scholarly journals Salinity reduced growth PS2 photochemistry and chlorophyll content in radish

2007 ◽  
Vol 64 (2) ◽  
pp. 111-118 ◽  
Author(s):  
Muhammad Jamil ◽  
Shafiq ur Rehman ◽  
Kui Jae Lee ◽  
Jeong Man Kim ◽  
Hyun-Soon Kim ◽  
...  
Keyword(s):  
Leaf Area ◽  
Chlorophyll Content ◽  
Salt Concentration ◽  
Germination Rate ◽  
Photochemical Efficiency ◽  
Germination Percentage ◽  
Photochemical Quenching ◽  
Leaf Water Content ◽  
Spad Value ◽  
Salt Level

When plants are grown under saline conditions, photosynthetic activity decreases leading to reduced plant growth, leaf area, chlorophyll content and chlorophyll fluorescence. Seeds and seedlings of radish (Raphanus sativus L.) were grown in NaCl solutions under controlled greenhouse conditions. The NaCl concentrations in complete nutrient solutions were 0 (control), 4.7, 9.4 and 14.1 dS m-1. The salinity reduced germination percentage and also delayed the germination rate as the salt level increased. Lengths and fresh weights of root and shoot decreased with the increasing salt concentration. Furthermore, photochemical efficiency of PS2 (Fv/Fm), photochemical quenching coefficient (qP), non photochemical quenching coefficient (qN), leaf area and chlorophyll content (SPAD value) were also reduced (P < 0.001) by salt stress. In contrast, the Fo/Fm ratio increased with increasing salt concentration while salinity showed no effect on the efficiency of excitation captured by open PS2 (Fv'/Fm'), electron transport rate (ETR), and leaf water content. Linear regression shows that the photochemical efficiency of PS2 (Fv/Fm) had a positive relationship with the photochemical quenching coefficient (qP), leaf area and chlorophyll content but had no relation with Fv'/Fm', Fo/Fm, and qN.

scholarly journals Effect of Light Emitting Diode (LED) Spectrum at Seedlings Production for Optimal Growth on Different Type of Lettuce in MARDI Plant Factory

2021 ◽  
Author(s):  
Mohamed Hafeifi Basir ◽  
Intan Nadhirah Masri
Keyword(s):  
Leaf Area ◽  
Plant Biomass ◽  
Light Emitting Diode ◽  
Germination Percentage ◽  
Seedling Production ◽  
Full Spectrum ◽  
Spad Value ◽  
Fresh Vegetables ◽  
Plant Factory ◽  
Production Area

Seedling production is a crucial part of the production of fresh vegetables in a plant factory. Light is one of the necessities for plants to produce a healthy seedling before being transplanted to the production area. Different light formulations resulted in different growth performances of the plant. Hence, this study was conducted to aim for suitable light formulation on various types of lettuce in the MARDI Plant Factory. The study was conducted in two stages: 1) seedling production and 2) production area. Treatments were evaluated at the seedlings' production stage using the split-plot experimental design with four replications. LED light treatments (LT) was the main factor with the various ratio of spectrum colour of Red (R), Blue (B), Green (G) and full spectrum. (LT 1; 5R:1B, LT 2; 1R:1B, LT 3; 1R: 2B, LT 4; 2R:1B, LT 5; 4R:1B:1G and LT 6; Full spectrum as control). The sub-factor was lettuce variety (V1; Butterhead, V2; Green Coral, V3; Red Coral and V4; Mini Cos). Variables measured at seedlings production were seed germination. Growth biomass and SPAD value were evaluated in the production area. At seedlings production, the full spectrum lighting shows significant seeds germination percentage compared to other LED lighting, and V1 performed well on germination percentage and time compare to other varieties. The interaction between light treatments and lettuce was observed on the leaf numbers, shoot fresh weight, leaf area, and the shoot-root ratio at the production area. LT 1 and LT 5 on butterhead and green coral significantly affected the number of leaves and leaf area, which were relatively influenced by light quality and ambient temperature. The yield on green coral lettuce grown under LT 1, LT 2, and LT 5 was significantly higher than others. However, plant biomass and SPAD value for all treatments were not significantly different. The allometry of plant was expressed on a shoot-root ratio with LT 2 on green coral shows a significantly higher shoot-root ratio than other treatments. The study's findings showed that light treatment with Red and Blue LED ratio of 5:1, 1:1, and Red, Blue, and Green LED ratio of 4:1:1 light arrangement on the seedling's productions provided optimal growing conditions in the production area butterhead and green coral lettuce in MPF cultivation.

scholarly journals Effects of Seed Size on the Germination and Early Growth of African Baobab (Adansonia digitata L.)

