Effect of environmental factors on growth performance of Nile tilapia (Oreochromis niloticus).

Aquaculture is the practice of developing aquatic animals and plants under artificial environmental conditions, either in a controlled or semi-controlled environment. Due to high animal protein demand, it is one of the world's growing food production industries. It plays a vital role in contributing to food security and lowering the unemployment rate of the world's growing population. This review article aims to scope sight on the environmental factors that affect the growth and economic production process of Nile tilapia. Many of these factors are listed and analyzed in this review, such as stocking densities; various feed frequencies and feeding rates; water quality; water temperature; dissolved oxygen concentration; water pH degree; ammonia (NH3), nitrite (NO2), and nitrate (NO3) concentration; feeding regimes; feed cost; and tank culturing system of Nile tilapia. These factors can significantly alter body weight, composition, survival, behavior, feed intake, feed conversion ratio, feeding efficiency, and the health and reproduction of Oreochromis niloticus. Furthermore, feeding, growth, disease risks, and survival rates are all affected by water quality parameters. In general, higher growth performance of O. niloticus in aquaculture can be obtained by keeping the optimum quantity of feed with proper feeding rate and frequency, maintaining a good proportion of stocking density, and regularly evaluating water quality. This review article highlights-in details-the impact of various environmental factors on growth performance criteria of Nile tilapia (Oreochromis niloticus).

Betaine and related compounds: Chemistry, metabolism and role in mitigating heat stress in poultry.

Betaine can operate as an osmolyte and a methyl donor. Betaine is an osmolyte and a methyl donor. Betaine is likewise a zwitterion with osmotic capabilities that can help an animal cope with osmotic stress. Previous investigations have suggested that betaine has various impacts, albeit these studies do not consistently provide the same results. Dietary betaine has received a lot of attention owing to its osmoprotectant, methionine-sparing and antioxidant properties. Betaine is extensively assessed concerning performance and body composition. The tolerance to high temperatures, flock livability, and breast meat output is among the factors frequently mentioned in the literature as being altered by betaine. Betaine, a multi-nutritional agent, may help poultry resist heat stress and poor management. A common subject of betaine research is the idea of betaine saving some methionine. Although research on betaine may not always come to the same results, some discoveries repeat themselves. Because of their effectiveness in increasing growth performance, feed utilization, meat quality, and alleviating heat stress in chicken farms, betaine and methionine are extensively used as feed supplements in poultry diets. This review highlights the influences of betaine on poultry performance, meat quality, carcass characteristics, antioxidant activity, in addition to its role in mitigating heat stress.

Assessing Soil Quality, Wheat Crop Yield, and Water Productivity under Condition of Deficit Irrigation.

Wheat is one of the most important cereal crops in Egypt and all over the world. Its productivity is adversely affected by drought due to deficient irrigation to provide nutrients required for plant growth. In a field experiment, silicon foliar applications at concentrations of 0, 200, and 400 mg L-1 were performed at different irrigation rates ranging from 1000 to 4000 m3 ha-1 to assess water irrigation productivity and wheat crop yield in a calcareous soil under arid climate conditions. Increased irrigation rates led to a significant increase in soil nutrient dynamics, as well as in the number and weight of grains per spike, leaf area index, grain yield, straw yield, and biological yield, with the exception of the weight of 1000 grains. Spraying with sodium silicate had a significant impact on grain yield and harvest index but did not significantly impact the other traits. Furthermore, the interaction between irrigation and silicate application rates showed significance only for grain yield, the number of spikes/m2, and the harvest index. Applying three times irrigation could produce the highest nutrient retention, wheat yield, and water irrigation productivity. No significance was observed between 3000 m3 ha-1 and 4000 m3 ha-1 irrigation, indicating a saving of 25% of applied irrigation water. It can be concluded that applying irrigation at 3000 m3 ha-1 could be a supplemental irrigation strategy. High wheat grain yield can be achieved under deficit irrigation (3000 m3 ha-1) on the northwestern coast of Egypt with an arid climate by spraying crops with sodium silicate at a rate of 400 mg L-1.

