【摘要】 采用盆栽试验,研究0.3%NaCl胁迫下全红苋菜(低Cd累积品种,简称全红)和柳叶苋菜(高Cd累积品种,简称柳叶)的有机酸代谢差异及其与Cd累积和耐盐性的关系。结果表明:相比对照,盐胁迫后两个品种根部、地上部和根际土壤溶液中的Cd含量均呈增加趋势,且表现为全红显著低于柳叶(P<0.05),同时全红和柳叶的Cd转运系数分别提高2.84、5.58倍;盐胁迫促进了苋菜对Na~+的积累且明显干扰K~+的吸收,K~+/Na~+均显著降低(P<0.05),且全红根部K~+/Na~+显著高于柳叶(P<0.05)。盐胁迫后,两个品种根部、地上部及根际土壤溶液中均检测到多种有机酸,其中根际土壤溶液中苹果酸和草酸含量均显著升高(P<0.05),且与根际土壤溶液中的Cd含量显著正相关;柳叶地上部草酸及根部乙酸的含量均显著升高(P<0.05),且分别与地上部及根部Cd含量显著正相关。研究表明,盐分胁迫下,全红具有较低的Cd累积性且表现出更强的耐盐性,不同品种的有机酸积累和分泌的差异是导致这一结果的重要原因之一。更多还原

【Abstract】 Soil Cd pollution and soil salinization have severely threatened agricultural development and human health.It is important to study Cd accumulation and salinity tolerance of vegetables.Here a pot experiment was conducted to examine the influence of organic acid metabolism on Cd accumulation and salinity tolerance of two amaranth cultivars(Quanhong and Liuye)under 0.3% Na Cl stress.Results showed that:Under salinity stress,the content of Cd in roots,shoots,and rhizospheric soil solution and the translocation ratios(from roots to shoots)of Cd in two cultivars increased compared with the control.Cadmium concentrations in Quanhong were obviously lower than those in Liuye.In addition,the content of Na+was significantly increased but K+absorption was obviously inhibited by salt stress;Under salinity stress,various organic acids were detected in roots,shoots and rhizospheric soil solution.Malic acid and oxalic acid were significantly increased,which were significantly positively correlated with Cd content in rhizospheric soil solution(P<0.05).In Liuye,the content of oxalic acid in shoots and acetic acid in roots was significantly increased,and were significantly positively correlated with the correspondling Cd content(P<0.05).These results suggest that Quanhong has lower Cd accumulation,stronger salinity tolerance,which was attributed to the variations of organic acids in the plants.更多还原