Exploring the Antimicrobial, Antioxidant, and Antiviral Potential of Eco-Friendly Synthesized Silver Nanoparticles Using Leaf Aqueous Extract of Portulaca oleracea L.

Herein, the prospective applications of green fabricated silver nanoparticles (Ag-NPs) within the biomedical field were investigated. The leaf aqueous extract of Portulaca oleracea L., a safe, cheap, and green method, was used to fabricate Ag-NPs. The maximum plasmon resonance of synthesized NPs has appeared at 420 nm. The various biomolecules present in the plant extract to assemble spherical Ag-NPs with sizes of 5-40 nm were analyzed using Fourier transform infrared and transmission electron microscopy. The Ag was the major content of the formed Ag-NPs with an atomic percent of 54.95% and weight percent of 65.86%, as indicated by EDX. The crystallographic structure of synthesized NPs was confirmed by the diffraction of the X-ray. The dynamic light scattering exhibits the homogeneity and mono-dispersity nature with a polydispersity index of 0.37 in the colloidal fluid and a zeta potential value of -36 mV. The synthesized Ag-NPs exhibited promising antimicrobial efficacy toward various prokaryotic and eukaryotic pathogenic microorganisms with low MIC values of 12.5 µg mL-1 and 6.25 µg mL-1, respectively. Additionally, the P. oleracea-formed Ag-NPs showed optimistic antioxidant activity assessed by DPPH and H2O2 assay methods with the highest scavenging percentages of 88.5 ± 2.3% and 76.5 ± 1.7%, respectively, at a concentration of 200 µg mL-1. Finally, the biosynthesized Ag-NPs showed high antiviral properties toward the hepatitis A virus and Cox-B4 with inhibition percentages of 79.16 ± 0.5% and 73.59 ± 0.8%, respectively. Overall, additional research is essential to explore the Ag-NP-based aqueous extract of P. oleracea for human health. In the current investigation the use of synthesized Ag-NPs as antimicrobial, antioxidant, and antiviral agents to protect against pathogenic microbes, degenerative diseases caused by various oxidative stresses, and deadly viruses is recommended.

Synthesis, Optimization, and Characterization of Cellulase Enzyme Obtained from Thermotolerant Bacillus subtilis F3: An Insight into Cotton Fabric Polishing Activity.

The efficacy of 40 bacterial isolates obtained from hot spring water samples to produce cellulase enzymes was investigated. As a result, the strain Bacillus subtilis F3, which was identified using traditional and molecular methods, was selected as the most potent for cellulase production. Optimization was carried out using one-factor-at-a-time (OFAT) and BOX-Behnken Design to detect the best conditions for the highest cellulase activity. This was accomplished after an incubation period of 24 h at 45°C and pH 8, with an inoculum size of 1% (v/v), 5 g/l of peptone as nitrogen source, and 7.5 g/l of CMC. Moreover, the best concentration of ammonium sulfate for cellulase enzyme precipitation was 60% followed by purification using a dialysis bag and Sephadex G-100 column chromatography to collect the purified enzyme. The purified cellulase enzyme was characterized by 5.39-fold enrichment, with a specific activity of 54.20 U/mg and a molecular weight of 439 kDa. There were 15 amino acids involved in the purified cellulase, with high concentrations of 160 and 100 mg/l for glycine and proline respectively. The highest stability and activity of the purified cellulase was attained at pH 7 and 50°C in the presence of 150 ppm of CaCl2, NaCl, and ZnO metal ions. Finally, the biopolishing activity of the cellulase enzyme, as indicated by weight loss percentages of the cotton fabric, was dependent on concentration and treatment time. Overall, the thermotolerant B. subtilis F3 strain has the potential to provide highly stable and highly active cellulase enzyme for use in biopolishing of cotton fabrics.

Exploring genotypic variability and interrelationships among growth, yield, and quality characteristics in diverse tomato genotypes.

