不同相思树种单株抗寒性综合评价

Comprehensive evaluation of cold resistance of individual plants of different Acacia species

选择赤云相思(Acacia mangium×A. auriculiformis (Chiyun))、杂交相思(A. mangium×A. auriculiformis)和马占相思(A. mangium) 3个品种的8个单株,对其扦插繁殖幼苗进行12、9、6、3、0℃的低温处理,以25℃为对照,测定幼苗叶片相对电导率、丙二醛、可溶性糖、游离脯氨酸、可溶性蛋白和超氧化物歧化酶含量等6个生理指标,应用隶属函数法综合各项生理指标进行抗寒性评价,筛选高度抗寒品种单株,为相思选育提供优质材料。结果表明:在低温胁迫下,幼苗叶片相对电导率升高,游离脯氨酸、可溶性蛋白和可溶性糖含量增加,且这4个指标可作为相思树种抗寒性评价的参考指标;结合生理指标的变化情况,相思发生寒害的温度主要是0～6℃;依据平均隶属函数值,综合筛选出抗寒性较强的品种单株依次是杂交相思1、杂交相思4和赤云相思,抗寒性最弱的是马占相思11。

Cold resistance of individual plants of three Acacia species[Acacia mangium×A.auriculiformis(Chiyun)(CY),A.mangium×A.auriculiformis(ZJ)and A.mangium(MZ)]was evaluated by subjecting the cutting seedlings of eight individuals to different low temperatures(12,9,6,3,0℃,and 25℃as the control).Six physiological indices(relative conductivity,malondialdehyde,soluble sugar,free proline,soluble protein,and superoxide dismutase content)were analyzed.Cold resistance ability of individual plants was evaluated by the membership function method.The results showed that relative conductivity,free proline,soluble protein and soluble sugar contents in the leaves increased under low temperature,which could be used as the reference indices for evaluating cold resistance of Acacia.Temperature threshold for cold injury of Acacia was 0-6℃after low temperature stress.Results from the membership function analyses showed that ZJ1,ZJ4 and CY1 had the highest cold resistance,while MZ11 had the lowest cold resistance.