远缘杂交转育抗烟草花叶病N基因同源基因片段的初步研究

Preliminary Study on N Gene Homologous Gene Fragment of Resistance to Tobacco Mosaic Disease in Transbreeding Based on Distant Hybridization

烟草普通花叶病(TMV)是烟区的主要病害之一,生产上所用抗源都来自烟属的心叶烟(Nicotiana glutinosa),其携带N基因对TMV免疫,但因连锁累赘导致烟叶品质差,难以在生产上大面积使用。因此,从烟属植物中挖掘新的TMV抗源尤为必要。本研究以烤烟品种红花大金元与野生种圆锥烟草(N.paniculata,PI 555550)为亲本,开展远缘杂交,获得了种间杂种。杂交种SSR、GISH及抗病性鉴定结果表明,杂交种含双亲特征条带,接种TMV后,叶片有枯斑反应。N基因特异引物在圆锥烟草及杂交种中未能扩增,而根据N基因同源基因Np片段设计的特异引物扩增到500 bp的片段,携带N基因的RBST及心叶烟草(N.glutinosa PI 555507)中未扩增到此特异片段,在杂交种扩增到此特异片段。该研究为获得新的TMV抗源奠定了材料基础。

Tobacco mosaic virus(TMV)is one of the main diseases in tobacco areas.The TMV-resistance sources used in tobacco production are all from Nicotiana glutinosa,which carries N gene and is immune to TMV,but it is difficult to be widely used in tobacco production due to the poor quality of tobacco leaves due to chain accumulation.Therefore,it is necessary to find new sources of TMV resistance in Nicotiana.In this study,a distant cross was carried out between the flue-cured tobacco variety Honghua dajinyuan and a wild conus tobacco(N.paniculata,PI 555550),and an interspecific hybrid was obtained.The SSR,GISH and disease resistance identification showed that the hybrid had the specific bands of both parents,and after TMV inoculation,leaf blight reaction was observed.The specific primers of N gene could not be amplified in conus tobacco and hybrid,and the specific primers designed based on Np fragment of N-homologous gene were amplified to 500 bp fragment,but the specific fragment was not amplified in RBST carrying N gene and heart leaf tobacco(N.glutinosa,PI 555507).The specific fragment was amplified in the hybrid.This study laid a material foundation for obtaining new TMV resistance source.