盐和水分胁迫对海蓬子、芦荟、向日葵幼苗生长及其离子吸收分配的效应

研究了NaCl和聚乙二醇6000(PEG 6000)处理对海蓬子、芦荟、向日葵幼苗生长及其离子吸收和分配的效应。结果表明，海蓬子幼苗的生长需盐，-1．76 MPa NaCI为其生长的最适浓度，其地上部积累的Na^ 和Cl^-分别是对照的6和8倍；但随着水分胁迫强度增强，其幼苗干物质积累显下降。在等渗透势胁迫下，向日葵和芦荟对水分胁迫的适应能力高于盐胁迫，与保持体内高的K^ ／Na^ 比率有关。盐处理下海蓬子维持K^ 稳态的能力较强；向日葵对盐分的适应主要取决于盐分在根系和茎杆的积累，对K^ 的选择性吸收、运输较强；而芦荟主要是对离子的选择性吸收和运输较强。

Effects of salt and water stresses on growth and ionic absorption and distribution in Salicornia europaea,Aloe vera and Helianthus annuus seedlings

Growth and ionic absorption and distribution in Salicornia europaea,Aloe vera and Helianthus annuus seedlings exposed to different NaCl and polyethylene glycol 6000(PEG 6000)concentrations were studied.The results showed that salt was required for the growth of Salicornia europae seedlings,and -1.76 MPa NaCl was the optimum concentration.The contents of Na + and Cl - in shoot were 6 and 8 times the value of control,respectively.But dry matter accumulation of the seedlings decreased dramatically with the increase of water stress intensity.Due to maintaining a higher K +/Na + ratio in Aloe vera and Helianthus annuus seedlings,they were more adaptative to water stress than to iso-osmotic salt stress.K + homeostasis was highly maintained in Salicornia europaea under salt stress.Adaptaion to salt in Helianthus annuus was mainly caused by salt accumulation in root and stem and strong K + selective absorption and transport.But for Aloe vera,it was mainly owing to ionic selective absorption and transport.