To determine photosynthetic dynamics of pepino leaves in growth stages and photosynthetic responses to light densities and CO2 concentrations under different fertilizations, gas exchange parameters and their diurnal changes at different growth stages, photosynthetic responses to PAR and CO2 were measured in a greenhouse experiment employing pepino cv. Ascar as the materials. The results showed that the chlorophyll contents of the pepino leaves increased initially and then decreased during plant growth, and reached the peak at fruit developmental stage. Chlorophyll contents with organic fertilizer application were significantly higher than those without fertilizer; the chla/chlb ratio was lower than species in the same family and at mid-winter implying low light adaptability to some degree. Leaf stomatal conductance (Gs) and evaporation (Tr) increased from seedling to fruit developmental stage and then decreased, with those from fertilized plants significantly higher than those without fertilization. Leaf Gs was very significantly positively correlated with Tr(r=0.816), and significantly correlated with net photosynthetic rate (Pn, r=0.555), while Tr and Pn was not significantly correlated (r=0.415). Gas exchange parameters of pepino leaves demonstrated a sigle peak type from flowring till fruit ripening, with the peaks at around noon, no midday depression of photosynthesis was found under greenhouse condition. Leaf Gs and Pn under fertilization was higher than those from no fertilization but no significant difference was found in EVAP between two treatemnts. Photosynthetic responese to photosynthtic avaible radiation could be fitted with the modified rectangular hyperbola model, and to the CO2 concentration with the rectangular hyperbola model. The initial quantum efficiency at fruit ripening stage was significantly higher than but the carboxylation efficiency was significantly lower than those at flowering or fruit developmental stage. The initial quantum efficiency under fertilization was significantly lower than but the carboxylation efficiency was significantly higher than those without fertilization. Light compensation point, CO2 compensation point and CO2 saturation point of leaves from fertilized plants were significantly lower than those from no fertilized plants, but no difference in light saturation point, maximum net photosynthetic rate, respiration rates under dark or light were found between the two treatments. The results suggest that pepino leaves have better ability to utilize high light intensity but poor capacity for low light, though they showed some weak light adaptability, and fertilization may have potential to increased low light utilization and carbon assimilation of pepino under greenhouse production.
[1] 刘宇锋,李伏生.灌溉方式与施肥水平对超级稻光合生理的影响[J].中国生态农业学报,2013,21(4):416-425.
[2] 王景燕,龚伟,包秀兰,等.水肥耦合对汉源花椒幼苗叶片光合作用的影响[J].生态学报,2016,36(5):1321-1330.
[3] 李廷亮,谢英荷,任苗苗,等.施肥和覆膜垄沟种植对旱地小麦产量及水氮利用的影响[J].生态学报,2011,31(1):212-220.
[4] 倪纪恒,毛罕平,马万征.不同营养液浓度对温室黄瓜叶片光合特性的影响[J].农业工程学报,2011,27(10):277-281.
[5] Shang G Z,Shao M,Dyckmans J.Effects of nitrogen nutrition and water deficit on net photosynthetic rate and chlorophyll fluorescence in winter wheat[J].Journal of Plant Physiology,2000,156(1):46-51.
[6] 赵海波,林琪,刘义国,等.氮磷肥配施对超高产冬小麦灌浆期光合日变化及产量的影响[J].应用生态学报,2010,21(10):2545-2550.
[7] 彭晚霞,王克林,宋同清,等.施肥结构对茶树(Camellia sinensis(L.) Kuntze)光合作用及其生态生理因子日变化的影响[J].生态学报,2008,28(1):84-91.
[8] 李小平,王景燕,王东,等.施肥水平对巨桉幼树叶片气体交换日变化的影响[J].应用生态学报,2010,21(11):2734-2741.
[9] 张大龙,张中典,李建明.环境因子对温室甜瓜蒸腾的驱动和调控效应研究[J].农业机械学报,2015,46(11):137-144.
[10] Ibrahim M H,Jaafar H Z E.Photosynthetic capacity,photochemical efficiency and chlorophyll content of three varieties of Labisia pumila,Benth.exposed to open field and greenhouse growing conditions[J].Acta Physiologiae Plantarum,2011,33(6):2179-2185.
