Direct introduction of foreign gene in higher plants

为了将常规外源基因引入高等植物，笔者尝试了以含有抗油菜素和野棕榈合成酶基因的转基因烟草植株为砧木嫁接的方法。将非转基因正常烟草植株嫁接到转基因烟草植株上。在卡那霉素（100ug/ml）培养基上，从接穗蒴果的自交种子中筛选出6km抗性植株33000株（0.08%）。从试交实验的结果来看，4个嫁接转化子在两条同源染色体中的一条染色体上各有1个km基因，1个有km基因处于纯合状态，另一个在其染色体上有2个以上km基因（可能有5个）处于独立状态。对移植物和子代进行Southern blot分析，发现存在maker km和Nos基因，条带模式复杂。结果表明，嫁接转化作为高等植物基因导入的常规方法是有希望的。然而，进一步明确机制，提高效率是必要的。

In order to introduce conventionally foreign gene to higher plants, I tried graft method using transgenic tobacco plants which contained kanasycin resistant and nopaline-synthase genes as stock. Non-transgenic normal tobacco plants were grafted on the transgenic tobacco ones. 6 km resistant plants in more than 33000 (0.08%) from the selfed seeds of scion capsules were selected on kanamycin medium (100ug/ml). Four graft transformants had one km gene in the respective one of two homologous chromesomes, one had km genes in homozygous state and the other one had more than 2 km genes (probably 5) in independent state on its chromosomes from the results of test cross experiment. Southern blot analysis of the graft transformants and the progenies show the existence of the maker km and Nos genes and complicated band patterns.It is concluded that the graft transformation is hopeful as a conventional method of gene introduction in higher plant. However, it is further necessary to make clear the mechanism and increase the efficiency.