盐胁迫对芦苇根系分泌物的影响

根系分泌物是植物与外界进行反应的重要媒介,其行为具有重要生态学意义.本文研究了盐胁迫下典型湿地植物芦苇根系分泌物成分和含量的变化,分析了盐胁迫质量浓度分别为0(对照)、1、3、6、10g·L-1,胁迫时间分别为2、4和12h时,芦苇根系分泌物的成分和含量的变化.结果表明:所有样品中一共检测出了99种根系分泌物,包括烷烃、烯烃、芳香烃、醇、酚、醚、酮、醛、酸、酯、噻唑以及其他含硫代、卤代化合物,各样品中检出的种类最多的化合物是烷烃类.在不同的质量浓度盐胁迫下,经2h胁迫检测出的化合物种类均高于经4和12h胁迫检测出的种类.盐质量浓度在6g·L-1及其以下时,根系分泌物的化合物总量在经2h胁迫后达到最大值,表明根系分泌物组分和含量随盐质量浓度和胁迫时间先升高后降低,而非单一正相关关系.

Effects of salt stress on root exudates in Phragmites australis

Root exudates have special ecological significance for interactions between plants and environment.The aim of this study was to elucidate the relationship between NaCl stress and types and contents of root exudates from constructed wetland plants such as Phragmites australis.NaCl concentrations used were 0,1,3,6,10 g·L-1 ,exposure times were 2,4,12 h,root exudates from Phragmites australis was subj ect to GC-MS analysis.A total of 9 9 compound classes were detected including alkanes,olefins, arenes,alcohols, phenols, ethers, ketones, aldehydes, acids, esters, thiazoles and other sulphured or halogenated compounds;compounds in the alkane series were higher than others.The variety of compounds was higher under 2 h exposure time than under 4 h and 1 2 h exposures.Total content of compounds reached maximum at 2 h exposure at salinity level less than 6 g·L-1 .It was concluded that variety and total content of Phragmites australis root exudates increased first and then went down with prolonged exposure and increased exposure level.