Tomato is the most consumed vegetable crop worldwide, with excellent beneficial health properties and high content of vitamins, minerals, carotenoids, total antioxidants, and phenolic compounds. Hence, improving its genotypes is crucial to sustain its production and ensure food security, principally under the fast-growing worldwide population and abrupt global climate change. The present study aimed to explore the genotypic variability associated with specific characteristics in twenty-five diverse tomato genotypes. In addition, the relationships between growth, yield, and quality traits using both univariate (correlation coefficient, path analysis) and multivariate (principal component, principal coordinates, canonical variate) analysis methods were explored. The results indicated that the evaluated genotypes possessed highly significant variation. This is appropriate for future hybridization through tomato breeding programs. All evaluated genotypes demonstrated considerable potential to develop strong hybrid vigour for growth, yield, and quality characteristics. In particular, the genotypes LS009, LS011, and LS014 could be considered promising, high-yielding, and resistant to yellow leaf curl virus infestation (YLCV) disease parents for future breeding schemes. The number of fruits per plant, fruit diameter, and fruit weight proved strong positive relationships with fruit yield. Accordingly, these characteristics demonstrate their importance in improving fruit yield and could be exploited as indirect criteria for selecting high-yielding tomato genotypes through breeding programs.

Characterization of Some Cichorium Taxa Grown under Mediterranean Climate Using Morphological Traits and Molecular Markers.

The verification of taxonomic identities is of the highest significance in the field of biological study and categorization. Morpho-molecular characterization can clarify uncertainties in distinguishing between taxonomic groups. In this study, we characterized five local taxa of the genus Cichorium using morphological and molecular markers for taxonomic authentication and probably future genetic improvement. The five Cichorium taxa grown under the Mediterranean climate using morphological traits and molecular markers showed variations. The examined taxa showed a widespread range of variations in leaf characteristics, i.e., shape, type, texture, margin, and apex and cypsela characteristics i.e., shape, color, and surface pattern. The phylogenetic tree categorized the Cichorium intybus var. intybus and C. intybus var. foliosum in a single group, whereas C. endivia var. endivia was grouped separately. However, C. endivia var. crispum and C. endivia subsp. pumilum were classified as a cluster. The recorded variance between classes using the molecular markers SCoT, ISSR, and RAPD was documented at 34.43%, 36.62%, and 40.34%, respectively. Authentication using molecular tools proved the usefulness of a dichotomous indented key, as revealed by morphological identification. The integrated methodology using morphological and molecular assessment could support improved verification and authentication of the various taxa of chicory. It seems likely that the Egyptian chicory belongs to C. endivia subsp. pumilum.

Postharvest physiology and biochemistry of Valencia orange after coatings with chitosan nanoparticles as edible for green mold protection under room storage conditions.

Because of their unique features, nanomaterials have been proposed and have gained acceptance in postharvest applications in fruit. Increasing the storage life and improving the quality of Valencia oranges was investigated using nano-chitosan. A chitosan nanoparticle was prepared by using high-energy ball milling. Chitosan nanoparticles were characterized by Dynamic light scattering, FTIR spectroscopy and Surface morphology by transmission electron microscopy. Fully mature Valencia oranges were harvested and then coated with one of these concentrations (0.2, 0.4, and 0.8% nano-chitosan) and control. The fruits were stored under room storage conditions for 75 days. The quality parameters (fruit weight losses, fruit decay percentage, fruit firmness, total acidity, total soluble solids percentage and T.S.S./acid ratio, ascorbic acid content) were taken in biweekly intervals after 0, 15, 30, 45, 60, and 75 days. Beside the in vitro testing of antifungal activity of chitosan nanoparticles. According to the findings of the two succeeding seasons, the nano-chitosan 0.8% treatment showed the best effects and had the lowest rate of fruit weight loss, fruit deterioration, and T.S.S./acid ratio in comparison to the other treatments in both seasons. Furthermore, the 0.8% nano-chitosan reveled the highest levels of fruit hardness and fruit pulp firmness. Fruit weight loss, fruit deterioration, TSS, and TSS/acid ratio, as well as other metrics, were steadily elevated prior to the storage time. The best results were obtained when Valencia oranges fruits were treated with 0.8% nano-chitosan for 75 days at room temperature.

