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咸水灌溉对沙漠中罗布麻适应性的调控

花匠小妙招
2025-01-11 23:03

摘要： 通过模拟测定不同矿化度咸水灌溉下红花罗布麻（Apocynum venetum）幼苗叶绿素荧光参数、叶水势和株高生长速率，研究了不同矿化度咸水灌溉对其适应性的调控。研究结果表明，随着灌水矿化度的增加，叶片样本的叶绿素含量呈先下降再升高的波动状态，叶水势基本保持稳定；光能的吸收、分配和耗散在10 g·L-1达到平衡，株高生长速率在10 g·L-1出现最大值9.8 mm·d-1；随着胁迫时间的延长，表征健康程度的最大量子产率Fv/Fm下降，对溶液中金属离子的吸收增加；第21天，表征抗逆性大小的非光化学淬灭系数NPQ出现极大值，吸收能量比例参数Y(Ⅱ)先下降再恢复，3种能量吸收、分配、耗散参数比例在10 g·L-1稳定于Y(Ⅱ):Y(NO):Y(NPQ)=65%∶20%∶15%。根据研究结果，建议在塔克拉玛干沙漠南缘红花罗布麻的育苗过程中，应该分阶段抚育，幼苗期宜采用5~10 g·L-1矿化度的咸水灌溉，保持较高叶水势，可以防止叶绿素分解；采用10 g·L-1的咸水灌溉可使其幼苗保持稳定的、较高的光化学能量转化比例，能够较好地调控其对塔克拉玛干沙漠南缘绿洲荒漠过渡带生境的适应性，有助于过渡带的恢复和建设。

关键词: 咸水灌溉, 叶水势, 能量分配策略, 生长速率

Abstract: The responses of chlorophyll fluorescence, leaf water potential and growth rate of Apocynum venetum seedlings to different saline water irrigation treatments were investigated. With the increase of saline water concentration, the leaf's chlorophyll content drops firstly and then increases, but the leaf water potential maintains stable basically; The absorption, assignment and dissipation of light energy reach equilibrium at saline water concentration of 10 g·L-1, and the growth rate of Apocynum venetum seedlings also reaches the highest value of 9.8 mm·d-1 at saline water concentration of 10 g·L-1. Along with the stress process extending, the greatest quantum yield Fv/Fm drops, and the absorption of metallic ion from the solution increases. In the 21st day after saline water irrigation, the non-photochemical quenching coefficient (NPQ) presents the maximum value; the energy absorption proportion parameter Y(Ⅱ) drops firstly and then restores again; the proportion of energy absorption to energy assignment and to energy dissipation parameters stabilizes at Y(Ⅱ):Y(NO):Y(NPQ) = 65%∶20%∶15% at saline water concentration of 10 g·L-1. In the A. venetum nursery process in the southern edge of the Taklimakan Desert, phase-difference nursing strategy should be adopted according to different seedling stage: 5~10 g·L-1 saline water should be used in irrigation in the seedling stage to maintain a higher leaf water potential, which could prevent the decomposition of chlorophyll. Besides, the 10 g·L-1 salt water irrigation treatment could maintain higher proportion of photochemical energy conversion, which is helpful to the restoration and construction of oasis-desert ecotone in southern margin of the Taklimakan Desert.

Key words: saline water irrigation, leaf water potential, energy allocation strategy, growth rate

中图分类号:

Q945.1