Evaluating the role of gamma irradiation to ameliorate salt stress in corn

PURPOSE

Salt stress is a significant issue in corn cultivation leading to corn yield reduction, especially in the arid and semi-arid regions. Nuclear technologies, along with other standard methods, can be used as an efficient method for mitigating salt stress effects on plants.

MATERIALS AND METHODS

In this research, gamma irradiation (GI) was studied on seeds in the salt stress amelioration of corn in laboratory and field conditions. A total of five doses of gamma rays (25, 50, 100, 150 and 200 Gy) were applied to corn seeds (SC.703) at the laboratory under saline and control conditions. The best gamma-ray treatment (25 Gy) was selected for studying corn under salt stress in the field condition.

RESULTS

The length of the radicle, seminal roots and shoot, dry weight of radicle, and seminal roots were affected by salt stress (p <.001). However, GI affected only the radicle and seminal root length (p < .001). The radicle length was decreased as much as 3, 11, 17, 25, and 27% in 25, 50, 100, 150 and 200 Gy of GI, respectively. In addition, the seminal root length was decreased in all GI treatments except 25 Gy (p < .05). Plants derived from seeds exposed to GI (25 Gy) had a higher chlorophyll content of 1, 17, and 29% at V3 (third leaf stage), R1 (silk stage, p < .001), and R4 (dough stage, p < .001), respectively. In GI treatment, the soluble carbohydrate content was significantly higher (p < .001) at all three measurement stages and the soluble protein was significantly higher (p < .001) only at the R4 stage. Moreover, proline content was higher in GI (25 Gy) at V3 (58%, p < .05) and R1 (98%, p < .001) treatment stages.

CONCLUSION

Since plants from gamma-irradiated seeds had a greater plant weight and their economic traits (cob and grain weight) were higher compared to control plants under salt stress conditions, it can be concluded that a low dose of GI may ameliorate the effect of salt stress on the corn plants.

Improved Whole Gamma Irradiated Avian Influenza Subtype H9N2 Virus Vaccine Using Trehalose and Optimization of Vaccination Regime on Broiler Chicken

Gamma (γ)-radiation can target viral genome replication and preserve viral structural proteins compared to formalin inactivation. Thus, a stronger immunity could be induced after the inoculation of the irradiated virus. In this study, γ-irradiated low-pathogenic avian influenza virus-H9N2 (LPAIV-H9N2) was used to immunize the broiler chicken in two formulations, including γ-irradiated LPAIV-H9N2 with 20% Trehalose intranasally (IVT.IN) or γ-irradiated LPAIV-H9N2 plus Montanide oil adjuvant ISA70 subcutaneously (IV+ISA.SC) in comparison with formalin-inactivated LPAIV-H9N2 vaccine intranasally (FV.IN) or formalin-inactivated LPAIV-H9N2 plus ISA70 subcutaneously (FV+ISA.SC). Two vaccination regimes were employed; the first one was primed on day 1 and boosted on day 15 (early regime), and the second one was primed on day 11 and boosted on day 25 (late regime). A challenge test was performed with a live homologous subtype virus. Virus shedding was monitored by quantifying the viral load via RT-qPCR on tracheal and cloacal swabs. Hemagglutination inhibition (HI) antibody titration and stimulation index (SI) of the splenic lymphocyte proliferation were measured, respectively, by HI test and Cell Proliferation assay. Cytokine assay was conducted by the RT-qPCR on antigen-stimulated spleen cells. The results of the HI test showed significant increases in antibody titer in all vaccinated groups, but it was more evident in the IVT late vaccination regime, reaching 5.33 log₂. The proliferation of stimulated spleen lymphocytes was upregulated more in the IVT.IN vaccine compared to other vaccines. The mRNA transcription levels of T-helper type 1 cytokines such as interferon-gamma (IFN-γ) and interleukin 2 (IL-2) were upregulated in all vaccinated groups at the late regime. Moreover, IL-6, a pro-inflammatory cytokine was upregulated as well. However, upregulation was more noticeable in the early vaccination than the late vaccination (p< 0.05). After the challenge, the monitoring of virus shedding for the H9 gene represented an extremely low viral load. The body weight loss was not significant (p > 0.05) among the vaccinated groups. In addition, the viral load of <10^0.5 TCID₅₀/ml in the vaccinated chicken indicated the protective response for all the vaccines. Accordingly, the IVT vaccine is a good candidate for the immunization of broiler chicken via the intranasal route at late regime.

