柑橘黄龙病菌侵染九里香不同方法研究

Comparison of different methods to transmit Candidatus liberibacter asiaticus to Murraya paniculata

采用不同的方法将柑橘黄龙病菌(Candidatus Liberibacter asiaticus)传染到九里香(Murraya paniculata),运用Nested-PCR技术确认九里香是否感染黄龙病菌。结果表明,采用汁液摩擦、注射和挤压法,接种2个月后不能在九里香植株体内检测到黄龙病菌;黄龙病阳性接穗红江橙(Citrus sinensis Osbeck)嫁接九里香能使黄龙病菌成功侵染九里香,但接穗不能抽芽。草地菟丝子(Cuscuta campestris)和虫媒柑橘木虱(Diaphorina citri)都能成功从阳性植株体内将黄龙病菌传播至九里香。柑橘木虱传"菌"效率结果表明,木虱在红江橙阳性植株上取食1.5～2 h就能携带黄龙病菌,病菌从柑橘木虱传到健康的九里香上最短需要12 h,单头木虱带菌就能使九里香成功感染黄龙病菌。温度对病原的传播效率有较大影响,气温高于35℃或低于15℃时,介体昆虫活力差,传播病原的效率较低,0℃温度下木虱几乎不传播病原。40℃时昆虫死亡率高,活力差。

Different transmission methods were taken to infect Murraya paniculata with Candidatus liberibacter asiaticus,and Nested-PCR was used to confirm the presence of Candidatus liberibacter asiaticus two months after inoculation.The results indicated that mechanical inoculation,injection and squeezing methods failed to transmit Candidatus liberibacter asiaticus to M.paniculata,whereas grafting scion from infected Hongjiang Sweet Orange（Citrus sinensis Osbeck） was successful in spite of no scion elongation,and both dodder（C.campestris） and psyllid（Diaphorina citri） were able to successfully transmit HLB bacterium from citrus Hongjiang Sweet Orange.It took 1.5 h to 2 h and 12 h for D.citri to get HLB bacterium from Hongjiang Sweet Orange and transmit to M.paniculata,respectively.Efficient temperature for HLB transmission by psyllid was between 15 ℃ and 35 ℃,and there were no transmission of HLB bacterium below 0 ℃ or above 40 ℃.The study laid a foundation for the large scale screening of resistant-related gene to Candidatus liberibacter asiaticus from M.paniculata.