滴灌水量和灌溉频率对温室番茄光合荧光特性与产量品质的影响

Effects of Irrigation Amount and Frequency on Photosynthetic Fluorescence Characteristics, Fruit Yield and Quality of Drip-irrigated Greenhouse Tomato

摘要:

为优化西北旱区日光温室膜下滴灌番茄灌溉制度，本研究于2023年开展春、秋两茬试验，设置4个灌水量（W1：125%ETc，W2：100%ETc，W3：75%ETc，W4：50%ETc，其中ETc为作物需水量）和3个灌溉频率（D1：每4d灌溉1次，D2：每7d灌溉1次，D3：每10d灌溉1次），综合评估灌水量与灌溉频率对土壤含水率分布、番茄根系构型、光合荧光特性、产量品质及水分生产力的影响。结果表明：灌水量与灌溉频率对根系构型、光合荧光特性、产量品质及水分生产力指标影响显著（P＜0.05）。高频灌溉（D1）显著提升0~60cm土层土壤含水率，且秋茬土壤含水率高于春茬。适当增加灌水量和高频灌溉有利于番茄根系生长，提高番茄叶片光合荧光参数，从而促进光合效率提升。W2D1处理总根长与根表面积显著高于其他处理（P＜0.05），而过量灌溉不利于根系生长。W2D1处理净光合速率、光系统最大光化学效率、PSⅡ实际光化学量子产量及叶片叶绿素相对含量均最大。适当增加灌水量和高频灌溉可提高产量5.74%~57.78%。高频灌溉可提高水分生产力，增加番茄果实中可溶性固形物含量、维生素C含量、可溶性糖含量、可滴定酸含量，提升番茄品质。基于TOPSIS多目标综合评价方法对番茄地下部根系特征指标、叶片光合荧光参数、产量品质、水分生产力综合评价，得出W2D1处理的综合指标相对贴近度最大，其综合评价最优。研究结果可为制定西北地区膜下滴灌温室番茄高效节水灌溉制度提供理论依据和技术支撑。

Abstract:

In order to optimize the irrigation system of tomato under film drip irrigation in solar greenhouse in Northwest China, two experiments in spring and autumn in 2023 were conducted, four irrigation amounts (W1: 125% ETc, W2: 100% ETc, W3: 75% ETc, W4: 50% ETc, ETc is crop evapotranspiration) and three irrigation frequencies (D1: every 4 days, D2: every 7 days, D3: every 10 days) were set, and the effects of irrigation amount and irrigation frequency on soil moisture content distribution, root architecture, photosynthetic fluorescence characteristics, yield quality and water productivity of tomatoes were systematically evaluated. The results showed that irrigation amount and irrigation frequency had significant effects on root architecture, photosynthetic fluorescence characteristics, yield quality and water productivity (P<0.05). High-frequency irrigation (D1) significantly increased the soil water content in the 0~60cm soil layer, and the soil moisture content in autumn was higher than that in spring. Appropriately increasing irrigation amount and high-frequency irrigation was beneficial to the growth of tomato roots, improving the photosynthetic fluorescence parameters of tomato leaves, and thus promoting the improvement of photosynthetic efficiency. The total root length and root surface area of W2D1 treatment were significantly higher than those of other treatments（P<0.05), while excessive irrigation was not conducive to root growth. The net photosynthetic rate, maximum photochemical efficiency of the photosystem, actual photochemical quantum yield of PSⅡ and relative content of leaf chlorophyll in the W2D1 treatment were maximized. Appropriately increasing irrigation amount and high-frequency irrigation could increase yield (5.74%~57.78%). High-frequency irrigation could improve water productivity, increase soluble solids content, vitamin C content, soluble sugar content, and titratable acid content in tomato fruits, thereby improving tomato quality. A comprehensive evaluation of underground root characteristics, leaf photosynthetic fluorescence parameters, yield and quality, and water productivity by using the TOPSIS multi-objective comprehensive evaluation method revealed that the W2D1 treatment had the highest relative similarity in comprehensive indicators, resulting in the optimal comprehensive evaluation. The research results can provide a theoretical basis and technical support for the formulation of efficient water-saving irrigation system for greenhouse tomatoes under mulched drip irrigation in Northwest China.