植物离体茎段嫁接

植物体茎段嫁接系统是在无菌条件下将茎切段嫁接后放入培养基中、使接穗和砧木分别与含不同成分的培养基接触，再署光下培养的一个模拟植物正常生理过程、环境条件可控的实验系统，离体茎段嫁接体的发育与整体类拟，包括接穗与砧木粘连、愈伤组织产生、次生甩间连丝形成和维管束分化等几个步骤，发育进程受植物激素如生长素和细胞分裂素调节。该系统的建立为阐明嫁接体发机理及嫁接亲和性机制提供了重要的依据。

The Grafting of ExcisedHypocotyl Segment of Plant in Sterile Culture

The grafting of excised hypocotyl segment of plant in sterile culture is describ ed in which two explanted internodes are grafted together in sterile culture and then inserted between two agar surfaces and incubated under light. It imitates the normal physiological process, and is a controllable experimental system. D evelopment of the graft union is similar to that observed in whole-plant graft u nions, including a sequence of several distinct steps: initial cohesion of stock and scion; proliferation of callus at graft interface; symplastic interconnecti on of individual cells of graft partners by secondarily formed plasmodesmata; an d vascular bridge formation. The process of development is regulated by plant h ormones such as auxin and cytokinin. Clearly this system can be used as a power ful tool in demonstrating the mechanisms of graft formation and graft compatibil ity.