Effects Of Ca²⁺ Treatment Improve Cold Resistance Of Korla Fragrant Pear

The paper treats5,15,25years old Korla Fragrant Pear Tree as the experimental material, whichstudied the effects of improving cold resistance of Ca2+in different tree ages of Korla Fragrant Pear Tree.The experience determined Ca, P, K and physiological index of leaves in different treatments, anddetermined index of cold resistance by low temperature stress on the branches of dormant period indifferent treatments, which adopted the method of spraying and the injection of different concentrations andkinds Ca2+to explore the relationship between Ca2+and mineral nutrition changes and cold hardiness ofKorla Fragrant Pear. The main results were showed as following,1.In the mid May to mid June, Kuerle Fragrant Pears of5years spraying20mmol/L CaCl2,15yearsspraying10mmol/L Ca(NO3)2,25years spraying20mmol/L CaCl2was more conducive to pear leaves oncalcium ion absorption. In the Mayto July of growth period, the total P content of5a,15a,25a KorlaFragrant Pear was downward trend, and the change of K content in leaves was big variance.2.The Ca accumulation of5year old Korla Fragrant Pear test tree branch is not obvious, the P, Kaccumulation content of Ca(NO3)2treatment was better. The Ca accumulation of CaCl2treatment on15year old Korla Fragrant Pear branch is better than Ca(NO3)2treatment,and the average of P, K content waslower than CK.The Ca accumulation of Ca(NO3)2treatment on25year old Korla Fragrant Pear branch wasbetter than CaCl2treatment, the P accumulation content of CaCl2treatment was better, the K content waslower than CK.3. In the May to July,the Ca content of16year old Korla Fragrant Pear leaves showed an upward trend,the accumulation P content showed decreased-slowly upward trend on the whole, the accumulation Pcontent showed slowly decreased-upward trend.4. The research on trunk injection of Ca2+treatment studied that the Ca, P, K absorption of leaves wasincreased slowly on the whole in the June to July.5. Foliar spraying treatment of5mmol/L Ca(NO3)2,15mmol/L CaCl2had a stong effect on4index ofMDA, soluble sugar, SOD enzyme, CAT enzyme activity.6. Trunk injection treatment of20mmol/L CaCl2had a stong effect on3index of soluble sugar, PODenzyme, ATP enzyme activity.7. The effect of cold resistance after spraying Ca2+treatment showed that, though analysis between theindex of cold resistance and low temperature stress and compared to the average of subordinate functionvalue, we can made a preliminary judgment that15mmol/LCaCl2spraying treatment effectively increasdproline content, reduced the content of starch, which increased the content of soluble sugar so as to improvethe cold resistance of tree body.8. The effect of cold resistance after trunk injection Ca2+treatment on16a Korla Fragrant Pear Treeshowed that the cold resistance of reatment50mmol/L CaCl2was the strongest. But there were littledifferencet among30-50mmol/L CaCl2、20-50mmol/L Ca(NO3)2treatments, which were level Ⅲ, middleresistance.9.Effect of cold resitance used spraying Ca2+treatment was better than that used trunk injection Ca2+treatment and the effect of15mmol/LCaCl2was the best treatment, level Ⅰ, highresistance;the effect of5mmol/L CaCl2、15mmol/L Ca(NO3)2were better, level Ⅱ, resistance.