Comparison of the Morpho-Physiological and Molecular Responses to Salinity and Alkalinity Stresses in Rice.

Rice is a major food crop that has a critical role in ensuring food security for the global population. However, major abiotic stresses such as salinity and alkalinity pose a major threat to rice farming worldwide. Compared with salinity stress, there is limited progress in elucidating the molecular mechanisms associated with alkalinity tolerance in rice. Since both stresses coexist in coastal and arid regions, unraveling of the underlying molecular mechanisms will help the breeding of high-yielding stress-tolerant rice varieties for these areas. This study examined the morpho-physiological and molecular response of four rice genotypes to both salinity and alkalinity stresses. Geumgangbyeo was highly tolerant and Mermentau was the least tolerant to both stresses, while Pokkali and Bengal were tolerant to only salinity and alkalinity stress, respectively. A set of salinity and alkalinity stress-responsive genes showed differential expression in the above rice genotypes under both stress conditions. The expression patterns were consistent with the observed morphological responses in these rice genotypes, suggesting the potential role of these genes in regulating tolerance to these abiotic stresses. Overall, this study suggested that divergence in response to alkalinity and salinity stresses among rice genotypes could be due to different molecular mechanisms conferring tolerance to each stress. In addition to providing a basis for further investigations into differentiating the molecular bases underlying tolerance, this study also emphasizes the possibilities of developing climate-resilient rice varieties using donors that are tolerant to both abiotic stresses.

Mode of gene action and heterosis for physiological, biochemical, and agronomic traits in some diverse rice genotypes under normal and drought conditions.

Water scarcity is a crucial environmental stress that constrains rice growth and production. Thus, breeding for developing high-yielding and drought-tolerant rice genotypes is decisive in sustaining rice production and ensuring global food security, particularly under stress conditions. To this end, this study was conducted to evaluate the effects of water deficit on 31 genotypes of rice (seven lines, viz., Puebla, Hispagran, IET1444, WAB1573, Giza177, Sakha101, and Sakha105, and three testers, viz., Sakha106, Sakha107, and Sakha108) and their 21 crosses produced by line × tester mating design under normal and water deficit conditions; this was to estimate the combining ability, heterosis, and gene action for some traits of physiological, biochemical, and yield components. This study was performed during the summer seasons of 2017 and 2018. The results showed that water deficit significantly decreased relative water content, total chlorophyll content, grain yield, and several yield attributes. However, osmolyte (proline) content and antioxidant enzyme activities (CAT and APX) were significantly increased compared with the control condition. Significant mean squares were recorded for the genotypes and their partitions under control and stress conditions, except for total chlorophyll under normal irrigation. Significant differences were also detected among the lines, testers, and line × tester for all the studied traits under both irrigation conditions. The value of the σ²GCA variance was less than the value of the σ²SCA variance for all the studied traits. In addition, the dominance genetic variance (σ2D) was greater than the additive genetic variance (σ2A) in controlling the inheritance of all the studied traits under both irrigation conditions; this reveals that the non-additive gene effects played a significant role in the genetic expression of the studied traits. The two parental genotypes (Puebla and Hispagran) were identified as good combiners for most physiological and biochemical traits, earliness, shortness, grain yield, and 1,000-grains weight traits. Additionally, the cross combinations Puebla × Sakha107, Hispagran × Sakha108, and Giza177 × Sakha107 were the most promising. These results demonstrated the substantial and desirable specific combining ability effects on all the studied traits, which suggested that it could be considered for use in rice hybrid breeding programs.

Response of nine triticale genotypes to different salt concentrations at the germination and early seedling stages.

