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以8年生银杏为试材,采用不同程度的断根处理,测定处理后树体超声(ultrasound acoustic emission,UAE)信号、枝条栓塞程度(percentage loss of hydraulic conductance,PLC)、树干液流通量、气孔导度、蒸腾速率以及叶片水势等生理指标,分析断根对银杏树体水力特征及生长状况的影响.结果表明:断根处理后,在短时间内有大量UAE信号产生,且随断根程度的加重而增大,在6h出现最大值,随后逐渐降低;枝条的PLC在起初的12h迅速增加,24h后增速趋于停滞;银杏树干液流通量、叶片气孔导度、蒸腾速率和水势明显降低,各处理间差异显著.经统计分析,累积UAE(cumulative number of UAE,cUAE)信号量与PLC呈现显著的正相关关系,与液流通量和叶片水势呈负相关关系.次年的单叶面积、新生枝条长度显著下降,下降程度随断根处理的加重而加剧.断根处理在短时间内增加了银杏管胞气穴数量和木质部栓塞的程度,影响到水分输送和叶片蒸腾,最终对叶片和枝条的生长产生负面影响.
Eight-year-old Ginkgo biloba was used as test material, and different degrees of root cutting were used to determine the effects of ultrasound acoustic emission (UAE) signal, percentage loss of hydraulic conductance (PLC), trunk flow rate, stomatal conductance Degree, transpiration rate and leaf water potential were analyzed to analyze the influence of root breaking on the hydraulic characteristics and growth of Ginkgo biloba L. The results showed that a large number of UAE signals were produced in a short time after root pruning, and increased with the increasing degree of root pruning The maximum appeared at 6h, then decreased gradually; the PLC of branches increased rapidly in the first 12h, and the growth tended to stagnation after 24h; the flow of ginkgo stem, the stomatal conductance, transpiration rate and water potential of leaves decreased significantly, There was a significant positive correlation between the cumulative number of UAE (cUAE) signal and PLC, and negative correlation between liquid flux and leaf water potential.The single leaf area in the following year, The length decreased significantly, and the degree of decline aggravated with the increase of root-cutting.The root-cutting treatment increased the number of cavities and the xylem embolism in a short time , Affecting water transport and leaf transpiration, eventually negatively affecting the growth of leaves and shoots.