马铃薯在生长期间容易受多种病毒的危害，病毒侵染造成马铃薯种质退化，产量降低，品质变劣。PVX、PVY、PLRV、PVS引起的病害是造成我国马铃薯退化的重要原因，严重危害马铃薯生产，尤其是2种甚至多种病毒混合侵染带来的损失远大于各病毒单独侵染。利用病毒来源的基因获得抗性转基因植物是植物抗病毒基因工程的重要途径，传统方法较难获得对相关病毒产生免疫的植株，而RNAi能够有效阻止病毒侵入，是一种更加有效、安全的提高对病毒抗性的途径。本研究拟利用RNA干扰技术，构建四种病毒外壳蛋白基因片段的融合基因，进而构建融合基因反向重复序列的表达载体，通过农杆菌介导法转化马铃薯，以期借助基因工程的方法，增强植株对病毒的抗性，培育同时抗PVX、PVY、PLRV、PVS的马铃薯植株，探索一条获得多免疫的抗病毒转基因马铃薯的有效途径。

Potatoes are easy to be harmed by multiple viruses in the growth period, that caused potato germplasm degradation, production drawdown, and worse quality. The diseases caused by PVX, PVY, PLRV，PVS are important reasones of degradation and reduction of output in potato. Especially, the damages of multiple infections are far greater than that causing by single infection. In antiviral plant gene engineering, it is a important way to get resistance transgenic plants using the genes from viruses, because traditional methods are harder to get to immune plant to related viruses. But, RNA interference (RNAi) technique can effectively prevent invades form virus, and is a more effective and safe way to improve the virus-resistance. In this study, we will construct a fusion gene of the shell protein gene segments form PVX PVY, PLRV, and build its expression vectors of inverted repeat sequence by RNAi technique, and then transform potatoes by agrobacterium-mediated approach in order to improve the resistance to viruses in potato. Our Our goal was to obtain transgenic potato strain with multiple resistant characters to PVX, PVY, PLRV and PVS viruses.