Study On The Rapid Propagation System And Secondary Metabolism Of Pinellia Ternata

Pinellia ternata (Thunb.) Breit is a perennial herbaceous plant of Araceae. It’s drying tuber is used as a common Chinese medicine, included in the first appendix of Chinese Pharmacopoeia. In this paper, we established the rapid propagation of tissue culture, by method of suspension culture. We have discussed the effects of different kinds of hormones and explants on the induction and proliferation of protocorm-like bodies of Pinellia ternata (Thunb.) Breit., the effects of calcium on heat stress of protocorm-like bodies of Pinellia ternata during suspension culture, the diurnal variation of chlorophyll fluorescence parameters, and the effects of different medium on the accumulation of secondary metabolites during suspension culture.The results are as following:1The optimum explant that induced the protocorm-like bodies and callus was the base of petiole; The single factor test demonstrated that0.5mg·L-12,4-D was optimum for callus induction, and the optimum concentration of6-BA,NAA and KT was respectively1.5mg·L-1,0.5mg·L-1, and1.0mg·L-1; The orthogonal test demonstrated that MS+0.1mg·L-12,4-D+0.5mg·L-16-BA+0.5mg-L-1KT was optimum medium for PLBs induction.2During suspension culture, the growth curve of PLBs was like "S"; The single factor test demonstrated that0.5mg·L-12,4-D was optimum for PLBs proliferation, and the optimum concentration of6-BA was1.0mg·L-1; If the PLBs were cultured in medium MS supplement with2kinds of hormones(2,4-D,6-BA), the PLBs proliferation was better than the one cultured in medium MS supplement with only2,4-D or6-BA. MS+0.2mg·L-12,4-D+1.0mg·L-16-BA was optimum medium for PLBs proliferation.3Cultured at (35±2)℃, in concentration range from0to660mg·L-1, with the Ca2+concentration rising, SOD, POD activity gradually increased, when Ca2+concentration equal to660mg-L-1, its activity reached the peak. However when Ca2+concentration of880mg·L-1, SOD and POD activity decreased; with different Ca2+concentrations MDA content did not change significantly. The results showed that the appropriate concentration of Ca2+could enhance the stress resistance of PLBs.4We took Pinellia ternate as the sample. The diurnal variation of fluorescence parameters was studied. The results showed that minimal fluorescence (Fo), maximal fluorescence (Fm), optimal photochemical efficiency of photo system Ⅱ (Fv/Fm), effective quantum yield of photo system Ⅱ (ΦPSⅡ), photochemical quenching coefficient (qP), non-photochemical quenching coefficient (qN) and apparent photo synthetic electron transport rate (ETR) all exhibited obvious diurnal variation. The declines in Fv/Fm, ΦPSII, qP were observed at midday strong sunlight. On the other hand, qN amounted to maximum value at midday; ETR varied as a two-peaked curve.5Studies on the effect of sucrose, hormones, Ca2+on the secondary metabolites formation in suspension culture of Pinellia ternate was carried out. The results showed that PLBs could not grow when cultured in the medium without sucrose, and the optimum concentration was30g·L-1and15g·L-1for alkaloids and organic acid synthesis;6-BA was better than2,4-D for alkaloids synthesis; The optimum2,4-D and6-BA concentration was respectively0.2mg·L-1and1.5mg·L-1for total organic acid synthesis; The optimum6-BA concentration was0.5mg·L-1for guanosine synthesis; The difference of content of alkaloids, guanosine, and organic acids varied in the different Ca2+concentration, when Ca2+concentration of440mg·L-1, the content of alkaloid reached the highest (0.158%), and when Ca2+concentration of660mg·L-1, the guanosine, organic acid accumulation were the highest (0.0173%,0.608%).