种植密度对封闭式槽培黄瓜产量、品质及光合作用的影响

以"中农26"黄瓜为试材,采用封闭式槽培循环供液系统,设定低密度33 330株·hm^-2(T1)、中密度49 995株·hm^-2(T2)与高密度66 660株·hm^-2(T3)3个种植密度处理,通过测定黄瓜株高、叶片数、最大叶面积和叶片的净光合速率、叶绿素含量等光合指标,结合叶片显微结构、叶片衰老速度及叶面积指数等分析,比较了不同种植密度对黄瓜生长、果实产量和品质以及光合特性的影响,并筛选出适宜的种植密度,以期为黄瓜封闭式无土栽培提供参考。结果表明:随密度增加,黄瓜的株高、最大叶面积及产量增高,而果实可溶性糖、可溶性固形物含量及单株产量降低。与T3处理相比,T2处理叶片叶绿素含量及群体光合速率较高,栅栏组织较为发达,表现了较强的自我调节能力;T2处理果实的果形指数、含水量、维生素C、可溶性糖及可溶性蛋白质含量较高,可滴定酸含量较低,且T2与T1处理差异不显著。T3处理提高了黄瓜总产量,但果实单株产量与品质显著低于T1、T2处理。综上,中密度49 995株·hm^-2处理的叶片结构较好,植株上下层叶片光合能力强,能提高黄瓜产量与品质。

Effect of Planting Densities on Yield,Quality and Photosynthesis of Cucumbers Grown in Enclosed Trough Culture

Cucumber variety of ‘Zhongnong 26' was used as experimental materials,with the system of enclosed circulation trough culture, the differences among different levels of planting densities treatment were investigated at 33 330 plants·hm^-2 (T1 ), 49 995 plants·hm^-2 (T2) and 66 660 plants·hm^-2 (T3). In order to select the suitable planting density and provide theoretical guidance of cucumber in enclosed trough culture, so we measured the plant height, leaf number, maximum leaf area,net photosynthetic rate and chlorophyll content of cucumber leaves. And also made a comprehensive analysis after combined with the leaf microstructure, leaf senescence rate and leaf area index. The results showed that the plant height, the maximum leaf area and yield of cucumbers increased with the increase of plant densities, while the contents of soluble sugar, soluble solids, and yield of per plant decreased. Compared with T3,T2 had higher chlorophyll content and photosynthetic rate in leaves,more developed palisade tissue and stronger self-regulation ability. The water content, vitamin C content,soluble protein content and fruit shape index of fruit were higher, which the content of tiratable acid was lower, there was no significant difference between T1 and T2. T3 increased the total yield of cucumber,but the yield of per plant and quality of fruit were significantly lower than T1 and T2. To sum up, the leaf structure of the medium density (49 995 plants·hm^2) treatment was better and the leaf photosynthetic capacity of the plants populations was strong, and the yield and quality of cucumber were improved.