Salinity stress poses a major challenge to agricultural productivity worldwide, and understanding their responses at the early growth stage is vital for devising strategies to cope with this stress. Therefore, to improve triticale productivity, this study investigated the salinity stress tolerance of different salt-tolerant triticale genotypes aiming to cultivate them on saline soils. To this end, salinity stress impacts on nine triticale genotypes, i.e., Zhongsi 1084, Gannong No. 2, Gannong No. 4, Shida No. 1, C6, C16, C23, C25 and C36 at germination and early seedling stages was evaluated. Each genotype was subjected to six treatments inducing control, 40, 80, 120, 160, and 200 mM NaCl treatments to study their effect on seedling and termination traits of the nine genotypes. Compared to the overall mean seedling vigor index, the seedling vigor index was higher in the genotypes Zhongsi 1084 and C6 (39% and 18.1%, respectively) and lower in Gannong No.2 (41%). Increasing NaCl concentrations negatively affected germination and seedling traits. Compared to other genotypes, Zhongsi 1084 had the highest mean germination rate, germination vigor index, germination percentage, mean daily germination and germination energy. It also showed the lowest relative salt injury. The relative salt injury was higher in the genotype Shida No. 1 than those in Gannong No. 2, Gannong No. 4, Shida No. 1, C16, and C36 genotypes. All genotypes exhibited desirable mean germination time except for line C6. High significant positive correlations were observed among germination rate, germination vigor index, germination percentage, mean daily germination, seedling vigor index, and root length. Principal component analysis (PCA) grouped the most desirable genotypes into two clusters. Our study determined salt stress tolerance of nine triticale genotypes at germination and early seedling stages. to select salt-tolerant genotypes that can be cultivated on saline soil or after salt irrigation.

Upgrading the preparation of high-quality chitosan from Procambarus clarkii wastes over the traditional isolation of shrimp chitosan.

Crustacean waste is one of the most severe issues, posing significant environmental and health risks. This study aims to improve managing marine waste by isolating chitosan from Procambarus clarkii by devising a new methodology, incorporating technical steps, e.g., washing, decolorization and deacetylation under a reflexive condenser and dialysis purification. A comparison was made between the prepared P. clarkii chitosan and four types of shrimp chitosans: commercial, high, low, and nano. The obtained chitosan has a low molecular weight and viscosity compared to the commercial shrimp chitosan used in various applications. P. clarkii chitosan was prepared in high quality from a cheap source, as its color and quality were better than those of the commercial shrimp chitosan. The new methodology has successfully extracted chitosan from P. clarkii in a good quality and high purity, achieving 89% deacetylation, high solubility, high purity, and medium molecular weight. Analysis of the different chitosan samples with Fourier transform infrared spectroscopy (FTIR), atomic force microscopy, Raman spectrum referred indicated high similarity between the chitosan different types, regardless of its source. The 3D image of P. clarkii showed the distance between the highest and most profound points of extracted chitosan is 728.94 nm, revealing homogeneous, smooth surfaces, apparently free of pores and cracks. FTIR and Raman spectrum of P. clarkii indicated various functional groups, e.g., alcohol, amines, amides, and phenols. These active groups are responsible for about 60% of the antioxidant activity of that product. Evaluating the quality traits indicated the excellence of the chitosan prepared from P. clarkii, especially in color, viscosity, and antioxidant activity, nominating it for different food applications.

The effect of abamectin seeds treatment on plant growth and the infection of root-knot nematode Meloidogyne incognita (Kofoid and White) chitwood.

