Studies On Relationship Between Structures, Development Of Vegetative Organs And Esculentosides A Accumulated In Phytolacca Acinosa Roxb.and Phytolacca Americana L.

Phytolacca acinosa Roxb. and Phytolacca americana L. which belong to Phytolacca in Phytolaccaceae are perennial herbaceous plants, they also included in the Chinese Pharmacopoeia. Both medicinal parts are roots, whose main medicinal ingredients are Esculentosides. At present study, plant Anatomy, histochemistry and phytochemistry methods were used to reasearch the structure and developent of vegetative organs of P. Americana L and P. acinosa Roxb., histochemical localization and content dynamic changes of esculentoside A in vegetative organs, and then explore the relationship between development of vegetative organs and their accumulation of esculentoside A. Results of the study are as follows:In root, Promeristem was made up of3groups of original cells, the cells had cytological characteristics of typical meristem; primary meristem included calyptrogens, dermatogen, periblems and pleromes. Primary structure consisted of epidermis, cortex and vascular cylinder. Primary xylem was diarch. The secondary growth mainly relied on the activity of vascular cambium, abnormal vascular cambium and cork cambium. The first layer of abnormal vascular cambiumwas formed by the dedifferentiation of parenchuma cells in the secondary phloem. The abnormal vascular cambium cells divided periclinally, and produced some vessels and parenchuma cells inside, phloem outside. The concentric rings of abnormal vascular tissue were formed as the same pattern stated above. The cork cambium was formed from pericycle.The development of stem of P. acinosa and P. americana also included four stages:promeristem, primary meristem, primary and secondary stages of growth. Promeristem was composed of tunica cells and a group of corpus cells. With the development of promeristem, the primary meristem, including protoderm, ground meristem and procambium was formed. The primary structure consisted of epidermis, cortex, vascular system, pith and pith ray. With the progressive development of stem, the activity of vascular cambium began. The cork was not found to form in the stem from beginning to end in its whole life.The leaf was the typical bifacial leaf, which composed of blade and stipe. The blade consisted of epidermis, mesophyll and vein. And the mesophyll was developed, with distinct differentiation of palisade tissue and spongy tissue. Palisade tissue was2-3cell wide, spongy tissue was3-5cell wide.Histochemical localization of Esculentosides A in vegetative organs of P. acinosa and P. americana showed that when Esculentosides encounters vanillin-sulfuric acid reagent, it showed pink or red purple, as a result, it can be used to determine the accumulation of Esculentosides in different vegetative organs. In the root, the parenchyma cells of abnormal structure were the main accumulation parts; in the stem, cortex and phloem parenchyma cells were the main accumulation parts; in the leaf, Esculentosides was mainly located in the mesophyll tissues.Phytochemical results showed that the content of Esculentosides A in root was the highest in three vegetative organs in P. acinosa and P. americana. The content of Esculentosides A in "skin areas" was higher than that in xylem, based on these results, the ratio of "skin areas" to xylem can be used as an anatomical criterion to estimate the Esculentosides A content. Through the study on the content of Esculentosides A in roots with different diameter, it could be found that the content of Esculentosides A in the root with diameter of30-45mm was higher than that of1-15mm,15-30mm, and45-60mm. Therefore, the root of30-45mm was the bset for harvesting, in which the Esculentosides A content was higher, the quality was better. The content of Esculentosides A in different seasons in a growth period was varied in the root. The content of Esculentosides A was higher in both pre-blossom of spring and fruit mature period of autumn, and it was higher in autumn than in spring. As a result, the best collecting season was fruit mature period of autumn because both the dry weight of the root and the content of Esculentosides A were high.The stem and leaf of P. acinosa.. and P. americana in the different development stages showed different content of Esculentosides A. The content of Esculentosides A was the highest in periods of vegetative growth, then with the growth of stem and during the transition of reproductive periods, the content fell gradually. The content of Esculentosides A was the lowest in withering period.