白桦木质部汁液产量及组分变异规律解析

Analysis of Xylem Sap Yield and Component Variation of Betula platyphylla

白桦汁液采集时间大多在早春阶段,容易采集且产量高,为探讨温度对白桦木质部汁液变化的影响及不同发育时期汁液组分质量浓度的变化,以黑龙江省东北林业大学帽儿山实验林场白桦天然次生林为研究对象,通过收集2022年和2023年的白桦汁液,统计春季汁液流量。对2023年白桦不同发育时期汁液中的碳水化合物、氨基酸、总三萜、可溶性蛋白、pH以及钾、钙、钠、镁离子质量浓度进行分析,解析汁液组分变异规律。通过连续2 a取汁的白桦与当年取汁的白桦汁液组分质量浓度对比分析,探索连续取汁是否对白桦生长发育产生影响。结果表明,白桦汁液在4—6月中产量整体呈现先增后降的趋势,高峰期集中在4—5月份,且温度的升高会促进产汁。白桦木质部汁液的总三萜、碳水化合物、氨基酸、蛋白质组分质量浓度在整个物候发育时期均呈现先升后降再升的趋势,均在旺盛生长期时达到最低值。随物候发育白桦汁液pH整体呈下降趋势,在完全展叶前不断酸化。离子质量浓度整体呈先上升后下降的趋势。持续取汁不会对白桦汁液中总三萜、氨基酸、蛋白质质量浓度造成显著影响,会使碳水化合物质量浓度及pH降低。研究结果可为黑龙江省东部山地白桦汁液的科学采集提供指导依据。

In early spring,the sap of Betula platyphylla was easy to collect and had a high yield.In order to explore the effect of temperature on the change of Betula platyphylla sap and the change of sap component concentration in different developmental peri⁃ods,the natural secondary forest of B.platyphylla in Mao′ershan Experimental Forest,Northeast Forestry University in Heilongjiang Province was selected.In 2022 and 2023,sap of B.platyphylla was collected to calculate the spring sap flow rate.The concentration of carbohydrates,amino acids,total triterpenes,soluble proteins,pH,potassium,calcium,sodium and magnesium in the sap of B.platyphylla was determined at different developmental periods in 2023,and the variation patterns of sap components were analyzed.The B.platyphylla sap component concentration extracted from two consecutive years was compared with that extracted in the same year,in order to explore whether continuous extraction of sap had an effect on B.platyphylla.The results showed that sap of B.platy⁃phylla production showed an overall trend of increasing and then decreasing from April to June,with the highest production in April and May.The increase in temperature promoted sap production.The concentration of total triterpenes,carbohydrates,amino acids and protein fractions in the sap showed a trend of increasing,then decreasing and then increasing during the whole period of phenologi⁃cal development.All of them were the lowest during the vigorous growth period.The pH value of sap showed an overall decreasing trend with the development of the phenology,and it was acidified continuously before the complete leaf expansion.The ion concentra⁃tion showed a trend of increasing and then decreasing.Continuous sap extraction did not significantly affect the total triterpenes,amino acids and protein concentration of sap,but decreased the carbohydrate concentration and pH.The research results provided sci⁃entific guidance for the collection of sap of B.platyphylla in the eastern mountainous of Heilongjiang Province.