Research On Key Technology Of Open Tissue Culture Of Taxus Cuspidata

The strongly active anti-cancer paclitaxel existing in Taxus plants has a good effecton controlling various types of common human cancers. Because Taxus has been on theverge of extinction, many domestic and foreign businessmen has established large areasof artificial forests of Taxus, in order to avoid the damage of wildlife resources, and thistrend has triggered an exploration of Taxus breeding techniques. Plant tissue culture hasbeen applied more and more widely in plant breeding techniques. Currently, there is littleresearch for rapid propagation technology of Taxus cuspidata tissue culture, and it is stillin the primary stage. Therefore, in this research, Taxus cuspidata was chosen as materials,and the selection the optimum explants, the medium composition in different culturestages, the simplification of the culture medium and the micro-cutting environment werestudied. Finally, the factory breeding technology system of Taxus cuspidata wasestablished and its cost budget was estimated, in order to provide the theoretical andtechnical support for the realization of Taxus cuspidata factory seedling. Conclusions areas follows:1) In the primary culture stage, the study focused on the effects on bud sprouting ofTaxus cuspidata of different types of explants, medium, hormone composition, simplifiedculture and so on. The results showed that the optimum explants of Taxus cuspidata werethose with2~3cm semi-lignified shoot tips. Before simplification, the optimum mediumcomposition was B5+agar0.6%+sucrose2%+IBA3mg/L+AC0.1%+streptomycin0.4g/L, which could insure more than95%callus induction rate, moderate callus volume,more than95%bud sprouting rate, larger bud sprouting coefficient and shorter time ofbud sprouting (6d). After simplification, the optimum composition was1/2B5+agar0.6%+sugar2%+IBA3mg/L+AC0.1%+streptomycin0.4g/L, which made bud sprouting rateup to89%with no remarkable negative effect on bud sprouting. Plastic cups were used toreplace triangle bottles. It would save the cost at about94.4%in which culture containersaccounts for about93.7%by means of the simplification of culture medium componentsand culture containers.2) In the subculture stage, the study focused on the effects on the shoot proliferationof Taxus cuspidata of different types of medium, hormone composition, subculture cycle,and simplified culture. The results showed that the optimum composition was MS+agar0.8%+sucrose3%+IBA2mg/L+BA0.05mg/L+0.1%AC+streptomycin0.4g/L beforesimplification, whereas after simplification, the optimum composition was1/2MS+agar0.8%+sugar3%+IBA2mg/L+BA0.05mg/L+AC0.1%+streptomycin0.4g/L, and ithad no negative effect on shoot proliferation. Plastic cups were still used to replace triangle bottles. It would save the cost at about93.4%in which culture containersaccounts for about92.5%by means of the simplification of culture medium componentsand culture containers.3) In the micro-cutting experiments, several small half lignification branches ofTaxus cuspidata were taken as experimental materials in order to research themicro-cutting environment and the matrix composition. The illumination time was16h/days (light intensity was1000lux), temperature was25℃, air humidity was80%~85%,which were initially screened as better micro-cutting environment. Simplex latticemixture design bounded by lower limit was applied to optimize matrix composition ofmicro-cutting, including sands, moss, vermiculite, hillside soil. The roots were developedunder nonartificial control condition (laboratory). The results showed that the optimummatrix composition of micro-cutting was moss: vermiculite: hillside soil=1:4:5and therooting rate was nearly100%.4) Based on the research stated above, the factory cultivation seedling technologysystem of Taxus cuspidata was established, including primary culture, subculture, androoting of micro-cutting three parts. The initial cost budget estimation of factorycultivation seedling showed that the cost was0.9691yuan each tissue cultivate seedlingin which labor accounted for50%. It would provide reference for factory cultivationseedling of Taxus cuspidata.