二斑叶螨对阿维菌素抗性的CAPS标记

为了实现二斑叶螨Tetranychus urticae Koch对阿维菌素抗药性的快速检测,本研究建立了一种叶螨对阿维菌素抗药性的快速分子检测技术,即酶切扩增多态性序列(cleaved amplified polymorphic sequences,CAPS)标记技术,检测二斑叶螨谷氨酸门控氯离子通道(Glu Cl3)基因片段上G326E的突变频率,并采用琼脂浸叶法测定田间5个种群对阿维菌素的抗药性。结果表明,北京密云、顺义、昌平、浙江宁波和海南吉阳5个种群对阿维菌素的抗性倍数分别达1 155.63、1 317.10、844.19、314.95和1 799.69倍,均为极高抗性水平;CAPS检测发现我国二斑叶螨抗性基因存在G326E位点突变,但在供试的5个不同种群中突变频率变异很大,其中北京昌平种群G326E突变频率高达90.00%,密云和顺义种群均为26.67%,浙江宁波种群为5.00%,而海南吉阳种群不存在该位点的突变。表明该CAPS标记还需与其它抗性机制或检测技术结合来实现叶螨对阿维菌素抗性的早期检测和预警。

CAPS marker monitoring abamectin resistance in twospotted spider mite Tetranychus urticae Koch

In order to reveal the abamectin resistance of twospotted spider mite Tetranychus urticae Koch, a molecular technique named cleaved amplified polymorphic sequences (CAPS) was established to detect the point mutation of G326E in glutamate-gated chloride channel 3 (GluCl3) gene from T. urticae. The abamectin resistance of the five T. urticae field populations was evaluated by the leaf-dip method. The results showed that the T. urticae populations from Miyun (MY-BJ), Shunyi (SY-BJ), Changping (CP-BJ) in Beijing, Ningbo in Zhejiang (NB-ZJ), and Jiyang in Hainan (JY-HN) all developed extremely high resistance to abamectin, with the resistance ratios of 1 155.63-fold, 1 317.10-fold, 844.19-fold, 314.95-fold and 1 799.69-fold, respectively. The results of CAPS detection revealed that G326E point mutation existed in T. urticae populations in China, but the mutation frequency differed greatly in the five tested field populations. The mutation frequency reached 90.00% for CP-BJ population and 26.67% for MY-BJ and SY-BJ populations, whereas 5.00% and 0.00% point mutation were observed in NB-ZJ and JY-HN populations, respectively. The results indicated that this CAPS marker in combination with other detection techniques would be helpful to monitor the abamectin resistance of T. urticae.