scholarly journals Positive effects of duckweed polycultures on starch and protein accumulation

2016 ◽  
Vol 36 (5) ◽  
Author(s):  
Yang Li ◽  
Fantao Zhang ◽  
Maurycy Daroch ◽  
Jie Tang

The effect of duckweed species composition (Lemna aequinoctialis 5505, Landoltia punctata 5506 and Spirodela polyrhiza 5507) in polyculture and monoculture on biomass and starch/protein content were investigated at different levels of temperature, light intensity, nitrogen and phosphorus concentrations. The three growth parameters significantly affect duckweed biomass accumulation. Different combinations of duckweed species greatly varied in starch/protein content. Although all the polycultures showed a median relative growth rate and the majority of the polycultures showed a median and starch/protein content as compared with their respective monocultures, some of the polycultures were found to promote the accumulation of starch/protein at different growth conditions. These findings indicated that proper combination of duckweed species could facilitate desirable biomass accumulation and improve biomass quality. The present study provides useful references for future large-scale duckweed cultivation.

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1610
Author(s):  
Branka Vinterhalter ◽  
Nevena Banjac ◽  
Dragan Vinterhalter ◽  
Dijana Krstić-Milošević

The hairy root clones of Gentiana dinarica cl-B, cl-D, cl-3, and cl-14 were cultivated in parallel in diverse simple bioreactors, including temporary immersion systems RITA® (TIS RITA®), bubble column bioreactors (BCB), and Erlenmeyer flasks (EF), and evaluated for biomass production and xanthone content. The obtained results showed that TIS RITA® and BCB containing ½ MS medium with 4% sucrose provided equally good growth conditions in which the majority of the clones displayed the higher percentage of dry matter (DM%), and xanthones norswertianin-1-O-primeveroside (nor-1-O-prim) and norswertianin production than those cultivated in EF. Thin and well branched hairy root clone cl-B grown in BCB for 7 weeks was superior regarding all growth parameters tested, including growth index (19.97), dry weight (2.88 g), and DM% (25.70%) compared to all other clones. Cl-B cultured in TIS RITA® contained the highest amount of nor-1-O-prim (56.82 mg per vessel). In BCB with constant aeration, cl-B accumulated the highest norswertianin content reaching 18.08 mg/vessel. The optimized conditions for cultivation of selected G. dinarica hairy root clones in highly aerated TIS RITA® and BCB systems contribute to the development of bioreactor technology designed for the large scale commercial production of xanthones nor-1-O-prim and norswertianin.


Author(s):  
A. Pagani ◽  
J. Molinari ◽  
E. Giardina ◽  
A. Di Benedetto

Pot ornamental plant productivity is related to the environmental growth facilities but negatively affected by the pot root restriction syndrome. Most ferns showed a lower relative growth rate and long production cycles (24 months or more) for which growers use small pots to increase yield per unit area of greenhouse. The aim of this work was to analyze growth changes in response to different pot volume in plants of A. nidus avis spore-propagated under the hypothesis that it would play a role as an abiotic stress which decrease commercial productivity. Our results showed that the use of big pots increased fresh and dry weight and frond area (the main aesthetic trait). When growth parameters were performed, a higher the frond appearance rate (RLA), the frond area expansion (RLAE) and the frond thickness (SLA) were found in 1500 cm3 pot as well as the relative growth rate (RGR) and the net assimilation rate. The use of biggest pot for fern cropping stimulated biomass accumulation through a higher capacity to initiate and expand fronds, to increase photosynthetic rates and change photo assimilate partitioning which favor shoots. From the grower´s point of view, our results suggested that higher yields of A. nidus avis fern would be reached decreasing root restriction, that is, to use the biggest pot volume from the early transplant from plug trays.


Author(s):  
Manal A. Asker

A field experiment was conducted to study the effect of nitrogen(0,200 and 300 kgNha-1) and phosphorus (0,60,and 180 kgPha-1) fertilization and their combination on yield and some growth parameters of sudangrass(Sorghum Sudanese). (Number of leaves per plant, plant height, number of heads per plant, weight of 1000 seeds, ,yields of seeds , dry weight of shoots and protein content in seeds)were measure . Results indicated that nitrogen and phosphate application and their combination had significant effects on all growth parameters and yield of Sudangrass . The combination treatment of 300kgNha-1 plus 180 kgPha-1) gave higher yield (71.86 gm.plant-1) and protein content in seeds( 5.79 %) and other growth parameters.


