| Bai-shou-wu is a famous traditional tonic medicine in the Traditional Chinese herbs, the effective components of the medicine (C21 steroidal glycosides, phospholipids, acetophenones, et al )come from the dry root tubers of Cynanchum auriculatum Royle ex Wight and function as anti-oxidation, anti-tumor, immunity stimulation and so on. This thesis tries to study the developmental anatomy of vegetative organs of Cynanchum auriculatu .and techniques of in vitro culture and rapid propagation of Cynanchum auriculatum. In the thesis, Organ morphgenetic mechanism and the histology of the adventitious buds induced from root segments in vitro were investigated. The results are as follows:The developmental processing of the root tuber of Cynanchum auriculatum were observed. The structural development of vegetative organs of the species was also studied with paraffin section .For the normal planting, adventitious roots generated from mother root tuber and the stem base of adventitious bud. The primary xylem of root is 2-3 arches. There were two types of secondary growth, normal secondary growth and anomalous secondary growth. The main components of its xylem were vessels and parachyma. By the primary and secondary growth of root, its mature root finally appeared. The anomalous secondary growth of its root is a main character of the species. In its xylem there are parenchyma, few vessels and fiber, et al. Accessory cambium was formed around the scattered vessels, which produced tertiary xylem and tertiary phloem. This anomalous secondary growth formed the medicinal part of Cynanchum auriculatum.The shape of transverse section of stem is oval, the primary vascular bundles of stem are bicollateral. In the base part of stem, beneath the epidermis, 1 circuit of non-continuous laticifer can be seen, and the result from the cross-section of stem showed the secondary xylem and secondary phlom finally developed into an irregular ring. Leaf is two-form leaf. Its mesophyll is composed of palisade cells and sponge cells. 3 vascular bundles exist in petiole. Its palisade tissue is composed of 1 layer of cylindrical cells and sponge tissue arranges loosenly. Both the primary vascular bundles of leaf and stem are bicollateral. Using stem as explants, in vitro culture and high frequency propagation of seedling have been achieved. The results showed that 10 min is suitable for disinfection with 0.1％HgCl2. 1/2MS+6-BA0.5mg·L-1+NAA0.05mg·L-1 is the appropriate medium in primary culture, MS+6-BA0.2mg·L-1+NAA0.05 mg·L-1 was much better than others medium for bud multiplication and bud multiplication was accelerated with 0.1mg·L-1PP333. MS+3/2 times Fe +0.2 mg·L-1BA+0.05mg·L-1NAA is beneficial to the turning green of yellow seedlings. 1/2MS is suitable for plantlet rootage and 1/2MS + IBA 0.2 mg·L-1 is the best medium for rooting. The survival rate of transplanting could reach 100％.Among induced callus, the character of leaf-derived callus is the best one and the appropriate medium for forming callus is 0.5mg·L-12,4-D+0.5mg·L-1BA in light. The medium of MS+0.5mg·L-1BA is good for callus proliferation and bud regeneration.Bulge root segments have been obtained after 150 days inducted from plantlets in the medium MS+10％sucrose+0.1mg·L-1IBA. Bulge root segments of 90 days induction could not form the adventitious buds, but the bulge root segments of 150 days induction could form, of which the best medium was MS+0.5mg·L-1BA. The formation process of the adventitious buds and their histology on the cutting root propagation of Cynanchum auriculatum was studied and investigated. The results showed that bud development is directly from cambium with no callus phase.
|
PDF Full Text Request