牛筋草(Eleusine indica)对百草枯抗性水平差异分子遗传机理研究

By use of resistant and susceptible populations of goosegrass (Eleusine indica) and SSH（suppression subtractive hybridization） method, the differential mRNA transcripts between resistant and susceptible genotypes will be analysed, cDNA subtractive library of goosgrass will be constructed, and the paraquat resistant genes in this species will be cloned and their functions will be identified. The resistant level of F 1 hybrid between resistant and susceptible genotypes, as well as segregation ratio of F2 generation after paraquat treatment will be evaluated, and therefore the genetic mode of anti-paraquat genes will be determined. The differences of paraquat absorption and transport between resistant and susceptible genotypes will be examined by using isotope labeled paraquat. The anti-paraquat levels in goosegrass populations in the different regions of China will be evaluated by dose-response experiments, and the anti-paraquat status and development will be defined. This study will elucidate the molecular mechanism and genetic laws of anti-paraquat in Goosegrass. The study can provide theoretical foundation for the study of resistant weeds, and also can enrich the genetic background of weeds herbicide-resistance. It is important for clarifying the paraquat resistant level of weeds in Chinese farmlands and developing comprehensive weed management strategy.

本项目以我国抗性和敏感型牛筋草(Eleusine indica)种群为材料，通过SSH（suppression subtractive hybridization）方法，分析比较牛筋草抗性植株和敏感植株mRNA的表达差异，构建牛筋草抗百草枯的正向抑制性差减cDNA文库，筛选得到抗药性基因；通过遗传学方法，研究牛筋草抗性植株和敏感植株杂交F1代的抗性水平和百草枯处理后F2代的性状分离比例，确定抗性牛筋草种群中抗百草枯基因的遗传方式；利用同位素标记示踪百草枯在牛筋草植株体内的运转，比较抗性和敏感型牛筋草对百草枯吸收和运输的差异；结合上述研究试验结果，深入分析两种牛筋草生物型对百草枯抗性水平差异分子遗传机理。该研究结果将揭示杂草抗除草剂的分子机理与抗药性遗传规律，为杂草抗药性研究提供理论基础，而且对制定抗药性杂草综合治理策略有重要参考价值。