Diurnal and seasonal responses of stomatal conductance for cowpea plants subjected to different levels of environmental drought
Diurnal and seasonal responses of stomatal conductance for cowpea plants subjected to different levels of environmental drought
复制标题
不同程度环境干旱下豇豆植株气孔导度的日间和季节响应
DOI：
10.1007/bf00379997
复制
发表时间：
1982
期刊：
影响因子：
2.7
通讯作者：
A. Hall
中科院分区：
文献类型：
--
作者：
L. Bates;A. Hall
之前我们报道过豇豆（Vigna unguiculata）的叶片电导随土壤水分状况的微小变化而降低，而叶片水分状况没有相关变化。在这些研究中，由于长期土壤干燥以及每周用不同量的水灌溉，在无雨环境中造成了更大范围的土壤水分亏缺。随着土壤水分逐渐亏缺，叶片电导率和木质部压力势均下降，但下降的方式表明它们之间并不相关。叶导度的日变化过程通常表明气孔开放发生在上午，气孔部分或完全关闭发生在中午和下午。这种气孔关闭与空气蒸气压不足的增加有关。当辐射不限制气孔开放时，叶片电导率的日常增加与空气蒸气压不足的减少有关。然而，对于土壤水分消耗较大的植物来说，最大叶片电导及其对蒸气压不足的响应通常较小。
Previously we reported that leaf conductance of cowpea (Vigna unguiculata) decreased with small changes in soil water status without associated changes in leaf water status. In these studies a larger range of soil water deficits was imposed in a rain-free environment by prolonged soil drying, and by weekly irrigation with different amounts of water. With progressive soil water deficits, leaf conductance and xylem pressure potential both declined, but in a manner which indicated that they were not related. Diurnal courses of leaf conductance usually indicated that stomatal opening occurred in the morning, and partial or complete stomatal closure occurred during midday and afternoon. This stomatal closure was associated with increases in air vapor pressure deficit. Day-to-day increases in leaf conductance, at times when radiation was not limiting stomatal opening, were associated with decreases in air vapor pressure deficits. However, maximum leaf conductances and their responses to vapor pressure deficit were generally smaller for plants subjected to greater depletion of soil water.