摘要
[目的]研究水分胁迫对华北景天(Sedum tatarinowii Maxim)叶片结构和叶绿素含量的影响,为其更广泛应用提供参考。[方法]取山西省霍山七里峪国家森林公园的野生华北景天,经过人工栽培后进行水分胁迫。试验共设4组,土壤绝对含水量分别为17.50%、13.60%、9.60%、6.20%,以土壤绝对含水量17.50%为对照。土壤绝对含水量采用烘干称重法测定;叶片中叶绿素含量采用丙酮浸提法测定;取生长良好、洁净的叶片,制备石蜡切片和表皮制片,观察气孔器类型和分布特征,测定气孔密度。[结果]在正常条件下,华北景天叶片表面具薄的蜡质层,叶内有发达的储水组织,并分布有吸水能力较强的异细胞;气孔白天关闭,夜晚开启,气孔器下陷;水分胁迫下,上表皮出现了发育不完全的气孔,成熟气孔密度呈下降趋势,下表皮气孔密度变化不明显。华北景天叶绿素a、b对活性氧的反应差异不明显,而且在一定程度的干旱条件下叶绿素含量有所增加;土壤绝对含水量为9.60%时,华北景天可维持正常光合作用;当土壤绝对含水量下降到6.20%时,叶绿素含量有所下降。[结论]华北景天具有典型的旱生植物形态特征,在较低的土壤绝对含水量时,叶绿素含量可保持不变或稳定增加的趋势,维持植物正常光合作用。
[Objective] To study the effect of water stress on the structure and chlorophyll content of S.tatarinowii Maxim leaves,so as to provide references for its wide application.[Method] Wild S.tatarinowii Maxim sampled from Qiliyu National Forestry Park in Huoshan of Shanxi Province were cultivated and then treated by water stress.Four groups were set up with the absolute water content in soil of 17.50%,13.60%,9.60% and 6.20% respectively,among which 17.50% was the control.The absolute water content of soil was determined by dry weighting method;while the chlorophyll content in the leaves was detected by acetone extraction method;the well-grown and clean leaves were sampled to prepare paraffin section and epidermis section so as to observe the type and distribution features of stomatal apparatus as well as the stomatal density.[Result] Under normal conditions,the leaves of S.tatarinowii Maxim were coated with wax on the surface,and had developed water storage tissue and idioblast with high water absorption capacity inside;the stomata closed during the daytime,while opened at night,the stomatal apparatus subsided;under water stress,the immature stomata appeared on the upper epidermis,and the density of mature stomata showed declining tendency,while the change of stomatal density on the lower epidermis was not obvious.The reaction of chlorophyll a and b to active oxygen was not significantly different,and the content of chlorophyll increased under certain degree of drought conditions;when the absolute water content in soil was 9.60%,S.tatarinowii Maxim could maintain its normal photosynthesis;while when the absolute water content in soil decreased to 6.20%,the chlorophyll content declined.[Conclusion]S.tatarinowii Maxim had typical features of xerophyte,when the absolute water content in soil maintained at a low level,the chlorophyll content remained unchanged or stable increasing trend,and the normal photosynthesis of plants could be maintained.
出处
《安徽农业科学》
CAS
北大核心
2011年第26期15902-15903,15912,共3页
Journal of Anhui Agricultural Sciences
基金
山西师范大学自然科学基金项目(YZ08017)
关键词
华北景天
水分胁迫
叶片结构
叶绿素含量
S.tatarinowii Maxim
Water stress
Leaf structure
Chlorophyll content
作者简介
那冬晨（1964-），女，辽宁台安人，副教授，博士，从事植物分子生物学研究。
