Photosynthetica - Latest articles
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Yield and photochemical activity of selected rice cultivars from Eastern India under medium depth stagnant flooding
D. PANDA, A. RAY, R.K. SARKAR
Photosynthetica 2019, 57(4):1084-1093 | DOI: 10.32615/ps.2019.126
Stagnant flooding (SF) is a serious threat for rice production in rainfed lowland areas of Southeast Asian countries. To overview the SF effect, photosynthetic performances and productivity were studied with three landraces (Ravana, Kamini, and Rashpanjor) and four high-yielding cultivars (Savitri, Savitri-Sub1, Gayatri, and Varshadhan) of rice under medium depth (40-50 cm) of water level. Stagnant flooding significantly increased the stem elongation and decreased yield and yield attributing parameters. The chlorophyll a fluorescence rises from O- to P-step with distinct J- and I-step were noticed in all the cultivars up to 75 d of SF. Prolonged...
Changes in photosynthesis, chloroplast ultrastructure, and antioxidant metabolism in leaves of sorghum under waterlogging stress
R.D. ZHANG, Y.F. ZHOU, Z.X. YUE, X.F. CHEN, X. CAO, X.X. XU, Y.F. XING, B. JIANG, X.Y. AI, R.D. HUANG
Photosynthetica 2019, 57(4):1076-1083 | DOI: 10.32615/ps.2019.124
Waterlogging limits plant growth and yield. We investigated the effects of waterlogging stress on leaf photosynthesis, chlorophyll fluorescence, antioxidant capacity, chloroplast ultrastructure, and yield of sorghum (Sorghum bicolor L.). Two sorghum cultivars, Jinuoliang01 (JN01, waterlogging-tolerant cultivar) and Jinza31 (JZ31, waterlogging-sensitive cultivar) were subjected to a 12-d waterlogging treatment; the plants of the two cultivars which were not subjected to waterlogging were used as control (CK), respectively. After waterlogging treatment, the yield of JZ31 and JN01 decreased by 72.3 and 52.9%, the net photosynthetic rate of JZ31...
Cotton leaf photosynthetic characteristics, biomass production, and their correlation analysis under different irrigation and phosphorus application
J.H. LI, Y.Y. WANG, N.N. LI, R.H. ZHAO, A. KHAN, J. WANG, H.H. LUO
Photosynthetica 2019, 57(4):1066-1075 | DOI: 10.32615/ps.2019.118
Water and fertilizer application are the yield improvement approaches in cotton production, especially in arid regions. We hypothesized that irrigation and phosphorus fertilization regimes would enhance cotton leaf photosynthesis capacity. We examined two irrigation levels, i.e., normal irrigation (W1: 3,750 m3 hm-2) and limited irrigation (W2: 2,500 m3 hm-2), combined with no phosphorus (P0) and P application (P1: applying P2O5 with the ratio of the fertilizer to dry soil being 0.15 g kg-1). Leaf area (LA), net photosynthetic...
Epiphytic orchids Stanhopea tigrina and Prosthechea cochleata are differentially affected by drought in a subtropical cloud forest
C.I. GUEVARA-PÉREZ, P. DELGADO-SÁNCHEZ, J.A. TORRES-CASTILLO, J.D. FLORES-RIVAS, G. MENDIETA-LEIVA, E. DE LA ROSA-MANZANO
Photosynthetica 2019, 57(4):1053-1065 | DOI: 10.32615/ps.2019.123
We investigated the physiological responses of two epiphytic orchids under three light regimes of 20, 50, and 70% of total daily radiation under drought and rewatering conditions. Stanhopea tigrina was the one more affected because it exhibited strong photoinhibition and reduction of both electron transport rate and nocturnal acidity under drought and high radiation. However, this species maintained relatively high relative water content (RWC) values and underwent osmotic adjustment during the drought period and recovered photosynthetic variables during watered period. Prosthechea cochleata maintained similar water and photosynthetic...