In this study, three concentrations (250, 500, and 1000 ppm) of abamectin 2% suspension concentration (SC) were used as cucumber seeds treatment. The seeds were treated with abamectin to reduce nematodes reproduction and their ability to penetrate the roots, then seed germination and plant growth were observed. All the concentrations didn't negatively affect seeds germination wherever the germination percent reached 80% at the concentration (1000 ppm) after 20 days of sowing. The effect of abamectin on root-knot nematode was studied by recording numbers of nematodes in 100 g/soil, numbers of the galls, egg mass on the root, and the nematode reproduction factor. All concentrations significantly affected the nematode reproduction parameters compared to control. Abamectin at (500 ppm) was the most effective concentration on reducing nematodes parameters, i.e., 26.57, 38.83, 47.40 %, and 3.15 for the above-mentioned parameters, respectively at the end of experimint. No significant difference between 500 ppm and 1000 ppm. We recommended using the abamectin in (500 ppm) concentration as a seed application to control Meloidogyne incognita in cucumber plants under greenhouse conditions to reduce its environmental toxic effect.

The larvicidal effect of neemazal T/S, clove oil and ginger oil on tomato leafminer, Tuta absoluta compared to coragen.

The present study aimed to evaluate the toxicity and biochemical changes of Tuta absoluta 3rd instar larvae affected by neemazal T/S, clove oil and ginger oil. These compounds were evaluated compared to the recommended pesticide, Coragen 20% SC. by means of sublethal concentrations, LC25 and LC50 under constant laboratory conditions. Results showed that neemazal T/S is more toxic than detected oils compared with higher toxicity of coragen with LC50 values of 57.52, 159.94, 633.38 and 930.71 µg mL-1 for coragen, neemazal, ginger oil and clove oil, respectively. There were highly significant differences between all treatments and untreated larvae. Neemazal possessed the greatest effect on activity level of most physiological parameters than selected oils. Larval content of digestive enzymes was decreased significantly 48 h after all treatments except for lipase, α-esterase and ß-esterase (in case of coragen and clove oil). Also, total proteins, total carbohydrates, total lipids and total free amino acids take the same trend. Based on this study, these sublethal doses caused a significantly dose-dependent perturbation in determined components.

Pathogenome comparison and global phylogeny of Escherichia coli ST1485 strains.

Escherichia coli ST1485 strains belong to the clinically important phylogroup F and have disseminated worldwide in humans, animals, and the environment. Here, we elucidated the pathogenome of a global collection of E. coli ST1485 isolates from diverse sources retrieved from public databases and a high-quality sequenced complete genome of colistin-resistant E. coli strain CFSAN061771 isolated from raw milk cheese which designated as a reference strain. CFSAN061771 belongs to O83:H42-ST1485 pathotype and carries a conjugative ColV plasmid, pCFSAN061771_01, combining extraintestinal virulence genes (ompt, sitA, iroN, etsC, traT, cvaC, hylF, iss, tsh, mchf, iucC, iutA) with a multidrug resistance island (blaTEM-1, aph(6)-Id, aph(3″)-Ib, sul2, dfrA14). Comparative genomic analysis revealed a high frequency of pCFSAN061771_01-like plasmids in E. coli ST1485. A notable evolutionary genetic event in E. coli ST1485 strains is the acquisition of a pCFSAN061771_02-like plasmid, which confers resistance to several antimicrobials, tellurium, and quaternary ammonium compounds. The identical virulence and antibiotic resistance profiles identified in some human and animal strains are worrisome. This is the first study to emphasize the significance of E. coli ST1485 as a global high-risk virulent and multidrug-resistant clone with zoonotic potential.

The hidden power of secondary metabolites in plant-fungi interactions and sustainable phytoremediation.