2020 ◽  
pp. 1-7
Author(s):  
J. I. Amonum ◽  
F. Sumaduniya ◽  
T. O. Amusa
Keyword(s):  
Leaf Area ◽  
Seed Size ◽  
Germination Rate ◽  
Germination Percentage ◽  
Early Growth ◽  
Adansonia Digitata ◽  
Size Classes ◽  
Randomized Design ◽  
Significant Difference ◽  
Viable Seeds

The effects of seed size on the germination and early growth of A. digitata were assessed. Seeds were sourced locally within the University of Ilorin Campus. One hundred viable seeds were selected from each of the size classes. The seed weight, length, breadth, and width were measured for all the selected seeds. Mean weight, length, breadth, and thickness were: 0.62 g, 9.16 mm, 7.45 mm, and 5.85 mm, respectively for small seeds. 0.41 g, 9.54 mm, 7.68 mm, and 6.03 mm, respectively for medium seeds; and 0.44 g, 9.92 mm, 7.89 mm, and 6.21 mm, respectively for large seeds. The experiment was laid out in a completely randomized design (CRD). Seed dormancy was broken through the acid scarification method by soaking in H2SO4 at 70% concentration for 20 minutes with constant stirring. Variables of interest include: leaves number, seedlings height, collar diameter and leaf area. Based on the results of this finding, medium and large seeds germinated in 7 days after sowing while small seeds germinated in 10 days after sowing. Large seeds had the highest germination percentage (55%), followed by medium seeds with 27%. The small seeds were the least in terms of germination rate (21%). There was no significant difference in mean seedling heights, collar diameters and number of leaves among the seed size classes (P˃0.05). Mean leaf area significantly differed among the three size classes (P˂0.05). The result showed that large seeds gave best germination at a shorter period than the medium and small seed sizes. Thus, large seeds of A. digitata are recommended in propagation activities involving the species.

scholarly journals Comparison Study on the Effect of Nano and Bulk Titanium Dioxide Particles on Seeds Germination, Growth and Chemical Composition of Wheat Invitro and Invivo

2018 ◽  
Vol 28 (3) ◽  
pp. 85
Author(s):  
Raghad D. Alshybany
Keyword(s):  
Leaf Area ◽  
Germination Rate ◽  
In Vitro Study ◽  
Germination Percentage ◽  
Chemical Compositions ◽  
Root Tips ◽  
Area Index ◽  
Vigor Index

The present study aimed to examine the effect of TiO2 nanoparticles (NPs) compared with bulk particles (BPs) on seed germination and growth of latefyha's cultivar wheat in vitro and in vivo and on chemical compositions with detecting the residuum of NPs in the plant. In the in vitro study, most concentrations of NPs and BPs have no effect on germination percentage, mean germination time, mean daily germination, promoter indicator, number of leaves, length and number of root and root tips viability but they reduced germination rate and germination value besides they induced shoot length and biomass. In the in vivo study, some parameters induced by most concentrations of NPs such as plant leaves area, leaf area index, length, of viability roots, height and total of plant length and biomass while no effect was seen on: mean daily germination, vigor index I and vigor index II, chlorophyll B, leaf area relative, in this regard, it reduced germination percentage, chlorophyll A, and carotene. There were some differences between the effect of NPs and those of BPs. There were increased in the total number of chemical compounds that identified in leaves of wheat plants treated with nanoparticles compared with control while the total numbers of compounds were decreased using bulk particles.

scholarly journals Silicon-Mediated Physiological and Agronomic Responses of Maize to Drought Stress Imposed at the Vegetative and Reproductive Stages

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1136
Author(s):  
Dongfeng Ning ◽  
Anzhen Qin ◽  
Zhandong Liu ◽  
Aiwang Duan ◽  
Junfu Xiao ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Drought Stress ◽  
Leaf Area ◽  
Chlorophyll Content ◽  
Photosynthetic Rate ◽  
Antioxidant Activities ◽  
Soil Column ◽  
Yield Reduction ◽  
Leaf Water Content ◽  
Maize Yields

