干旱条件下小麦叶片膨压维持方式的研究

STUDY ON THE MODE OF TURGOR MAINTENANCEIN WHEAT LEAVES UNDER DROUGHT CONDITION

用Ｐ－Ｖ技术研究了冬小麦苗期、拔节期和孕穗期功能叶膨压维持方式。结果表明，在水分胁迫条件下，各时期小麦叶片均产生渗透调节能力，水分胁迫越重，渗透调节能力越强。苗期中度水分胁迫使叶组织｜β｜和ＥＶｍ减小，弹性改善。拔节期和孕穗期水分胁迫使组织弹性减小，而且，水分胁迫越重，叶组织弹性越差。说明除苗期渗透调节和弹性调节并存外，在小麦生育中后期，干旱条件下叶片主要靠渗透调节维持膨压，不存在弹性调节能力。

P-V technique was used to test the mode of turgor maintenance of wheat leaf at seedling, jointing and earing stages. Results showed that osmotic adjustment occured at eachgrowth stage of wheat under water stress condition. The more plants suffered from waterstress, the stronger osmotic adjustment ability got. At seedling stage,EVm and |β|decreased and cell wall elasticity improved under soil water stress.However,at jointing andearing stages, cell wall elasticity decreased under soil water stress. This indicates that exceptseedling stage, at which both osmotic and elastic adjUstment occured simultaneously, elasticad justment does not play a role in maintaining turgor of leaf at mid-late growth stage ofwheat.