短周期桉树无性系苗木低温胁迫试验  

Testing of Low Temperature Stress on Short-rotation Eucalypt Cuttings

作　　者：李娟[1] 魏润鹏[1] 

机构地区：[1]华南农业大学林学院,广州510642

出　　处：《广东林业科技》2007年第3期1-6,共6页Forestry Science and Technology of Guangdong Province

摘　　要：本试验共测定了54个短周期桉树无性系在人工气候培养室中的低温胁迫伤害指数和死亡率.结果表明,不同低温处理对无性系伤害差异极其显著;苗木不同培育年份对低温伤害指数的影响明显,但对苗木死亡率的作用不大.苗木在低温胁迫处理后1～3 d内观察评分结果具有相当的稳定性和准确性.由于受测试的不同树种和无性系苗木的低温伤害或致死低温范围窄,而直接影响林分的野外环境温度变化较大,因此外界环境的极低温限制应是制约桉树往偏寒地区扩大种植规模的主要因素.在一定的低温范围内,低温胁迫伤害指数在无性系间存在一定水平的遗传变异,通过选择育种可以适度提高无性系抗低温胁迫能力,而结合耐寒桉树树种选育和改进环境与养分条件应可以获得更好的抗性效益.苗木或林木的生长状态对受低温伤害程度有一定的影响.In a controlled chamber stress experiment, we tested the damage index and mortality of cuttings caused by low temperature of 54 short-rotation eucalypt clones. As expected, the low temperatures imposed markedly decided the damage consequence, the age of the cuttings had an effect on the damage index but not on mortality. The observed results were consistent over the first to 3 days after low temperature imposed. While the temperature that caused damage or death of cuttings changed narrowly over clones tested, the actual climate of a plantation site varies much largely. Field climate is thus a vital factor that limits the large-scale expansion of eucalypt clones suitable for warm climate to relatively cold regions. Within certain geographic extent, there also existed clonal or genetic variation in cold damage or tolerance, which provides possibility of improving the cold tolerance of planting materials through selective breeding. A better solution is probably to combine the genetic breeding and improvement of site environment and nutritional conditions. It implied that the growing status of cuttings or trees may have an effect on the damage caused by low temperature.

关 键 词：桉树 无性系 低温胁迫 伤害指数 死亡率 

分 类 号：S792.39[农业科学—林木遗传育种]