Microscopic anatomy and ultrastructure of the resin ducts of Ferula ferulaeoides (Steud.) Korov. in Xinjiang.

Ferula ferulaeoides (Steud.) Korov. is a perennial herb that belongs to Umbelliferae (Apiaceae). Its resin and roots have extensive commercial and medicinal value in the Xinjiang region. However, the resin-secreting resin ducts (RDs) of F. ferulaeoides have not been studied in detail. This study used optical and transmission electron microscopy to explore the anatomical features, including the distribution, size, and structure, of the RDs among different organs of F. ferulaeoides. The microstructure data revealed that the RDs consisted of a round lumen, a layer of secretory cells, and multiple layers of sheath cells. Notably, the RDs in stem were arranged alternatively in a multilayered ring with vascular bundles of three distinct sizes. The ultrastructural analysis revealed that organelles in the secretory cells potentially play important roles in resin secretion. Those data may be of great significance to understanding the anatomy of the RDs in Ferula L. and Umbelliferae.