Magnetic Iron-Improved Growth, Leaf Chemical Content, Yield, and Fruit Quality of Chinese Mandarin Trees Grown under Soil Salinity Stress.

Chinese mandarin fruits are an inexpensive and rich source of vitamin C. They have potential benefits in treating acute respiratory infections and mitigating inflammation in critical patients with COVID-19. In Egypt, citrus is the most important fruit tree but is sensitive to salinity stress, resulting in poor vegetative tree growth and reductions in productivity and fruit quality. Magnetic iron has emerged as a promising approach in the citrus tree industry, since it improves vegetative growth, yield, and fruit quality and alleviates salinity stress in Chinese mandarin trees grown in soils suffering from high salt stress. This research is aimed at studying the influence of adding magnetic iron (as soil treatment) on tree canopy growth, yield, and fruit quality of 'Chinese' mandarin trees. Therefore, the treatments were as follows: 0, 250, 500, and or 750 g of magnetic iron.tree-1. Our results indicated that all applications of magnetic iron significantly improved tree canopy volume, leaf total chlorophyll, relative water content, yield (kg.tree-1), and the fruit physical and chemical characteristics of Chinese mandarin. In contrast, leaf Na and Cl content, (%), proline, and total phenolic content were decreased by magnetic iron soil treatments. In respect to vegetative growth, our results indicated that adding magnetic iron at the concentration 750 g.tree-1 caused the best values of tree canopy volume. A similar trend was noticed regarding yield. The increase in yield attained was nearly 19%; the best values were obtained when magnetic iron were used at 750 g.tree-1. In conclusion, the application of magnetic iron can lead to improved fruit production and fruit quality of Chinese mandarin trees grown in salinity stress conditions.

Effects of Plant-Growth-Promoting Rhizobacteria (PGPR) and Cyanobacteria on Botanical Characteristics of Tomato (Solanum lycopersicon L.) Plants.

Tomatoes are an important agricultural product because they contain high concentrations of bioactive substances, such as folate, ascorbate, polyphenols, and carotenoids, as well as many other essential elements. As a result, tomatoes are thought to be extremely beneficial to human health. Chemical fertilizers and insecticides are routinely utilized to maximize tomato production. In this context, microbial inoculations, particularly those containing PGPR, may be utilized in place of chemical fertilizers and pesticides. In this study, we investigated the effects of PGPR (Bacillus subtilis, and Bacillus amyloliquefaciens) and cyanobacteria when utilized alone, and in conjunction with each other, on the growth, quality, and yield of fresh fruits of tomato plants. The results showed that the inoculation significantly increased all measured parameters of tomato plants compared with the control. Combined use of B. subtilis and B. amyloliquefaciens had a positive impact on tomato yield, increasing fruit yield. Moreover, leaflet anatomical characteristics were altered, with increased thickness of the upper epidermis, lower epidermis, palisade tissue, spongy tissue, and vascular bundles. Tomato fruit quality was improved, as measured by an increased number of fruit per plant (76% increase), fruit weight (g; 33% increase), fruit height (cm; 50% increase), fruit diameter (cm; 50%), total soluble solids (TSS; 26% increase), and ascorbic acid (mg/100 g F.W.; 75% increase), relative to the control, in the first season. In addition, fruit chemical contents (N, P, and K) were increased with inoculation. The results suggest that inoculation with B. subtilis and B. amyloliquefaciens could be successfully used to enhance tomato plant growth and yield.

Trehalose-Induced Regulations in Nutrient Status and Secondary Metabolites of Drought-Stressed Sunflower (Helianthus annuus L.) Plants.

