Influence of zinc sulfate and municipal solid waste compost on chemical forms of zinc in calcareous soils

Zinc (Zn) is an essential micronutrient for crop growth. This metal can be found in chemical forms or fractions in the soil. The objective of this study was to investigate the distribution of Zn in special chemical forms using the sequential extraction method after treating eight calcareous soils by zinc sulfate and municipal solid waste (MSW) compost. Zn was separated in seven defined forms as exchangeable (Ex), carbonate (Car), organic (Om), manganese oxide bound (MnOX), amorphous iron oxide bound (FeAOX), crystalline iron oxide bound (FeCOX), and residual (Res). According to the results, the mean concentrations of Zn in chemical forms in untreated soils from higher to lower were 31.84, 8.13, 2.64, 2.57, 0.45, 0.39, and 0.16?mg?kg^?1 for the Res, FeCOX, Car, FeAOX, Om, MnOX, and Ex forms, respectively. The total applied Zn to the studied soils from both the sources of zinc sulfate and MSW compost after incubation for 30 days was converted to chemical forms in the following order: Car?>?Res?>?FeCOX?>?Om?>?FeAOX?>?MnOX?>?Ex. On average, 30.3% of total Zn from zinc sulfate and 28.8% of total Zn in the MSW compost were converted into the Car form. The high content of calcium carbonate (CaCO₃) in the studied soils is an important factor affecting the conversion of Zn forms, mostly in the Car form through the application of both the inorganic and the organic sources of Zn.     

Constitutive expression of feedback-insensitive cystathionine γ-synthase increases methionine levels in soybean leaves and seeds

Soybean(Glycine max(L.) Merr.) is a major crop that provides plant-origin protein and oil for humans and livestock.Although the soybean vegetative tissues and seeds provide a major source of high-quality protein,they suffer from low concentration of an essential sulfur-containing amino acid,methionine,which significantly limits their nutritional quality.The level of methionine is mainly controlled by the first unique enzyme of methionine synthesis,cystathione γ-synthase(CGS).Aiming to elevate methionine level in vegetative tissues and seeds,we constitutively over-expressed a feedback-insensitive Arabidopsis CGS(At D-CGS) in soybean cultivars,Zigongdongdou(ZD) and Jilinxiaoli 1(JX).The levels of soluble methionine increased remarkably in leaves of transgenic soybeans compared to wild-type plants(6.6-and 7.3-fold in two transgenic ZD lines,and 3.7-fold in one transgenic JX line).Furthermore,the total methionine contents were significantly increased in seeds of the transgenic ZD lines(1.5-to 4.8-fold increase) and the transgenic JX lines(1.3-to 2.3-fold increase) than in the wild type.The protein contents of the transgenic soybean seeds were significantly elevated compared to the wild type,suggesting that the scarcity of methionine in soybeans may limit protein accumulation in soybean seeds.The increased protein content did not alter the profile of major storage proteins in the seeds.Generally,this study provides a promising strategy to increase the levels of methionine and protein in soybean through the breeding programs.     

Transfer of Heavy Metals from Soils to Vegetables and Associated Human Health Risks at Selected Sites in Pakistan

Contamination of the food chain with heavy metals is considered as one of the major environmental pathways of human exposure to metals leading to potential health risks. This study aimed to investigate the concentrations of heavy metals such as copper (Cu), zinc (Zn), chromium (Cr), nickel (Ni), and manganese (Mn) in agricultural soils and food crops (fruit, leaf, and root vegetables), and their associated health risks to the local population in selected southern districts of Khyber Pakhtunkhwa Province, Pakistan. The concentrations of the selected metals in soil varied over a wide range, in the following decreasing order: Mn > Zn > Cr > Ni > Cu. The bioaccumulation of metals in vegetables was within the permissible risk limits, except for Cr which showed higher contamination in all the tested food crops. The trend of metal transfer factors for different vegetables was in the order of Cu > Ni > Cr > Mn > Zn, while the calculated daily intake of metals (DIM) in adults and children through consumption of food crops was in the decreasing order of Mn > Zn > Ni > Cr > Cu. The health risk index (HRI) values for the heavy metals for both adults and children were less than 1. Therefore, no significant health risk is anticipated for the local consumers through ingestion of these food crops.     