[11] Wei M A,Niu Y Y,Luo Q W,et al.Differences of photosynthetic characteristics of the grape cultivated in greenhouse and open field in Turpan[J].Agricultural Science & Technology,2016,17(6):1285-1288.
[12] 郑麟,陈清浩,董祖林,等.南美香瓜梨引种栽培初报[J].中国果树,1988(2):19-21.
[13] 蒲凌奎,朱元珍,祝英,等.人参果漫谈[J].甘肃农业,2008(1):82-84.
[14] Lim T K.Solanum Muricatum[M].Netherlands:Springer 2013:389-394.
[15] Rodríguez-Burruezo A,Prohens J,Fita A M.Breeding strategies for improving the performance and fruit quality of the pepino (Solanum muricatum):a model for the enhancement of underutilized exotic fruits[J].Food Research International,2011.44(7):1927-1935.
[16] 邹琦.植物生理学实验指导[M].北京:中国农业出版社,2000:72-75.
[17] 李晓宇,杨成超,于雷,等.DPS软件在中绥12杨光响应曲线拟合中的应用[J].湖南林业科技,2015(3):85-89
[18] 叶子飘.光合作用对光和CO2响应模型的研究进展[J].植物生态学报,2010,34(6):727-740.
[19] Sarijeva G,Knapp M,Lichtenthaler H K.Differences in photosynthetic activity,chlorophyll and carotenoid levels,and in chlorophyll fluorescence parameters in green sun and shade leaves of Ginkgo and Fagus[J].Journal of Plant Physiology,2007,164(7):950-955.
[20] Zheng Y,Mai B,Wu R,et al.Acclimation of winter wheat (Triticum aestivum cv.Yangmai 13) to low levels of solar irradiance[J].Photosynthetica,2011,49(3):426-434.
[21] 吴明开,刘海,沈志君,等.珍稀药用植物白芨光合与蒸腾生理生态及抗旱特性[J].生态学报,2013,33(18):5531-5537.
[22] 王顺才,呼丽萍.温室栽培欧洲甜樱桃"红灯"和"美早"光合特性研究[J].果树学报,2014(S1):84-89.
[23] 王发林.温室内外杏、油桃的光合特性研究[D].兰州:兰州大学,2007.
[24] Evans J R,Poorter H.Photosynthetic acclimation of plants to growth irradiance:the relative importance of specific leaf area and nitrogen partitioning in maximizing carbon gain[J].Plant Cell & Environment,2001,24(8):755-767.
[25] Farquhar G D,Sharkey T D.Stomatal conductance and photosynthesis[J].Annual Reviews of Plant Physiology,1982,33(33):317-345.
[26] 丁小涛,金海军,张红梅,等.遮荫处理对温室四种蔬菜生长及光合作用日变化的影响[J].浙江农业学报,2010,22(1):51-56.
[27] 王帅.长期不同施肥对玉米叶片光合作用及光系统功能的影响[D].沈阳:沈阳农业大学,2014.
[28] 谭博,曹晓艳,刘怀峰,等.不同施肥方式对全球红葡萄光合日变化及品质的影响[J].新疆农业科学,2014,51(3):410-416.
[29] 程乾斗,肖志东.不同施肥处理对核桃幼苗光合特性的影响[J].林业科技,2016,41(5):39-41.
[30] 熊珺,曲英华,范冰琳,等.不同CO2浓度下番茄苗期及果期的光合特性[J].北方园艺,2015(9):6-9.
[31] 孙丽,陈景玲,王谦,等.日光温室边际区温度变化及其对茄子光合特性的影响[J].河南农业大学学报,2010,44(6):639-643.
[32] Wang H,Wang F,Wang G,et al.The responses of photosynthetic capacity,chlorophyll fluorescence and chlorophyll content of nectarine (Prunus persica var.Nectarina,Maxim) to greenhouse and field grown conditions[J].Scientia Horticulturae,2007,112(1):66-72.
[33] 谢飞,魏慧,张凯,等.间作时期和种植密度对甜瓜/向日葵间作系统光能利用效率的影响[J].中国沙漠,2015,35(3):652-657.
