4个白杨派新无性系抗寒性鉴定和综合评价

以西北农林科技大学选育的意大利银白杨（I-101）×毛白杨4个优良杂种无性系和84k、I-101、新疆杨和毛白杨30号4个对照无性系的1年生休眠苗为试验材料，对其进行低温处理，以常温（CK）为对照，设置5个温度梯度:-10、-15、-20、-25℃和-30℃，低温冷冻处理24 h，研究8个白杨无性系1年生枝条生理生化指标的变化，包括半致死温度、丙二醛（MDA）、可溶性蛋白含量、超氧化物歧化酶和过氧化物酶活性5个指标，并利用隶属函数法对8个无性系的抗寒性进行评价。结果表明:各无性系间抗寒性差异明显，抗寒性强弱表现为‘03-4-22’> 84k > I-101 >新疆杨>‘03-5-17’>毛白杨30号 >‘03-6-11’>‘03-4-9’；研究认为无性系‘03-4-22’在5个抗寒指标综合评价结果中表现最好，属于抗寒无性系，可为白杨派优良新品种的选育、推广提供理论依据。

Determination and Comprehensive Evaluation on Cold-tolerance of Four New Populus Clones

Taking four hybrid clones of I-101×Populus tomentosa bred by Northwest A&F University and four control clones (84k,I-101,P.alba,P.tomentosa No.30) as experimental materials,we studied the changes of dehydration rate,LT₅₀,MDA,soluble protein contents,SOD and POD activities after the plants were treated under a series of low temperatures (10,15,20,25,30℃,ambient temperature as control) for 24 h,aimed to analyze the differences of eight kinds of Populus species in cold resistance by using membership function method.There were obvious differences among the clones in the ability of cold resistance.The order was ‘03-4-22’>84k>I-101>Populus alba>‘03-5-17’>Populus tomentosa No.30>‘03-6-11’>‘03-4-9’.Clone ‘03-4-22’ showed the best resistance to cold stress among the five evaluated indicators,which could provide a theoretical basis for the new breeding of Populus.