Effects of foliar spray of nano-particles of FeSO4 on the growth and ion content of sunflower under saline condition

This study investigated the effects of foliar spray of normal and nano-particles of iron sulfate (FeSO₄) on the response of sunflower cultivars to salinity. Treatments included five cultivars (Alstar, Olsion, Yourflor, Hysun36 and Hysun33), two salinity levels (0 and 100 mM sodium chloride (NaCl)), and three levels of fertilizer application. Fertilizer treatments were the foliar application of normal and nano-particles of FeSO₄. Foliar application of FeSO₄ in either form increased leaf area, shoot dry weight, net carbon dioxide (CO₂) assimilation rate (A), sub-stomatal CO₂ concentration (Ci), chlorophyll content, Fv/Fm and iron (Fe) content and decreased sodium (Na) content in leaves. The extent of increase in chlorophyll a content by foliar spray of FeSO₄ nano-particles was significantly greater than normal form. The results showed that the FeSO₄ nano-particles increased biomass production of sunflower plants greater in comparison with normal form, although no significant difference was found between two forms.     

Toxicity of selected biorational insecticides to Pulvinaria aurantii Cockerell and its predator,Cryptolaemus montrouzieri Mulsant in citrus field

The citrus cottony scale, Pulvinaria aurantii Cockerell, is the most important pest of citrus orchards in northern Iran in recent years. Owing to the harmful impacts of chemical insecticides, the use of biorational pesticides seems a safe and convenient way to control this pest. The present investigation was set up to study contact toxicity of various biorational and chemical compounds on the first, second instar nymph and overwintering adult of the citrus cottony scale, P. aurantii, and its predator, Cryptolaemus montrouzieri Mulsant under field conditions. The results indicated that the highest percentage of mortality of first instar nymph of the citrus cottony scale was observed in the Dayabon treatment of 9 and 10?ml/L, 100.0%?±?0.0% and the lowest percentage was observed in Palizin treatment of 1.5?ml/L, 34.7%?±?2.9%. In the second instar nymph, the highest mortality was seen in the Dursban treatment of 2?ml/L, 94.7%?±?2.4% and the lowest mortality in the Palizin treatment of 1.5?ml/L, 30.0%?±?2.3%. Also, for overwintering adults Dayabon 10?ml/L caused the highest mortality, 96.0%?±?4.0% during 24?h. In the case of ladybird insects, the highest and lowest percentage of mortality was observed in the Dursban treatment of 2?ml/L, 76.7%?±?8.8%, Dayabon 5?ml/L, and Palizin 2?ml/L, 3.3%?±?3.3%, respectively. The highest and lowest mortality rate of larvae of ladybird was estimated in the Dursban treatment of 2?ml/L, 83.3%?±?3.3% and Dayabon 5?ml/L, 3.3%?±?3.3%, respectively. Also, for overwintering predator adults Palizin 1.5?ml/L had the lowest mortality, 3.3%?±?3.3% during 24?h and this rate remain unchanged after 96?h after treatment. According to the results obtained, treatments with Dayabon 9 and 10?ml/L, can be a viable alternative to other high-risk chemical pesticides in addition to effectively controlling citrus cottony scale without having any adverse impacts on predator ladybird.     

Dietary arginine requirement of Heteropneustes fossilis fry (Bloch) based on growth,nutrient retention and haematological parameters

Dietary arginine requirement of Heteropneustes fossilis fry (3.0 ± 0.5 cm; 5.1 ± 0.3 g) was determined by feeding casein‐gelatin‐based isonitrogenous (400 g kg^?1 crude protein) and isocaloric (17.97 kJ g^?1) amino acid test diets containing graded levels of l ‐arginine (15, 17, 19, 21, 23 and 25 g kg^?1 dry diet) for 12 weeks. Maximum absolute weight gain (AWG) (44.4), best feed conversion ratio (FCR) (1.22), highest protein retention efficiency (PRE%) (41%), energy retention efficiency (ERE%) (75%), best condition factor, hepatosomatic index and viscerosomatic index were noted at 21 g kg^?1 arginine of the dry diet. Maximum body protein (189.8 g kg^?1) was also obtained in fish fed above diet. Highest haematocrit value (35%), Hb concentration (9.54 g dL^?1), RBC count (3.44 × 10⁹ mL^?1) and lowest Erythrocyte sedimentation rate (ESR) (1.93 mm h^?1) were obtained at the above level of arginine in the diet. AWG, FCR, PRE% and ERE% data were analysed using broken‐line and an exponential fit to obtain more precise dietary arginine requirement. On the basis of broken‐line and exponential analyses of AWG, FCR, PRE and ERE data, inclusion of dietary arginine in the range of 20.4–22.6 g kg^?1 dry diet, corresponding to 51–56.5 g kg^?1 dietary protein, is recommended for formulating arginine‐balanced feeds for rearing H. fossilis fry.     

