Alleviation of salinity stress effects on agro-physiological traits of wheat by auxin, glycine betaine, and soil additives

Generation Mean Analysis, Heterosis, and Genetic Diversity in Five Egyptian Faba Beans and Their Hybrids

The faba bean (Vicia faba L.) is a major legume crop; thus, it is important to apply various biometrical techniques to develop the most efficient breeding procedures to face biotic and abiotic stressors. During the four consecutive winter seasons of 2017–2021, five populations of five faba bean hybrids were studied at Sakha agricultural research station in Egypt. Five basic generations, including two parents (P1 and P2) and the first, second, and third generations, were studied. This analysis found significant variations between generations in all attributes studied in all crosses (P1, P2, F1, F2, and F3). Sakha 4 was the earliest parent (138 days) based on the maturity date, whereas Giza 40 had the most significant number of pods and seeds per plant (25.68–78.94), and Giza 716 had the tallest plant height (124.00 cm). Giza 843 and Sakha 4 had the highest seed yield per plant values (62.84 g and 61.77 g). The data demonstrated highly substantial heterosis in the favorable direction over mid and better parents for all features, except for the number of branches in Cross 3 (Giza 40 × Giza 843) over mid and better parents and a maturity date in Cross 1 over mid parents. Contrarily, opposite-direction dominance and dominance × dominance effects increased narrow-sense heredity. Broad-sense heritability values for all examined characteristics were high in all crosses, ranging from 90.24% to 97.67%. In both Crosses 5 (Giza 716 × Qahera 4) and 3, genetic advance through selection ranged from 1.73% at the maturity date to 95.12% for seed yield per plant. Cross 3 (Giza 40 × Giza 843) had the greatest number of branches, pods, and seeds per plant. In conclusion, this study advances our understanding of employing faba beans in breeding programs.

Plant Metabolomics: An Overview of the Role of Primary and Secondary Metabolites against Different Environmental Stress Factors

Several environmental stresses, including biotic and abiotic factors, adversely affect the growth and development of crops, thereby lowering their yield. However, abiotic factors, e.g., drought, salinity, cold, heat, ultraviolet radiations (UVr), reactive oxygen species (ROS), trace metals (TM), and soil pH, are extremely destructive and decrease crop yield worldwide. It is expected that more than 50% of crop production losses are due to abiotic stresses. Moreover, these factors are responsible for physiological and biochemical changes in plants. The response of different plant species to such stresses is a complex phenomenon with individual features for several species. In addition, it has been shown that abiotic factors stimulate multi-gene responses by making modifications in the accumulation of the primary and secondary metabolites. Metabolomics is a promising way to interpret biotic and abiotic stress tolerance in plants. The study of metabolic profiling revealed different types of metabolites, e.g., amino acids, carbohydrates, phenols, polyamines, terpenes, etc, which are accumulated in plants. Among all, primary metabolites, such as amino acids, carbohydrates, lipids polyamines, and glycine betaine, are considered the major contributing factors that work as osmolytes and osmoprotectants for plants from various environmental stress factors. In contrast, plant-derived secondary metabolites, e.g., phenolics, terpenoids, and nitrogen-containing compounds (alkaloids), have no direct role in the growth and development of plants. Nevertheless, such metabolites could play a significant role as a defense by protecting plants from biotic factors such as herbivores, insects, and pathogens. In addition, they can enhance the resistance against abiotic factors. Therefore, metabolomics practices are becoming essential and influential in plants by identifying different phytochemicals that are part of the acclimation responses to various stimuli. Hence, an accurate metabolome analysis is important to understand the basics of stress physiology and biochemistry. This review provides insight into the current information related to the impact of biotic and abiotic factors on variations of various sets of metabolite levels and explores how primary and secondary metabolites help plants in response to these stresses.

The effect of using fresh farmyard manure (animal manure) on the severity of Fusarium verticilioides in soil, root, stem, and kernels as well as lodging and borer incidence of maize plants

