Germination Percentage Research Articles

Genetic Variation for Tolerance to High Temperatures in Tomato Using Critical Sterility Temperature

Tomato (Solanum lycopersicum L.) reproduction is influenced by temperature, prominently impacting yield. The ideal daytime range is between 25°C and 30°C and the nighttime temperature is around 20°C for tomato and deviations of a few degrees from these temperatures can have negative effects. The study assessed the effect of temperature on tomato pollen germination and aimed to ascertain the critical sterility temperature for pollen germination. In an open field, pollen from 10 genotypes (Anagha, Manuprabha, Vellayani Vijay, Akshaya, Nandi, IIHR26372, Pusa Rohini, Arka Saurabh, Arka Rakshak, and Arka Vikas) underwent In-vitro temperature exposure ranging from 32 to 40°C at 2°C intervals. Variations in In-vitro pollen germination percentage were observed across the genotypes, notably revealing a sharp decline after 36°C. This decline indicated a pivotal shift in pollen germination and viability. Genotypes, Anagha and Arka Saurabh, were identified as temperature tolerant and susceptible, respectively. The findings present an opportunity to incorporate temperature-dependent pollen response functions and identified genotypes into tomato breeding programs, offering significant implications for enhancing yield under varying temperature conditions.

Effect of pre-sowing treatments on seed germination and postgerminative seedling growth of acacia angustissima (mill.)

Seeds of Acacia angustissima were subjected to a control and five pre-sowing (soaking in cold water for 24 hours, soaking in hot water (100° C) for 5 minutes, immersion in 60 % H2SO4 for 30 seconds, immersion in 60 % H2SO4 for 5 minutes, and immersion in 60 % H2SO4 for 15 minutes) treatments. The number of seeds that sprouted was recorded daily for calculation of germination indices. When there had been no further germination in any of the treatments for four weeks, the height, number of leaves, number of leaflets, and root length of seedlings were determined. One-way analysis of variance was used to test the effects of the pre-sowing treatments on seed germination and seedling growth. Final Germination Percentage, Germination Rate Index, and Seedling Vigour Index were significantly higher in the warm water than other five treatments which displayed similar responses of the traits. Similar, the warm water pre-treatment resulted in the longest seedlings, when shoot height and / or root length was considered. There was no significant effect of treatment on Mean Germination Time, number of leaves, and number of leaflets. The findings suggest that hot water pre-sowing treatment is the most suitable for seed germination and initial seedling height attainment of Acacia angustissima.

Effects of Drought Stress on Germination and Seedling Growth of Seed Primed with Boron in Spinach

This study aimed to examine the effects of seed priming with different boron concentrations on the germination and seedling growth of spinach under drought-stress conditions. Seeds of the spinach cultivar Matador and sodium borate (Na2B8O13.4H2O) were used as materials. The seeds were primed with 0 (distilled water), 1, 10, 100, 500, and 1000 ppm B for 24 hours, with unprimed seeds serving as a control. Drought stress was induced by polyethylene glycol (PEG 6000) solution at a water potential of -3 bar and distilled water denoted as control conditions. A standard germination test was performed between papers at 20°C for 14 days. The germination percentage, mean germination time, germination index, seedling growth parameters, and root/shoot length ratio were investigated. The findings revealed that drought stress reduced germination percentage, germination index, and seedling growth of unprimed seeds of spinach. However, boron priming improved these parameters while mitigating the negative effects of drought stress. Under drought conditions, seed priming with 1 ppm B shortened mean germination time. Similarly, seedling fresh and dry weight of spinach were improved by seed priming with 100-1000 ppm B, whereas root growth was stimulated by 10 ppm B. The highest root/shoot ratio was found at 10 ppm B. Boron priming was more efficient in promoting seedling growth than germination in spinach. As a result, seed priming with 10-100 ppm B should be recommended to improve the germination and seedling growth performance of spinach in the event of drought stress after planting.