Photosynthetic induction is slower in young leaves than in mature leaves in a tropical invader, Chromolaena odorata
S.B. ZHANG, Y.J. HAO, Q.L. DENG
Photosynthetica 2019, 57(4):1044-1052 | DOI: 10.32615/ps.2019.120
Chromolaena odorata is a noxious invasive perennial herb in tropics and subtropics throughout the world. However, photosynthetic induction of this invader is not well understood. Here, we measured the induction of gas exchange and chlorophyll fluorescence in young and mature leaves of Chromolaena odorata. During photosynthetic induction, the young leaves exhibited higher biochemical and total limitations to photosynthesis than that of the mature leaves. Photosynthetic induction in this invader was affected by a mix of biochemical and stomatal limitations. Under a strong photosynthetic photon flux density, nonphotochemical quenching was rapidly...
Factors playing role in heat acclimation processes in barley and oat plants
É. DARKÓ, R. KHALIL, N. ELSAYED, M. PÁL, K.Á. HAMOW, G. SZALAI, J. TAJTI, Q.T. NGUYEN, N.T. NGUYEN, V.N. LE, T. JANDA
Photosynthetica 2019, 57(4):1035-1043 | DOI: 10.32615/ps.2019.122
In the present study, the heat acclimation processes (growing at 30/27°C for 2 weeks) in spring and winter varieties of barley (Hordeum vulgare L., varieties 'Conchita' and 'Mv Initium') and oat (Avena sativa L., varieties 'Mv Pehely' and 'Mv Hópehely') were characterized. Temperature dependence of certain chlorophyll a fluorescence induction parameters indicated the efficiency of heat acclimation. Heat treatment induced the activity of glutathinone-S-transferase, but decreased the amounts of the major polyamines. A significant increase in cadaverine content was found in 'Conchita'. 1,3-diaminopropane contents after heat acclimation...
Mitigation mechanism of ozone-induced reduction in net photosynthesis of Bangladeshi wheat under soil salinity stress
M.Z.U. KAMAL, M. YAMAGUCHI, Y. KINOSE, T. IZUTA
Photosynthetica 2019, 57(4):1025-1034 | DOI: 10.32615/ps.2019.115
To clarify the combined effects of O3 and soil salinity on net photosynthetic rate, stomatal conductance, and radical scavenging system of Bangladeshi spring wheat cv. BAW1059, plants were grown in two soil salinity levels (irrigated with 0 and 150 mM NaCl solutions) and exposed to three O3 concentrations [charcoal-filtered air (CF), 1.0-fold the ambient O3 concentration (1.0×O3), and 1.5-fold the ambient O3 concentration (1.5×O3)]. The soil salinity mitigated adverse effects of O3 on net photosynthesis in the 7th and flag leaves. The soil salinity did not induce...
Characterization of the ecophysiological responses of three pomegranate cultivars to salinity
A. OLMO, F. GARCIA-SANCHEZ, I. SIMON, V. LIDON, M. ALFOSEA-SIMON, J.M. CAMARA-ZAPATA, J.J. MARTINEZ-NICOLAS, S. SIMON-GRAO
Photosynthetica 2019, 57(4):1015-1024 | DOI: 10.32615/ps.2019.103
In order to understand photosynthetic responses of pomegranate plants (Punica granatum L.) to salinity, an experiment was conducted with three varieties, 'Mollar de Elche', 'Valenciana', and 'Wonderful', irrigated with seven salt concentrations (0, 40, 60, 80, 100, 120, and 140 mM NaCl). At the end of the experiment, parameters of gas exchange, chlorophyll fluorescence, water relations, and sugar and chloride concentrations were measured in leaves. As the concentration of NaCl increased, the concentration of Cl- in leaves was elevated, and the CO2 assimilation rate, stomatal conductance, variable fluorescence/maximum fluorescence...