Trehalose regulates key physio-biochemical parameters, antioxidants, and the yield of plants exposed to a dry environment. A study was conducted to assess the regulatory roles of exogenously applied trehalose in drought-stressed sunflower plants. Two cultivars of sunflowers (Hysun 33 and FH 598) were subjected to drought stress (60% field capacity) and varying (0, 10, 20, and 30 mM) concentrations of trehalose. The data indicated that water stress significantly reduced the shoot length, root length, total soluble proteins, shoot Ca2+, root P, relative water content (RWC), and achene yield per plant. The foliar spray of trehalose was effective at improving plant growth, RWC, total soluble proteins, total soluble sugars, the activities of enzymatic antioxidants, Ca2+ (shoot and root), root K+, and the yield attributes. Exogenously supplemented trehalose considerably suppressed relative membrane permeability (RMP), but did not alter ascorbic acid, malondialdehyde, the total phenolics, shoot K+, or P (shoot and root) in both sunflower cultivars. The cv. Hysun 33 had better ascorbic acid, total soluble sugars, non-reducing sugars, shoot P, and root P than the other cultivar, whereas cv. FH 598 was relatively better at regulating RMP, malondialdehyde, peroxidase, and root Ca2+ concentration. Overall, exogenously supplemented trehalose, particularly at 10 mM, was effective at improving the physiochemical parameters and yield of sunflower plants under stress conditions. Therefore, a better performance of sunflower cv. Hysun 33 under drought stress can be suggested as a trehalose-induced enhancement of yield and oxidative defense potential.

Hydrogel Improved Growth and Productive Performance of Mango Trees under Semi-Arid Condition.

Nowadays, the production of new mango cultivars is increased in many countries worldwide. The soil application of hydrogel represents a novel approach in the fruit trees industry. This investigation aims to study the effect of adding hydrogel (as soil conditioner) on the growth and yield of Shelly cv. mango trees. The experimental groups were assigned to a control group and three other treated groups, including 250, 500, or 750 g hydrogel∙tree-1. The results demonstrated that all applications of hydrogel composite had higher vegetative growth parameters, yield, and fruit quality characteristics of Shelly cv. mango trees compared to the control. The treatment of 750 g hydrogel∙tree-1 had higher values of vegetative growth parameters such as the leaf area, shoot length and tree canopy volume, compared to the control group and the other treatments. Similarly, higher values for yield and fruit quality were observed in the treatment of 750 g hydrogel∙tree-1. In conclusion, different amounts of hydrogel agent can improve the production and fruit quality of Shelly cv. mango trees in arid and semi-arid conditions in a dose-dependent manner.

Improving Winter Wheat Photosynthesis, Nitrogen Use Efficiency, and Yield by Optimizing Nitrogen Fertilization.

Wheat is the third most producing crop in China after maize and rice. In order to enhance the nitrogen use efficiency (NUE) and grain yield of winter wheat, a two-year field experiment was conducted to investigate the effect of different nitrogen ratios and doses at various development stages of winter wheat (Triticum aestivum L.). A total of five N doses (0, N75, N150, N225, and N300 kg ha-1) as main plots and two N ratios were applied in split doses (50%:50% and 60%:40%, referring to 50% at sowing time and 50% at jointing stage, 50% at sowing time + 50% at flowering stage, 50% at sowing time + 50% at grain filling stage, and 60% + 40% N ratio applied as a 60% at sowing time and 40% at jointing stage, 60% at sowing time and 40% at flowering stage, and 60% at sowing time and 40% at grain filling stage in subplots). The results of this study revealed that a nitrogen dose of 225 kg ha-1 significantly augmented the plant height by 27% and above ground biomass (ABG) by 24% at the grain filling stage, and the leaf area was enhanced by 149% at the flowering stage under 60 + 40% ratios. Furthermore, the N225 kg ha-1 significantly prompted the photosynthetic rate by 47% at the jointing and flowering stages followed by grain filling stage compared to the control. The correlation analysis exhibited the positive relationship between nitrogen uptake and nitrogen content, chlorophyll, and dry biomass, revealing that NUE enhanced and ultimately increased the winter wheat yield. In conclusion, our results depicted that optimizing the nitrogen dose (N225 kg/ha-1) with a 60% + 40% ratio at jointing stage increased the grain yield and nitrogen utilization rate.

