| Using Sasa versicolor as the material which was came from Japan and had a wild ornamental value.This study besides focused on the tissue culture and plant regeneration of S. versicolor, thecold-resisitance and its mechanism under nature low temperature were also investigated from the levelsof physiological and biochemical. The purpose was to lay a technical foundation for mass productionand cultivation of S. versicolor. The main results were as follows.1. Used current-year stem segment with bud as explants, the suitable method of sterilizing wasdipped in75%ethyl alcohol for30s, then agitating in a solution of2.5%NaClO for30min. Whichcultured in Murashige and Skoog （MS） medium had a highest germination rate.2. The best medium for bud induction was MS+BA3mg·L-1+30g·L-1Sucrose+0.3g·L-1Gelrite.The best medium for bud proliferation was MS+BA2.0mg·L-1+TDZ0.005mg·L-1+ZT1.0mg·L-1+30g·L-1Sucrose+0.3g·L-1Gelrite. The best medium for bud rooting and seedling cultivation was MS+IBA3.0mg·L-1+30g·L-1Sucrose+0.5g·L-1Gerilte. The regenerated plantlet was transplanted inperlite: vermiculite: loam （1:1:1） and the survival rate was higher than90%.3. With the tempearture decreasing, the trend of REC （the relative electric conductivity） showed“increase-decrease-increase”, the minimum was occurred at20℃andthere was a significant differenceamong treatments.The change of MDA content increased first and then decreasd, and the maximumoccurred at20℃, in addition there was only a significant difference between treatment at20℃and thatat8℃. Both REC and MDA was showed a similar trend and displayed a substantial change. Theresults indicated that as the temperature dropped to a certain extent, cell membrane was overoxidatedand damaged, resulting with an increased REC, which ultimately damaged S. versicolor leaves tissue.4. With the tempearture decreasing, both the trend of SOD and CAT activity showed“decrease-increase-decrease”. While SOD got a maximum activity at8℃, andthere was a significantdifference among20℃,17℃and5℃, but no significant difference with11℃and14℃,but there wasno significant difference among different treatments on CAT. The trend of activity of POD was“decrease-increase-decrease-increase”, with a maximum activtity at20℃, and there was a significantdifference with other four treatment （17℃,14℃,11℃,8℃） except5℃. The results indicated that in theprocess of natural cooling, SOD and POD activity reflected more sensitive to low temperature andrevealed to be closely related with the cold-resistance.5. With the tempearture decreasing, the trend of the content of proline and soluble protein showed“increase-decrease-increase”. Those lowest content occurred at20℃while thehighest content at11℃,between which and other treatments there were significant difference. The results indicated that inresponse to the decreased tempreture, the protection mechanism in plant was activated to ligheten thedamage from low temperature stress by enhacing the osmotic adjustment ability, maintaining the cellwater potential and decreasing its freezing-point.6. With the tempearture decreasing, a trend of chlorophyll and anthocyanin content showed“decrease-increase-decrease”. It was showed that there were significant difference in the content of chlorophyll between20℃and other treatments, but there was no significant difference among differenttreatments of anthocyanin content.The results indicated that the chlorophyll content reduced with thedecreased tempreture, resuting a weakened photosynthesis in plant, which ultimately alleviated the lowtempreture damage.7. Application of conductance method combined with the Logistic equation, which calculated thehalf lethal temperature of S. versicolor was-2.16℃.8. From the result of correlation analysis, the physiological indexes of S.versicolor are relativelycorrelated. Then combination with principal component analysis, cold-resistance indexes, includingSOD activity, the relative electric conductivity, content of soluble protein, proline, chlorophyll andanthocyanin were important in cold-resistance of S. versicolor. Consequently the determination ofplantlet cold-resistance ablitiy need to comprehensive analysis of the indexes. |
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