Silicon dioxide nanofertilizers improve photosynthetic capacity of two Criollo cocoa clones (Theobroma cacao L.)

2021 ◽  
pp. 1-18
Author(s):  
Pedro Gómez-Vera ◽  
Héctor Blanco-Flores ◽  
Ana Marta Francisco ◽  
Jimmy Castillo ◽  
Wilmer Tezara

Summary Studies on the effect of nanofertilizers (NF) in physiological performance of plants is scarce, especially that related to substances encapsulated into silicon dioxide (SiO2) nanoparticles in cocoa plants. The effect of foliar application of SiO2-NF on nutrient contents, gas exchange, photochemical activity, photosynthetic pigments, total soluble protein (TSP), photosynthetic nitrogen use efficiency (PNUE), and growth in seedlings of two cocoa clones (OC-61 and BR-05) in a greenhouse was assessed. Spraying with SiO2-NF increased net photosynthetic rate (A) by 16 and 60% and electron transport rate (J) by 52 and 162% in clones OC-61 and BR-05, respectively, without changes in photosynthetic pigment concentration in either clone. The SiO2-NF caused a decrease of 37 and 22% in stomatal conductance in OC-61 and BR-05, respectively; a similar trend was observed in transpiration rate, causing an increase of 42 and 100% in water use efficiency in OC-61 and BR-05, respectively. In both clones, diameter of graft increased on average 28% with SiO2-NF. Higher photosynthetic capacity was related to an increase in leaf N, P, and TSP. A significant reduction in PNUE (A/N ratio) was found in OC-61, whereas in BR-05 PNUE increased after spraying with SiO2-NF. Overall, spraying with SiO2-NF had a positive effect on photosynthetic processes in both cocoa clones, associated with an increase in nutrients content, which translated into improved growth. A differential physiological response to spraying with SiO2-NF between clones was also found, with BR-05 being the clone with a better physiological response during the establishment and development stages.

2019 ◽  
Author(s):  
Marwa A. Qotob ◽  
Mostafa A. Nasef ◽  
Heba K. A. Elhakim ◽  
Olfat G. Shaker ◽  
Nader R. Habashy ◽  
...  

ABSTRACTAny improvement in agricultural systems that results higher production aimed to reduce negative environmental impacts and enhance sustainability plant growth regulators (PGRs) such as gibberellin have similar physiological and biological effects to those of plant hormones, and therefore used widely in agriculture to minimize unwanted shoot growth without lowering plant productivity.An experimental field was conducted at Giza Experimental Station Egypt, on sugar beet plants (Beta vulgaris L. var. Sara poly) with some plant growth regulators (gibberellin and proline) foliar application at three rates of zero (control), 100 and 200 mg l−1 and boron sources (Boric acid and B-NPs) with 75% of macro-nutrients from full dose.The main target of this study to evaluate another plant growth regulator source like proline which is safer than gibberellin for maximizing sugar beet biological parameters to reduce the gap between sugar consumption and production in presence of boron sources.Data showed that the foliar applications of gibberellin (GA3) at rate 100 mg l−1 and proline at 200 mg l−1 were found to be the more effective without significant differences for plant growth, productivity and quality may be due to increased N use efficiency, especially at sub-optimal macro nutrient fertilizers. Regard to boron sources, B-NPs had positive effect on all biological parameters under study due to sugar transport, cell membrane synthesis, nitrogen fixation, respiration, carbohydrate metabolisms, root growth, functional characteristics and development.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xin Jia ◽  
Ke Mao ◽  
Ping Wang ◽  
Yu Wang ◽  
Xumei Jia ◽  
...  

