亚低温胁迫下补光对番茄幼苗生长及光合性能的影响

【目的】研究亚低温逆境胁迫下,补光对番茄幼苗生长发育及光合性能等生理指标的影响,分析亚低温胁迫下番茄幼苗对补光的生理响应,为亚低温胁迫下培育番茄壮苗提供理论依据和技术支撑。【方法】以番茄Money maker为材料,利用改良Hoagland营养液定期定量灌溉,采用白∶蓝为2∶1的复合光于亚低温胁迫条件下(昼15℃/8夜℃)对番茄叶片补光,共设置4个处理:正常温度处理(CK)、正常温度补光处理(CK+USL)、亚低温胁迫处理(LT)和亚低温胁迫补光处理(LT+USL)。【结果】与亚低温胁迫相比,亚低温补光后,番茄植株株高、茎粗分别显著增加24.92%和4.58%,叶、茎、根鲜重及总鲜重分别显著增加了24.71%、23.68%、31.01%和25.23%;番茄幼苗总根长、根系表面积、根系体积及投影面积分别显著增加了25.73%、29.31%、25.93%和14.22%;叶片净光合速率(Pn)、气孔导度(Gs)及蒸腾速率(Tr)分别增加85.77%、19.09%和44.59%,而胞间二氧化碳浓度(Ci)降低15.60%。【结论】亚低温胁迫条件下,叶背面补光可以显著改善番茄幼苗的生长及光合性能,促进番茄幼苗的健壮生长。

Effects of Supplemental Lighting of Leaves on Growth and Photosynthetic Performance of Tomato (Coreopsis tinctoria) Seedlings under Sub-Low Temperature Stress

【Objective】 This experiment aims to clarify the physiological response of tomato seedlings to supplemental lighting under sub-low temperature stress by studying the effects of supplemental lighting on tomato seedling growth and photosynthetic performance with a view of providing theoretical basis and technical support for the cultivation of strong tomato seedlings under such stress.【Method】 The experiment used the tomato variety 'Money Maker' as the material and employed regular Hoagland nutrient solution for regular quantitative irrigation, and applied white: blue (2∶1) compound light to treat tomato seedlings under sub-low temperature conditions of 15℃/8 (day/night) supplemental lighting. A total of four treatments were set, namely normal temperature without light treatment (CK), normal temperature with supplemental lighting (CK+USL), sub-low temperature stress (LT), sub-low temperature stress supplemental lighting (LT+USL).【Result】 Compared with the sub-low temperature stress, plant height and stem diameter of tomato plants increased significantly by 24.92% and 4.58%, respectively, and the fresh weight of leaves, stems, roots and total fresh weight increased significantly by 24.71%, 23.68%, 31.01% and 25.23%, respectively, total root length, surface area, total volume and projected area of tomato seedlings increased significantly by 25.73%, 29.31%, 25.93% and 14.22% , respectively. In addition, leaf net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) increased by 85.77%, 19.09% and 44.59%, respectively, while the intercellular carbon dioxide concentration (Ci) decreased by 15.60% after supplemental lighting under sub-low temperature.【Conclusion】 Under sub-low temperature stress, supplemental lighting of the leaves can significantly improve the photosynthetic performance of tomato seedlings, thus promoting robust growth of tomato seedlings.