Weed Science ◽  
1999 ◽  
Vol 47 (6) ◽  
pp. 712-719 ◽  
Author(s):  
Anne Légère ◽  
Yuguang Bai

The robustness of competitive attributes of cereals such as rapid and uniform seedling emergence, tillering, early biomass accumulation and canopy closure, and height advantage over weeds have not yet been tested under environmental conditions typical of no-till (NT) cropping systems. Our objective was to evaluate the effects or NT practices on growth and productivity ofAvena sativa, Triticum aestivum, Hordeum vulgare, and associated weeds. The experiment was conducted on a Kamouraska clay at La Pocatière, QC, in 1994, 1995, and 1996.Avena sativa, T. aestivum, andH. vulgarewere grown under tilled and NT practices. Cereal growth parameters were measured six (1994) or seven (1995) times between planting and the 11th week after planting but only once in 1996. Grain yields and yield components were determined at crop maturity.Avena sativaandH. vulgarepopulations were little affected by tillage, whereasT. aestivumpopulations were reduced by 16 to 20% in NT systems. Growth in height in NT systems was either similar or greater than in tilled systems in all three cereals. Cereal leaf area index (LAI) and biomass accumulation was also comparable between tillage systems, except forT. aestivumLAI in 1994, which was greater in tilled plots on two sampling dates. Response of annual dicots to tillage was inconsistent in all crops. Annual monocots dominated in some but not all NT systems. Perennial dicots dominated in NT systems, whereas perennial monocots were more abundant in tilled systems in all three cereals.Avena sativaandT. aestivumyields in NT plots were comparable or greater than in tilled plots, in spite of having either lower test weights (A. sativa) or lower 1,000-grain weights (T. aestivum). NTT. aestivumproductivity was maintained in spite of reduced plant establishment.Hordeum vulgareyields were also similar across tillage systems, except in 1995, when yields in tilled plots were greater than in NT plots. The height advantage observed for NTH. vulgaredid not result in improved yields. All three cereals, and particularlyA. sativa, appeared well suited to NT systems, despite the pressure provided by different weed groups, compared to tilled systems. However, results suggest that NT production of cereals could benefit from improved attention to perennial dicot control and crop seedling establishment, particularly forT. aestivum.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 380
Author(s):  
Abdoul Kader Mounkaila Hamani ◽  
Jinsai Chen ◽  
Mukesh Kumar Soothar ◽  
Guangshuai Wang ◽  
Xiaojun Shen ◽  
...  

Soil salinization adversely affects agricultural productivity. Mitigating the adverse effects of salinity represents a current major challenge for agricultural researchers worldwide. The effects of exogenously applied glycine betaine (GB) and salicylic acid (SA) on mitigating sodium toxicity and improving the growth of cotton seedlings subjected to salt stress remain unclear. The treatments in a phytotron included a control (CK, exogenously untreated, non-saline), two NaCl conditions (0 and 150 mM), four exogenous GB concentrations (0, 2.5, 5.0, and 7.5 mM), and four exogenous SA concentrations (0, 1.0, 1.5, and 2.0 mM). The shoot and roots exposed to 150 mM NaCl without supplementation had significantly higher Na+ and reduced K+, Ca2+, and Mg2+ contents, along with lowered biomass, compared with those of CK. Under NaCl stress, exogenous GB and SA at all concentrations substantially inversed these trends by improving ion uptake regulation and biomass accumulation compared with NaCl stress alone. Supplementation with 5.0 mM GB and with 1.0 mM SA under NaCl stress were the most effective conditions for mitigating Na+ toxicity and enhancing biomass accumulation. NaCl stress had a negative effect on plant growth parameters, including plant height, leaf area, leaf water potential, and total nitrogen (N) in the shoot and roots, which were improved by supplementation with 5.0 mM GB or 1.0 mM SA. Supplementation with 5.0 mM exogenous GB was more effective in controlling the percentage loss of conductivity (PLC) under NaCl stress.


