Xiao Huai-Juan, Li Juan-Qi, Wang Ji-Qing, DU Qing-Jie
College of Horticulture, Henan Agricultural University, Zhengzhou 450002, China.
Ying Yong Sheng Tai Xue Bao. 2020 Aug;31(8):2630-2636. doi: 10.13287/j.1001-9332.202008.028.
We explored the effects of sub-low temperature and drought on water transport in tomato seedlings under normal temperature (25 ℃ day/18 ℃ night) and sub-low temperature (15 ℃ day/8 ℃ night) within the artificial climate chamber, and under normal irrigation (75%-85% field water holding capacity) and drought treatment (55%-65% field water holding capacity). We analyzed the effects of temperature and soil moisture on water transport, stomata and xylem vessel morpholo-gical and anatomical structure of tomato plants. The results showed that compared with condition of normal temperature + normal irrigation, drought treatment significantly reduced leaf water potential, transpiration rate, stomatal conductance, hydraulic conductance, sap flow rate, stomatal length, and diameter of leaf, stem and root conduit, and thus thickened the cell wall and enhanced the anti-embolism ability of conduit in leaf, stem and root. Leaf water potential, transpiration rate, stomatal conductance, hydraulic conductance, and conduit diameter in leaf, stem and root were significantly reduced by sub-low temperature treatment, but the stomata became larger, cell wall was thickened and the anti-embolism ability was enhanced in leaf, stem and root conduit. Under sub-low temperature condition, soil moisture did not affect leaf water potential, transpiration rate, stomatal conductance, hydraulic conductance, stomatal morphology, conduit structure of leaf and root. In conclusion, under drought treatment, the homeostasis in water relationship was obtained by the coordination of leaf, stem and root structure. Under sub-low temperature treatment, the regulation of water relationship was mainly dependent on the changes of conduit structure in leaf and root, which was less affected by soil moisture.
我们在人工气候箱内，探究了亚低温和干旱对番茄幼苗在正常温度（白天25℃/夜晚18℃）和亚低温（白天15℃/夜晚8℃）条件下，以及正常灌溉（田间持水量的75%-85%）和干旱处理（田间持水量的55%-65%）时水分运输的影响。我们分析了温度和土壤湿度对番茄植株水分运输、气孔以及木质部导管形态和解剖结构的影响。结果表明，与正常温度+正常灌溉条件相比，干旱处理显著降低了叶片水势、蒸腾速率、气孔导度、水力导度、液流速率、气孔长度以及叶、茎和根导管的直径，从而增厚了细胞壁并增强了叶、茎和根中导管的抗栓塞能力。亚低温处理显著降低了叶、茎和根的叶片水势、蒸腾速率、气孔导度、水力导度以及导管直径，但叶、茎和根中的气孔变大，细胞壁增厚，导管的抗栓塞能力增强。在亚低温条件下，土壤湿度不影响叶片水势、蒸腾速率、气孔导度、水力导度、气孔形态以及叶和根的导管结构。总之，在干旱处理下，通过叶、茎和根结构的协调实现了水分关系的稳态。在亚低温处理下，水分关系的调节主要依赖于叶和根中导管结构的变化，受土壤湿度的影响较小。