Effect of particle size and partial replacement of alfalfa hay by soya bean hulls on nutrient intake, total tract digestibility and rumen degradability of diets by Holstein steers

This study examined the effect of alfalfa hay (AH) particle size and the replacement of soya bean hull (SH) for AH within the diet of restricted fed Holstein steers on dry matter intake (DMI), total tract digestion, ruminal digestion, ruminal pH and ammonia nitrogen content, and faecal pH. Four rumen-cannulated Holstein steers averaging 353 ± 9.6 kg of BW were assigned to a 4 × 4 Latin square experiment with four periods and a 2 × 2 factorial arrangement of treatments. Factor A was AH particle size (fine vs. coarse) and factor B was diet SH content (0% vs. 10%; substituted for AH). Steers were fed at 1% of body weight of TMR containing 400 g/kg forage and 600 g/kg concentrate. Chopping of AH to fine particles decreased (p = 0.01) amount of dietary materials retained on the medium sieve (8 mm). The inclusion of SH significantly increased (p = 0.01) materials retained on the 1.18-mm sieve and tended to decrease (p = 0.07) materials on 19-mm sieves. The inclusion of SH increased (p = 0.01) ether extract (EE) intake and increased (p = 0.07) DMI. Inclusion of SH increased (p = 0.01) EE digestion and decreased (p < 0.01) faecal pH. Neither AH particle size nor SH inclusion in diets affected (p > 0.10) the in situ ruminal degradability coefficients of DM ('a', 'b', 'c' or 'a+b'). No interaction of AH×SH was seen on nutrient intake, digestibility and in situ ruminal degradability of Holstein steers.

Evaluate of heavy metal concentration in shrimp (Penaeus semisulcatus) and crab (Portunus pelagicus) with INAA method

The level of the heavy metal in green tiger shrimp (Penaeus semisulcatus) and crab (Portunus pelagicus) caught off the Persian Gulf near Bushehr province were investigated. This study was performed to evaluate instrumental neutron activation analysis (INAA) to analyze heavy metal concentration in crab and shrimp whole body tissue. The order of the swimmer crab and shrimp heavy metal concentrations were Zn>Fe>As>Mn>Co and Fe>Zn>Mn>As>Co, respectively. The results showed swimmer crab (Portunus pelagicus) and shrimp (Penaeus semisulcatus) caught off Persian gulf, were contaminated with high level of As (21.38±3.31ppm and 8.28±2.82 ppm, respectively). High levels of As and Mn were noted in crabs and shrimp, respectively.

Effect of dietary Ergosan on growth performance, digestive enzymes, intestinal histology, hematological parameters and body composition of rainbow trout (Oncorhynchus mykiss)

Present study examined the effects of Ergosan on growth performance, digestive enzyme activities, hematological parameters and gastrointestinal structure of rainbow trout. Rainbow trout (mean weight 100-110 g) were fed basal diet (control) and diet treated with Aquavac Ergosan (5 g kg⁻¹ of diet) for 50 days. Results of this study showed that Ergosan supplementation significantly increased weight gain (94.27 g vs. 65.04 g), specific growth rate (4.09 vs. 3.10) and feed intake (136.85 g vs. 111.22 g) and decreased feed conversion ratio (1.43 vs. 2.03) compared to control (P<0.05). Lipase activity and leukocyte and erythrocyte count also increased in juvenile fish fed Ergosan-treated diet compared to control (P<0.05). Light microscopy demonstrated that both groups of fish displayed normal morphology of proximal intestine and pyloric caeca. In Ergosan-treated group, higher percentage of goblet cell was shown in proximal intestine and pyloric caeca. Present study suggests that Ergosan effectively promotes growth performance, lipase activity and gastrointestinal structure in rainbow trout.

Effects of pistachio by-product in replacement of lucerne hay on microbial protein synthesis and fermentative parameters in the rumen of sheep

This study was conducted to evaluate the effect of partial and total substitution of lucerne hay with pistachio by-product on nutrient intake, apparent digestibility, rumen fermentation, digesta kinetics, blood metabolites, nitrogen retention and microbial protein synthesis in Baloochi sheep. Six sheep with a bodyweight of 40.1 ± 1.77 kg fitted with ruminal and abomasal cannulae were assigned at random to three diets in a double 3 × 3 Latin-square design. The dietary treatments included a control (basal diet), low pistachio by-product diet (50% of the lucerne hay in the basal diet was replaced by pistachio by-product), and high pistachio by-product diet (all of the lucerne hay in the basal diet was replaced by pistachio by-product). The daily basal diet was 500 g/kg DM lucerne hay, 250 g/kg DM wheat straw, 210 g/kg DM barley grain, 30 g/kg DM cotton seed meal, 8 g/kg DM vitamin–mineral supplement and 2 g/kg DM salt. Faeces and urine were collected for 8 days and used to estimate digestibility, nitrogen retention and microbial protein synthesis. Sheep were dosed ruminally with Cr-EDTA (2.27 g/L) and rumen samples were evaluated for pH, volatile fatty acids, ammonia nitrogen concentrations and digesta kinetics. The intake of neutral detergent fibre, purine derivatives excretion, volatile fatty acid concentrations in the rumen and ammonia nitrogen in the abomasum decreased (P < 0.05). Ether extract intake and ruminal pH was increased at 5 h after feeding (P < 0.05) as the level of pistachio by-product in the diet increased. Total pistachio by-product replacement for lucerne hay increased (P < 0.05) apparent digestibility of nitrogen, ether extract, organic matter and nitrogen retention and decreased (P < 0.05) microbial protein synthesis, efficiency of microbial protein synthesis and ammonia nitrogen in the rumen. The inclusion of pistachio by-product had no effect on blood metabolites and digesta kinetics. Based on these results it was concluded that pistachio by-product can be considered as a useful replacement for lucerne hay in the diet of Baloochi sheep without any negative impacts on their responses. Moreover, pistachio by-product inclusion in diet improved nitrogen metabolism in Baloochi sheep.