Validation of simple sequence repeats associated with quality traits in durum wheat

Over recent years, quality has become an important commercial issue for durum wheat breeders. Modern breeding methods are most efficient for producing and supplying the best quality raw materials to the pasta industry. Here we assessed the effectiveness of molecular marker-assisted selection of quality traits in durum wheat. To this end, DNA and quality trait markers were jointly used to analyze quality-related traits in a durum wheat collection. A total of 132 durum wheat (Triticum turgidum ssp. durum) Mediterranean landraces, international lines, and Moroccan cultivars were analyzed for seven important qualityrelated traits including thousand-kernel weight (TKW), test weight (TW), gluten strength, yellow pigment (YP), and grain protein content (GPC). Additionally, 18 simple sequence repeat (SSR) markers previously reported to be associated with different quality traits were analyzed. Of these, 14 (78%) were polymorphic and four were monomorphic. There were between two and seven alleles per locus, with an average of four alleles per locus. The average phenotypic variation value (R²) ranged from 2.81 to 20.43%. Association analysis identified nine markers significantly associated with TKW, TW, and YP, followed by eight markers associated with GPC, six markers associated with yellow index b, four markers associated with brightness L, and three markers associated with SDS-sedimentation volume. This study highlights the efficiency of SSR technology, which holds promise for a wide range of applications in marker-assisted wheat breeding programs.     

Kinetics of nutrient release from different organic residues using a laboratory system

Organic residues play a vital role in maintaining soil fertility in arid and semi-arid regions. Knowledge of the nutrient release from organic residues will help in optimizing nutrient efficiency in agricultural crop production systems. This study was conducted to assess the continuous release of phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) from eight different organic residues (sheep manure, beet, waste material, rape, poultry manure, sunflower, potato and garlic) using successive extractions with distilled water. The residues were shaken for 1 h and equilibrated for longer intervals (1, 3.5, 18, 42, 72, 192, 768, 1248, 1608, 1968 and 2328 h) with successive extractions. Cumulative nutrient release curves by different organic residues versus time showed an initial rapid phase followed by a slow phase. The average percentage of nutrients released and the average release rate of nutrients found using a power model was different and were in the order K > P > Ca > Mg and Ca > Mg > P > K, respectively. According to MINTEQ software, the partitioning of total P between HPO₄ ^2? and H₂PO₄ ^? is sensitive to the type of organic residue. On average (pooled over all extractions), between 13% (rape) to 40% (poultry) and 27% (poultry manure) to 79% (beet) of total P in aqueous solutions present as HPO₄ ^2? and H₂PO₄ ^?, respectively. Among the various organic residues and in the first stage of release, sunflower residue, beet residue, poultry manure and garlic residue had the highest rate constant for Ca, Mg, P and K, respectively, indicating the high potential availability of these nutrients in the early stage of application to soils.     

Wastes to be the source of nutrients and energy to mitigate climate change and ensure future sustainability: options and strategies

Abstract

Waste production is associated with human inhabitation and its rate is increasing over time. Globally, the major proportion of waste is disposed of through landfilling and open dumping, which is environmentally unsafe due to emission of greenhouse gases (GHGs). Thus, in order to avoid emission of GHGs from wastes it is important to use techniques that can convert wastes to energy/nutrients on eco-friendly economical way. Furthermore, quantification of the impacts of these waste management techniques on ecosystem is also needed through the application of tools like modeling, remote sensing, geographical information system (GIS), Unmanned Aerial Vehicles (UAVs) and life cycle assessments (LCA). Thus, this review was conducted by considering focus on potential of nutrient and energy recovery techniques from various types of wastes and approaches to enhance the efficiency of the process. The outcomes depicted that the aerobic and anaerobic digestion is suitable to deal with biodegradable and organic fraction of the waste, but anaerobic digestion seem to be more sustainable waste management techniques. Additionally, the review covers the techniques to drive energy and recover nutrient from non-biodegradable proportion. Different modern analytical tools; such as remote sensing, GIS and simple/dynamic models could be useful tool to help in the decision-making processes for waste managements. These tools can help us to design integrated solid waste management processes. Finally, we suggest that LCA should be considered to determine the environmental load of material/product from its production to final disposal (from cradle to grave).     