Fusarium verticillioides, an important maize pathogen, produce fumonisins, causes stalk rot and consequentially reduce crop growth and yield. Therefore, herein we aimed to evaluate the potential use of two farmyard soil organic manures, i.e., fresh (5-6 days old) and stored (5-6 months old) organic manure, to manage F. verticillioides infections as well as borer incidence and lodging in maize plants. After 30, 60, and 90 days of sowing, samples of soil, roots, and stems were collected to isolate F. verticillioides. Moreover, we estimated ear and kernel rot induced by F. verticillioides at the final harvest. Fresh organic manure treatment increased infection rates of F. verticillioides in soil, roots, stem and kernels compared to the control treatment. In contrast, stored organic manure plots treatments decrease F. verticillioides frequency. At 90 days after sowing, stored organic manure suppressed the survival of F. verticillioides, which reduced the F. verticillioides incidence percent. These results were similar to the effect of herbicides-and insecticide-treated plots demonstrated, which show a significant decrease in F. verticillioides incidence rates. Mycological analysis on symptomless kernels revealed a higher % of pathogen infection in opened husks variety (Balady) than closed husks variety (SC10). Compared with stored organic manure, the stem borer incidence and lodging percentage were the highest in fresh organic manure plots. Finally, these results demonstrated that storing organic manure within five to six months as farmyard manure led to high-temperature centigrade within organic manure, thereby destroying spores of F. verticillioides, whereas fresh organic manure did not.

Foliar spray of silica improved water stress tolerance in rice (Oryza sativa L.) cultivars

Rice (Oryza sativa L.) is a major cereal crop and a staple food across the world, mainly in developing countries. Drought is one of the most important limiting factors for rice production, which negatively affects food security worldwide. Silica enhances antioxidant activity and reduces oxidative damage in plants. The current study evaluated the efficiency of foliar spray of silica in alleviating water stress of three rice cultivars (Giza178, Sakha102, and Sakha107). The seedlings of the three cultivars were foliar sprayed with 200 or 400 mg l^-1 silica under well-watered [80% water holding capacity (WHC)] and drought-stressed (40% WHC)] conditions for two summer seasons of 2019 and 2020. The obtained results demonstrated that drought stress caused significant decreases in growth, yield, and physiological parameters but increases in biochemical parameters (except proline) of leaves in all rice cultivars compared to well-irrigated plants (control). The roots of drought-stressed seedlings exhibited smaller diameters, fewer numbers, and narrower areas of xylem vessels compared to those well-watered. Regardless of its concentration, the application of silica was found to increase the contents of photosynthetic pigments and proline. Water relation also increased in seedlings of the three tested rice cultivars that were treated with silica in comparison to their corresponding control cultivars when no silica was sprayed. Foliar application of 400 mg l^-1 silica improved the physiological and biochemical parameters and plant growth. Overall, foliar application of silica proved to be beneficial for mitigating drought stress in the tested rice cultivars, among which Giza178 was the most drought-tolerant cultivar. The integration of silica in breeding programs is recommended to improve the quality of yield and to provide drought-tolerant rice cultivars under drought-stress conditions.

Exogenous naphthaleneacetic acid alleviated alkalinity-induced morpho-physio-biochemical damages in Cyperus esculentus L. var. sativus Boeck

Cyperus esculentus L. var. sativus Boeck (commonly called Chufa) is a perennial species that produces nutritious underground tubers and contributes to the diet and health of human worldwide. However, it is salt-sensitive and its adaptation to salinity stress remains an enigma. Naphthaleneacetic acid (NAA) plays a vital role in regulating plant salt stress tolerance. Thus, we aimed to investigate the impact of NAA (150 mg/L) application on growth and physio-biochemical response mechanisms of Chufa plants to different levels of salinity stress (0-, 90-, and 180 mM of alkaline stress ([1:1 ratio of Na₂CO₃ and NaHCO₃]). In response to increasing stress levels, shoot-root growth decreased, whereas malondialdehyde (MDA), hydrogen peroxide (H₂O₂), osmolytes (soluble protein, proline, and soluble sugars), and activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) significantly increased. Alkalinity led to significant increase in Na⁺ and Cl^-, but decrease in Mg²⁺ concentration in both roots and leaves; however, K⁺ decreased significantly in leaves under both stresses. Additionally, NO 3 - and. levels, nitrate reductase (NR) activities, and glutamate synthase (GOGAT) decreased significantly. However, glutamine synthetase (GS) increased non-significantly at 90 mM but declined at 180 mM. Foliar NAA application reduced Na⁺ and Cl^-, MDA, and H₂O₂ but increased photosynthetic pigments, K⁺ and Mg²⁺, osmolytes, nitrogen (N) metabolism, and upregulating the enzymatic antioxidant system to reduce oxidative stress under alkaline conditions. Hence, our findings manifest that NAA application is an effective strategy that can be utilized to enhance tolerance of chufa plants to alkaline stress. Future studies should explore whether NAA can positively alter the nutrient composition of chufa tubers at deeper molecular levels, which might offer solutions to nutritious problems in developing countries.

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.