Cold Resistance Of Ten Garden Trees

Trees have large crown, long life, fast growth, with a shade, cool,stagnant dust, noise and absorb harmful gases and other functions,and became the main species of landscaping. In this paper,Diospyroskaki, Melia azedarach Lin., Euonymus mssckii Rupr,Sophorajaponica Li-nn., Fraxinus chinensis, Acer elegantulu Fang et PL Chiu, Prunus persica Batsch. var. duplex Rehd, Prunus cerasifera Ehrhar f., Koelreuteria panicul and Catalpabungei C.A.Mey,these dormant buds of species as the test material, compared discrepancy of different temperatures with different processing time, ang these physiological index with soluble sugar, soluble protein content, O₂^-generation rate, MDA, free proline content, SOD,POD, CAT activity and the rate of change of dehydration; electrolyte leakage rate combined with Logistic equation was deduced for each species of semilethal temperature(LT₅₀), and correlation analysis of all indicators, the last comprehensive evaluation of ten species of anti-Grey Relational Analysis and fuzzy membership function method cold strength, and with cold resistance order LT₅₀ obtained were compared. The following conclusions:With the growing temperature and duration of hypothermia,electrolyte leakage rate showed an upward trend, and the electrolyte leakage rate and a negative correlation between cold hardiness. The electrolyte leakage fitting Logistic equationcalculate the various species of semilethal temperature(LT₅₀):Melia azedarach Lin.-44.73^-41.92℃, Sophorajaponica Linn-41.21^-38.80℃,Fraxinus chinensis-37.84^-34.24℃, Catalpabungei C.A.Mey-35.76^-30.62℃,Prunus persica Batsch. var. duplex Rehd-23.09^-20.14℃, Prunus cerasifera Ehrhar f.-22.25^-17.95℃, Diospyroskaki-29.13^-26.85℃,Euonymus mssckii Rupr-27.70^-24.25℃, Koelreuteria panicul-29.94^-26.17℃, Acer elegantulum Fang et P. L. Chiu-32.52 ^-27.08 ℃. According LT₅₀, infer these types of trees cold hardiness order: Melia azedarach Lin. > Sophorajaponica Linn. >Fraxinus pennsylvanica>Catalpabungei C.A.Mey>Acer elegantulum Fang et P. L. Chiu > Koelreuteria integrifoliola > Diospyroskaki >Euonymus mssckii Rupr.>Prunus persica Batsch. var. duplex Rehd.>Prunus cerasifera Ehrhar f.With treatment to reduce the temperature, in addition to increasing the lead after Prunus persica Batsch. var. duplex Rehd reduce water loss and dehydration of Sophor-ajaponica Li-nn increased the lead in reducing outside after remaining species showed a loss rate increasing trend; with prolonged duration of hypothermia, dehydration each species rate showed an upward trend, in which the smallest variation width Melia azedarach Lin.,the largest variation width Prunus.With decreasing temperature, ten species of Catalpabungei C.A.Mey, Fraxinus chinensis, Sophorajaponica Li-nn., Melia azedarach Lin.’s soluble sugar content continues to increase, decrease, after remaining species of soluble sugar content increased first; with the stress time, each species generally soluble sugar content increase.Decreased with the treatment temperature, soluble protein content after Prunus, Diospyroskaki and Acer elegantulum in the first increases and then decreases, the remaining species of soluble sugar content was increased, with the processing time, the general increase in soluble protein content of each species（except Mrs White outside）, after Euonymus mssckii Rupr soluble protein content first increases and then decreases.O₂^-generation rate and MDA content of each species were decreased with treatment and time of treatment temperature was rising, and O₂^-generation rate, MDA and cold hardiness were negatively correlated. According to MDA and O₂^-content analysis of variance showed: Melia azedarach Lin. is strongest and Prunus cerasifera Ehrhar f. is weakest.With decreasing temperature, ten species of Catalpabung ei C.A.Mey, Fraxinus chinensis, Sophorajaponica Li-nn., Melia azedarach Lin. soluble sugar content continues to increase, ten decrease,after remaining species of soluble sugar content increased first;with the stress time, each species generally soluble sugar content increase. Decreased with the treatment temperature, soluble protein content after Prunus, Diospyroskaki and Acer elegantulum in the first increases and then decreases, the remaining species of soluble sugar content was increased, with the processing time, the general increase in soluble protein content of each species（except Euonymus）, Euonymus soluble protein content first increases and then decreases.Ten species of Melia azedarach Lin., Sophorajaponica Li-nn., and Prunus with declining temperature treatment showed an increasing trend, remaining species of free Procontent with the process to reduce the temperature of the reduced increase. With the increase of stress time, cold strong species proline content increased, then decreased cold weaker species proline content increased first.All indicators correlation analysis showed that LT₅₀ and soluble sugar, soluble protein, SOD, POD, CAT were negatively correlated with O₂^-, MDA, water loss rate, Pro positive correlation; In addition to water loss rate and soluble sugar content, uncorrelation between SOD and MDA, between these indexes were correlated, and the correlation coefficient of 0.7 or more. According gray correlation analysis results weights found that low temperature for 24 h maximum weight and minimum weight difference of 0.027; low temperature 48 h, the maximum weight and minimum weight difference of 0.031; after 72 h low temperature treatment, the maximum weight and the minimum weight difference of 0.023, so we considerer that ten indicators selected may be represented garden arbor cold resistance evaluation requirements. Using fuzzy membership function method combined with the use of Add by law to evaluate cold resistance of these species, the order: Melia azedarach Lin. > Sophorajaponica Linn. > Fraxinus pennsylvanica >Catalpabungei C.A.Mey > Acer elegantulum Fang et P. L. Chiu >Koelreuteria integrifoliola>Euonymus mssckii Rupr.>Diospyroskaki Prunus persica Batsch. var. duplex Rehd.>Prunus cerasifera Ehrhar f.