Foliar application of selenium (Se) at heading stage induces regulation of photosynthesis, yield formation, and quality characteristics in fragrant rice
H.W. LUO, L.X. HE, B. DU, Z.M. WANG, A.X. ZHENG, R.F. LAI, X.R. TANG
Photosynthetica 2019, 57(4):1007-1014 | DOI: 10.32615/ps.2019.114
In order to study the effect of foliar application of sodium selenate on fragrant rice performance at the heading stage, the present study was conducted with two fragrant rice cultivars, 'Meixiangzhan-2' and 'Xiangyaxiangzhan'. At the heading stage, six concentrations of sodium selenate solution (0, 10, 20, 30, 40, and 50 μmol L-1) were sprinkled to plants. Our results showed that foliar application of sodium selenate increased chlorophyll contents in rice leaves and upregulated net photosynthetic rate at the grain-filling stage. The enhancement was observed in grain yield, seed-setting rate, and in 1,000-grain mass. The highest yield...
Effect of intercropping on leaf senescence related to physiological metabolism in proso millet (Panicum miliaceum L.)
X.W. GONG, C.J. LIU, U. FERDINAND, K. DANG, G. ZHAO, P. YANG, B.L. FENG
Photosynthetica 2019, 57(4):993-1006 | DOI: 10.32615/ps.2019.112
The field experiments were conducted to explore the changes in metabolism related to leaf senescence in proso millet (Panicum miliaceum L.) under proso millet/mung bean intercropping system. Results showed that intercropping increased leaf photosynthesis, as measured by the increased net photosynthetic rate and chlorophyll content, maximum photochemical efficiency of PSII, and decreased nonphotochemical quenching coefficient. These responses resulted in the increased leaf number and area and reduced yellowing leaf rate; leaf photosynthetic capacity was maintained for longer periods. Such improvements occurred due to enhanced activities of protective...
Whole leaf photosynthetic light response in a carnivorous plant species Sarracenia alata
K.A. HOPKINS, D.A. GRAVATT
Photosynthetica 2019, 57(4):985-992 | DOI: 10.32615/ps.2019.119
Photosynthetic light-response curves of mature leaves of Sarracenia alata were generated and characterized using a custom built chamber (2.79 L) capable of accommodating whole leaves, or pitchers, coupled to a LI-COR 6400XT Portable Photosynthesis System. In addition to generating light-response curves, chlorophyll content, leaf area, and dry mass measurements were obtained for each pitcher. Gas-exchange variables from the light-response curves are reported on a leaf area and dry mass basis. Calculated light-saturated photosynthesis was found to be 2.09 µmol(CO2) m-2 s-1 with a light-saturation...
Advances in the members and biosynthesis of chlorophyll family
N.W. QIU, D.C. JIANG, X.S. WANG, B.S. WANG, F. ZHOU
Photosynthetica 2019, 57(4):974-984 | DOI: 10.32615/ps.2019.116
Chlorophylls are vital for photosynthesis, allowing plants to absorb energy from light for photosynthesis. More than one hundred species of chlorophyll have been identified. Among them, chlorophylls a, b, c (c1, c2, and c3), d, and f exist in oxygenic photosynthetic organisms (e.g., higher plants, algae, and cyanobacteria), whereas anoxygenic photosynthetic bacteria possess bacteriochlorophylls a, b, c, d, e, and g. These chlorophylls have different chemical structures and properties that enable photosynthetic organisms...
Effects of cadmium exposure on the growth, photosynthesis, and antioxidant defense system in two radish (Raphanus sativus L.) cultivars
J. XIN, X.H. ZHAO, Q.L. TAN, X.C. SUN, Y.Y. ZHAO, C.X. HU
Photosynthetica 2019, 57(4):967-973 | DOI: 10.32615/ps.2019.076
Radish is representative root vegetable; its edible parts are directly in contact with Cd-contaminated fields. Two radish cultivars (H4 and L19) with different resistance to Cd were selected to compare their growth, photosynthesis, and antioxidant systems. Our results revealed that H4 was more sensitive to Cd pollution than L19; a significant decrease in the biomass of H4 was observed at higher Cd concentrations. With increasing Cd concentrations, the net photosynthetic rate, effective quantum yield of PSII photochemistry, electron transport rate through PSII, and photochemical quenching were all lowered, however, reductions were more obvious in H4...