Silicon (Si) enhances maize resistance to drought. While previous studies have mainly focused on the seedling stage, the mediation of drought stress by Si imposed at the vegetative and reproductive stages has been rarely investigated. A soil-column experiment was thus conducted under a rainproof shelter to quantify the effect s of Si application on the physiological and agronomic responses of maize to drought stress imposed at the 6-leaf (D-V6), 12-leaf (D-V12), and blister (D-R2) stages. The observed parameters included plant growth, photosynthesis, osmolytes, antioxidant activity, and grain yield. The results showed that drought stress strongly decreased the leaf area, leaf water content, photosynthetic rate, chlorophyll content, and antioxidant activity (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)) and markedly increased lipid peroxidation. D-V6, D-V12, and D-R2 decreased grain yields by 12.9%, 28.9%, and 44.8%, respectively, compared to the well-watered treatment (CK). However, Si application markedly increased leaf area, chlorophyll content, photosynthetic rate, osmolyte content, and enzymatic antioxidant activities (SOD, POD, and CAT), and decreased malondialdehyde (MDA) and superoxide radical accumulation, ultimately improving maize yields by 12.4%, 69.8%, and 80.8%, respectively, compared to the non-Si treated plants under drought stress at the V6, V12, and R2 stages. Furthermore, maize yields had a significant positive correlation with chlorophyll content and SOD and POD activity during the three stages. Our findings suggest that Si-induced changes in chlorophyll content and antioxidant activity might constitute important mechanisms for mitigating drought stress. In conclusion, this study provides physico-biochemical evidence for the beneficial role of Si in alleviating drought-induced yield reduction in maize, particularly during the late vegetative or early reproductive stages. Thus, Si application constitutes an effective approach for improving maize yield in rain-fed agricultural systems.

scholarly journals Waterlogging tolerance and recovery capability screening in peanut: a comparative analysis of waterlogging effects on physiological traits and yield

PeerJ ◽  
2022 ◽  
Vol 10 ◽  
pp. e12741
Author(s):  
Ruier Zeng ◽  
Jing Cao ◽  
Xi Li ◽  
Xinyue Wang ◽  
Ying Wang ◽  
...  
Keyword(s):  
Photochemical Efficiency ◽  
Significant Negative Correlation ◽  
Photochemical Quenching ◽  
Waterlogging Tolerance ◽  
Sod Activity ◽  
Ps Ii ◽  
Spad Value ◽  
Mda Content ◽  
Non Photochemical Quenching ◽  
Maximum Photochemical Efficiency

Fifteen peanut varieties at the pod filling stage were exposed to waterlogging stress for 7 days, the enzyme activities and fluorescence parameters were measured after 7 days of waterlogging and drainage. The waterlogging tolerance and recovery capability of varieties were identified. After waterlogging, waterlogging tolerance coefficient (WTC) of relative electrolyte linkage (REL), malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, and catalase (CAT) activity, non-photochemical quenching (NPQ) and photochemical quenching (qL) of leaves of most peanut varieties were increased, while the WTC of the soil and plant analysis development (SPAD) value, PS II actual quantum yield (ΦPS II), maximum photochemical efficiency (Fv/Fm) were decreased. After drainage, the WTC of REL, MDA content, SOD and CAT activity of leaves were decreased compared with that of after waterlogging, but these indicators of a few cultivars were increased. ΦPS II, Fv/Fm and qL can be used as important indexes to identify waterlogging recovery capability. There was a significant negative correlation between recovery capability and the proportion of reduction in yield, while no significant correlation was found between waterlogging tolerance and the proportion of reduction in yield. Therefore, it is recommended to select varieties with high recovery capability and less pod number reduction under waterlogging in peanut breeding and cultivation.

scholarly journals Changes in Assimilation Area and Chlorophyll Content of Very Early Potato (Solanum tuberosum L.) Cultivars as Influenced by Biostimulants

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 387 ◽  
Author(s):  
Wanda Wadas ◽  
Tomasz Dziugieł
Keyword(s):  
Leaf Area ◽  
Chlorophyll Content ◽  
Tuber Yield ◽  
Foliar Application ◽  
Solanum Tuberosum L ◽  
Abiotic Stress Tolerance ◽  
Control Group ◽  
Early Potato ◽  
Area Index ◽  
Spad Value

This paper analyses the effects of foliar application of the seaweed extracts Bio-algeen S90 (Ascophyllum nodosum) and Kelpak SL (Ecklonia maxima), as well as the humic and fulvic acids ini HumiPlant (leonardite extract), on the assimilation area and chlorophyll content of very early potato cultivars (‘Denar’, ‘Lord’, Miłek’). The field experiment was carried out in central-eastern Poland over three growing seasons, using Luvisol. The biostimulants were applied according to the manufacturers’ recommendations. The use of biostimulants resulted in enlargement of the assimilation area, but had no effect on the specific leaf area (SLA) or chlorophyll content (Soil Plant Analysis Development (SPAD) value). The assimilation area was larger, on average, by 0.0505 m2 and leaf area index (LAI) was higher by 0.30 compared with the plants from the control group without a biostimulant. The SLA and SPAD depend on the cultivar and weather conditions, or nitrogen and magnesium content in soil, to a greater extent. The biostimulants enhanced abiotic stress tolerance and increased marketable tuber yield (diameter above 30 mm) 75 days after planting (the end of June), on average by 2.15 t·ha−1. Bio-algeen S90 and Keplak SL produced better results in a warm and very wet growing season, whereas HumiPlant produced better results in a year with lower air temperature and with drought periods during potato growth. No correlations were found between the tuber yield and assimilation area or between the tuber yield and SPAD value, although a significant negative correlation was found between the tuber yield and SLA.

