Botanical And Pharmacognostic Studies On Test-tube Plants Of Bupleurum Chinese DC.

The honewort is a traditional Chinese medicinal material as well as of staple and popular crude drugs in China, which belong to Bupleurum L.of Umnelliferae. The Roots or the whole grass of honewort are used as medicine, and their medicinal value is extremely high.The honewort is widely used in clinic, because it has the efficacy of relieving the depressed liver, reconciliati-on exterior and interior, uplifting yang qi.The wild honewort resource tends to be exhausted, so artificial planting of honewort has become a major source of supply. Now the issue of hybrid varieties and low germination rate was universally existed on production of honewort. And the purification and cultivate of germplasm resources has become the bottleneck of thorowax industrial development.Taking honewort test-tube plantlets and test-tube plants as the research objects, the paper has studied their main inheritable parameters in different growing periods, has detected the contents dynamic of saikoside and seed vigor, has compared the differences between test-tube plants and seed plants of honewort on saikoside contents and seed vigor, has observed the root development process.The experimental evidence was provided by experime-nt results for the application of honewort rapid propagation technology in vitro and the cultivation of honewort fine germplasm resources.The analysis results of campestral observation and measurement:Each genetic characters standard deviation and relative standard deviation are all smaller at each growth phase.The plants population grows consistently. Its variability is low. Its length and weight of root relative standard deviation are all low. The average root length and weight are more predominant than ordinary seed plants.The pharmaceutical character of plants population is excellent. The number of branch stem and effective fruit bunch is bigger. The aerial part yield is large,the seed production is higher. The correlation between each character of test-tube plants of honewort is different from the ordinary seed plants in diferent growing periods.The measurement results of saikosaponins, spoaikosanin a and spoaikos-anin d:The contents of saikosaponins, spoaikosanin a and spoaikosanin d were minimum in test-tube plantlets.They were uppermost in annual test-tube plants, and were second at vegetative growth phase of biennial test-tube plants.The contents were reduced ordinally at bud forming phase, seed ripening phase and die away phase of biennial test-tube plants.The contents of the root were much higher than in aerial part of test-tube plants. The contents of test-tube plants which introduced from Zuoquan, Shanxi were higher than which from Wanrong and Lingchuan, Shanxi.The contents in test-tube plants were higher than in seeding plants.The determination results of seed vigor show that the seed vigor of test-tube plants was equivalent with whose seeding plants, its cold resisitance was superior to the seeding plants, the seed quality of Lingchuan test-tube plants was the best.The microscopic observation results show that the roots of test-tube plantlets were in primary growth, the primary xylem was diarch and the development of primary xylem was exarch. The roots developed from both superficial meristemoids and the meristematic regions deep within calli,the lateral root was endogenesis in origin.The root structure was related to growth environment.The endodermis of the root was without casparian strip in primary structure.The roots were without root cap or with a spot of root cap cells.With the deterioration of growth environment, the root cap cells increased, and they were gradual as same as seedling root cap structure. The roots secondary phloem of test-tube plants distributed a large number of secretory canals.