Exogenous ascorbic acid delayed leaf senescence of early flowering rice mutant FTL10
Q.L. ZHANG, W.Q. DING, Y.X. WEI, H. GAO, C.L. PENG
Photosynthetica 2019, 57(4):960-966 | DOI: 10.32615/ps.2019.113
FTL10 is an early flowering mutant of OsFTL10-suppressed transgenic rice (Oryza sativa L.) with premature senescence phenotype. Early leaf senescence can cause negative effects on rice yield, therefore delaying leaf senescence and prolonging the leaf functional stage is one of the important approaches to increase the rice yield. It is well known that ascorbic acid (AsA) is involved in regulating plant growth. To explore the effect of AsA on leaf senescence of FTL10, we treated rice leaves with 0.28 mM AsA. Results showed that total antioxidant capacity was higher and reactive oxygen species were lower in the AsA-treated group. The expression...
Chlorophyll fluorescence for prediction of yellow lupin (Lupinus luteus L.) and pea (Pisum sativum L.) susceptibility to drought
K. JUZOŃ, I. CZYCZYŁO-MYSZA, A. OSTROWSKA, I. MARCIŃSKA, E. SKRZYPEK
Photosynthetica 2019, 57(4):950-959 | DOI: 10.32615/ps.2019.102
Drought has become an essential environmental factor limiting plant productivity. In order to detect differences in chlorophyll (Chl) a fluorescence, Chl concentration (in SPAD units), and yield parameters of yellow lupin ('Morocco 4' and 'Taper') and pea ('Wenus' and 'SZD165'), drought stress was initiated by withholding water for 14 d (25% of field water capacity). A significant decrease of leaf relative water content was found in tested cultivars. SPAD values did not show significant changes in all cultivars. The maximum photochemical efficiency and area over the Chl a fluorescence induction curve decreased in both species under drought....
Photosynthesis in reciprocal grafts of drought-tolerant and drought-sensitive cultivars of soybean under water stress
S.Y. LI, W.B. WANG, X.D. YAO, C.L. WANG, Y.Q. CAO, L.J. ZHANG, H.J. ZHANG, F.T. XIE, S.H. SONG
Photosynthetica 2019, 57(4):942-949 | DOI: 10.32615/ps.2019.109
Maintaining greater photosynthetic performance is important to improve drought resistance in soybean. However, photosynthetic response mechanisms to drought via the interaction between root and shoot remain to be clarified. Here, we investigated the roles of roots and shoots in photosynthetic responses to water stress. Grafted plants of drought-tolerant cultivar L14 and drought-sensitive cultivar L21 were grown in the pot-culture experiments. Some photosynthetic and physiological traits were measured after water-stress treatments during a podding stage. The L14 as rootstock showed a stronger growth vigor under water stress, leading to increases...
Selenium improves the transport dynamics and energy conservation of the photosynthetic apparatus of in vitro grown Billbergia zebrina (Bromeliaceae)
A.F.C. SOUZA, J.P.R. MARTINS, A.B.P.L. GONTIJO, A.R. FALQUETO
Photosynthetica 2019, 57(4):931-941 | DOI: 10.32615/ps.2019.105
Selenium (Se) is a nonessential element to plants. However, Se is known to have a beneficial effect when present in low concentrations (Pilon-Smith et al. 2009). Several studies have demonstrated multiple impacts of Se on plant physiology, such as increased biomass production (Chen et al. 2014, Jiang et al. 2015, Feng et al. 2016), delayed senescence (Xue et al. 2001), increased tolerance to oxidative damage (Feng et al. 2013, Diao et al. 2014, Qing et al. 2015, Tang et al. 2015), increased production of carotenoid pigments (Ning et al. 2016), higher tolerance to photooxidative stresses...
