中国农业科学 ›› 2022, Vol. 55 ›› Issue (20): 4011-4019.doi: 10.3864/j.issn.0578-1752.2022.20.012

• 园艺 • 上一篇    下一篇

光期湿度对植物工厂生菜干烧心及其营养品质的影响

李扬眉(),刘鑫,贾梦晗,仝宇欣()   

  1. 中国农业科学院农业环境与可持续发展研究所,北京 100081
  • 收稿日期:2022-01-10 接受日期:2022-04-11 出版日期:2022-10-16 发布日期:2022-10-24
  • 通讯作者: 仝宇欣
  • 作者简介:李扬眉,Tel:17683058646;E-mail: liyangmei@caas.cn
  • 基金资助:
    国家重点研发计划战略性科技创新合作专项(2020YFE0203600)

Tipburn Injury and Nutritional Quality of Lettuce Plants as Affected by Humidity Control During the Light Period in A Plant Factory

LI YangMei(),LIU Xin,JIA MengHan,TONG YuXin()   

  1. Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081
  • Received:2022-01-10 Accepted:2022-04-11 Online:2022-10-16 Published:2022-10-24
  • Contact: YuXin TONG

摘要:

【背景】 近年来,植物工厂因具有可在垂直立体空间进行周年计划性、省力化和无农药、洁净安全生产等传统农业无可比拟的优势,在全球得到蓬勃发展。然而,由于植物工厂内叶菜生长速度较快,而新叶部位的蒸腾较弱等原因,较易发生干烧心,大幅降低叶菜外观和内在品质。【目的】 研究光期不同湿度对水培生菜干烧心、生长及其营养品质的影响,优化预防或减缓生菜干烧心发生的植物工厂湿度环境参数,为防控生菜干烧心发生,提高植物工厂生菜品质和运行效益提供技术和理论支撑。【方法】 选用在植物工厂环境下较易发生干烧心的‘Tiberius’生菜作为研究对象,在光环境、温度、二氧化碳等环境条件保持一致的情况下,使光期(16 h)各处理空气相对湿度分别维持在50%(RH50)、70%(RH70)和90%(RH90),暗期(8 h)各处理空气相对湿度保持一致为70%,湿度控制正负误差在5%以内。调查各处理组生菜干烧心发生情况、叶片光合参数、产量及营养品质的差异。【结果】 与RH70和RH90相比:(1)RH50处理显著提高了生菜新叶中钙离子含量,降低了采收时干烧心发生率,并且随着相对湿度水平降低,干烧心的初次发生时间得到显著推迟;(2)RH50处理未对试验光强下生菜的净光合速率产生影响,但却显著增加了生菜气孔导度、蒸腾速率和胞间CO2浓度,促进了茎叶的钙离子运输;(3)RH50处理未显著降低生菜的总叶面积及茎叶鲜重,但却明显改善了生菜营养品质,使淀粉、抗坏血酸和可溶性蛋白的含量得到显著提高。【结论】 植物工厂高湿环境是生菜干烧心频发的原因之一,通过合理降低湿度水平能够在不显著影响生菜光合能力及产量的情况下,有效减缓生菜干烧心的发生,提高生菜的外观和营养品质,增加其商品价值,保障植物工厂优质高效生产。

关键词: 植物工厂, 湿度调控, 干烧心, 生菜, 营养品质

Abstract:

【Background】In the recent years, the plant factories have been developing very fast in the world due to the incomparable advantages, such as labor-saving, pesticide-free, clean, safe and annual planned leafy vegetables production with vertical multi-layer cultivation systems. However, because of the faster growth rate and the weaker transpiration rate of the newly developed leaves, the vegetables in plant factories are very susceptible to tipburn caused by calcium deficiency, and therefore the appearance and nutritional qualities of leafy vegetable are significantly reduced. 【Objective】In this study, the effects of different relative humidity levels on the tipburn injury, growth and nutritional qualities of hydroponically grown lettuce were investigated. The objective of this study was to find out the optimum relative humidity levels for preventing or alleviating tipburn occurrence of vegetable in plant factories. Furthermore, this study also could provide the technical and theoretical support to prevent the tipburn occurrence, and improve vegetable quality and economic benefits of plant factories. 【Method】‘Tiberius’ lettuce, which was susceptible to calcium deficiency, was used in this experiment. Three different air relative humidity levels of 50% (RH50), 70% (RH70) and 90% (RH90) were set up during the light period (16 h), while the relative humidity was maintained at 70% during the dark period (8 h). The other environmental factors, such as light environment, air temperature and carbon dioxide concentration, were kept constant during this study. The tipburn occurrence, yield, photosynthetic parameters and nutritional quality of the lettuce plants were investigated. 【Result】Compared with RH70 and RH90, the calcium content in the newly developed lettuce leaves plants under RH50 was increased significantly, the percentage of lettuce plants with tipburn injury was decreased while harvesting, and the initial tipburn occurrence time was postponed significantly. The stomatal conductance and transpiration rate of lettuce plants increased significantly, which in turn enhanced transpiration and accelerated the absorption and transportation of Ca2+, under the lower relative humidity. The photosynthesis rate and fresh weight of lettuce plants were not significantly affected by different relative humidity levels. Moreover, the lower relative humidity also improved the nutritional quality of lettuce plants, including improving the contents of starch, ascorbic acid, and soluble protein. 【Conclusion】The high humidity environment in a plant factory was also one of the reasons for the frequent tipburn occurrence of lettuce plants. Based on the above analysis, it could be concluded that the tipburn occurrence of lettuce plants could be alleviated, the nutritional and commercial qualities of lettuce plants could be improved without affecting its yield and photosynthetic capacity by appropriately controlling the air relative humidity in a plant factory.

Key words: plant factory, humidity control, tipburn, lettuce, nutritional quality