Evaluation Of Cold Resistance Of Different Kiwifruit Germplasm Resources

Objective:Through field investigation and identification and laboratory identification,two ways and methods were used to evaluate the cold resistance of some kiwifruit species or varieties in order to provide basis for cultivar selection and selection in kiwifruit production.Method:From November 28,2016 to January 18,2017,every 10 days,go to Wuquan Town,Shaanxi Baiheng Organic Orchard Co.,Ltd.to collect a'Qihong'kiwifruit shoots and sand it,collecting a total of 6 times,in 2017 In April of this year,the branches were taken out to count the germination rate of the branches at each time period.February 23,2017 Field Survey Statistics The number of plants and shoots of‘Qihong'kiwifruit caused by chilling damage in Shaanxi Baiheng Organic Orchard Co.,Ltd.were calculated,and the disease rate and diseased plant rate were calculated.10 kiwifruit species?varieties?planted at the Kiwifruit Experimental Station of Northwest A&F University as experimental materials.one-year-old dormant shoots were treated at 3?,0?,-5?,-10?,-15?,-20?,-25?,-30? for 12h.Measure the electrolyte leakage rate of kiwifruit branches after cryogenic treatment and fit Logistic curve through the electrolyte extravasation rate to calculate the critical semi-lethal temperature(LT₅₀).Analysis of variance and correlation analysis were used to evaluate the cold resistance,which provided a theoretical basis for the introduction and cultivation of kiwifruit.Comparing the electrolyte leakage rate of the thickness and thickness of kiwifruit twigs of two varieties of‘Nongda Mixiang'and“Nongda Jinmi',the thickness and diameter of shoots were determined by using conductivity method to evaluate the cold resistance of kiwifruit.Conclusion:1.Through research,it was discovered that from the end of November 2016to the middle or later of January 2017,the budding rate of the'Qihong'kiwifruit twigs in Wuquan Town,Shaanxi Baiheng Organic Orchard Co.,Ltd.was low,while the same time in the same region,the germination rate of the‘Xuxiang'kiwifruit sand shoots was more than90%,indicating that the'Qihong'kiwifruit had weaker cold resistance;second,the germination rate did not decrease with time,the germination rate decreased,indicating that before the end of November,the Guanzhong area in Shaanxi was'Qihong'kiwifruit has suffered a certain degree of frost damage.By observing the weather conditions,it was found that there was a cooling situation before the end of November.Therefore,before the end of November,the corresponding‘Qihong'kiwifruit in Guanzhong area should be put into use.2.Through field statistics,the incidence of'Qihong'kiwifruit in Guanzhong area of Shaanxi Province is high due to frost damage,and the diseased plant rate is as high as 29.05%.This shows that the cold chilling injury has a serious impact on the production and cultivation of kiwifruit,so the kiwi fruit is resistant to cold.Evaluation is also of great significance.3.10 kiwifruit species?varieties?have stronger cold resistance were'Ruanzao'and'Gezao';The ability to resist cold is generally were‘Haiwode','Xuxiang',‘Nongda Mixiang',‘Cuiyu',‘Nongda Jinmi',‘Maohua';have weaker cold resistance were‘Hort-16A','Qihong'.According to the semi-lethal temperature,the order of cold resistance of 10 species?species?is Ruanzao>Gezao>Haiwode>Nongda Mixiang>Xuxiang>Nongda Jinmi>Maohua>Cuiyu>Hotrt-16A>Qihong.The electroosmotic leakage rates of the 5 kiwifruit species also showed significant differences.The electrolyte leakage rates of'Ruanzao Kiwifruit'and'Gezao Kiwifruit'were lower than those of the other three species,the electrolyte leakage rates of‘Chinese kiwifruit'and'Maohua Kiwifruit'was higher than the other three species.According to the semilethal temperature,the order of the cold resistance of the five species was‘Ruanzao Kiwifruit'>‘Gezao Kiwifruit'>Delicious kiwifruit>Chiese kiwifruit>‘Maohua Kiwifruit'.4.By comprehensive comparison,the best conditions for determining the cold resistance of kiwifruit by conductivity measurement were determined as follows:the thickness of the shoots was 0.5cm,and the diameter of the shoots was 1.3±0.1cm.