The global environment is dominated by various small exotic substances, known as secondary metabolites, produced by plants and microorganisms. Plants and fungi are particularly plentiful sources of these molecules, whose physiological functions, in many cases, remain a mystery. Fungal secondary metabolites (SM) are a diverse group of substances that exhibit a wide range of chemical properties and generally fall into one of four main family groups: Terpenoids, polyketides, non-ribosomal peptides, or a combination of the latter two. They are incredibly varied in their functions and are often related to the increased fitness of the respective fungus in its environment, often competing with other microbes or interacting with plant species. Several of these metabolites have essential roles in the biological control of plant diseases by various beneficial microorganisms used for crop protection and biofertilization worldwide. Besides direct toxic effects against phytopathogens, natural metabolites can promote root and shoot development and/or disease resistance by activating host systemic defenses. The ability of these microorganisms to synthesize and store biologically active metabolites that are a potent source of novel natural compounds beneficial for agriculture is becoming a top priority for SM fungi research. In this review, we will discuss fungal-plant secondary metabolites with antifungal properties and the role of signaling molecules in induced and acquired systemic resistance activities. Additionally, fungal secondary metabolites mimic plant promotion molecules such as auxins, gibberellins, and abscisic acid, which modulate plant growth under biotic stress. Moreover, we will present a new trend regarding phytoremediation applications using fungal secondary metabolites to achieve sustainable food production and microbial diversity in an eco-friendly environment.

ٍSome biologically active microorganisms have the potential to suppress mosquito larvae (Culex pipiens, Diptera: Culicidae).

Malaria is a disease caused by protozoan species of the genus Plasmodium. It is widespread and becoming a challenge in several African countries in the tropical and subtropical regions. In 2010, a report was published showing that over 1.2 million death cases were occurred globally due to malaria in just one year. The transmission of the disease from one person to another occurs via the bite of the Anopheles female. It is known that Plasmodium ovale, P. vivax, P. malariae, P. falciparum, and P. knowlesi are the highly infective malaria species. The problem of this disease is the absence of any effective medical treatment or vaccine, making the mosquito control is the only feasible way for disease prevention. Pesticides are currently the most widely used method for mosquito control, despite its well-known negative effects, including health hazards on human, the increasing insecticidal resistance, and the negative impact on the environment and beneficial organisms. Biological control (also called: biocontrol) of insects has been a promising method to overcome the negative effects of using chemical insecticides, as it depends on just using the natural enemies of pests to either minimize their populations or eradicate them. This article provides an overview of the recent and effective biological means to control malaria, such as bacteria, fungi, viruses, larvivorous fish, toxorhynchites larva and nematodes. In addition, the importance, advantages, and disadvantages of the biocontrol methods will be discussed in comparison with the traditionally used chemical methods of malaria control with special reference to nanotechnology as a novel method for insects' control.

Impact of plant growth regulators spray on fruit quantity and quality of pepper (Capsicum annuum L.) cultivars grown under plastic tunnels.

The study aims to investigate the effect of foliar spray with three plant growth regulators (PGRs) p-Chlorophenoxyacetic acid (CPA) at 20 and 40 ppm; Gibberellic acid (GA3) at 20 and 30 ppm, 1-Naphthaleneacetic acid (NAA) at 10 and 20 ppm on the response of fruit set, yield, and fruit quality of some hot pepper cultivars (Chillina, Parbirian, Shampion, and Hyffa) grown in sandy soil under plastic tunnels as compared to the control. Spraying Chillina cultivar GA3 at 30 ppm significantly increased the number of fruits/ plant and fruit set (%), yield/plant, and total yield/fad. In addition, the contents of TSS and Vit C, furthermore, maximum capsaicin content were observed in chili fruits in both seasons. However, the interaction between Chillina cultivar and spraying with GA3 at 20 ppm ranked second in yield and quality. The interaction between Parbirian cultivars and spraying with GA3 at 20 or 30 ppm increased the number of flowers/plants in both seasons. On the other hand, the interaction between Shampion cultivar and spraying with tap water (control) gave the lowest values of the number of flowers/ plants, the number of fruits/ plant and fruit set (%), yield, and its components, and fruit quality in both seasons.

Efficacy of Bacillus subtilis, Moringa oleifera seeds extract and potassium bicarbonate on Cercospora leaf spot on sugar beet.

