养分和水分胁迫下2年生落叶松根系有机酸的分泌行为研究

Studies on the Secretion of Organic Acids from Roots of Two-year-old Larix olgensis under Nutrient and Water Stress

[目的]研究养分和水分胁迫对2年生落叶松根系有机酸分泌行为的影响。[方法]通过设置不同的养分和水分胁迫条件,研究不同程度土壤胁迫下2年生落叶松根系有机酸的分泌种类和数量。[结果]在养分和水分胁迫下,2年生落叶松苗根系有机酸的分泌种类增多,且胁迫水平不同增加分泌的有机酸种类也不同。养分和水分胁迫处理还增加了有机酸的分泌数量。从有机酸分泌总量看,胁迫最重的水平1增幅最大。从单个有机酸分泌量看,柠檬酸增幅最大,其次为苹果酸,草酸较小;且都以水平1增幅最大。[结论]各有机酸分泌量在有机酸总量中所占的比例稍有变化,但整体排序未变。

[Objective] This study aimed to investigate the effects of nutrient and water stress on the secretion of organic acids from roots of two-year-old Larix olgensis.[Method] Different nutrient and water stress conditions were designed to investigate the types and quantities of organic acids secreted from roots of two-year-old Larix olgensis.[Result] Under nutrient and water stress,the types of organic acids secreted from roots of two-year-old Larix olgensis increased,which varied with different stress levels.Nutrient and water stress also increased the quantities of organic acids secreted from roots of two-year-old Larix olgensis.The increment in total amount of organic acids reached the maximum at level 1 （the most serious stress）.Among different types of organic acids,the increment in amount of citric acid reached the maximum,followed by malic acid,while oxalic acid presented relatively small increment.Furthermore,the increment in amount of these three organic acids all reached the maximum at level 1.[Conclusion] The proportion of the quantity of each organic acid accounting for the total quantities of organic acids varied slightly,but the overall order was unchanged.