摘要
运用PV技术研究了土壤干旱胁迫下四种盆栽植物幼苗 (辽东栎Quercusliaotungensis、大叶白蜡Fraxi nusrhynchophylla、柔毛绣线菊Spiraeapubescens和二色胡枝子Lepsedezabicolor)叶片的细胞水分关系 ,以期认识叶片细胞水分在叶龄及生长型上的差异 .结果发现 :幼叶的渗透调节大于成熟叶和老叶 ;干旱增加了叶片细胞束缚水含量 (θ)和细胞壁弹性模量系数 (ε) ,降低了叶片水分饱和状态下的渗透势 (Ψsat)、质壁分离渗透势 (Ψπtlp)、质壁分离时细胞水分相对含量 (RWCtlp) ,以及水分饱和状态下的重量与干重的比率 (TW∶DW ) .干旱引起两种乔木幼苗叶片的细胞水分参数显著变化 ,而对两种灌木影响不显著 ,说明前者的抗旱性较强 .
Quercus liaotungensis forest which is very common in northern China where water is the major factor influencing plant survival and growth, especially for seedlings. In order to get the differences in leaf cell water relations between tree and shrub species, leaf cell water relations were investigated using pressure-volume technique in two tree species (Quercus liaotungensis and Fraxinus rhynchophylla) and two shrub species (Spiraea pubescens and Lepsedeza bicolor) which were one-year-old potted seedlings subjected to natural soil drought by withholding water. The results showed that the osmoregulation in young leaves was greater than that in mature and old ones for four species seedlings all. Drought increased bound water (θ) and modulus of bulk elasticity (ε), whereas decreased osmotic potential at full turgor point (Ψ_(sat)), osmotic potential at turgor loss point (Ψ_(πtlp)) and relative water content at turgor loss point (RWC_(tlp)) and the ratio of weight at full turgor: dry weight (TW:DW). Soil drought caused significant changes in water relation parameters in two tree species while not markedly alterations in two shrub species, indicating that the drought resistance may be greater in tree species than in shrub species. The findings, in combination with changes in plasticity of cell tissues, showed that drought resistance can be ranked with such an order for these four species seedlings: Quercus liaotungensis>Fraxinus rhynchophylla>Spiraea pubescens>Lepsedeza bicolor. Meanwhile, the results here also suggest that responsive differences in water relations of plant leaves to soil drought may be related to appearances of potential growth forms, namely, plant growth forms could be affected by environmental conditions like water stress.
出处
《南京师大学报（自然科学版）》
CAS
CSCD
2004年第4期72-75,共4页
Journal of Nanjing Normal University(Natural Science Edition)
基金
国家自然科学基金"九五"重大资助项目 ( 3 9893 3 60 )
关键词
干旱
PV技术
水分关系
生长型
soil drought, PV technique, water relations, growth form