Genetic Diversity, Analysis of Some Agro-Morphological and Quality Traits and Utilization of Plant Resources of Alfalfa.

Alfalfa (Medicago sativa L.) is one of the most important perennial forage crops to build effective diets for livestock producers. Forage crop improvement depends largely on the availability of diverse germplasms and their efficient utilization. The present investigation was conducted at Ismailia Agricultural Research Station to assess twenty-one alfalfa genotypes for yield components, forage yield and quality traits during 2019/2020 and 2020/2021. The genotypes were evaluated in field experiments with three replicates and a randomized complete block design, using analysis of variance, estimate of genetic variability, estimate of broad sense heritability (hb2) and cluster analysis to identify the inter relationships among the studied genotypes as well as principal component analysis (PCA) to explain the majority of the total variation. Significant differences were found among genotypes for all studied traits. The general mean of the studied traits was higher in the second year than the first year. Moreover, the combined analysis showed highly significant differences between the two years, genotypes and the year × gen. interaction for the traits studied. The genotype F18 recorded the highest values for plant height, number of tiller/m2, total fresh yield and total dry yield, while, the genotype F49 ranked first for leaf/stem ratio. The results showed highly significant variation among the studied genotypes for crude protein %, crude fiber % and ash %. Data revealed that the genotypes P13 and P5 showed the highest values for crude protein %, whereas, the genotype F18 recorded the highest values for crude fiber % and ash content. The results revealed high estimates of genotypic coefficient and phenotypic coefficient of variation (GCV% and PCV%) with high hb2, indicating the presence of genetic variability and effective potential selection for these traits. The cluster analysis exhibited considerable genetic diversity among the genotypes, which classified the twenty one genotypes of alfalfa into five sub-clusters. The genotypes F18, F49, K75, S35, P20, P5 and P13 recorded the highest values for all studied traits compared with other clusters. Furthermore, the PC analysis grouped the studied genotypes into groups and remained scattered in all four quadrants based on all studied traits. Ultimately, superior genotypes were identified can be utilized for crop improvement in future breeding schemes.

Assessment of Pharmacological Potential of Novel Exopolysaccharide Isolated from Marine Kocuria sp. Strain AG5: Broad-Spectrum Biological Investigations.

With more than 17 clinically approved Drugs and over 20 prodrugs under clinical investigations, marine bacteria are believed to have a potential supply of innovative therapeutic bioactive compounds. In the current study, Kocuria sp. strain AG5 isolated from the Red Sea was identified and characterized by biochemical and physiological analysis, and examination of a phylogenetic 16S rRNA sequences. Innovative exopolysaccharide (EPS) was separated from the AG5 isolate as a major fraction of EPS (EPSR5, 6.84 g/L-1). The analysis of EPSR5 revealed that EPSR5 has a molecular weight (Mw) of 4.9 × 104 g/mol and number average molecular weight (Mn) of 5.4 × 104 g/mol and contains sulfate (25.6%) and uronic acid (21.77%). Analysis of the monosaccharide composition indicated that the EPSR5 fraction composes of glucose, galacturonic acid, arabinose, and xylose in a molar ratio of 2.0:0.5:0.25:1.0, respectively. Assessment of the pharmacological potency of EPSR5 was explored by examining its cytotoxicity, anti-inflammatory, antioxidant, and anti-acetylcholine esterase influences. The antioxidant effect of EPSR5 was dose- and time-dependently increased and the maximum antioxidant activity (98%) was observed at 2000 µg/mL after 120 min. Further, EPSR5 displayed a significant repressive effect regarding the proliferation of HepG-2, A-549, HCT-116, MCF7, HEP2, and PC3 cells with IC50 453.46 ± 21.8 µg/mL, 873.74 ± 15.4 µg/mL, 788.2 ± 32.6 µg/mL, 1691 ± 44.2 µg/mL, 913.1 ± 38.8 µg/mL, and 876.4 ± 39.8 µg/mL, respectively. Evaluation of the inhibitory activity of the anti-inflammatory activity of EPSR5 indicated that EPSR5 has a significant inhibitory activity toward lipoxygenase (5-LOX) and cyclooxygenase (COX-2) activities (IC50 15.39 ± 0.82 µg/mL and 28.06 ± 1.1 µg/mL, respectively). Finally, ESPR5 presented a substantial hemolysis suppressive action with an IC50 of 65.13 ± 0.89 µg /mL, and a considerable inhibitory activity toward acetylcholine esterase activity (IC50 797.02 µg/mL). Together, this study reveals that secondary metabolites produced by Kocuria sp. strain AG5 marine bacteria serve as an important source of pharmacologically active compounds, and their impact on human health is expected to grow with additional global work and research.

