低温胁迫下不同苹果矮化砧木品种的抗寒性研究

Study on Cold Resistance of Different Apple Dwarf Rootstock Varieties under Low Temperature Stress

为伊犁河谷苹果抗寒栽培和筛选抗寒性强的苹果矮化砧木提供理论依据,以10个苹果矮化砧木品种深度休眠的1 a生枝条为试材,分别进行-16、-20、-24、-28、-32、-36和-40℃的低温处理,利用电导法测定枝条的电解质渗出率,结合Logistic方程计算枝条的半致死温度(LT_(50)),同时结合低温胁迫后的冻害分级和恢复生长试验,综合评价10个苹果矮化砧木品种的抗寒性。结果表明:低温处理下,参试苹果矮化砧木品种的电解质渗出率变化趋势基本一致,均呈升高—降低—升高的变化,其中62-396、Y-1和青砧1号的电解质渗出率变化相对较小;通过拟合Logistic方程,得到10个苹果矮化砧木品种的LT_(50)为-41.15~-25.75℃,指标值顺序为62-396<Y-1<青砧1号<BP-176<SH1<SH6<GM256<KM23<M26<T337,其中62-396、Y-1和青砧1号的LT_(50)达到-40℃以下;枝条冻害分级显示,62-396、Y-1、SH1、SH6和青砧1号冻害程度较轻,T337冻害程度较重;恢复生长试验中,62-396、BP-176和青砧1号的枝条萌芽率较高,T337的萌芽率较低。综合分析低温处理下枝条的电解质渗出率、LT_(50)、冻害程度以及低温处理后恢复生长的萌发率4个指标,认为10个苹果矮化砧木品种中62-396、青砧1号、Y-1和BP-176抗寒性较强,SH1、SH6、GM256、KM23和M26抗寒能力次之,T337抗寒能力相对较差。

To provide a theoretical basis for cold resistant apple cultivation and screening dwarf apple rootstocks with strong cold resistance in Yili Valley,the 1-year-old branches of 10 apple dwarf rootstock varieties with deep dormancy were treated at-16,-20,-24,-28,-32,-36 and-40℃respectively.The electrolyte leakage rate of the branches was measured by conductivity method,and the half lethal temperature(LT_(50))of the branches was calculated by combining with logistic equation.At the same time,the cold resistance of 10 apple dwarf rootstock varieties was comprehensively evaluated by combining the freezing injury classification and growth recovery test after low temperature stress.The results showed that under low temperature treatment,the change trend of electrolyte exudation rate of dwarf apple rootstock varieties was basically the same,showing an increase-decrease-increase change,in which the change of electrolyte exudation rate of 62-396,Y-1 and Qingzhen No.1 was relatively small.By fitting the logistic equation,the LT50 of 10 apple dwarf rootstock varieties was-41.15--25.75℃,and the order of index values was 62-39650 of 62-396,Y-1 and Qingzhen No.1 reached below-40℃.The classification of branch freezing injury showed that 62-396,Y-1,SH1,SH6 and Qingzhen No.1 had a light degree of freezing injury,while T337 had a heavy degree of freezing injury.In the recovery growth test,the sprouting rate of branches of 62-396,BP-176 and Qingzhen No.1 was higher,while that of T337 was low.By comprehensively analyzing the electrolyte exudation rate,LT50,the degree of freezing injury and the sprouting rate of growth recovery after low temperature treatment,it is considered that among the 10 apple dwarf rootstock varieties,62-396,Qingzhen No.1,Y-1 and BP-176 have strong cold resistance,SH1,SH6,GM256,KM23 and M26 have the second cold resistance,and T337 has relatively poor cold resistance.