重庆番茄根结线虫病的病原种类鉴定

Identification of Pathogen Species of Root Knot Nematode on Tomato in Chongqing

为了明确危害重庆市番茄的根结线虫种类,于2020年,在重庆市潼南区、璧山区、九龙坡区、巴南区、合川区、江津区等主要蔬菜基地利用5点取样法采集番茄根结线虫病根样品,分离根结线虫,利用形态学和分子生物学鉴定方法对其进行种类鉴定。结果表明,根结线虫雌成虫为白色柠檬形,雌虫会阴花纹接近圆形,线纹呈波浪形,没有明显的侧线,背弓高,呈梯形,顶部平滑,这些特征与报道的南方根结线虫形态特征相似;研究发现,根结线虫DNA只有用南方根结线虫特异性引物能扩增出目的片段,对该扩增出的目的片段的测序结果进行blastn比对,发现该片段与南方根结线虫的一段cDNA序列(Sequence ID:JK286281.1)一致性为93.75%。结合形态学和分子生物学鉴定结果,本研究中危害重庆番茄的根结线虫种类为南方根结线虫。该研究结果对重庆番茄根结线虫病害防治以及抗根结线虫病育种具有重要意义。

In order to identify the species of root knot nematodes endangering tomato in Chongqing,root samples of tomato root knot nematodes were collected by 5-point sampling method from major vegetable bases in Tongnan District,Bishan District,Jiulongpo District,Banan District,Hechuan District and Jiangjin District in Chongqing in 2020.Root knot nematodes were isolated and identified by morphological and molecular biological identification methods.The results showed that the female adults of root knot nematode were white lemon shaped,the perineal pattern of female adult was nearly circular,the line grain were wavy,there was no obvious side line,the back arch was high,trapezoidal,and the top was smooth,these characteristics were similar to the morphological characteristics of Meloidogyne incognita reported;this study found only the specific primers of Meloidogyne incognita could amplify the target fragment.The sequencing results of the amplified target fragment were compared by blastn.The result showed that the consistency between the fragment and a cDNA sequence(Sequence ID:JK286281.1)of Meloidogyne incognita was 93.75%.Combining with the identification results of morphology and molecular biology,the species of root knot nematode endangering tomato in Chongqing was Meloidogyne incognita.The results of this study indicated great effect on contolling of root knot nematode disease and breeding for resistance to the disease on tomato in Chongqing.