2014 ◽  
Vol 71 (7) ◽  
pp. 1717-1727 ◽  
Author(s):  
A. Jason Phillips ◽  
Lorenzo Ciannelli ◽  
Richard D. Brodeur ◽  
William G. Pearcy ◽  
John Childers

Abstract This study investigated the spatial distribution of juvenile North Pacific albacore (Thunnus alalunga) in relation to local environmental variability [i.e. sea surface temperature (SST)], and two large-scale indices of climate variability, [the Pacific Decadal Oscillation (PDO) and the Multivariate El Niño/Southern Oscillation Index (MEI)]. Changes in local and climate variables were correlated with 48 years of albacore troll catch per unit effort (CPUE) in 1° latitude/longitude cells, using threshold Generalized Additive Mixed Models (tGAMMs). Model terms were included to account for non-stationary and spatially variable effects of the intervening covariates on albacore CPUE. Results indicate that SST had a positive and spatially variable effect on albacore CPUE, with increasingly positive effects to the North, while PDO had an overall negative effect. Although albacore CPUE increased with SST both before and after a threshold year of 1986, such effect geographically shifted north after 1986. This is the first study to demonstrate the non-stationary spatial dynamics of albacore tuna, linked with a major shift of the North Pacific. Results imply that if ocean temperatures continue to increase, US west coast fisher communities reliant on commercial albacore fisheries are likely to be negatively affected in the southern areas but positively affected in the northern areas, where current albacore landings are highest.


2021 ◽  
Vol 11 (10) ◽  
pp. 4388
Author(s):  
Haifeng Zhang ◽  
Laihong Shen ◽  
Huijun Ge ◽  
Hongcun Bai

Due to the more and more serious cyanobacteria bloom problem, it is particularly urgent to find a technology suitable for large-scale disposal and the efficient recovery of abundant nitrogen and phosphorus resources in cyanobacteria. The combination of chemical looping combustion (CLC) and biomass densification technology is thought to be a promising utilization selection. Based on the experimental results, the mechanical strength and energy density of briquette cyanobacteria are evidently increased with the compressive load; whereas, 10% is the optimal moisture content in the densification process. A higher heating rate in TGA would result in the damage of the internal structure of the briquette cyanobacteria, which are conducive to the carbon conversion efficiency. The presence of a hematite oxygen carrier would enhance the carbon conversion and catalyzed crack liquid products. CO2 yield is increased 25 percent and CH4 yield is decreased 50 percent at 900 °C in the CLC process. In addition, the lower temperature and reduction atmosphere in CLC would result in a lower NO emission concentration. The reactivity and porous property of hematite OC in CLC also increased during 10 redox cycle experiments. The CLC process accelerates the generation of CaH2P2O7 and CaHPO4 in cyanobacteria ash, which is more conducive to phosphorus recovery.


2015 ◽  
Vol 20 (2) ◽  
pp. 128-138 ◽  
Author(s):  
Juan Carlos Pérez Mesa ◽  
Emilio Galdeano-Gómez

Purpose – This purpose of this study is to provide empirical evidence of how cooperation is related to suppliers’ performance, a relationship that is thought to be affected by the type of customer and the extent to which the market is diversified. It analyzes horticultural exporting firms in southeastern Spain, which are the main suppliers of European markets. Together with their primary customers (large-scale retail companies such as Carrefour, Tesco and Aldi), these firms constitute a complex supply network composed of a variety of agents and sales channels. This network will be studied from the perspective of the supplier–supplier relationship that is critical to their survival. Design/methodology/approach – Starting with a detailed description of Europe’s vegetable supply chain, a hierarchical regression is used with an index of cooperation intensity, moderated by retail sales and market concentration. The authors test the hypotheses using panel data on a set of 118 horticultural marketing firms in southeast Spain for the period 2009-2011. Findings – Cooperation strategies are shown to have positive effects on performance (market creation, promotion, quality, training, joint supply purchases and research ventures). Moreover, the retail channel and market diversification are observed to have a positive effect on the relationship between cooperation and the supplier’s performance. They demonstrate that active cooperation strategies have a greater bearing on performance in those firms whose primary customers are retailers. This circumstance provides evidence of the synergies and benefits that may arise when the supplier integrates the retailer in the supply chain, but which do not arise with other types of customers. Research limitations/implications – Although this study refers to a specific sector (fruits and vegetables) and the statistical results are limited, they provide insights that may assist in understanding how other perishable produce-related industries work: such industries share many common features. Practical implications – A more stable relationship between suppliers and retailers in the perishable produce market will render the supply firm more cooperative, competitive and profitable. Increased performance does not arise from the better conditions and improved sales power offered by the customer but instead from the adaptability of the supplier. Likewise, market diversification drives the supply firm toward a cooperative strategy, making it more profitable and competitive. As a practical norm, market diversification alone will not have positive results on performance unless the firm proves capable of enhancing its capacity for cooperation. Social implications – Proper management of the agricultural produce supply chain has repercussions on all of the members of that chain, although special emphasis should be placed on producers and consumers. The availability of food, its quality and its safety depend on management during the production phase. Along these lines, and more specifically for the consumer, this work is relevant because the sector analyzed accounts for 40 per cent of the vegetables consumed in Europe. Originality/value – This article defends the supplier–supplier relationship as the starting point for the analysis of a supply network. In certain sectors, the suppliers’ ability both to solve their clients’ problems and to be profitable is conditioned on maintaining the network and, therefore, the basic focus must center on analyzing their relationships, always including the customer, who has a direct or indirect influence on those relationships. Previous research has not comprehensively addressed this issue, let alone that of a sector with agile and perishable products in which, due to its nature, decision-making about market destinations and sales channels is the order of the day.