Photosynthesis response to severe water deficit in terminal stems of Myriolimon ferulaceum
M.À. CONESA, J. GALMÉS
Photosynthetica 2019, 57(4):921-930 | DOI: 10.32615/ps.2019.110
Myriolimon ferulaceum is a leafless species and close relative to Limonium inhabiting the same harsh environments in the rocky coast and salt marshes, with discontinuous distribution in western and central coast of the Mediterranean Basin and southern Iberian Peninsula. In order to test for the drought adaptive importance of photosynthesis in stems, and to decipher advantages and drawbacks of stem vs. leaf photosynthesis under drought conditions, M. ferulaceum was grown under the well-watered and severe water deficit conditions used in previous experiments with Limonium. Growth, stem anatomy, photosynthesis and gas exchange,...
Effects of polyamines on agronomic traits and photosynthetic physiology of wheat under high temperature stress
J.G. JING, S.Y. GUO, Y.F. LI, W.H. LI
Photosynthetica 2019, 57(4):912-920 | DOI: 10.32615/ps.2019.104
Two spring wheat varieties were used to study alleviating effects of exogenous spermine (Spm) and spermidine (Spd) on agronomic traits and photosynthesis under high temperature treatment (HT). Our results showed that HT significantly decreased grain mass per panicle of heat-resistant variety (XC 6) by 25% and heat-sensitive variety (XC 31) by 32%. After HT, i.e., at 13 d after flowering, the decrease in net photosynthetic rate of XC 6 (38%) was lower than that of XC 31 (53%); the reason for this was related to XC 6, which could maintain correspondingly normal chlorophyll content (Chl), stomatal conductance (gs), transpiration...
Relationship between leaf gas-exchange characteristics and the performance of Ziziphus spina-christi (L.) Willd. seedlings subjected to salt stress
M. GORAI, R. BEN ROMDHANE, M. MARAGHNI, M. NEFFATI
Photosynthetica 2019, 57(3):897-903 | DOI: 10.32615/ps.2019.093
Ziziphus spina-christi (L.) Willd., known as Christ's thorn jujube, is a multipurpose species of the Rhamnaceae family. Seedlings were subjected to various NaCl concentrations (0 to 200 mM) for 21 d. They grew well under control conditions, however, biomass production and relative growth rate decreased with increasing NaCl salinity. This decline in growth was closely associated with a reduction in photosynthetic characteristics and plant water relations. However, the intrinsic water-use efficiency significantly increased as salt stress intensified. The relative water content declined although it still maintained high values (≥ 57%). At high salinity,...
Physiological characterization and thylakoid ultrastructure analysis in super high-yield hybrid rice leaves under drought stress
Y.W. WANG, D.X. JIANG, J.J. HOU, G.X. CHEN
Photosynthetica 2019, 57(3):890-896 | DOI: 10.32615/ps.2019.106
Rice serves for more than a third of the world's population. However, drought stress (DS) affects its growth and yield. In order to understand plant drought adaptability, we explored the physiological and thylakoid ultrastructural alteration in super high-yield hybrid rice Liangyoupeijiu (LYPJ) under DS. Results showed that DS altered the thylakoid ultrastructure; twisted and fractured stroma thylakoids and more starch granules in chloroplast of LYPJ were present. Also, DS lowered chlorophyll and carotenoid contents in LYPJ after 7 d. DS reduced the proportion of unsaturated fatty acids in thylakoid membranes and increased the content of linoleic...