scholarly journals Effects of the red:far-red light ratio on photosynthetic characteristics of greenhouse cut Chrysanthemum – Short communication

2013 ◽  
Vol 40 (No. 1) ◽  
pp. 40-43 ◽  
Author(s):  
Z.Q. Yang ◽  
Y.X Li ◽  
J.B. Zhang ◽  
J. Zhang ◽  
J. Zhu ◽  
...  
Keyword(s):  
Photosynthetic Rate ◽  
Red Light ◽  
Photochemical Efficiency ◽  
Photosynthetic Characteristics ◽  
Photochemical Quenching ◽  
Light Sources ◽  
Chlorophyll Fluorescence Parameters ◽  
Spad Value ◽  
Red Led ◽  
R:Fr Ratio

For the use of LED as a light source to regulate the photosynthesis of chrysanthemum leaves under greenhouse conditions, the effects of different red (660 &plusmn; 30 nm) to far-red (730 &plusmn; 30 nm) radiation ratios (R:FR) on the photosynthetic characteristics and chlorophyll fluorescence parameters of chrysanthemum leaves were studied. Red and far-red LED light sources were combined in different proportions to produce four R:FR ratio treatments: 0.5, 2.5, 4.5 and 6.5. The chlorophyll a content, SPAD value, net photosynthetic rate, light-saturated maximum photosynthetic rate, CO<sub>2</sub>-saturated carboxylation rate, apparent quantum efficiency and carboxylation efficiency were all the highest under the R:FR ratio of 2.5, followed by the R:FR ratio of 4.5. Potential photochemical efficiency of photosystem II, photochemical quenching and electron transport rate for the R:FR ratios of 2.5 and 4.5 were markedly higher than those for 0.5 and 6.5, however, those parameters did not differ significantly between the R:FR ratios of 2.5 and 4.5.

scholarly journals Impacts of Reduced Nitrate Supply on Nitrogen Metabolism, Photosynthetic Light-Use Efficiency, and Nutritional Values of Edible Mesembryanthemum crystallinum

2021 ◽  
Vol 12 ◽  
Author(s):  
Jie He ◽  
Lin Qin
Keyword(s):  
Leaf Area ◽  
Reductase Activity ◽  
Soluble Sugar ◽  
Mesembryanthemum Crystallinum ◽  
Photochemical Quenching ◽  
Leaf Water Content ◽  
Growth Media ◽  
Dry Matter Accumulation ◽  
Effective Quantum Yield ◽  
Nutritional Values

Mesembryanthemum crystallinum (common ice plant), as a nutritious ready-to-eat salad in Singapore, has become popular in recent years. However, basic data about the impacts of NO3– supply on its NO3– accumulation and nutritional quality are lacking. In this study, all plants were first grown indoor hydroponically in 10% artificial seawater (ASW) with modified full-strength Netherlands Standard Composition nutrient solution for 11 days, before transferring them to different reduced NO3– solutions. All plants grew well and healthy after 7 days of treatment. However, plants grown with 3/4 N and 1/2 N were bigger with higher shoot and root fresh weight (FW), greater leaf number, and total leaf area (TLA) than those grown with full nitrogen (N), 1/4 N, and 0 N. Mesembryanthemum crystallinum grown with full N, 3/4 N, and 1/4 N had similar specific leaf area (SLA), while 0 N plants had significantly lower SLA. All plants had similar leaf succulence (LS). However, leaf water content (LWC) was lower, while leaf dry matter accumulation (LDMC) was higher in 0 N plants after 7 days of treatment. Compared with plants grown with full N, shoot NO3– concentrations in 3/4 N, 1/2 N, and 1/4 N plants were constant or slightly increased during the treatments. For 0 N plants, shoot NO3– concentration decreased significantly during the treatment compared with other plants. Shoot NO3– accumulation was associated with nitrate reductase activity (NRA). For instance, after 7 days of treatment, shoot NO3– concentration and NRA on a FW basis in 0 N plants were, respectively, 45 and 31% of full N plants. After transferring full N to 0 N for 7 days, all M. crystallinum had higher chlorophyll (Chl) content coupled with higher electron transport rate (ETR) and higher effective quantum yield of PSII, while full N plants had higher non-photochemical quenching (NPQ). The 0N plants had much higher concentrations of proline, total soluble sugar (TSS), and total ascorbic acid (ASC) than other plants. In conclusion, totally withdrawing NO3– from the growth media prior to harvest could be one of the strategies to reduce shoot NO3– concentration. Reduced NO3– supply further enhanced nutritional values as concentrations of proline, TSS, and ASC were enhanced markedly in M. crystallinum plants after transferring them from full N to 0 N.

