不同种植方式和亏缺灌溉对设施黄瓜生理特性及WUE的影响

【目的】揭示滴灌水分亏缺和种植方式对设施黄瓜叶片光合特性、物质积累与水分利用效率的调控效应,筛选适宜的亏缺灌溉栽培模式。【方法】以"津优316"黄瓜为试材,在定植密度相同时,设置了"等行距+70%灌溉量"(T1)、"宽窄行+70%灌溉量"(T2)、"等行距+常规灌溉量"(T3)、"宽窄行+常规灌溉量"(T4)4个处理,定植后第5天开始不同灌溉量处理,分析了定植后6周内黄瓜叶片生理特性、光合作用、水分利用率(WUE)、形态指标和物质积累、以及全生育期黄瓜总产量对滴灌水分亏缺和种植方式的响应规律。【结果】不同种植方式对黄瓜生理特征、光合作用、形态指标、物质积累、水分利用效率的影响均不显著。亏缺灌溉黄瓜植株受到不同程度水分胁迫,可溶性物质量和脱落酸量显著增加;由于气孔限制值(Ls)增加,净光合速率(Pn)降低了10.75%,蒸腾速率(Tr)降低了15.03%,物质积累减少了15.46%,总产量降低了12.60%,但水分利用效率提高了20.97%。不同处理中,T4处理产量最高,作物水分利用效率(WUEET)最低,与T4处理相比,T1处理的黄瓜植株受到一定程度的水分胁迫,Pn显著降低了13.68%,干物质积累显著降低了9.41%,黄瓜总产量降低了9.30%,但WUEET提高了23.96%;T2处理黄瓜叶片过氧化物酶(POD)活性、丙二醛(MDA)量、可溶性蛋白量、脱落酸(ABA)量显著增加,植株受到水分胁迫,Pn显著降低了10.52%,干物质积累显著降低了23.55%,总产量显著降低了12.37%,但WUEET显著提高了23.96%;T3处理黄瓜植株未受到水分胁迫,Pn、干物质积累、总产量、WUEET差异不显著。【结论】亏缺灌溉黄瓜虽然产量降低,但由于耗水量的大幅降低,水分利用效率显著提高。T1处理虽然总产量降低了9.30%,但提高黄瓜水分利用率23.96%,是适宜的滴灌水分亏缺模式。

The Effects of Planting Patterns and Deficit Irrigation on Photosynthesis and Water Use Efficiency of Greenhouse Cucumber

【Objective】Inappropriate planting pattern compounded by excessive irrigation and fertilization is a main problem causing the reduced water use efficiency in greenhouse cucumber production.The purpose of this paper is to elucidate the impact of different combinations of planting patterns and deficit irrigation on photosynthesis and water use efficiency of cucumber in attempts to find an improved cultivation for greenhouse cucumber production.【Method】The cultivar of“Jinyou316”was use as the model plant and we compared four deficit irrigation and planting pattern combinations:planting with equally spaced rows+70%of conventional irrigation amount(T1),planting with alternate wide and narrow rows+70%of conventional irrigation amount(T2),planting with equally spaced rows+conventional irrigation amount(T3),planting with alternate wide and narrow rows+conventional irrigation amount(T4).Irrigation in all treatments started five days after transplanting,and six weeks after the transplanting,we began to measure the physiological traits,photosynthesis,morphological traits and material accumulation of the plants in all treatments.We also calculated and measured the water use efficiency(WUE)and yield of the cucumber.【Result】Planting patterns did not have significant impacts on physiological traits,photosynthesis,morphological traits,material accumulation and WUE of the cucumber.Deficit irrigation led to a significant increase in solute matter content and abscisic acid(ABA)in the plant.Since deficit irrigation reduced the stomatal limit value,it reduced the net photosynthetic rate(Pn),transpiration rate(Tr),dry material accumulation and total yield by 10.75%,15.03%,15.46%and 12.60%respectively,while increased the WUE by 20.97%,compared to the conventional irrigation.T4 gave the highest fruit yield but the lowest water use efficiency.T1 resulted in water stress thereby reducing Pn by 13.68%,dry material accumulation by 9.41%and total yield by 9.30%,while increasing WUEET by 23.96%,compared to the control.T2 led to a significant increase in Peroxidase(POD)activity,malondialdehyde(MDA)content,soluble protein and ABA content in the leaves,and a decrease in Pn,dry material accumulation and total yield by 10.52%,23.55%and 12.37%respectively,compared to the control;it also increased WUE by 23.96%over the control.Plant in T3 was not under water stress and its Pn,dry material accumulation,total yield and WUE were comparable to those in the control.【Conclusion】Although the deficit irrigation slightly reduced yield,it significantly improved the WUE due to the reduced water consumption.T2 was a best compromise,improving WUE by 23.96%while reducing the yield only by 9.30%.