Carbon assimilation in oak (Quercus spp.) populations under acute and chronic high-temperature stress
R. HORAK, M. ŽUPUNSKI, S. PAJEVIĆ, M. BORIŠEV, D. ARSENOV, N. NIKOLIĆ, S. ORLOVIĆ
Photosynthetica 2019, 57(3):875-889 | DOI: 10.32615/ps.2019.090
This study tried to evaluate the influence of high temperatures (HT) on carbon assimilation of two oak species (Quercus cerris and Quercus robur). The screening of their populations, which are assumed to have a different resistance and acclimatization potential to adverse environmental conditions, can provide essential information for its implementation in reforestation strategies. By employing principal component analysis, the aim was to determine the most variable physiological characteristics of plants exposed to extremely HT during vegetation periods. After 2 d of HT treatment, a significant decline of photosynthetic and transpiration...
Proteomic analysis of chloroplasts from chlorophyll-deficient melon mutant
C.M. ZHAO, J.Z. CUI, X.G. LI, B.J. CHEN, R.R. JIN, Z.Y. YU
Photosynthetica 2019, 57(3):866-874 | DOI: 10.32615/ps.2019.078
We aimed to understand the molecular-level changes occurring in the photosynthetic metabolic network in mutant chloro-plasts. We performed comparative liquid chromatography-mass spectrometry protein profiling of wild-type (WT) and chlorophyll-deficient melon (Cucumis melo L.) mutants. We identified 390 differentially expressed proteins and 81 shared proteins varied significantly in abundance, of which 76 were upregulated and 5 were downregulated. Differentially expressed proteins were involved in the following biological processes: binding, catalytic, structural, transporter, and antioxidant activities. The mutant had 6.08-fold higher expression...
Influence of shading on photosynthesis and antioxidative activities of enzymes in apple trees
Y.J. LIU, W. ZHANG, Z.B. WANG, L. MA, Y.P. GUO, X.L. REN, L.X. MEI
Photosynthetica 2019, 57(3):857-865 | DOI: 10.32615/ps.2019.081
This study investigated the effects of shading on photosynthesis in 3-year-old potted apple trees. The trees were grown either in full sunlight or in a shade environment with about 50% of sunlight filtered through black plastic nets. Under the shade conditions, the net photosynthetic rate (PN), the stomatal conductance, the transpiration rate, and the intercellular CO2 concentration decreased before midday, which was due to low light energy but the PN of the shaded trees increased relative to the control trees during the afternoon. In addition, the concentrations of chlorophyll (Chl) a, b,...
Physiological and molecular responses of maize (Zea mays L.) plants to drought and rehydration
P.Yu. VORONIN, S.N. MAEVSKAYA, M.K. NIKOLAEVA
Photosynthetica 2019, 57(3):850-856 | DOI: 10.32615/ps.2019.101
Physiological and molecular responses of maize seedlings (Zea mays L. cv. Troinaya sladost) to 5-d drought and rehydration for 48 h were investigated. Plant water status was determined by a new method of water potential measurement in mesophyll cells' apoplast in substomatal cavity (ψwa). Drought caused the changes in water status, plant growth, the rates of photosynthetic CO2/H2O gas exchange, and metabolism of carbohydrates and proline. The increase in carbohydrate and proline content under drought was observed simultaneously with the decline in ψwa. Rewatering of seedlings for 24 and 48...
Sensitivity of wild and domesticated Rhododendron chrysanthum to different light regime (UVA, UVB, and PAR)
J. LYU, C. WANG, D.Y. LIANG, L. LIU, L.K. PANDEY, H.W. XU, X.F. ZHOU
Photosynthetica 2019, 57(3):841-849 | DOI: 10.32615/ps.2019.098
Effects of UV radiation on photosynthetic capacity of wild and domesticated Rhododendron chrysanthum were compared by applying PAR (P), P + UVA (PA), and P + UVA + UVB (PAB) radiation for 3 d, respectively. Results showed that photosynthetic activity of two R. chrysanthum types was not affected by UVA but inhibited by UVB, and the inhibitory effects of UVB were dose-dependent. Changes in nonphotochemical quenching suggest that the range of photosynthetic capacity is ranked as follows: 24-48 h of UVB dose < wild type < 72 h of UVB dose < domesticated type, indicating that the wild type initiated photoprotective function in response...
