根域限制对温室膜下滴灌网纹甜瓜耗水特征与果实品质的影响

【目的】利用根域限制技术调节温室网纹甜瓜生长及耗水特性,研究适宜的根域限制方式和限根深度。【方法】以西州蜜25号为试材,设置2种限根方式(纱网布和塑料布)和6种限根深度(10、20、30、40、50、60 cm)组合的根域限制处理,研究了限根对温室膜下滴灌甜瓜耗水特性、干物质积累、果实产量和品质的影响。【结果】与常规种植相比,纱网布限根对甜瓜植株干物质积累量、果实产量和果实外观品质影响不显著(P>0.05);塑料布限根显著降低了甜瓜植株干物质积累量、果实产量、果实横纵经和果形指数(P<0.05)。适度根域限制显著提高了甜瓜的水分利用效率,10 cm和20 cm纱网布限根甜瓜的水分利用效率分别比CK提高了10.90%和5.47%,10 cm和20 cm塑料布限根甜瓜的水分利用效率分别比CK提高了8.06%和4.39%,限根深度过深水分利用效率显著降低。限根显著影响了果实营养品质,限根深度为10、20、30 cm的纱网布限根和限根深度为20、30、40 cm的塑料布限根提高了甜瓜果实可溶性总糖、可溶性固形物量和酸糖比。【结论】温室膜下滴灌条件下,限根深度10~20 cm的纱网布限根对温室网纹甜瓜的营养生长和生殖生长影响不显著,可提高水分利用效率和果实品质,是适宜根域限制方式。

The Effects of Root-zone Restriction on Water Consumption and Fruit Quality of Greenhouse Muskmelon under Mulched Drip Irrigation

【Background】Improvement in living standard has shifted the demand of people for foods from quantity to quality.Given that roots not only anchor crops but also take up nutrients from soil to sustain crops growth,it has been conjectured that managing root growth and development could be an effective way to improve food nutrition while in the meantime reducing agrichemicals leaching and mitigating soil salinization in irrigated fields.Root restriction is one of such technologies,but inappropriate root restriction could impede reproductive growth of the crops,thereby reducing dry matter accumulation and leading to a decline in yield and food quality.Efficacy of root restriction is thus crop-specific.【Objective】Taking muskmelon as an example,this paper aims to experimentally find an optimal root zone restriction that can constraint unnecessary root growth while in the meantime improving water use efficiency and fruit quality of the muskmelon.【Method】The experiment was conducted in a greenhouse and we used the cultivar Xizhoumi 25 as the model crop.Roots were restricted to grow by placing gauze or plastic mesh at a depth between 10~60 cm,with no root restriction as the control(CK).In each treatment,we measured the water consumption,dry matter accumulation,yield and fruit quality of the muskmelon.【Result】Compared with the CK,restricting root growth by the gauze mesh did not affect dry matter accumulation,yield and appearance of the fruit at significant level,as opposed to the plastic mesh that significantly reduced dry matter accumulation,yield,transverse and longitudinal size of the fruits,as well as fruit shape index.Placing the gauze mesh at depths of 10 cm and 20 cm increased water use efficiency by 10.90%and 5.47%respectively,while replacing the gauze mesh by plastic mesh increased the water use efficiency by 8.06%and 4.39%respectively.Burying either mesh too deep resulted in a significant decrease in water use efficiency,suggesting that the depth of the root restriction mesh had an impact on fruit nutrition.It was also found that placing the gauze mesh at depths of 10,20 and 30 cm,or the plastic mesh at the depths of 20,30 and 40 cm,significantly increased the contents of soluble sugar,soluble solids and acid sugar ratio of the fruits.【Conclusion】For muskmelon grown in greenhouse,placing a gauze mesh at a depth between 10~20 cm to restrict its root growth did not have a significant impact on its vegetative and reproductive growth but could effectively improve its water use efficiency and fruit quality.