摘要： 以薄皮甜瓜品种清雅白玉为研究对象，通过对薄皮甜瓜从苗期开始施用4种不同浓度CO₂后在伸蔓期对植株的光合及生长的影响，来揭示光合提高的初步机制，同时确定北方地区冬春季温室薄皮甜瓜栽培最适的CO₂浓度，为薄皮甜瓜的冬春季设施内栽培的精准施肥提供理论依据。甜瓜植株分别设（400±12）μmol/mol （CK）、（800±24）μmol/mol （T1）、（1 200±36）μmol/mol （T2）、（1 600±48）μmol/mol （T3）共4种CO₂浓度，测定甜瓜植株伸蔓期干鲜质量、叶绿素含量、光合参数、光响应曲线、CO₂响应曲线、叶绿素荧光参数。结果表明，T3处理相对于CK使植株鲜质量增加116.03%、地上部分鲜质量增加118.66%、干质量增加78.70%、干鲜比降低17.28%、根冠比减少50.12%、净光合速率提高221.55%、气孔导度提高208.85%、胞间二氧化碳浓度提高429.74%、蒸腾速率提高394.49%、最大净光合速率提高71.52%、光饱和点提高64.07%、表观量子效率提高16.9%、光补偿点减少40.0%、RuBP的最大再生速率提高78.43%，PSⅡ实际量子产量提高44.3%，光化学淬灭qP、qL提高32.79%，43.14%，光合电子传递速率ETR提高41.1%；T1处理相对于CK使叶绿素a含量提高6.28%、Rubisco酶的最大催化速率提高52.8%和磷酸丙糖的运输速率（VTPU）提高35.13%，Fo降低11.69%、Fo'降低14.09%、Fm降低16.01%、Fm'降低18.92%、Ft降低22.03%。因此得出，CO₂施肥可以有效提高植株生长，提高光合作用、电子传递效率，提高光饱和点、CO₂饱和点，降低光补偿点，增大植物的生物产量，综合来说，T3（（1 600±48）μmol/mol）处理效果最显著。光合作用提高的原因在低浓度是由于叶绿素含量的提高、磷酸丙糖的运输速率提高的结果，高浓度主要是由于PSⅡ实际量子产量、光合电子传递速率以及光化学淬灭提高的结果。

关键词: 薄皮甜瓜, CO₂施肥, 光合, 荧光, 精准施肥

Abstract: In this experiment, Qingya Baiyu, a thin-skinned melon cultivar, was used as the research object. Four different concentrations of CO₂ were applied to thin-skinned melon from seedling stage. Afterwards, the effects of vine elongation on photosynthesis and growth of plants were studied to reveal the primary mechanism of photosynthesis improvement and determine the optimum CO₂ concentration for thin-skinned melon cultivation in greenhouse in winter and spring in Northern China, providing theoretical basis for precise fertilization of thin-skinned Melon Cultivation in winter and spring facilities. Four kinds of CO₂ concentrations:(400±12) μmol/mol(CK), (800±24) μmol/mol(T1), (1 200±36) μmol/mol(T2), (1 600±48) μmol/mol (T3), were applied to melon plants, respectively. Dry and fresh weight, chlorophyll content, photosynthetic parameters, light response curve, CO₂ response curve and chlorophyll fluorescence parameters of melon plants at elongation stage were determined. The results showed that compared with CK, T3 treatment increased plant fresh weight 116.03%, aboveground fresh weight 118.66%, dry weight 78.70%;reduced dry-fresh ratio 17.28%, root shoot ratio 50.12%;increased net photosynthetic rate 221.55%, stomatal conductance 208.85%, intercellular carbon dioxide concentration 429.74%, transpiration rate 394.49%, maximum net photosynthetic rate 71.52%, the light saturation point 64.07%, apparent quantum efficiency 16.9%; reduced light compensation point 40.0%; increased maximum regeneration rate of RuBP 78.43%, actual quantum yield of PSⅡ 44.3%, photochemical quenching qP, qL 32.79%, 43.14%, photosynthetic rate ETR 41.1%. Compared with CK, T1 treatment increased chlorophyll a content 6.28%, maximum catalytic rate of Rubisco enzyme 52.8%, The VTPU 35.13%; reduced Fo 11.69%, Fo' 14.09%, Fm 16.01%, Fm' 18.92%, Ft 22.03%. So CO₂ fertilization could effectively improve plant growth, improve photosynthesis, electron transfer efficiency, increase light saturation point, increase CO₂ saturation point, reduce light compensation point, increase plant biomass, T3 ((1 600±48) μmol/mol) treatment effect significantly. The reason for increasing photosynthesis was due to the increasing chlorophyll content and the transport rate of propionate phosphate in low concentration, while the high concentration was mainly due to the increasing actual quantum yield Y(Ⅱ) of PSⅡ, photosynthetic electron transfer rate and photochemistry quenching.

Key words: Thin-skinned melon, CO₂ fertilization, Photosynthesis, Fluorescence, Precise fertilization

中图分类号: 

• S652.01