Impact of dielectric barrier discharge plasma and plasma-activated water on cotton seed germination and seedling growth

Unfavorable environmental conditions during planting can reduce seed germination and hinder seedling growth. To address this issue, manufacturers are exploring innovative and cost-effective methods, such as cold plasma discharge. This simple, low-cost, and efficient physical technique induces significant biological responses in seeds and plants without the use of traditional, environmentally hazardous chemicals. This study investigated the impact of dielectric barrier discharge (DBD) plasma and plasma-activated water (PAW), produced by gliding arc plasma, on the germination and seedling growth of My344 cotton seeds. The seeds were pre-treated with 80 W of DBD plasma for 0, 1, 2, and 3 min, and subsequently soaked for 90 min in PAW with varying pH levels of 5.82, 3.88, 3.63, and 3.38. The results showed that plasma treatment positively influenced seed germination and seedling growth. The highest germination percentage (98.89 %) was observed with 1 min of DBD treatment, followed by PAW priming at pH levels of 3.63 and 3.38. Additionally, a 3-min DBD treatment followed by soaking in PAW with a pH of 3.63 led to significant increases in stem length (76.76 %), root length (48.77 %), and wet weight (76.44 %). Furthermore, it was observed that the electrical conductivity of the seeds in all groups decreased significantly with increased PAW acidity. The physical and chemical effects of cold DBD plasma on the seed surface, as well as changes in hydrophilicity, were further examined using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and water contact angle imaging.

Physiological quality of green corn seeds under water stress conditions

This study aimed to evaluate the physiological quality of green corn seeds subjected to water stress. The experimental design used was completely randomized, in a 2 x 5 factorial arrangement, consisting of two corn hybrids (AG1051 and BRS3046) and five osmotic potentials (0; -0.4; -0.8; -1.2 and – 1.6 MPa) simulated with aqueous solutions of polyethylene glycol 6000 (PEG 6000), with four replications of 50 seeds per treatment, totaling 40 experimental units. The analyzed variables were: water content, germination, root protrusion, final root protrusion, germination speed index, root length and coleoptile length. There was a significant effect of the interaction between hybrid factors and osmotic potentials for all analyzed variables, except for final root protrusion, which showed an isolated effect for the two factors studied. The results obtained indicated a higher percentage of germination and initial development of green corn seedlings for green corn seeds, hybrids AG1051 and BRS3046 at the osmotic potential of 0.0 MPa. The germination and vigor of green corn seeds decrease under water stress conditions from the osmotic potential of -0.4 MPa induced by PEG 6000, inhibiting the development of normal seedlings, affecting seed viability. Hybrid AG1051 presents superior germination and vigor compared to BRS3046.

Changes in the fruits and seeds morphometric, germination, phytochemicals content, and antioxidant capacity in seed ripening of Echinocereus stramineus

Within the cacti family, most studies have focused on the physicochemical characterization of the stems, fruits, and seeds from Mammillaria, Opuntia, Hylocereus, and Stenocereus genera. However, few information is focused on the morphological and physicochemical characterization of the stems, fruits, and seeds of other genera widely distributed in the arid and semiarid zones of the Chihuahuan desert, such as the genus Echinocereus. The objective of this study was to analyze the fruit morphology, morphometry, germination process, and phytochemical content in four stages of seed in fruit ripening from E. stramineus. Morphometric parameters were measured by picking ten fruits and sixty seeds for each ripening stage. The characterization of the germination process included the germination percentage, mean germination time, germination speed, and mean germination speed which were computed 21 days after germination. The quantification of total phenols, flavonoids, tannins, reducing sugars, protein, and antioxidant activity of seeds was determined using colorimetric approaches under basal conditions. The morphometric results revealed a negative correlation between the fruit ripening stage and total mass (r= -0.980, p = 0.020), shell mass (r= -0.986, p = 0.014), pulp mass (r = -0.979, p = 0.021), fruit length (r = -0.978, p = 0.022), fruit width (r = -0.968, p = 0.032) and fruit area (r = -0.960, p = 0.04). The germination characterization process showed a negative association between the fruit ripening stage and the seed germination percentage (r = -0.979, p = 0.021) and between the seed mean germination time and the mean germination speed (r= -0.986, p = 0.014). The content of flavonoids, reducing sugars, proteins, and antioxidant capacity showed significant differences among the four stages of fruit ripening; however, no association was found between seed phytochemical content and the ripening stage. This study provides the first data on seed phytochemicals and information on the germination process of E. stramineus seeds.