Effect of nitrogen and potassium fertilizer on growth,yield and chemical composition of sweet fennel

Abstract

In this study, the effect of different levels of nitrogen (N) and potassium (K) fertilizers on vegetative fresh bulb yield, quality and biochemical attributes of sweet fennel were investigated in spring 2017 and 2018. Treatments consisted of 0, 50, 100, or 150?kg ha^?1 of N and K in a randomized complete block design with three replications. Results showed that, the bulb fresh yield increased with application of N and K in both years, while the higher level of K had significant adverse effect in first year. Results also showed that sweet fennel bulb treated by N and K exhibited higher vitamin C, total phenols and flavonoid contents, and antioxidant capacity, especially in first year. In both years, alone or combined application of N and K increased total soluble solids (TSS) content as compared to control, and this effect was more pronounced in 2017 season. Macronutrient contents of bulb including magnesium (Mg), phosphorus (P), K, N, and calcium (Ca) were significantly enhanced by NK fertilizer, however an alone application of K decreased Ca and Mg nutrient contents. Therefore, to improve fresh bulb yield, quality and antioxidant capacity in sweet fennel, 150?kg ha^?1 K and 100?kg ha^?1 N is recommended.     

Selenium in lemon balm plants: Productivity,phytotoxicity and drought alleviation

Since studies on the effects of selenium (Se) supplementation in water-stressed plants have mainly focused on cereal crops, the specific reports regarding Se-mediated adaptation to drought stress in medicinal vegetables are scant. Thus, we investigated the responses of Melissa officinalis to Se supplementation. Selenium contents were increased in leaves and grains by supplemental Se. Selenium foliar application at 1 mg l^?1 could be useful to increase the vegetative and reproductive growth of Se-enriched plants under well-watered conditions but at 20 mg l^?1 led to toxicity and caused damage to shoots. Drought stress significantly inhibited plant growth by chlorophyll degradation and reduced net carbon dioxide (CO₂) assimilation rate. Although Se at 1 mg l^?1 could increase biomass production under well-watered conditions in addition to the stimulation of antioxidant system under water stress, it could not ameliorate the negative effect of drought on productivity.     

Enantiomeric discrimination and quantification of the chiral organophosphorus pesticide fenamiphos in aqueous samples by a novel and selective ³¹P nuclear magnetic resonance spectroscopic method using cyclodextrins as chiral selector

A rapid, selective, and accurate quantitative 31P nuclear magnetic resonance (31P NMR) spectroscopy method was used for the chiral recognition of the racemic organophosphorus pesticide fenamiphos using chiral solvating agents (CSAs). Six neutral cyclodextrins (CDs) (α-CD, β-CD, methyl-β-CD, hydroxyethyl-β-CD, hydroxypropyl-β-CD, and hydroxypropyl-γ-CD) and two anionic CDs (carboxymethyl-β-CD and carboxyethyl-β-CD) were selected for these experiments. The shift displacement values (Δδ), after addition of each of the eight CDs in the highest possible molar ratio to a guest, were recorded. The results showed that β-CD and hydroxypropyl-β-CD were the best chiral solvating agents for the enantiomeric discrimination of fenamiphos. Two-dimension rotating frame nuclear Overhauser spectroscopy (ROESY) was used to investigate the structure of the β-CD-fenamiphos inclusion complex in aqueous solution. To determine the fenamiphos enantiomers, a calibration curve was drawn for two enantiomers over the range of 0.05-0.25 mg mL?1. The limits of detection (S/N = 3) were obtained as 0.0068 and 0.0060 mg mL?1 for fenamiphos enantiomers. The recovery studies were performed on aqueous real samples ranging from 94 to 107% with coefficients of variation of ≤ 9%.     

Intra-specific Variation for Salt Tolerance in Linseed (Linum usitatissimum L.)