Integrative Application of Foliar Yeast Extract and Gibberellic Acid Improves Morpho-Physiological Responses and Nutrient Uptake of Solidago virgaurea Plant in Alkaline Soil.

Alkaline soils have fertility issues due to poor physical qualities, which have a negative impact on crop growth and output. Solidago is used in flower arrangements, bouquet filler, and traditional medicine. The possible biological fertilizers' eco-friendly and cost-effective nature favours farmers because of the vital role in soil productivity and environmental sustainability. A field experiment was performed during two successive seasons to explore the effect of applying yeast extract (YE) at (0, 0.5, 1.0, and 1.5 g/L) and/or gibberellic acid (GA3) at (control, 100, 200, and 300 ppm) on the morpho-physiological parameters, macronutrients, and biochemical constituents of Solidago virgaurea. The results emphasize that YE (1.5 g/L) and/or GA3 (300 ppm) treatments show the highest significant increase in plant growth (i.e., plant height, no. of branches, fresh and dry weight of shoots); photosynthetic efficiency (i.e., chlorophyll (a), chlorophyll (b) and total carotenoids); macronutrient content (i.e., N, P, and K); and biochemical constituents (i.e., total soluble sugars, total phenolic, total flavonoids, and total glycosides). The study results recommend using YE and GA3 in combination at concentrations of 1.5 g/L and 300 ppm, respectively, to improve Solidago production sustainability under alkaline soil conditions.

Antimicrobial, Antiviral, and In-Vitro Cytotoxicity and Mosquitocidal Activities of Portulaca oleracea-Based Green Synthesis of Selenium Nanoparticles.

The aqueous extract of Portulaca oleracea was used as a biocatalyst for the reduction of Na2SeO3 to form Se-NPs that appeared red in color and showed maximum surface plasmon resonance at a wavelength of 266 nm, indicating the successful Phyto-fabrication of Se-NPs. A FT-IR chart clarified the role of plant metabolites such as proteins, carbohydrates, and amino acids in capping and stabilizing Se-NPs. TEM, SAED, and XRD analyses indicated the formation of spherical, well-arranged, and crystalline Se-NPs with sizes in the range of 2-22 nm. SEM-EDX mapping showed the maximum peaks of Se at 1.4, 11.3, and 12.4 KeV, with weight and atomic percentages of 36.49 and 30.39%, respectively. A zeta potential of -43.8 mV also indicated the high stability of the synthesized Se-NPs. The Phyto-synthesized Se-NPs showed varied biological activities in a dose-dependent manner, including promising activity against pathogenic bacteria and Candida species with varied MIC values in the range of 12.5-50 µg·mL-1. Moreover, the Se-NPs showed antiviral activity toward HAV and Cox-B4, with percentages of 70.26 and 62.58%, respectively. Interestingly, Se-NPs showed a target orientation to cancer cell lines (HepG2) with low IC50 concentration at 70.79 ± 2.2 µg·mL-1 compared to normal cell lines (WI-38) with IC50 at165.5 ± 5.4 µg·mL-1. Moreover, the as-formed Se-NPs showed high activity against various instar larvae I, II, III, and IV of Culex pipiens, with the highest mortality percentages of 89 ± 3.1, 73 ± 1.2, 68 ± 1.4, and 59 ± 1.0%, respectively, at 50 mg L-1. Thus, P. oleracea-based Se-NPs would be strong potential antimicrobial, anti-viral, anti-cancer, and anti-insect agents in the pharmaceutical and biomedical industries.