Pre-Germinative Treatments and In Vitro Germination of Dianthus caryophyllus and Alstroemeria spp. Seeds

Alstroemeria spp. and carnation (Dianthus caryophyllus L.) have considerable and increasing economic importance in the floriculture market, therefore breeders carry out intense breeding programs to select new superior varieties. However, poor germination of hybrid seeds remains a bottleneck. Based on this assumption, seed pre-treatments and in vitro germination protocols, using different germination substrates, were applied in Alstroemeria spp. and carnation to improve germinability. Seed viability was tested using the 2,3,5-triphenyl tetrazolium chloride (TTC) test, and resulted in 91.10% ± 2.33 and 86.66% ± 3.85 in Alstroemeria and carnation, respectively. In Alstroemeria, pre-treatment with potassium nitrate (KNO3) in combination with modified ½ Murashige and Skoog (MS) medium ensured high germination uniformity combined with high germination percentage, showing significantly higher values than the control. In carnation, a suitable seed sterilization procedure was set up (up to 95.8% sterility); treatments with gibberellic acid (GA3) and KNO3 did not influence germination percentage compared to the control. A high multiplication rate of seedling lines was obtained on hormone-free MS medium.

Genome-Wide Association Study Reveals Loci and New Candidate Gene Controlling Seed Germination in Rice

Improving seed germination and seedling development can potentially increase crop yield and improve quality in direct-seeded rice. This study aimed to detect loci or genes associated with rice seed germination. We reported the phenotypic analysis of seed germination in 103 rice accessions across two years, and a genome-wide association study (GWAS) was conducted to identify loci underlying the genetic regulation of seed germination. A total of seven genetic loci were found to be associated with seed germination, including five loci that overlapped with the previously reported loci/genes, and two novel loci. Of these, two loci (qGP2 and qGP4.1) were stable across different environments. GP4 (Germination percentage 4), encoding a 9-cis-epoxycarotenoid dioxygenase, was identified as the candidate gene of the major locus qGP4.1. A sequence analysis of GP4 revealed that four functional polymorphic sites in the coding region were significantly associated with germination percentage. The disruption of GP4 by gene editing resulted in faster seed germination and seedling establishment. Taken together, we have identified GP4 as a novel gene involved in rice seed germination, and we provide a potential target gene for improving rice seed vigor via gene editing or molecular breeding.

Seed priming with graphene oxide improves salinity tolerance and increases productivity of peanut through modulating multiple physiological processes

Graphene oxide (GO), beyond its specialized industrial applications, is rapidly gaining prominence as a nanomaterial for modern agriculture. However, its specific effects on seed priming for salinity tolerance and yield formation in crops remain elusive. Under both pot-grown and field-grown conditions, this study combined physiological indices with transcriptomics and metabolomics to investigate how GO affects seed germination, seedling salinity tolerance, and peanut pod yield. Peanut seeds were firstly treated with 400 mg L⁻¹ GO (termed GO priming). At seed germination stage, GO-primed seeds exhibited higher germination rate and percentage of seeds with radicals breaking through the testa. Meanwhile, omics analyses revealed significant enrichment in pathways associated with carbon and nitrogen metabolisms in GO-primed seeds. At seedling stage, GO priming contributed to strengthening plant growth, enhancing photosynthesis, maintaining the integrity of plasma membrane, and promoting the nutrient accumulation in peanut seedlings under 200 mM NaCl stress. Moreover, GO priming increased the activities of antioxidant enzymes, along with reduced the accumulation of reactive oxygen species (ROS) in response to salinity stress. Furthermore, the differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) of peanut seedlings under GO priming were mainly related to photosynthesis, phytohormones, antioxidant system, and carbon and nitrogen metabolisms in response to soil salinity. At maturity, GO priming showed an average increase in peanut pod yield by 12.91% compared with non-primed control. Collectively, our findings demonstrated that GO plays distinguish roles in enhancing seed germination, mitigating salinity stress, and boosting pod yield in peanut plants via modulating multiple physiological processes.

