美洲黑杨×青杨派杂种无性系苗期抗寒性的鉴定与筛选
Identification and Selection on the Cold Tolerance in the Hybrids of Populus deltoids×Section tacamahaca

以美洲黑杨×青杨派7个杂种无性系与中绥12和陕林4号2个对照无性系的1年生休眠苗为试验材料，分别测定了各无性系枝条的失水率、半致死温度、丙二醛（MDA）与可溶性蛋白含量以及SOD与POD酶活性共6项指标，依据各项测定指标对各无性系抗寒性进行综合分析与鉴定。结果表明：各无性系间抗寒性差异极显著（p＜0.01），抗寒性大小依次为07-69×青1>06-57×川1>06-69×卜1>中绥12>07-西大寨×卜1>陕林4号>08-69×青2>08-69×青4>E24-01；无性系07-69×青1在6个抗寒鉴定指标的评价结果中均表现最好，属于抗寒无性系，可为杨树生产和育种提供参考。
Taking 7 hybrids of P.deltoides×Section tacamahaca and two control clones (Zhongsui 12, Shaanxi No.4) as experimental materials, 6 indicators of the one-year-old seedlings were measured, including dehydration rate, LT50, MDA and soluble protein contents, SOD, and POD activities. The cold tolerance of the clones was comprehensively compared according to those indicators. The results showed that there were obvious cold tolerance differences among the clones at 0.01 statistical level, and the order was 07-69×P.cathayana 1, 06-57×P.szechuanica 1, 06-69×P.purdomii 1, Zhongsui12, 07-Westda-zhai×P.purdomii 1, Shaanxi No.4, 08-69×P.cathayana 2, 08-69×P.cathayana 4, E24-01. Among all the hybrid materials, 07-69×P.cathayana 1 showed the best cold tolerence for its six evaluated indicators, which belonged to the cold tolerance clone. The results would provide a theoretical support for the breeding and production of poplar