AbstractWater deficit is one of the major limiting factors for apple (Malus domestica) production on the Loess Plateau, a major apple cultivation area in China. The identification of genes related to the regulation of water use efficiency (WUE) is a crucial aspect of crop breeding programs. As a conserved degradation and recycling mechanism in eukaryotes, autophagy has been reported to participate in various stress responses. However, the relationship between autophagy and WUE regulation has not been explored. We have shown that a crucial autophagy protein in apple, MdATG8i, plays a role in improving salt tolerance. Here, we explored its biological function in response to long-term moderate drought stress. The results showed that MdATG8i-overexpressing (MdATG8i-OE) apple plants exhibited higher WUE than wild-type (WT) plants under long-term moderate drought conditions. Plant WUE can be increased by improving photosynthetic efficiency. Osmoregulation plays a critical role in plant stress resistance and adaptation. Under long-term drought conditions, the photosynthetic capacity and accumulation of sugar and amino acids were higher in MdATG8i-OE plants than in WT plants. The increased photosynthetic capacity in the OE plants could be attributed to their ability to maintain optimal stomatal aperture, organized chloroplasts, and strong antioxidant activity. MdATG8i overexpression also promoted autophagic activity, which was likely related to the changes described above. In summary, our results demonstrate that MdATG8i-OE apple lines exhibited higher WUE than WT under long-term moderate drought conditions because they maintained robust photosynthesis, effective osmotic adjustment processes, and strong autophagic activity.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. A. Gomaa ◽  
Essam E. Kandil ◽  
Atef A. M. Zen El-Dein ◽  
Mamdouh E. M. Abou-Donia ◽  
Hayssam M. Ali ◽  
...  

AbstractIn Egypt, water shortage has become a key limiting factor for agriculture. Water-deficit stress causes different morphological, physiological, and biochemical impacts on plants. Two field experiments were carried out at Etay El-Baroud Station, El-Beheira Governorate, Agriculture Research Center (ARC), Egypt, to evaluate the effect of potassium silicate (K-silicate) of maize productivity and water use efficiency (WUE). A split-plot system in the four replications was used under three irrigation intervals during the 2017 and 2018 seasons. Whereas 10, 15, and 20 days irrigation intervals were allocated in main plots, while the three foliar application treatments of K-silicate (one spray at 40 days after sowing; two sprays at 40 and 60 days; and three sprays at 40, 60, and 80 days, and a control (water spray) were distributed in the subplots. All the treatments were distributed in 4 replicates. The results indicated that irrigation every 15 days gave the highest yield in both components and quality. The highly significant of (WUE) under irrigation every 20 days. Foliar spraying of K-silicate three times resulted in the highest yield. Even under water-deficit stress, irrigation every fifteen days combined with foliar application of K-silicate three times achieved the highest values of grain yield and its components. These results show that K-silicate treatment can increase WUE and produce high grain yield requiring less irrigation.


2011 ◽  
Vol 129 (3) ◽  
pp. 353-360 ◽  
Author(s):  
A.A. Amin ◽  
Fatma A.E. Gharib ◽  
M. El-Awadi ◽  
El-Sherbeny M. Rashad

Author(s):  
Bengü Türkyılmaz Ünal ◽  
Oğuzhan Mentiş ◽  
Ethem Akyol

In our study we aim to increase frost resistance and improve the yield and quality of apple is important in Turkey and world economy. Phenological and morphological observations, physiological and biochemical analyzes were carried out in apple (Malus domestica L.) plants. It was studied to determine the effects of foliar Salicylic acid (0, 500 ppm/plant and 1000 ppm/plant) on adaptation of this plant when exposed to freezing stress, the quality and yield. Leaf photosynthetic pigment contents, total protein amount, proline amount, superoxide dismutase and peroxidase enzymatic activities were measured. The study planned by random experimental design and statistical analysis of data with SPSS program (LSD test) were made. It was determined that fruit and shoot numbers were increased in samples exposed to 500 ppm salicylic acid and while fruit weights were increased in samples exposed to 500 ppm and 1000 ppm salicylic acid compared to the control. Also, colour of plants were darkened. Chla, chlb, total chl, proline, superoxide dismutase and peroxidase amounts were increased significantly compared to the control group. Increases occured in the carotenoid and the protein amounts are not significant statistically. In the light of obtained data, foliar application of salicylic acid were found to reduce the effects of freezing stress and to increase the yield and quality of apple plants.


2021 ◽  
Vol 12 ◽  
Author(s):  
Chenqian Kang ◽  
Yuqi Zhang ◽  
Ruifeng Cheng ◽  
Elias Kaiser ◽  
Qichang Yang ◽  
...  

