亚低温下水分对番茄幼苗干物质积累与养分吸收的影响

【目的】揭示亚低温条件下水分对番茄幼苗氮钾营养元素吸收与分配的影响，为冬季温室番茄水肥科学管理提供依据。【方法】以番茄为材料，在温室内采用盆栽的方式，以适温( 18—30℃ )环境为对照，研究亚低温(4—20℃ )条件下，灌溉补充蒸腾蒸发量(ET) 分别为 60%、80%、100%和 120% 的水分对温室番茄幼苗干物质积累分配及养分吸收分配的影响。【结果】与适温相比，亚低温下番茄幼苗根、茎、叶干物质的积累量随着补充水分的减少逐渐降低，且处理时间越长降低得越多；干物质向叶片分配的比例减少，向根茎中的分配比例增大；亚低温下番茄幼苗植株中N、K的总含量降低，N总量随着补充水分的减少而减少，K总量在补充100% ET时最大；亚低温使番茄幼苗根茎叶中N的含量增加，K的含量降低；根茎中N的含量随着补充水分的减少而降低，叶片中N的含量在补充100% ET 时最高，根茎叶片中K的含量在补充60% ET时最高。亚低温下补充的水分小于80% ET时，根茎叶中N的积累量显著下降；随着处理时间的延长，N向叶片中的分配率降低，根茎中的分配率升高。随着生长时间的延长，番茄幼苗K向叶片中的分配率先降低后升高，根中的分配率大于适温下生长的番茄，且随补充的水分减少而逐渐升高。亚低温下补充100% ET水分叶片水势最大。【结论】在亚低温条件下补充100% ET水分有利于番茄幼苗干物质的积累以及对氮、钾元素的吸收。亚低温下番茄幼苗植株N的总量受水分影响较大，K总量受温度的影响较大。

Effects of Water on Dry Matter Accumulation and Nutrition Absorption of Tomato Seedling Under Sub-Low Temperature

【Objective】 This study aims at discovering the effects of water on nitrogen and potassium nutrient absorption and distribution by tomato seedling growing at sub-low temperature, so as to provide a theoretical basis for nutrient management of greenhouse tomato cultivation in winter. 【Method】 With potted tomato plants in greenhouse as the experiment materials, and with the plants under normal temperature (18-30℃) and 100%ET as control treatment, the influences of supplement 60%, 80%, 100% and 120% of ET of irrigation amount on the nutrition absorption and the influence of the distribution in tomato under sub-low temperature (4-20℃) in greenhouse were investigated. 【Result】 Compared with the control treatment, dry matter accumulation in root, stem and leaf of tomato seedlings decreased with the decrease of ET water under sub-low temperature, and the longer the treatment time, the more reduction. The distribution proportion of dry matter in leaf decreased, but that in the stem and root increased. Under sub-low temperature the total content of N and K in tomato seedlings was lower than the control, the amount of N element reduced when the supplementary water dropped. The amount of K element was the highest with 100% ET of irrigation amount. The sub-low temperature increased the N content but reduced the K content in leaf, stem, and root. N content in the roots and stem reduced with the supplementary of water. N content in the leaf was the highest when 100% ET of irrigation amount was supplied, while that in the root and stem was the highest when 60% ET of irrigation amount was supplied. When the water supplied was less than 80% ET under low temperature, the accumulation of N in root, stem and leaf decreased significantly. As the treatment time prolonged, the distribution rate of N in the leaf was reduced, while that in the root and stem increased. When the growth time prolonged, the distribution rate of K in leaf decreased first but then rose. The distribution rate in root was larger than that in the control treatment, and rose when the supplementary water reduced. Under sub-low temperature, leaf water potential was the highest when 100% ET of water was supplied. 【Conclusion】 Under the sub-low temperature condition, supplying 100% ET water favors dry matter accumulation and absorption of nitrogen and potassium by tomato seedling. Total nitrogen is influenced greatly by water amount and total K is influenced greatly by temperature.