Long-term high light stress induces leaf senescence in wheat (Triticum aestivum L.)
Y.N. LIU, Q.Z. XU, W.C. LI, X.H. YANG, Q. ZHENG, B. LI, Z.S. LI, H.W. LI
Photosynthetica 2019, 57(3):830-840 | DOI: 10.32615/ps.2019.086
In order to explore the association of long-term high light (HL) with leaf senescence in wheat, two wheat genotypes Xiaoyan 54 (HL-tolerant) and Jing 411 (HL-sensitive) grown in low light were subjected to HL for 2-8 d. The results showed that 6-8 d of HL led to dramatic decline of chlorophyll content, photochemical efficiency, and activity of Rubisco and antioxidant enzymes. Meanwhile, the content of malondialdehyde (MDA), soluble proteins, soluble sugars, superoxide anion, and ascorbic acid increased markedly. Additionally, the expression of senescence-associated genes (SAGs) was induced by HL. Xiaoyan 54 accumulated less MDA, soluble sugars,...
Irrigation improves plant vitality in specific stages of mango tree development according to photosynthetic efficiency
L. FARIA-SILVA, C. Z. GALLON, P. R. FILGUEIRAS, D. M. SILVA
Photosynthetica 2019, 57(3):820-829 | DOI: 10.32615/ps.2019.091
The plant fruiting process requires more energy and availability of soil water. Consequently, identifying the appropriate time for additional water supplying for cultivation of mango is an important part of successful crop handling for production of fruit with high quality. Therefore, we studied effects of additional water supplied by irrigation on chlorophyll fluorescence parameters in a field experiment during phenological stages of Mangifera indica L. cv. Ubá. Our results showed that the irrigation at specific periods of plant development improved fluorescence parameters (resulting in high values of the performance index), preventing damage...
Melatonin confers drought stress tolerance in soybean (Glycine max L.) by modulating photosynthesis, osmolytes, and reactive oxygen metabolism
L. CAO, X.J. JIN, Y.X. ZHANG
Photosynthetica 2019, 57(3):812-819 | DOI: 10.32615/ps.2019.100
In order to investigate the role of melatonin in the drought tolerance, we examined pigments, gas exchange, osmolytes, and reactive oxygen radical metabolism in soybean plants. Drought declined photosynthetic pigments and caused irreversible reduction in net photosynthesis, which was followed by stomatal limitation for 5 and 10 d and nonstomatal limitation for 15 d. Soluble sugar, soluble proteins, and proline concentrations were higher in drought-stressed seedlings compared with the control. The contents of superoxide anion, hydrogen peroxide, and malondialdehyde increased during drought stress indicating oxidative stress. Drought stress also increased...
Light-response characteristics of photosynthesis of drip-irrigated sugar beet under different nitrogen fertilizer managements
C. FEI, J.X. SU, Y.Y. LI, Z.F. LI, K.Y. WANG, H. FAN, F.Y. MA
Photosynthetica 2019, 57(3):804-811 | DOI: 10.32615/ps.2019.089
Effects of two split application ratios of nitrogen fertilizer (R1: half of the total nitrogen fertilizer was applied on 13 June, and the rest was applied on 1 July; R2: two equal amounts of N fertilizer accounting for 70% of total were applied on 15 June and 1 July, respectively, and the rest was applied on 1 August) and three N fertilizer application rates (75, 150, and 225 kg ha-1) on chlorophyll content, photosynthetic characteristics, and root yield of sugar beets were studied. The results showed that with N fertilizer application rates of 150 and 225 kg ha-1, R2 treatment significantly decreased light-compensation point,...