scholarly journals MITIGATION OF EXCESSIVE SOLAR RADIATION AND WATER STRESS ON ‘KEITT’ MANGO Mangifera indica TREES THROUGH SHADING

2021 ◽  
Vol 20 (4) ◽  
pp. 77-88
Author(s):  
Ayman E.A. Shaban ◽  
Ahmed A. Rashedy ◽  
Mohammed I.M. El-Banna
Keyword(s):  
Powdery Mildew ◽  
Solar Radiation ◽  
Water Content ◽  
Leaf Area ◽  
Chlorophyll Content ◽  
Fruit Set ◽  
Proline Content ◽  
Leaf Water Content ◽  
Irrigation Level ◽  
Relative Water

Excessive solar radiation “global warming” and water scarcity are consider the main environmental constraints for plant growth and production under arid and semi-arid regions. The current research was aimed to study the effect of irrigation levels (100%, 85%, 70% of irrigation requirements), and shading levels (60%, 40%, 0%) on the growth and productivity of ‘Keitt’ mango trees. This experiment was conducted during two growing seasons (2016/2017 and 2017/2018) at El Behera Governorate, Egypt. Decreasing irrigation level (IR) decreased leaf area, malformed panicle, powdery mildew infection, final fruit set, fruit numbers, yield but it increased chlorophyll content, proline content, leaf water content. While, increasing shading levels (SH) increased leaves number, leaf area, fruit set, powdery mildew infection, malformed panicle but it decreased fruit sunburn damage, proline content, chlorophyll content and relative water content. Moreover, accumulative effects of 85% IR + 40% SH significantly increased leaf area, fruit set, fruit number, yield, chlorophyll content, WUE, proline content, relative water content, leaf water content while decreasing powdery mildew and sunburn damage. Results suggest that shading at 40% increased the yield up to 20% and decreased sunburn damage up to 0% under irrigation level of 70%. Shading may be a new technique to alleviate the adverse effects of water stress beside their role in avoiding excessive solar radiation on ‘Keitt’ mango trees.

scholarly journals Germination potential of Hymenaea courbaril L. in different maturation stages

2021 ◽  
Vol 42 (6supl2) ◽  
pp. 3667-3684
Author(s):  
Hugo Roldi Guariz ◽  
◽  
Halley Caixeta de Oliveira ◽  
Huezer Viganô Sperandio ◽  
Jean Carlo Baudraz de Paula ◽  
...  
Keyword(s):  
Leaf Area ◽  
Relative Frequency ◽  
Germination Rate ◽  
Germination Percentage ◽  
Seedling Production ◽  
Hymenaea Courbaril ◽  
Germination Time ◽  
Germination Potential ◽  
The Matrix ◽  
Maturation Stages

The production of quality forest seedlings in large quantities is essential for the restoration of environments that have been deforested and degraded. However, obtaining seeds with high vigor is a challenge for several tree species native to Brazil. The objective of this work was to verify the germination potential of jatobá-da-mata seeds at different stages of maturation, in order to favor the production of seedlings of this species in nurseries. The seeds were extracted from green and ripe fruits detached from the mother plant and ripe fruits collected from the ground. The germination percentage, average germination time, emergence speed index, average speed, relative frequency, leaf area of the seedling, and length of the aerial part and root were measured. The planting was carried out with mechanically scarified and intact seeds from each maturation group. The results indicated that non-scarified green seeds can be used for planting and seedling production, as they do not require pre-germination treatment and have a favorable germination percentage (79%). Fruit seeds harvested from the ground, on the other hand, needed a method to overcome integumentary dormancy, such as mechanical scarification, obtaining a germination rate of 85%. The seeds of ripe fruits harvested in the matrix showed greater vigor, with a higher percentage of germination (96 to 100%), a higher emergence speed index, shorter average germination time, and seedlings with greater leaf area and greater length of shoot.

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