关键词: 田菁, 解剖结构, 根瘤, 茎瘤

Abstract: The anatomical structures of Sesbania cannabina vegetative organs were studied by paraffin and tissue segregation. The results showed that there were typical secondary structure characteristics of root of S. cannabina while there were casparian strip in the endoderm, a lot of nodules on the surface of root; rhizobia were distributed in the cortex of root, and its vascular tissue was connected to form a channel network. Cuticle appeared in epidermal cell walls of stem. There was specialized collenchyma in the cortex, which consisted of parenchyma cells. Vascular tissue had crystal phloem fiber. There were 3—4 stem nodules of different size, and distributing discontinuously. The outer layer of stem was cortex while the inner layer was bacteria tissue. The leaves were bifacial. The cuticle and epidermis of leaves were thick, and palisade tissues were well-developed, nearly half of leaf thickness. As for its sponge tissue, the intercellular space was large, and there were many small stomas. Xylems were rather rich in the root and stem of S. cannabina, with a number of large aperture vessels and rich wood fibers. Thickness rate of palisade and spongy and leaf palisade tissue tightness (CTR) were high. The anatomical features of S. cannabina showed its characteristics of nitrogen fixation and ecological adaptation of salt tolerance and drought resisting.

Key words: Sesbania cannabina, anatomical structure, root nodule, stem nodule