萝卜根部有害细菌的作用初探

 本文对萝卜(Raphanus Sativus L.,品种:国光)根部有害细菌的存在、作用及可能的机制进行初步探讨得知:1.在健康萝卜根部,确实分离到了对植物生长有害的细菌;2.有害细菌的作用可不同程度地为根围另一类有益细菌或增产菌(Plant growth-promoting rhizobacteria,简称PGPR)所消除;3.害菌可产生毒素,直接致害寄主植物;4.普通电镜扫描和免疫荧光电镜扫描均在萝卜根表发现有所接种的害菌分离物附着;透射电镜观察没有在萝卜幼根内部发现有细菌分离物存在。

A PRIMARYSTUDY ON THE ACTIONS OF DELETERIOUS RHIZOBACTERIA IN RHIZOSPHERE OF RADISH

This is a primary study on existence and actions of deleterious rhizobacteria (DRB) in rhizosphere of radish (Raphanus sativns L.).The results are as follows:
1.DRB can be isolated from healthy roots of radish and sugar beets seedlings.They can produce green fluorescence when cultured in King's B medium.In greenhouse assay they could reduce fresh weight of radish seedlings and roots statistically and sometimes cause distortion of cotyleden of radish.
2.Actions of DRB could be inhibited by another kind of shizobae-teria called plant growth-promoting rhizobacteria (PGPR) in some cases,but are not always effective.
3.The isolates of DRB could produce soluble toxins to damage "host" plants directly.The physical and chemical property of the toxins and their acting mechanisms have not been known by now.
4.By scanning electron microscopy(SEM) we found that many bacteria cells inoculated attached to the root surface of plants.Using fluoreseent scanning electron microscopy we also found isolated cells markedby immunofluorescent antibody.Using transmission electron microscopywe did not find any bacteria cells in roots of radish.