Study On Cold Resistance Of Some Varieties Of Prunus Persica Mainly Planted In Shanxi Province

Peach(Prunus persica L.)is one of the most important fruit in the life because of its sweet fruit and rich nutrition.Hardiness is one of the important indexes which can reflect environmental adaptability of fruit tree.Previous studies on cold resistance of peach mostly by field investigation of freezing damage identificate and screen cold resistant varieties.The experimental study of peach tree under low temperature stress,physiological reaction conditions and growth recovery performance,to explore the mechanism of cold resistance,to establish an identification system of cold resistance in peach,to verify the new varieties of cold resistance,which has important practical significance for guiding peach varieties suitable planting.This experiment use 10 varieties of peach which are mainly planted in north area as the test materials,using artificial cooling treatment,in the shoots recovery growth was determined based on the cold hardiness of peach,furtherly study the relationship between the physiological indexes of the dormant branches and flower buds and cold resistance.The main research results are as follows:1.With the decrease of temperature and the low temperature stress time prolonged,the varieties of dormant branches and flowerbuds physiological changes are basically the same.Through correlation analysis,there is a strong positive correlation between the dormant branches and flower buds of each index,indicating that the peach dormant branches and flower buds to low temperature stress make physiological responses is consistent.2.According to the relative electrical conductivity,use Logistic equation can obtained the semi-lethal temperature of dormant branches of 10 varieties of peach is between-20 ? to 25 ?,flower buds semi-lethal temperature is between-17 ? to 24 ?,dormant branches cold resistance is strong than the flower buds.Through correlation analysis,there is a strong negative correlation between the relative conductivity of flower bud and the recovery and growth rate of branches after low temperature treatment,indicating that the relative conductivity can reflect the cold hardiness of peach.3.Combined with correlation analysis and principal component analysis,relative conductivity,MDA,soluble protein,proline,SOD activity are close to cold resistance in the study of peach hardiness,under the low temperature,these indexes can be referenced as important indexes;the relationship between POD activity,soluble sugar and hardiness is small,so they are not suitable as a evaluation index of cold resistance alone;proline content can be singly used as a cold hardiness evaluation index.4.Using the membership function to comprehensively evaluate 10 varieties of peach of cold resistant ability,the result is: ‘Dajiubao' >‘75614' > ‘Zaijin' > ‘21010' > ‘Gangshanbai' > ‘Huayu' > ‘9618' >‘Jinyu' > ‘Wanmi' > ‘Tianwang'.According to the experimental results,more than-20 ? temperature is suitable for testedvarieties,and they can be cultivated in the area witch is rarely occur-20? temperature and persists for more than 24 h.