Cercospora leaf spot caused by Cercospora beticola are among the most dangerous plant diseases on sugar beet plants. It causes heavy economic losses, whether on the yield of roots, the percentage of sugar in them, or the quality of sugar produced. In addition to the economic cost caused by chemical control, these chemical pesticides cause an imbalance in the ecosystem and harm the health of humans and animals. In an attempt to search for a safer method than pesticides and environmentally friendly, an evaluation of using biocontrol agents, Bacillus subtilis as cell suspension (108 cell/ml), was conducted in this study. Seeds extract of Moringa oleifera with two concentrations (25 and 50 g/L) and potassium bicarbonate at (5 and10 g/L (compared to fungicide Montoro 30% EC (Propiconazole 15% + Difenoconazole 15%). The evaluation results for twenty-five sugar beet varieties showed a significant discrepancy between these varieties in the extent of their susceptibility to infection with the disease under investigation. In-Vitro, B. subtilis induced an antagonist to C. beticola, and both M. oleifera seeds extract and potassium bicarbonate significantly reduced the linear growth of this pathogen. Under field conditions, the treatments used have given positive results in controlling Cercospora leaf spots. They significantly decreased the severity of disease and prevented C. beticola from creating conidiophores and conidiospores, along with examining their cell walls with the formation of plasmolysis of the fungus cells and reducing both the number and diameter of the spots on the surface leaves; this was demonstrated using a scanning electron microscope (SEM). It is worth noting that the best results obtained were most often when treated with M. oleifera seeds extract, followed by potassium bicarbonate, then cell suspension of B. subtilis. In addition, the percentage of the content of beet roots from total soluble solids and sucrose has improved significantly due to spraying sugar beet plants with the substances mentioned earlier. These treatments also contributed to a significant improvement in the enzymes polyphenol oxidase, peroxidase, and phenylalanine ammonia-lyase.

Performance of some elite potato cultivars under abiotic stress at North Sinai.

The current experiment was adopted during the summer 2018, fall 2018/2019 and summer 2019 respectively at the Experimental Farm of Baloza station, Desert Research Center. North Sinai Governorate, Egypt to study the effect of different doses of irradiation (0, 20, 30 and 40 Gy), three irrigation levels (100, 80 and 60% field capacity on growth, yield and its quality of some potato cultivars (Spunta, Cara, Caruso and Hermes). Treated Spunta cultivar pre planting with 20 (Gy) and irrigated with 80% field capacity was the best treatment for increasing number of aerial stem/plants, leaf area, total chlorophyll in leaves, average tuber weight, and total yield/fed. Hermes cultivar with 20 (Gy) and irrigation level of 80% was the best for increasing dry matter content in tuber in both mutagenic generations.

Investigation of many bacterial and viral infections circulating in pigeons showing nervous symptoms.

Pigeon's flocks have shown several neurological symptoms including circling, torticollis, tremors, paralysis, which caused suspicion for viral or bacterial natural infections. Pigeon paramyxovirus type-1 (PPMV-1) is a notifiable disease-causing high morbidity and mortality with severe nervous symptoms. Clinical represented tissue specimens were collected from 50 infected pigeon flocks in eight governorates. All samples were examined bacteriologically (isolation, identification and serotyping) for E. coli, Salmonella spp., S. aureus and pseudomonas aeruginosa. Antimicrobial susceptibility test (AST) was accomplished for all isolates using a disk-diffusion test. For viral identification, RT-PCR specific oligonucleotide primers were used for distinguishing of Avian influenza virus, PPMV-1 and PPMV-3. Neurological manifestations were observed in pigeon's flocks mainly in winter and autumn. The mortality rate in eight governorates was about 50% in 10 flocks and other houses mortality rate was ranged from 10 to 20%. Post mortem examination have shown hemorrhagic enteritis, soft and friable brain tissues and/or hemorrhages. The percentage of isolated bacteria E. coli, Salmonella spp., S. aureus and Pseudomonas aeruginosa were 75%, 75%, 50% and 18.75%; respectively. The antibiotic resistance pattern for bacterial isolates showed resist to ampicillin, amoxicillin- clavulinic acid, teteracyclin, ceftriaxone, doxycycline, sulfamethoxazole-trimethoprim and ceftazidine with different result for each type of bacteria, while Salmonella spp., isolates showed only a highly intermediate result for ciprofloxacin. Eight samples are positive with 16% to PPMV-1. Also, sample No.5,6,9 was co-infected with different types of bacterial isolates in addition to NDV. In conclusion, we reported several neurological symptoms in pigeon's flocks mainly of bacterial infections (E. coli, Salmonella spp., S. aureus and Pseudomonas aeruginosa).

