甘肃南部曼地亚红豆杉引种抗寒性研究

分别以甘肃南部酸性土壤和碱性土壤条件下5年生曼地亚红豆杉为材料,从低温半致死温度(LT50)、自由水和束缚水含量等生理指标研究了曼地亚红豆杉在自然降温过程中抗寒力的变化,实验表明:曼地亚红豆杉低温半致死温度在自然降温过程中均随着气温的降低而降低,与采样前半月平均最低温度显著线性相关,酸性土壤条件下束缚水含量、束缚水与自由水比值均明显高于碱性土壤条件;酸性土壤比碱性土壤条件下的红豆杉低温耐受力提高1.7℃,连续15d环境最低温平均值为-6.16℃时,曼地亚红豆杉功能叶的半致死温度在-15.51~-17.12℃之间。

An Anti-cold Research of the Introduced Taxus media in Southern Gansu

The article tries to study the anti - cold changes of Taxus media in the natural cooling process from its physiological indicators like LT50, free water and bound water content, which uses 5 - year - old southern Taxus media that breeds in acidic soil and alkaline soil conditions in Sounthern Gansu as its research subject. The experiments show that LTSO of Taxus media declines with the decreasing of temperature at the natural cooling process, which has a linear correlation with the average minimum temperature half a month be- fore the sampling. Bound water content and the ratio of bound water and free water over the condition of acidic soil are higher than those under its counterpart alkaline soil＇ s condition. Nevertheless, compared with alkaline soil conditions, yew＇ s low temperature tolerance under the conditon of acidic soil increases by 1.7℃, average minimum temperature is -6. 16℃ over a continuous 15d environment, LT50 of the Taxus media＇ s functions leaves comes to - 15.51 - - 17.12℃.