南方根结线虫毒性变异相关基因高通量沉默及功能验证

南方根结线虫（Meloidogyne incognita）是一种非常重要的植物内寄生线虫，每年给世界农业生产造成巨大的经济损失。南方根结线虫无毒群体突破Mi基因抗性转变为毒性群体，从而导致品种抗性丧失，目前这一毒性变异机制尚不明确。本项目以南方根结线虫近等基因系（Near-Isogenic Lines，NIL）为研究对象，利用代表性差异显示技术（RDA）分离根结线虫无毒群体和毒性群体侵染Mi抗性番茄后的差异表达基因；采用烟草脆裂病毒（Tobacco rattle virus，TRV）介导的基因沉默体系对差异表达基因进行高通量沉默，通过比较表型变化分离影响线虫毒性变异的关键基因；并进一步研究关键基因与番茄Mi抗性基因的互作模式，从而揭示在Mi抗性基因选择压力下南方根结线虫的毒性变异规律，研究结果对于合理利用抗性资源、有效防治根结线虫为害具有重要指导意义。

Root-knot nematode Meloidogyne incognita is an important plant endo-parasitic nematode and annually causes serious damage to agricultural industry in the world. Avirulent population of M. incognita broke Mi-gene resistance and became virulent which resulted in the resistance loss of crop varieties. The mechanism of virulence variation is still unknown. The study will focus on the Near-Isogenic Lines of M. incognita. The cDNA libraries for differential expressed genes will be constructed with materials of virulent and avirulent M. incognita infected Mi-gene tomatoes by Representational Difference Analysis (RDA). The high-through silencing of differential expressed genes will be carried out by RNAi system mediated by Tobacco Rattle Virus (TRV). The vital genes affecting the virulence variation will be selected by phenotype comparison. The functional model of vital genes involved in the interaction with Mi-gene of tomato will be studied in order to elucidate the rules of virulence variation for M. incognita under the selection pressure of Mi-gene. The results of the study will benefit the reasonable utilization of resistance varieties and provide the effective control strategy for root-knot nematode disease.