Raising young plants is important for modern greenhouse production. Upon transfer from the raising to the production environment, young plants should maximize light use efficiency while minimizing deleterious effects associated with exposure to high light (HL) intensity. The light spectrum may be used to establish desired traits, but how plants acclimated to a given spectrum respond to HL intensity exposure is less well explored. Cucumber (Cucumis sativus) seedlings were grown in a greenhouse in low-intensity sunlight (control; ∼2.7 mol photons m–2 day–1) and were treated with white, red, blue, or green supplemental light (4.3 mol photons m–2 day–1) for 10 days. Photosynthetic capacity was highest in leaves treated with blue light, followed by white, red, and green, and was positively correlated with leaf thickness, nitrogen, and chlorophyll concentration. Acclimation to different spectra did not affect the rate of photosynthetic induction, but leaves grown under blue light showed faster induction and relaxation of non-photochemical quenching (NPQ) under alternating HL and LL intensity. Blue-light-acclimated leaves showed reduced photoinhibition after HL intensity exposure, as indicated by a high maximum quantum yield of photosystem II photochemistry (Fv/Fm). Although plants grown under different supplemental light spectra for 10 days had similar shoot biomass, blue-light-grown plants (B-grown plants) showed a more compact morphology with smaller leaf areas and shorter stems. However, after subsequent, week-long exposure to full sunlight (10.7 mol photons m–2 day–1), B-grown plants showed similar leaf area and 15% higher shoot biomass, compared to plants that had been acclimated to other spectra. The faster growth rate in blue-light-acclimated plants compared to other plants was mainly due to a higher photosynthetic capacity and highly regulated NPQ performance under intermittent high solar light. Acclimation to blue supplemental light can improve light use efficiency and diminish photoinhibition under high solar light exposure, which can benefit plant growth.


2021 ◽  
pp. 1-12
Author(s):  
R. Dietrich ◽  
F.W. Bell ◽  
M. Anand

Given the large contribution of forests to terrestrial carbon storage, there is a need to resolve the environmental and physiological drivers of tree-level response to rising atmospheric CO2. This study examines how site-level soil moisture influences growth and intrinsic water-use efficiency in sugar maple (Acer saccharum Marsh.). We construct tree-ring, δ18O, and Δ13C chronologies for trees across a soil moisture gradient in Ontario, Canada, and employ a structural equation modelling approach to ascertain their climatic, ontogenetic, and environmental drivers. Our results support previous evidence for the presence of strong developmental effects in tree-ring isotopic chronologies — in the range of −4.7‰ for Δ13C and +0.8‰ for δ18O — across the tree life span. Additionally, we show that the physiological response of sugar maple to increasing atmospheric CO2 depends on site-level soil moisture variability, with trees only in relatively wet plots exhibiting temporal increases in intrinsic water-use efficiency. These results suggest that trees in wet and mesic plots have experienced temporal increases in stomatal conductance and photosynthetic capacity, whereas trees in dry plots have experienced decreases in photosynthetic capacity. This study is the first to examine sugar maple physiology using a dendroisotopic approach and broadens our understanding of carbon–water interactions in temperate forests.


2015 ◽  
Vol 1 (1) ◽  
pp. 112-122 ◽  
Author(s):  
Shiva Chandra Dhakal ◽  
Punya Prasad Regmi ◽  
Resham Bahadur Thapa ◽  
Shrawan Kumar Sah ◽  
Dilli Bahadur Khatri-Chhetri

The study was conducted to determine the productivity, profitability and resource use efficiency of maize-pumpkin mix crop production in Chitwan. The study used 53 maize-pumpkin mix crop adopting farmers from among 300 farmers adopting different pollinator friendly practices. Descriptive and statistical tools including Cobb-Douglas production function were used to analyze data, collected from structured interview schedule. The benefit cost ratio (1.58) indicates that maize-pumpkin mix cropping was profitable with productivity of 2.83 ton per ha on maize main product equivalent basis. The magnitude of regression coefficients of maize-pumpkin mix cropping implied that expenditure on seed and fertilizer and irrigation had significant positive effect on gross return with estimated decreasing return to scale (0.85). According to estimated allocative efficiency indices, it is suggested to increase expenditure on seed and fertilizer cum irrigation by about 90% and 55% respectively. Extension of modern technologies with adjustment on resource use is to be encouraged for increase in productivity and profitability of maize-pumpkin mix crop production which indirectly promotes and ensure forage for pollinatorsJournal of Maize Research and Development (2015) 1(1):112-122DOI: http://dx.doi.org/10.5281/zenodo.34290


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