沙棘共生固氮根瘤及其内生弗兰克氏菌

NITROGEN FIXING ROOT NODULES AND ITS FRANKIA ENDOPHYTE OF HIPPOPHAE RHAMNOIDES L.

用透射电镜研究了中国沙棘（ＨｉｐｐｏｐｈａｅｒｈａｍｎｏｉｄｅｓＬ．）根瘤的超微结构。它的侵染细胞位于皮层中部，非侵染细胞与之相间排列，富含多酚和淀粉粒。在根瘤的发育过程中，具有以下特征：（１）早期侵染细胞中具有核仁联合体；（２）由内生菌丝趋核生长而形成的核膜内陷处，有许多核孔出现；（３）在中期侵染细胞的内生菌丝和泡囊的荚膜附近，有成束的微管存在；（４）在４、５月瘤样的维管束细胞、非侵染细胞及早期侵染细胞中，有大量脂体存在。

The ultrastructure of actinorhizal root nodules of Hippophae rhamnoides L.had been studied by optical and transmission electron microscopy.The infected cells are restricted to the middle region of the nodule cortex,and its neighbour always have at least one uninfected cell.The latter usually has a lot of phenolic and starch granules.During development,besides general structural changes,the root nodules show some distinct features:(1) Nucleolus associated bodies are present in young infected cells;(2) More nuclear pores appear on the sunken nuclear membrane made by endogrowth of hyphae;(3) Bundles of microtube are found near the capsule of endophyte hyphae and vesicles in the mature infected cells;(4) Numerous lipid bodies distribute in the vascular cells,uninfected cells and young infected cells of nodules collected in April and May.We havent found any others have reported this structure.They have been described in detail in this arcticle,and the significance and the relationship to the development of root nodule is discussed as well.