硅对盐胁迫下黄瓜幼苗生长和矿质元素吸收的影响

采用幼苗水培实验,研究外源硅对盐胁迫下黄瓜幼苗生长过程中吸收某些矿质元素的影响。对植株地上部和地下部各元素的分析表明,盐胁迫条件下,外源硅有效调节了黄瓜根系对Na+、Ca2+、K+的吸收以及向地上部的转运。适量的硅降低了黄瓜根系从介质中吸收Na+量,并减少其向地上部的运输,而增加了植株体对K+、Ca2+的吸收和转运量,有效缓解了Na+对黄瓜植株体造成的盐胁迫伤害,保证了黄瓜幼苗的正常生长。在相同的处理条件下,盐分敏感品种的Na+在根系和地上部累积量都要比耐盐品种高,而K+的积累量却正好相反,这可能是耐盐品种减轻盐害的主要方式。对其它营养元素的研究表明,施硅抑制了对N素的吸收,对P素的吸收则影响不大。

Effects of Silicon on Cucumber Seeding Growth and Plant Nutrition Under Salt Stress

Seed water culture experiments were conducted to study the effects of silicon on the cucumber seeding growth under salt stress.Analysis of the elements in the shoot and root showed that silicon inhibited Na~+ uptake,but inhanced the K~+、and Ca~(2+) uptake under salt stress,indicating that silicon could alleviate the damage induced by salt stress.The absorption and the root-to-shoot transportation of Na~+,Ca~+ and K~+,were effectively adjusted by the addition of silicon under salt stress.Exogenous silicon increased the uptake and transport of K~+ and Ca~(2+),but there was a negative effect on Na~+.The lower uptake and accumulation of Na~+ mitigated the salt damage and enhanced the growth of salt-stressed cucumber.The accumulation of Na~+ in the root and shoot was higher in salt-sensitive cultivar than in salt-tolerance one,but an opposite was found for K~+ and Ca~(2+).Analysis on the other nutrient elements showed that silicon application decreased the content of N but it had minor effects on P content.