佛手山药线虫病害发生调查与病原鉴定

Investigation of bergamot yam nematode disease in Wuxue city and identification of pathogens

湖北省武穴市佛手山药是“农产品地理标志产品”,近年佛手山药线虫病害严重,为此在病源地采集山药土样进行了病害发生调查及病原鉴定。通过形态特征观察、形态特征测计值比较,以及基于rDNA 28S D2/D3区序列构建短体线虫属线虫群体系统进化树并进行SCAR验证,对引起佛手山药线虫病的病原线虫进行种类鉴定。结果表明:危害佛手山药的病原线虫的群体特征与咖啡短体线虫Pratylenchus coffeae相似。系统进化树显示:该病原群体与中国香港群体(HQ688677.1)聚类在一个分支上,置信度达99%。因此,将该群体线虫鉴定为咖啡短体线虫Pratylenchus coffeae。此外田间调查表明:线虫主要集中分布于10~20 cm深度的土层中,线虫密度随土壤深度的增加而呈递减趋势,且连作1年地较连作2年地的线虫数量少,施用阿维菌素的地块较未施用的线虫数量少。上述结果表明,在佛手山药生产中实行轮作和科学选择药剂防治,避免连作,可降低该线虫发生量。

Chinese yam is an agricultural product with geographical indication in Wuxue city,Hubei province.The nematode disease on Chinese yam is serious.In this study,soil samples of Chinese yam were collected to investigate the disease occurrence and identify the pathogen.The phylogenetic tree was constructed based on rDNA 28 S D2/D3 sequence and SCAR verification was carried out to identify the species of the pathogen.The results showed that the population characteristics of the nematodes were similar to those of Pratylenchus coffeae.Phylogenetic tree revealed that the pathogen population and Hongkong population(HQ688677.1) clustered on the same branch,with a confidence of 99%.Therefore,this population of nematodes was identified as P.coffeae.Nematodes mainly distributed in the soil layer of 10 to 20 cm depth,and the nematodes density decreased with the increase of soil depth,the number of nematodes in continuous cropping for one year was less than that in continuous cropping for two years,and the number of nematodes in the plots with abamectin was less than that in the plots without application.These results indicated that the amount of nematode could be reduced by crop rotation and scientific application of pesticides.