2015 ◽  
Vol 95 (1) ◽  
pp. 20-26 ◽  
Author(s):  
E.M. Mostafa ◽  
A.M.A. Hassan

Exposure ofAzollaplants to UV-B radiation for 6 h resulted in a decrease in biomass and relative growth rate (RGR), which coincided with an increase in doubling time (DT) as compared with the control. Also, the protein content decreased. On the other hand, hydrogen peroxyde (H2O2) and malondialdehyde (MDA) accumulated significantly in UV-treatedAzollaplants. Conversely, the addition of selenium (Se) at 1 ppm resulted in a significant increase in biomass and protein content of untreated and UV-treatedAzollaplants, and a significant reduction in both H2O2and MDA. Moreover, the addition of Se to UV-treated and untreatedAzollaplants resulted in a significant increase in total ascorbate and total glutathione (GSH) contents compared with the control and UV-stressedAzollaplants. Also, glutathione redox potential (GSH/TG) increased significantly in UV-treatedAzollaplants in the presence of Se. There also was a significant increase (38%) in ascorbate peroxidase (APX) activity in UV-treated plants compared with the control. APX activity in the presence of Se did not change significantly compared with the control. Glutathione reductase (GR) activity increased significantly in UV-treatedAzolla, while glutathione peroxidase (GSH-PX) activity did not. On the other hand, both GSH-PX and GR activity in untreated and UV-treatedAzollaplants were significantly enhanced by the application of Se to the nutrient media at a concentration of 1 ppm. Therefore, we can conclude that Se protectsAzollaplants from UV-B stress.


2021 ◽  
Author(s):  
Bingyu Zhao ◽  
Meiling Liu ◽  
Jiianjun Wu ◽  
Xiangnan Liu ◽  
Mengxue Liu ◽  
...  

<p>It is very important to obtain regional crop growth conditions efficiently and accurately in the agricultural field. The data assimilation between crop growth model and remote sensing data is a widely used method for obtaining vegetation growth information. This study aims to present a parallel method based on graphic processing unit (GPU) to improve the efficiency of the assimilation between RS data and crop growth model to estimate rice growth parameters. Remote sensing data, Landsat and HJ-1 images were collected and the World Food Studies (WOFOST) crop growth model which has a strong flexibility was employed. To acquire continuous regional crop parameters in temporal-spatial scale, particle swarm optimization (PSO) data assimilation method was used to combine remote sensing images and WOFOST and this process is accompanied by a parallel method based on the Compute Unified Device Architecture (CUDA) platform of NVIDIA GPU. With these methods, we obtained daily rice growth parameters of Zhuzhou City, Hunan, China and compared the efficiency and precision of parallel method and non-parallel method. Results showed that the parallel program has a remarkable speedup (reaching 240 times) compared with the non-parallel program with a similar accuracy. This study indicated that the parallel implementation based on GPU was successful in improving the efficiency of the assimilation between RS data and the WOFOST model and was conducive to obtaining regional crop growth conditions efficiently and accurately.</p>


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