水分胁迫对三峡库区消落带桑树幼苗生理特性的影响

Effects of Water Stress on Physiological Characteristics of Mulberry(Morus alba) seedlings in the Hydro-Fluctuation Belt of the Three Gorges Reservoir Area

对消落带和河岸带受损生态系统进行植物生态修复是非常有效的治理途径之一（马利民等,2009;戴方喜等,2006;滕衍行等,2005;Lowrance etal.,2000;Naima,2000;Dennis,1999）,而植被恢复首先要解决的问题是适生植物的筛选（马菲等,2010）。按照国内外现有研究方法消落带植被修复树种在三峡库区消落带的治理实践屡屡失败,许多耐干旱的植物不耐水淹,

Guisang 12,a variety of mulberry（Morus alba）,was used to study the effects of different levels of water hardening on physiological characteristics of the mulberry seedlings in the hydro-fluctuation belt of the Three Gorges Reservoir Area.The seedlings were subjected to different water regimes for 30 days.The results showed that：the chlorophyll content of mulberry seedlings was increased by 10.4% under the drought hardening（DH） condition than that of CK,while decreased by 3.2% under the waterlogging hardening（WH） condition than that of CK.With the soil moisture content reducing,the stomatal conductance（Gs） and transpiration rate（Tr） of mulberry seedlings both declined remarkably;The photosynthetic rate（Pn） of mulberry seedlings under the drought hardening and waterlogging hardening conditions was all higher than that of CK,and the intercellular CO2 concentration（Ci） under the two conditions was lower than that of CK;The instantaneous water use efficiency of mulberry seedlings under the drought hardening and waterlogging hardening conditions was remarkably increased by 57% and 27% than that of CK,respectively,and the abscisic acid（ABA） content in the two conditions were remarkably increased by 79% and 29% than that of CK,respectively.