| Pyrethrins,widely used natural insecticides,offer all the advantages of chemical compounds,that is,rapidity of action,activity against a broad tange of insects,and low costs,and because of their rapid biological agents such as weak development of resistant strains and low toxicity for mammals. Plant tissue and cell culture of pyrethrum cinerariifolium Trev. for producing pyrethrins were studied in this paper in order to provid basic data and theories for producing pyrethrin and other botanic pesticidal substance and evaluate the usefulness of biotechnological processes for their biosynthesis.Some seeds of pyrethrin-producing pyrethrum cinerariifolium Trev. was obtained from KungMing institute of botany of Chinese academy of science.Plant were grown from seeds in peatmoss under glasshouse conditions(natural daylight and photoperiod,maximal temperature 30 癈 ).Shoot of pyrethrum cinerariifolium Trev. were washed thoroughly with water,disinfected with 0.1% HgC12 for 4min,The shoot were rinsed 6 times with sterilized distilled water and placed in Petri dishes containing MS culture medium.Firstly,we got the calli of pyrethrum cinerariifolium Trev. from the stems and leaves of sterilized plantlet by orthogonal experiment design. The optimum media and culture conditions were determined through the researches of induction, continuer growing and preservation of calli derived from immature leaves and stem tip of pyrethrum cinerariifolium Trev. Callus induction frequency reached to 88 percent on MS+2,4-D 1.0mg/L+KT 0.4mg/L. The calli Increment Per day can get to 0.127g/d on MS medium with 25g/L of sucrose. Subculture period of the calli were about 27d under 4h illumination per day on the same medium. Cell growth process in calli culture of pyrethrum cinerariifolium Trev. presented a S-shaped curve. We studied the differentiation of the explant and found MS61(NAA/6-BA=0.25/0.4),MS66 (NAA/6-BA =0.25/0.8) and MS67(NAA/6-BA=0.5/0.8) were suitable for differentiation of shoots and roots.Secondly,we have done some work on suspension cultures and obtained a stable cell suspension from pyrethrum cinerariifolium Trev. calli. This cell line can get 0.106g/d increment per day.Thirdly, The influence of nitrogen-stress on growth and pyrethrin production in in vitro cultures and tissues of pyrethrum cinerariifolium Trev. has been studied.lt was observed that nitrogen-stress with growth regulators inhibited callus growth and enhanced bioactivity of the callus culture.N4,One of the sample,8 hours antifeedant rate to Plutella xylostella L. was 100% under the concentration of 0.8g/ml.N3,the other sample,12 hours lethal rate to the larvaof Aedes albopictus was 75.6% under the concentration of 8mg/ml.The influence of formaldehyde on growth and pyrethrin production in in vitro cultures and tissues of pyrethrum cinerariifolium Trev. has also been studied.lt was observed that formaldehyde in the range of concentrations 0.5 to 2.0% slightly inhibited callus growth and enhanced bioactivity of the callus culture.The 12hours and 8 hours lethal rate of F2 to the larvae of Aedes albopictus and Musca domestica L. was 82.2% and 76.7% under the concentration of 8mg/ml and 0.4g/ml. When we concentrated F2(about 30g/ml),it can knock down the Mythimna separated Walker.The knock down rate was about 70%. The influence of ascorbic acid has also been studied.lt was observed that ascorbic acid in the range of concentrations 0.5 to 8.0% strongly inhibited callus growth and slightly enhanced bioactivity of the callus culture.Finally,we studied the extract process of the culture's production. We found two extract process of the culture's production are feasibility.One of the process is general extraction,the other is supercritical fluid extraction. We bioassaied the production of callas culture and cell culture of pyrethrum cinerariifolium Trev. We believe the larvae of Aedes albopictus and Musca domestica L. are appropriate insects to the bioassay of the culture production. And we set up a kind of method to judge the bioactivity of the culture produ...
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