转Lchi1烟草T_2代对梨腐烂病菌的抗性研究

获得转化梨几丁质酶基因Lchi1的烟草,检测组成型表达Lchi1基因烟草是否能提高对梨腐烂病菌(Valsa ceratosperma)的抗性,从而初步确定Lchi1基因的功能,为进一步开展梨抗腐烂病分子育种工作提供参考。构建梨几丁质酶基因Lchi1的植物表达载体,通过农杆菌介导的叶盘法转化烟草,进而对转化的烟草T2代进行PCR及RT-PCR检测。利用离体叶片接种法,更直观地验证转基因烟草对梨腐烂病菌的抗性。Lchi1基因已经整合到烟草基因组中,并在烟草T2代中有效表达,在接种腐烂病菌后转基因烟草较未转基因烟草的抗腐烂病菌能力明显增强。梨几丁质酶基因Lchi1与腐烂病抗性相关联,可作为今后梨的抗腐烂病分子育种研究重要的基因来源。

Resistance Research of Transgenic Tobacco T2 Generation with Lchi1 Against Valsa ceratosperma

The study aims to obtain the transgenic tobacco containing Lchi1 which is the chitinase gene, and detect whether the transgenic tobacco with constitutive Lchi1 gene expression can improve resistance to Valsa ceratosperma, thus to preliminarily determine the function of Lchi1 gene and provide a reference for the further research on molecular breeding about pear Valsa canker. Plant expression vector with gene Lchi1 was constructed and transformed into tobacco by leaf disc mediated with Agrobacterium tumefaciens, and transgenic tobacco T₂ generation was detected by PCR and RT-PCR. The resistance of transgenic tobacco against Valsa ceratosperma was verified more intuitively by isolated leaf inoculation method. Lchi1 was integrated into tobacco genome, and it was expressed effectively in the transgenic tobacco T₂ generation. After inoculating Valsa ceratosperma, the resistance of transformant against Valsa ceratosperma was obviously more enhanced compared with non transgenic tobacco. In conclusion, Lchi1, which is the pear chitinase gene, is associated with the resistance of pear Valsa canker, and it will be used as an important genetic source in the research of molecular resistance breeding.