Biochemical and molecular diagnosis of different tomato cultivars susceptible and resistant to Tuta absoluta (Meyrick) infestation.

Resistant plant cultivars which used in breeding programs are considered one of the modern integrated management programs to reduce the usage of synthetic insecticides and environmental contamination the present study aimed to characterize the resistant and susceptible tomato cultivars to Tuta absoluta based on biochemical and molecular levels, in Egypt. The biochemical characters of the tested tomato cultivars (tomato- 86, tomato- Alissa, tomato- Fayarouz, tomato- Omniya, tomato- 036, tomato- GS) were determined colorimetrically and characterized by using native- polyacrylamide gel electrophoresis (PAGE) and agarose gel. Our results showed that there were variations highly significant in all biochemical constituents of the resistant tomato cultivar (tomato- 86) compared with the susceptible one (tomato- GS). Also, native-(PAGE) for peroxidase (POD) isoenzymes techniques of the tested tomato cultivars showed variations in protein band numbers and densities in tomato-86 resistant compared with tomato-GS susceptible to Tuta absoluta infestation. The correlation coefficient between total phenols and peroxidases in infested tomato leaves and percentages of damaged leaves with the tested insect pest was negative and highly significant, while in case of total proteins and reducing sugars in infested tomato leaves as well as lycopene contents in infested tomato fruits was positive, highly significant and significant, respectively. The correlation coefficient between tomato yield means and the infested fruit percentage with T. absoluta larvae was negative and highly significant. Respecting molecular diagnosis random amplified polymorphism DNA- polymerase chain reaction (RAPD- PCR), the results demonstrated that the presence of polymorphism in the resistant tomato cultivar (tomato- 86) compared with (tomato- GS), the most susceptible to the tested insect pest infestation.

Stability and anatomical parameters of irradiated potato cultivars under drought stress.

This study was carried out in Desert Research Center and Faculty of Agriculture, Zagazig University, Egypt, under North Sinai conditions during three growing seasons, i.e., summer 2018, fall 2018/2019 and summer 2019 to assess the effect of radiation mutants on leaf histological features and genetic stability of the productivity of some potato cultivars under drought stress conditions. Results reveal that the genotypes can be statistically classified based on regression coefficient (bi), deviation from regression (S2di) to 4 groups (with low in S2di are considered in all groups) as: (i) Genotype with elevated average, bi = 1, it is considered as stable genotype where Cara cultivar (both generations) was included. (ii) Genotype with elevated average, bi > 1 as genotype with average stability where spunta cultivar was involved. (iii) Genotype with low mean, bi < 1 as genotype with low stability where hermes (both primary (M1) and secondary (M2) radiated generations) and Caruso (2nd generation) cultivars were involved. (iv) Genotypes including a few bi values in one generation, as genotype including low stability but are not recommended for use in this generation where Caruso cv in M1 was included. The results indicated that 20 Gy irradiation exposure revealed that Spunta cultivar produced markedly high mean combined over yield during M1 (11.771 ton/fed) and M2 (10.97 ton/fed) generations than other genotypes and ranked first over all environments. It proves that Hermes could be employed as anti-stress genotypes under stress conditions (negative conditions or poor yielding). However, spunta followed by cara cv. represented a good performance in M2 production yield (10.97 and 8.51 ton/fed, respectively), slight drift from the regression line and coefficient close to 1, therefore, both cultivars were excellent between genotypes in shape of yield stability and is recommended for different conditions. According to anatomical studies, 80 % from field capacity (FC) decreased the thickness of medvein and lamina of potato cv. spunta, also, dimensions of medvein bundle and mean diameter of vessels. In conclusion, plants treated with gamma ray at level 20 and grown under 80 % FC induced prominent increase in all previous characters.

