不同溶氧量对油麦菜生长、光合指标和产量的影响

通过大棚立体种植油麦菜试验,以灌溉水中溶氧量为试验因素,研究不同溶氧量(T1处理6.8 mg/L、T2处理8 mg/L、T3处理7.4 mg/L、T4处理1.2 mg/L)对油麦菜生长量、光合指标、植株鲜质量、干质量和产量的影响。结果表明,(1)不同溶氧量对油麦菜株高、叶片数和茎粗有显著性影响;各处理株高均值次序为:T2处理T3处理T1处理T4处理,叶片数均值次序与株高的相同;(2)不同溶氧量对叶绿素质量分数、净光合速率、蒸腾速率、气孔开度有显著性影响,但是对胞间CO2摩尔分数影响并不显著;(3)不同溶氧量对单株鲜质量和干质量影响显著,T2处理的单株鲜质量和干质量最大,分别为56.25、10.71 g;T4处理的最小,分别为42.64、3.52 g;T1、T2、T3处理与T4处理相比产量分别提高了13.2%、22.6%、28.3%。以产量为研究目标时,7.4 mg/L溶氧量+灌水定额45 m3/hm2为最佳组合。

Effects of Dissolved Oxygen on Growth,Photosynthesis and Yield of Leaf Lettuce

We studied the impact of dissolved oxygen concentration in irrigating water on growth, photosynthe-sis, fresh weight,dry weight and yield of leaf lettuce grown in a greenhouse. Four concentrations were examined:6.8 mg/L (T1), 8 mg/L (T2), 7.4 mg/L (T3) and 1.2 mg/L(T4). The findings were as follows:①The dissolved ox-ygen concentration has a significant impact on lettuce height, leaf numbers and stem diameter;both height and leaf number of the lettuce under different treatments decreased in the order of T2>T3>T1>T4.②The dissolved oxygen concentration also has a significant effect on chlorophyll content, net photosynthetic rate, transpiration rate, and stomatal aperture, but has less impact on intercellular CO2 concentration.③The dissolved oxygen has re-markable impact on fresh and dry plant weights. The highest fresh weight and dry weights were in T2, being 56.25 g and 10.71 g respectively. The lowest fresh and dry weights were in T4, being 42.64 g and 3.52 g respec-tively. The yield in T1, T2 and T3 increased by 13.2％, 22.6％and 28.3％respectively compared with that in T4. The results showed that a combination of dissolved oxygen concentration of 7.4 mg/L with amount of irrigation of 45 m3/hm2 achieved the highest yield.