RELATIONSHIP BETWEEN TROPHIC LEVEL AND ECONOMICS IN AQUACULTURE

The rising share of aquaculture in supplying seafood changes the mixture of species in the world's market, because capture fisheries target carnivorous species whereas aquaculture focuses on species that are lower in the food chain. Trophic level correlates with production volume (tons/yr) and with unit value (US$/ton) in aquaculture but not in capture fisheries (FAO's fisheries data). Apparently, sustainability and economics in aquaculture both depend on ecological efficiency, i.e., the use of resources and the production of waste. Species feeding low in the food chain use efficiently the natural resources. Each level up the food chain inflates costs related to the use of resources, the production of waste and the maintenance of water quality. This effect has further repercussions on the economics of aquaculture: (1) cost influences profit and unit price, and (2) price influences demand and market share. The overall ecological efficiency, sustainability and economics of culturing carnivorous fish are improved by growing them in an ecological balance with species from low trophic levels in integrated multi-trophic aquaculture.     

Transmission of transmissible mink encephalopathy to raccoons (Procyon lotor) by intracerebral inoculation.

To determine the transmissibility of transmissible mink encephalopathy (TME) agent to raccoons and to provide information about clinical course, lesions, and suitability of currently used diagnostic procedures for detection of transmissible spongiform encephalopathies (TSEs) in raccoons, 4 raccoon kits were inoculated intracerebrally with a brain suspension from mink experimentally infected with TME. One uninoculated raccoon kit served as a control. All 4 animals in the TME-inoculated group showed clinical signs of neurologic disorder and were euthanized between 21 and 23 weeks postinoculation (PI). Necropsy examinations revealed no gross lesions. Spongiform encephalopathy was observed by light microscopy, and the presence of protease-resistant prion protein (PrPres) was detected by immunohistochemistry and Western blot techniques. Scrapie-associated fibrils were observed by negative-stain electron microscopy in the brains of 3 of the 4 inoculated raccoons. These findings confirm that TME is experimentally transmissible to raccoons and that diagnostic techniques currently used for TSE in livestock detect prion protein in raccoon tissue. According to previously published data, the incubation period of sheep scrapie in raccoons is 2 years, whereas chronic wasting disease (CWD) had not shown transmission after 3 years of observation. Because incubation periods for the 3 US TSEs (scrapie, TME, and CWD) in raccoons appear to be markedly different, it may be possible to use raccoons for differentiating unknown TSE agents. Retrospective genotyping of raccoons using frozen spleens showed that the raccoon PrP gene is identical to the mink gene at codons 179 and 224. Further studies, such as the incubation periods of bovine spongiform encephalopathy and other isolates of scrapie, CWD, and TME in raccoons, are needed before the model can be further characterized for differentiation of TSE agents.     

Sodium exclusion is a reliable trait for the improvement of salinity tolerance in bread wheat

Identification of novel wheat (Triticum aestivum L.) germplasm is imperative to develop salt tolerant varieties. In the first phase, 400 accessions were screened against high salt stress (200 mM NaCl) on the basis of Na⁺ accumulation in leaf blade, and 40 genotypes with contrast reaction to salinity were selected. Salt tolerant group (25 genotypes) had higher leaf K⁺/Na⁺ ratio, maximum root and shoot lengths, leaf fresh/dry weights and chlorophyll content as compared to the salt sensitive group (15 genotypes). In second phase, physiologically based screening was performed on selected genotypes against varying salinity levels (0, 100 and 200 mM NaCl). GGE biplot analysis indicates that genotypes TURACO, V-03094, V0005, V-04178, Kharchia 65 and V-05121 were the most salt-tolerant and declared winners as depicted by more gaseous exchange relations and growth potential which was strongly correlated with proper Na⁺, K⁺ discrimination in leaf and root tissues. Genotypes PBW343*2, NING MAI 50, PGO, PFAU, V-04181, PUNJAB 85, KIRITATI, TAM200/TUI and TAM200 were poor performer due to more Na⁺ accumulation in leaf ultimately retarded growth. In conclusion, low Na⁺ accumulation in leaf can be used as the best screening criteria, employing a large set of genotypes in a breeding program.