| The plant Rehmannia glutinosa (Gaertn.) Libosch. belongs to Scrophulariaceae, its root, Dihuang , has been used in traditional Chinese medicine. Since Ming Dynasty, it has been mainly cultivated in the counties such as Xiuwu, Wuzhi, Wenxian, Mengxian and Boai, which were called "Huaiqing-fu" in the Ming Dynasty. Therefore, name of locally produced drug has since been prefixed with the word "Huai", as has been passed down through history. Dihuang has been used in three types, i.e. Fresh Dihuang, Row Dihuang and Prepared Dihuang in Chinese medicine. In this study, we investigated the morphogenesis and growth structure of the root tuber of Rehmannia glutinosa f. Hueichingensis (Chan et Sehih) Hsiao, fixed the storing location of catalpol in the root tuber, determined the content of catalpol and explored the accumulation of catalpol in vegetative organs by using anatomical, phytochemistry and histochemistry methord. The outward appearances, interior structures and contents of catalpol of different producing areas were studied. The correlation between the content of catalpol in the root tuber from different producing areas and the environmental factors were analysed by SPSS 10.0 software. Finally the genuineness of Rehmannia glutinosa f. Hueichingensis (Chan et Sehih) Hsiao, and its GAP were approached.The results showed, 1. With the normal planting methord of Rehmannia glutinosa f. Hueichingensis (Chan et Sehih) Hsiao, two types adventitious rootsgenerated from mother root tuber and the stem base of adventitious bud. One had normal primary structure and secondary structure. This type of adventitious root did not become thick obviously in the growth and development course. Therefore it was normal root, which functions were absorbtion and fixation. The other, from the outward appearance, expanded as a small ball at the end after 15-20 days from generation. 30 days later, the end of the root became cylinder, which diameter was about 6-10 mm. Then the middle of the cylinder grew more quickly than its two ends. At last it became a root tuber shaped as a spindle. From the interior structures the primary structure and the genesis of vascular cambium of the second type of adventitious root of Rehmannia glutinosa f. Hueichingensis (Chan et Sehih) Hsiao were similar to those of normal root. But the division activity of vascular cambium was different. At early time the secondary xylem and the phloem accounted for nearly equal proportion in cross section of root. Some time later, vascular cambium produced more secondary xylem inward than secondary phloem outward. So secondary xylem accounted more and more proportion than secondary phloem in cross section of the root tuber. For the more, there were more parenchyma cells than vessels. Some of the parenchyma cells came from vascular cambium, and others from the division of themselves. So the main components of xylem were parenchyma cells, few vessels scattered among them. In cross section vessels only accounted for 10-15 percent. Through the anomalous secondary growth the root tuber became thick quickly and formed a spindle at last. 2. All the root tuber, stem and leaf contained catalpol in Rehmannia glutinosa f. Hueichingensis (Chan et Sehih) Hsiao but their catalpol levels were significantly different. The content of catalpol was higher in leaf and stem than that in root tuber. Both in leaf and root tuber the content of catalpol was higher and higher with their growth and development. The content of catalpol in xylem of root tuber is higher than that in phloem. 3. The investigation of histochemistry showed that parenchyma cells of xylem and phloem were the mainly storage location of catalpol. The observation of TEM showed that in the early time parenchyma cells of xylem and phloem have densecy toplasm, big nucleus and lot of organelles. Some time later, small vacuole appeared in the cell. With the increase of vacuole and vacuolization,small vacuole merged into a big central vacuole, which was abundant of osmiophilic materials. The parenchyma cells became mature. 4. Not o...
|
PDF Full Text Request