Thirty-six accessions of linseed ( Linum usitatissimum L.) were screened for salt tolerance at the seedling stage after 2 weeks growth in solution culture salinized with 150mol m⁻³ NaCL Considerable variation in salt tolerance was observed in this set of germplasm. Two salt-tolerant accessions, T-5(69-S9)B and LS-2 and two salt-sensitive accessions P-70 and Aver-Rer-Seic, selected at the seedling stage, were grown to maturity in sand culture salinized with 0 (control), 70, 140, and 210 mol m⁻³ NaCl. Both the salt-tolerant accessions exceeded the two salt-sensitive accessions in biomass production, seed yield, and yield components, but the accessions did not differ significantly in seed oil content in the salt treatments. The tolerant accessions accumulated greater amounts of Na⁺ in the shoots and less in the roots compared with the salt-sensitive accessions. The shoot K⁺, K: Na ratios, and K⁺ versus Na⁺ selectivity were lower in the salt-tolerant accessions compared with the salt-sensitive accessions; the reverse was true for their roots. Contributions of Na⁺ and Ca²⁺ to osmotic adjustment were much higher in the two salt-tolerant accessions than in the salt-sensitive ones.
It has been established that there is a great deal of variation for salt tolerance in linseed. The degree of salt tolerance of this crop does not vary during ontogeny. The physiological basis of salt tolerance of this species appears to be associated with the inclusion of Na⁺ in the shoots.     

Cadmium accumulation and partitioning in Ocimum basilicum as influenced by the application of various potassium fertilizers

Potassium (K) is one of the major essential nutrient elements whose application of organic or nano-chelate-fertilizers has received increased attention recently. Cadmium (Cd) contamination in agricultural soils and environment is increasing due to the over-application of Cd-containing phosphate fertilizers. But few studies have been carried out on the environmental influences of K-nano-chelate fertilizers especially on Cd-polluted soils. Therefore, the effects of K-fertilizer application in different rates (0, 100 and 200 mg kg^?1 soil) and forms (KCl, K₂SO₄ and K-nano-chelate) on Cd content and partitioning in Ocimum basilicum grown on an artificially Cd-contaminated calcareous soil (with 40 mg Cd kg^?1 soil) were studied under greenhouse conditions. Cadmium decreased shoot dry weight (SDW), but did not affect root dry weight (RDW) and no consistent trend was observed with applied K. Cadmium increased shoot and root Cd concentration or uptake. KCl and K₂SO₄ increased shoot Cd concentration compared to that of control, whereas K-nano-chelate did not affect it. In Cd-treated soils the mean value of Cd translocation factor (ratio of Cd concentration in shoots to that of roots) decreased by 60% as compared to that of the control. Application of 100 mg K-K₂SO₄ and 100 and 200 mg K-nano-chelate increased the Cd translocation factor by 49, 59 and 112% in Cd-treated soils, respectively. In Cd-treated soils, greater amounts of Cd accumulated in roots. K-nano-chelate could mitigate the adverse effect of Cd on SDW and Cd accumulation in plants grown on Cd-polluted soils, so the risk of Cd entrance to the food chain is reduced (however, in Cd-untreated soils, K-nano-chelate increased the Cd translocation factor higher than other K sources). In Cd-polluted soils KCl was the most inappropriate fertilizer that may intensify Cd accumulation in plants. However, it may be useful in the phytoremediation of Cd-polluted soils.     

Identification of some main <Emphasis Type="Italic">Streptococcus iniae</Emphasis> associated proteins: relationship

The surface-associated proteins play a key role in bacterial physiology and pathogenesis, and are the major targets in the development of new vaccines. These proteins contribute to the adaptation of bacteria to different hosts and environments. To study differences at the genomic level, we first sequenced the whole genome of Streptococcus iniae from fish (IUSA-1 strain) and compared it to Streptococcus iniae from human (9117 strain), revealing a high similitude between both strains. To gain further insights into host- and environment-specific differences, we then studied proteins in silico and by High Performance Liquid Chromatography. This approach successfully identified 54 secreted and surface proteins, including several proteins involved in cell wall synthesis and transport of solutes, as well as proteins with yet unknown function. These proteins highlight as interesting targets for further investigation in the interaction between Streptococcus iniae and its environment. Results reported in this study have shown a first analysis about the predicted and experimental associated proteins of Streptococcus iniae isolated from two different hosts: human and fish.