种类,2014年8-9月,采用Z字型取样法,对天祝燕麦主要种植区进行了调查。结果表明,采集到的80份燕麦根际土样中孢囊线虫发生率为44%,孢囊密度为4.3个·100g-1土样。安远镇的发生率最高,为54.2%,华藏寺的发生率最低,为14.3%。孢囊浅褐色,阔柠檬形,长571μm（447~727μm）,宽449μm（375~595μm）。阴门双膜孔,膜孔长31μm（28~33μm）,膜孔宽16μm（13~20μm）,阴门裂长9μm（8~11μm）,泡状突明显,未见阴门下桥。天祝5个乡镇孢囊线虫rDNA-ITS区片段长度均为1 045bp,经Blast比对发现,所测序列与燕麦孢囊线虫（Heterodera avenae）的ITS序列相似度达99%-100%。系统进化关系分析显示,天祝孢囊线虫与国内及国外燕麦孢囊线虫在同一个大的进化分支,与中国的燕麦孢囊线虫在同一个小的分支。因此,形态特征结合rDNA-ITS序列分析将甘肃天祝燕麦田的孢囊线虫鉴定为燕麦孢囊线虫。

In order to define the occurrence and distribution of oat cyst nematode in agricultural and pastoral areas of Tianzhu of Gansu,investigations were carried out from August to September in 2014, based on methods of Z type. The results showed that the incidence of cyst nematode was 44% in the 80 soil samples with 4.3 cysts per 100 g soil sample. The highest incidence of cyst nematodes was 54.2% ,appearing in Anyuan town. The lowest incidence of cyst was 14.3% ,appearing in Huazansi town. The cysts were light brown and large lemon-shaped,with the average length of 571 μm（447-- 727 μm） and average width of 449μm（375--595 μm. The vulva cones were double Fenestra area, with the length of 31 μm（28--33 μm） and the width of 16 μm（13--20 μm）,and the length of vulval slit was 9 μm（8--11μm）. There was obvious bullaeno without under-bridge in vulva. The fragments of rDNA-ITS from five counties in Tianzhu were all 1 045 bp length. The similarities between these groups and Heterodera avenae were 99%--100% by alignment blasting on Gene Bank. The phyloge- netic tree revealed that the Tianzhu populations were grouped with domestic and abroad populations ofH. avenae into a branch and Tianzhu populations were grouped with China populations of H. avenae. Thus, the nematodes collected from oats in Tianzhu were identified as H. avenae.