K. Murakami, T. Hamasaki, M. Nemoto, S. Inoue, T. Hirota
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After its peak in the morning, P n decreased in the afternoon, presumably owing to ‘midday depression’ caused by suppressed water uptake in the root zone. Observed diurnal [CO 2 ] change was consistent with a significant CO 2 uptake during the daytime. The change also suggested that respiration was active immediately after sunset and suppressed at night. In addition, we calculated the whole-greenhouse CO 2 emission rate ( R ) as a measure of night respiration in the plants, taking into account the air ventilation of the greenhouse. The R value was positive under sub-zero air temperatures in the greenhouse and was positively correlated with the nighttime air and soil temperatures. These experimental data suggest active photosynthesis and respiration of winter-sweetened spinach in the greenhouse, despite the low air and soil temperatures and growth retardation, and implies their involvement in the","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":null,"pages":null},"PeriodicalIF":1.4000,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":"{\"title\":\"Photosynthetic and respiratory activities of spinach in an unheated greenhouse during winter in Sapporo, Japan\",\"authors\":\"K. Murakami, T. Hamasaki, M. Nemoto, S. Inoue, T. Hirota\",\"doi\":\"10.2480/AGRMET.D-20-00033\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Leafy vegetables cultivated in greenhouses during the winter are sometimes exposed to cold air from outside the greenhouse to enhance sugar and nutrient content. 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引用次数: 3
摘要
冬季在温室种植的叶菜有时会暴露在温室外的冷空气中,以提高糖和营养含量。为了分析光合和呼吸活动可能参与了这一过程,我们对菠菜(Spinacia oleracea L.)的气体交换活性进行了评估。在札幌的冬季中期,在没有加热的温室中种植的植物,那里的日平均空气和土壤温度分别约为- 5°C和0°C。茎部鲜重增幅不大,叶片净光合速率(pn)达到20µmol m -2 s -1,温室内co2浓度([co2])有时低于200µmol mol mol -1,表明光合co2吸收活跃。磷在上午达到峰值后,下午开始下降,这可能是由于根区水分吸收受到抑制而导致的“午间抑制”。观测到的日[co2]变化与白天显著的co2吸收一致。这一变化还表明,呼吸在日落之后立即活跃,而在夜间受到抑制。此外,考虑到温室的空气流通情况,我们计算了整个温室的co2排放率(R),作为植物夜间呼吸的度量。温室气温低于零度时R值为正,与夜间空气温度和土壤温度呈正相关。这些实验数据表明,尽管空气和土壤温度较低,生长迟缓,但温室中冬甜菠菜的光合作用和呼吸作用仍很活跃,并暗示它们参与了温室的光合作用
Photosynthetic and respiratory activities of spinach in an unheated greenhouse during winter in Sapporo, Japan
Leafy vegetables cultivated in greenhouses during the winter are sometimes exposed to cold air from outside the greenhouse to enhance sugar and nutrient content. To analyze the possible involvement of photosynthetic and respiratory activities in this process, we evaluated the gas-exchange activity of spinach ( Spinacia oleracea L. ) plants cultivated in an unheated greenhouse in mid-winter in Sapporo, where the daily mean air and soil temperatures are approximately - 5 and 0 ° C, respectively. Shoot fresh weight showed little increase, whereas the net leaf photosynthetic rate ( P n ) attained 20 µmol m -2 s -1 and the CO 2 concentration in the greenhouse ( [CO 2 ] ) was sometimes lower than 200 µmol mol -1 , which was suggestive of active photosynthetic CO 2 uptake. After its peak in the morning, P n decreased in the afternoon, presumably owing to ‘midday depression’ caused by suppressed water uptake in the root zone. Observed diurnal [CO 2 ] change was consistent with a significant CO 2 uptake during the daytime. The change also suggested that respiration was active immediately after sunset and suppressed at night. In addition, we calculated the whole-greenhouse CO 2 emission rate ( R ) as a measure of night respiration in the plants, taking into account the air ventilation of the greenhouse. The R value was positive under sub-zero air temperatures in the greenhouse and was positively correlated with the nighttime air and soil temperatures. These experimental data suggest active photosynthesis and respiration of winter-sweetened spinach in the greenhouse, despite the low air and soil temperatures and growth retardation, and implies their involvement in the
期刊介绍:
For over 70 years, the Journal of Agricultural Meteorology has published original papers and review articles on the science of physical and biological processes in natural and managed ecosystems. Published topics include, but are not limited to, weather disasters, local climate, micrometeorology, climate change, soil environment, plant phenology, plant response to environmental change, crop growth and yield prediction, instrumentation, and environmental control across a wide range of managed ecosystems, from open fields to greenhouses and plant factories.