盐胁迫对两种吊兰光合特性和气孔形态的影响.docVIP

盐胁迫对两种吊兰光合特性和气孔形态的影响 　　摘要：选用吊兰（Chlorophytum comosum）和金边吊兰（Chlorophytum comosum cv. variegatum）一年生幼苗进行盆栽试验，设置盐分（NaCl）梯度为0和0.8%，研究了盐胁迫对两种吊兰生长、光合特性及气孔形态的影响。结果表明，在盐胁迫下，两种吊兰的叶片叶绿素含量、净光合速率（Pn）、气孔导度（Gs）和蒸腾速率（Tr）均下降，而细胞间CO2浓度（Ci）增加，说明非气孔限制因素可能是两种吊兰光合能力下降的主要原因。两种吊兰通过改变根冠比和气孔密度、开放度来适应盐胁迫环境，表现出了一定的耐盐性，但两个品种间的耐盐性并无明显差异。本试验过程中发现两种吊兰都有泌盐的现象，通过扫描电镜技术分析发现，两种吊兰叶片和幼茎表皮气孔内都有残留的盐颗粒存在，说明吊兰气孔不仅仅用于气体和水分的交换，可能还兼有泌盐的功能。 　　关键词：吊兰（Chlorophytum comosum）；盐胁迫；气孔；泌盐 　　中图分类号：S682.31 文献标识码：A 文章编号：0439-8114（2016）19-4982-05 　　DOI：10.14088/j.cnki.issn0439-8114.2016.19.021 　　Abstract： The pot culture technique was used to study growth，photosynthetic characteristics and stoma structure of Chlorophytum comosum and Chlorophytum comosum cv. Variegatum，under two levels of salt stress（0% and 0.8%）. Photosynthetic rate （Pn），stomatal conductance（Gs），transpiration rate（Tr），the chlorophyll content were lower and intercellular CO2 concentration （Ci） was increased than control，and non-stomata factors were probably the main causes of photosynthetic capacity decrease.Under the high concentration of salt stress，the density of leaf stomas was significantly increased，and the relative opening degree was decreased than those in the control， dry-weight of the overground was decreased，and root cap ratio was increased，this showed that two cultivars’ root cap ratio，density and the relative opening degree of stomas were changed to adapt high salinity environment，they had certain salt tolerance，but two varieties showed no marked difference. In addition， crystallized salt was accumulated on the surface of young leaves and stems，the results showed that excess salt was maybe discharged through two kinds of bracketplant’ s stomas by scanning electron microscope，it has revealed that stomata were not only controlling gas and water exchange，but also could secrete salt. 　　Key words： Chlorophytum comosum； salt stress； stomata； salt excretion 　　吊兰（Chlorophytum comosum）是百合科吊兰属多年生草本，原产南非，世界各地广泛栽培，喜欢温暖湿润、半阴环境，适应性强，吸收甲醛等有毒气体的能力强，