Study On Cold Resistance Of Paeonia Rockii In Gansu

Peony is a unique precious flower in our country, In this paper, we selectedPaeonia rockii as the object of the research. It is one of the important variety of thepeony family,which has the unique purple patch on the base and vigorous petaltexture.This kind of Peony growed robustly and resisted strongly.It is an importantresource in the northern cold region ornamental flower and is also the special plant inGansu province. in order to realize Paeonia rockii Large-scale and industrializedplanting in the Northwest cold area. we selected five kinds of Paeonia rockii fromGansu province and did the research of Simulation of low temperature andPhysiological changes during overwintering period.the specific research as follows:First,Through cold stress treatment on five varieties of Paeonia rockii in GanSu,the changes of the relative electrical conductivity, malondialdehyde, free proline andsoluble sugar of their branches were measured and analyzed Soluble protein contentas well as changes in the activity of SOD, drawn: the relative conductivity, MDA,soluble sugar, proline, soluble protein, SOD and Paeonia rockii hardiness correlated.The results showed that, with temperature decreasing, the electrical conductivity of P.rockii increased and MDA content in the disorder that occurs after the peakfluctuations, proline content first increased and then stabilized, very few declinedslightly and soluble sugar first increased and then decreased the soluble proteincontent decreased after rising, SOD activity increased slightly after the first decreasein the temperature fluctuations disorder that was too low.Second,Relative conductivity and temperature were obtained from the analysisof variance was significantly negatively correlated; MDA and the temperature was asignificant negative correlation; soluble sugar, proline, soluble protein and thetemperature was a significant positive correlation; SOD and the temperature was asignificant positive correlation.Third,In the natural temperature variations, each physiological index correlationwith temperature variation is similar, but with the accumulation of changes or analoglow temperature stress slightly different. Electrolyte leakage, MDA with temperaturechange, and a similar trend both proline and soluble sugar in mid-winter has remained at a high level.Fourth,The use of electrolyte leakage rate equation fitted with Logistic equationseeking inflection point temperature estimated its semi-lethal temperature LT50/℃：Ziloushanjin> Shushengpengmo> Helingbai> Lanhaiyinbo> Yanguanqunfang.Fifth,The cold resistance of each variety was evaluated by fuzzy membershipgrade method. The cold tolerance of variety Yanguanqunfang is the best, and thenfollowed by Lanhaiyinbo，Helingbai, Ziloushanjin and Shushengpengmo in order.