The Binary Mixtures of Lambda-Cyhalothrin, Chlorfenapyr, and Abamectin, against the House Fly Larvae, Musca domestica L.

The house fly Musca domestica L. is one of the medical and veterinary pests that can develop resistance to different insecticides. Mixing insecticides is a new strategy for accelerating pest control; furthermore, it can overcome insect resistance to insecticides. This study aims to evaluate three insecticides, chlorfenapyr, abamectin, and lambda-cyhalothrin, individually and their binary mixtures against 2nd instar larvae of M. domestica laboratory strain. Chlorfenapyr exhibited the most toxic effect on larvae, followed by abamectin then the lambda-cyhalothrin. The half-lethal concentrations (LC50) values were 3.65, 30.6, and 94.89 ppm, respectively. These results revealed that the high potentiation effect was the mixture of abamectin/chlorfenapyr in all the mixing ratios. In contrast, the tested combination of lambda-cyhalothrin/abamectin showed an antagonism effect at all mixing ratios against house fly larvae. The total protein, esterases, glutathione-S-transferase (GST), and cytochrome P-450 activity were also measured in the current investigation in the larvae treated with chlorfenapyr. Our results indicate that GST may play a role in detoxifying chlorfenapyr in M. domestica larvae. The highest activity of glutathione-S-transferase was achieved in treated larvae with chlorfenapyr, and an increase in cytochrome P-450 activity in the larvae was observed post-treatment with Abamectin/chlorfenapyr.

Growth Regulators Improve Outcrossing Rate of Diverse Rice Cytoplasmic Male Sterile Lines through Affecting Floral Traits.

Cytoplasmic male sterility (CMS) provides an irreplaceable strategy for commercial exploitation of heterosis and producing high-yielding hybrid rice. The exogenous application of plant growth regulators could improve outcrossing rates of the CMS lines by affecting floral traits and accordingly increase hybrid rice seed production. The present study aimed at exploring the impact of growth regulators such as gibberellic acid (GA3), indole-3-acetic acid (IAA), and naphthalene acetic acid (NAA) on promoting floral traits and outcrossing rates in diverse rice CMS lines and improving hybrid rice seed production. The impact of foliar applications of growth regulators comprising GA3 at 300 g/ha or GA3 at 150 g/ha + IAA at 50 g/ha + NAA at 200 g/ha versus untreated control was investigated on floral, growth, and yield traits of five diverse CMS lines. The exogenously sprayed growth regulators, in particular, the combination of GA3, IAA, and NAA (T3) boosted all studied floral, growth, and yield traits in all tested CMS lines. Moreover, the evaluated CMS lines exhibited significant differences in all measured floral traits. L2, L3, and L1 displayed the uppermost spikelet opening angle, duration of spikelet opening, total stigma length, style length, stigma brush, and stigma width. In addition, these CMS lines exhibited the highest plant growth and yield traits, particularly under T3. Consequently, exogenous application of GA3, IAA, and NAA could be exploited to improve the floral, growth, and yield traits of promising CMS lines such as L2, L3, and L1, hence increasing outcrossing rates and hybrid rice seed production.