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分子标记技术的发展为目标基因定位提供了新手段。本文在McMullen和Simcox(1 995 )的研究基础上综述了近几年来玉米抗病虫基因的分子标记定位最新研究结果 ,发现这些抗性基因或数量性状位点 (QTL)均不同程度地连锁在一起 ,聚集成几群 ,位于染色体的特定区域。由于在同一聚群内经常发现不同抗性基因对不同病原菌 (虫 )的抗性反应 ,因此这些抗性基因间的功能关系目前还不清楚。研究抗病虫基因或OTL的染色体位置 ,发现许多抗性位点的产生与染色体片段重复有关。为应付快速演化的病原菌 (虫 )侵染 ,存在对新小种具有专化抗性的基因群是必要的。染色体上的特定区域在某一时期可能快速进化 ,以获得足够力量来抵抗共演化的病原菌 (虫 )的侵染。玉米抗病虫基因在染色体上聚群存在 ,可以用来提高克隆抗性基因的效率
The development of molecular marker technology provides a new means for target gene localization. Based on the researches of McMullen and Simcox (1995), the latest research results on the molecular marker localization of maize resistance to pests and diseases were reviewed in this paper. It was found that these resistance genes or QTLs were linked to different degrees Together, gathered into groups, located in a particular area of the chromosome. The functional relationships between these resistance genes are not clear at present because the resistance of different resistance genes to different pathogens (worms) is often found within the same cluster. To study the chromosomal location of the pest-resistant genes or OTLs, it was found that the generation of many resistance sites is related to chromosome segment duplication. To cope with the rapidly evolving pathogen (insect) infection, it is necessary to have a gene cluster that is resistant to new race. Specific regions of the chromosome may evolve rapidly during a certain period of time to obtain sufficient power to resist the co-evolutionary infection of pathogenic bacteria (worms). Maize pest-resistant genes clustered in chromosomes and could be used to increase the efficiency of cloned resistance genes