Nitrogen-molybdenum-manganese co-fertilization reduces nitrate accumulation and enhances spinach (Spinacia oleracea L.) yield and its quality.

Spinach (Spinacia oleracea L.) is considered a nitrogen (N) intensive plant with high nitrate (NO3 -) accumulation in its leaves. The current study via a two-year field trial introduced an approach by combining N fertilization from different sources (e.g., ammonium nitrate; 33.5 % N, and urea; 48 % N) at different rates (180, and 360 kg N ha-1) with the foliar spraying of molybdenum (Mo) as sodium molybdate, and/or manganese (Mn) as manganese sulphate at rates of 50 and 100 mgL-1 of each or with a mixture of Mo and Mn at rates of 50 and 50 mg L-1, respectively on growth, chemical constituents, and NO3 - accumulation in spinach leaves. Our findings revealed that the highest rate of N fertilization (360 kg N ha-1) significantly increased most of the measured parameters e.g., plant length, fresh and dry weight plant-1, number of leaves plant-1, leaf area plant-1, leaf pigments (chlorophyll a, b and carotenoids), nutrients (N, P, K, Fe, Mn, Zn), total soluble carbohydrates, protein content, net assimilation rate, and NO3 - accumulation, but decreased leaf area ratio and relative growth rate. Moreover, plants received urea-N fertilizer gave the highest values of all previous attributes when compared with ammonium nitrate -N fertilizers, and the lowest values of NO3 - accumulation. The co-fertilization of N-Mo-Mn gave the highest values in all studied attributes and the lowest NO3 - accumulation. The best treatment was recorded under the treatment of 360 kg N-urea ha-1 in parallel with the combined foliar application of Mo and Mn (50 + 50 mg L-1). Our findings proposed that the co-fertilization of N-Mo-Mn could enhance spinach yield and its quality, while reducing NO3 - accumulation in leaves, resulting agronomical, environmental and economic benefits.

Genetic behavior of earliness and yield traits of some rice (Oryza sativa L.) genotypes.

Rice (Oryza sativa L.) is a critical staple food crop that provides more than half of the world's population with its primary nutritional source. Breeders and growers of rice would profit from robust genotypes with improved morphological and yield-related characteristics. The aim of this work is to determine the nature and magnitude of gene action on yield quantity and quality, to define the best combinations of earliness and yield characters, develop hybrids that perform better on yield quantity and quality. Three replications were used in the experiment's randomized complete block design (RCBD). During the 2016 season, seven different parents, namely Sakha 101, Sakha 104, Sakha 105, Giza 177, Black rice 1, Black rice 2, and Black rice 3, were crossed using A 7 × 7 half-diallel set analysis without reciprocals to generate 21 F1 crosses. The results indicated that genotype-dependent mean squares were very significant for main characteristics. Significant combining ability SCA variance estimates were more considerable than general combining ability (GCA) variance for all characters except days to 50% flowering. It demonstrated that both additive and non-additive genetic variance played a role in expressing the attributes investigated. The Parents, Black rice, Sakha 105, and Sakha 101, were recognized as the best general combiner for most growth and yield attributes. Sakha105 × Black Rice 1, Sakha105 × Black Rice 2, Sakha101 × Sakha104, Sakha105 × Giza 177, and Sakha101 × Giza 177 all demonstrated non-additive gene activity for the majority of maturity and yield traits. Heterosis breeding would be most efficient for qualities where high performance was determined by dominance and dominance gene effects. The increased yield of crosses results from parents with a diverse genetic background and genetic diversity.