土壤碱胁迫下杜梨高生长与矿质元素含量的关系

摘要

To investigate the effects of soil alkalization on growth performance and mineral nutrition of afforestation species preferred on saline-alkaline areas,one-year-old seedlings of Pyrus betulaefolia Bunge were grown for 1 growth season under 7 artificial soil alkali stress treatments via adding NaOH solutions of different concentrations,which were 0,100,200,300,400,500 and 600 mmol/L respectively,to a total of 50 L each to each treatment.Soil pH and electric conductivity were monitored every month,while survival and height growth of seedlings and also mineral element contents (Cu,Mg,Zn,Fe) of their roots,stems and leaves were measured each month too.The results showed that at soil pH 10.16 by adding a NaOH solution of 600 mmol/L,survival of Pyrus betulaefolia Bunge were relatively lower (about 60％),and relative height growth (RHG) and Fe content were significantly reduced than other treatments (pH9.08-10.06).Also at soil pH 10.16,root Cu content was significantly lower than stem and leaf and root Fe content was same as leaf,in contrary to the differences of Cu and Fe contents among different organs at soil pH9.08-10.06.Meanwhile,RHG of Pyrus betulaefolia Bunge at soil pH 9.08-10.06 was positively related to root Cu and Fe contents,demonstrating the importance of root contents of these 2 mineral elements in growth of Pyrus betulaefolia Bunge under soil alkalization.%为了解土壤碱化对杜梨苗期高生长和矿质营养的影响,本研究以1年生杜梨(Pyrus betulaefolia Bunge)幼苗为材料,在大田中通过逐级递增添加合计50L的不同浓度NaOH溶液设置了7个人工土壤碱胁迫处理(添加的NaOH浓度分别为0、100、200、300、400、500、600 mmol/L),于1个生长季内按月连续监测土壤pH和电导率,统计幼苗存活率和测量高生长,并测定根、茎、叶中铜、镁、锌、铁等4种矿质元素的含量.结果表明,添加600 mmol/L NaOH溶液处理下(pH=10.16)杜梨的存活率降至60％,相对高生长(RHG)显著低于其他6个处理(pH为9.08～10.06),整株全铁含量显著较少.在土壤pH为10.16时,杜梨幼苗根中铜含量显著少于茎、叶.此外,在pH为9.08～10.16的碱性土壤,杜梨RHG与根中铜、铁元素的含量呈显著的正相关.