摘要
探讨了以叶片水势((?)_L)、气孔阻力(Rs)、蒸腾速率(Tr)作为果树水分亏缺指标的可行性.结果表明:黎明前(?)_L与上午10时左右的净光合速率(Pn)Tr以及果实直径、土壤水分含量明显相关;晴朗天气下,上午10时左右的Rs、Tr对水分亏缺反应明显,与(?)_L、Pn、果实直径增长、土壤含水量明显相关.三个指标较好地反映出与树体水分亏缺相联系的生理过程及土壤含水量,可作为评估树体水分状况适宜程度的良好指标.研究也证明:相同条件下,树体各部分三指标的大小不同,根据灌溉应满足树体水分竞争代谢“弱者”的原则,(?)L的取样部位应为树冠上部枝条的下位叶,而Rs、Tr则为内膛无果短梢叶.
The probability of L, Rs, Tr as parameters of water stress of fruit crops was approached. The results showed that L at predawn was correlated with Pn and Tr at 10 A. M. , fruit growth and soil water content significantly; Rs and Tr at 10 A. M. in sunny day were very sensitive to water stress of fruit crops and were correlated with L, Pn and soil water content signficantly. These three parameters closely related to the physiological process concerning water stress and soil water content, so that they are good indexes indicating the water status of fruit trees. The results showed that L, Rs, Tr were different when the samples were collected from different parts in the tree canopy. According to the principle that due to water competition irrigation should satisfy the need of leaves with most severe water stress ('weak part') in the plant, the sample collected for L determination should be the lower leaves from the upper shoot of the crown while for Rs and Tr determinations should be the leaves from nonbearing spurs inside the crown.
出处
《果树科学》
CSCD
北大核心
1995年第4期211-214,共4页
Journal of Fruit Science
关键词
果树
水分亏缺
叶片水势
蒸滕速率
Fruit tree
Water dificit
Leaf water potential
Stomatal resistance
Transpiration rate