Enhancement in Seed Germination through Pre-sowing Treatments in Cinnamomum glaucescens (Nees) Hand.-Mazz., A Native Tree of Eastern Himalaya, India

Cinnamomum glaucescens (Nees) Hand.-Mazz. belongs to family Lauraceae, is an aromatic evergreen tree, prized for its scented timber and fruits which are rich in essential oil commercially. The key challenges of forest establishment are indiscriminate collection methods of fruit and poor seed germination. The aim of this study was to enhance the germination response of C. glaucescens seeds to various pre-sowing treatments. The seeds were collected from mature and healthy trees and sixteen different pre-sowing seed treatments, arranged in a randomized complete block design in nursery bed were applied to analyse their effect on germination. Depulped seeds soaked in 4% hydrogen peroxide in dark for 12 hours significantly (P<.05) enhanced the germination percentage (66.67 %), peak value (0.55), germination value (0.31), germination speed (0.66) followed by seeds treated in 8% H2O2 with 60.56% germination, as compared to others. Therefore, it is suggested to use 4% hydrogen peroxide to promote seed germination rates, that could be useful to propagate C. glaucescens seedlings to satisfy the demands of planting stock.

The impact of chitosan nanoparticles on seedling and germination attributes and enzymatic activity of guar (Cyamopsis tetragonoloba L.) under osmotic stress

This research was conducted to examine the effects of nano chitosan particles on seed germination and seedling growth of guar (Cyamopsis tetragonoloba L.) under osmotic stress conditions. This experiment was conducted in a factorial layout based on a completely randomized design with two factors and four replications. The experimental factors included: osmotic stress at five levels (0, −3, −6, −9 and −12 bar) and seed priming with nano chitosan particles at five concentrations (0, 50, 100, 200, and 300 ppm). The evaluated parameters in this study were alometric traits and enzymatic activities including proline, catalase, ascorbate peroxidase, superoxide dismutase, and total soluble sugar, as well as the content of chlorophyll a, b, and carotenoids. The results indicated the significant effect of most of the studied quantitative and qualitative traits. The highest values of seedling, plumule and radicle length (48.20, 17.79 and 30.15 mm, respectively), and the fresh weight of seedlings and plumule (0.9743 and 0.9192 g, respectively) were observed at a concentration of 200 ppm of chitosan nanoparticles. The highest amount of all studied parameters observed under non-stress conditions (control), and the lowest values of them obtained in −12 bar of osmotic stress. Furthermore, by increasing of osmotic stress levels, germination percentage and rate and seed vigor showed a decreasing trend about 56, 83 and 95% compared to the control. Besed on the interaction effects, the maximum values of seedling and plumule length were achieved with the application of 200 ppm chitosan nanoparticles in combination with no osmotic stress. Under non-osmotic conditions, concentrations of 300, 100, and 200 ppm chitosan led to the highest values of germination percentage and rate and seed vigor, respectively. Additionally, the highest percentage of normal seedlings (94%) and the lowest percentage of abnormal seedlings (zero) were obtained under the application of 200 ppm of nano chitosan and no osmotic stress. In relation to qualitative traits, the lowest values of soluble sugar and proline were obtained at the osmotic level of −12 bar. Moreover, the application of 200 ppm of nano chitosan and −6 bar of osmotic stress resulted in the highest levels of catalase, superoxide dismutase, ascorbate peroxidase, chlorophyll a, b, and carotenoids. As a whole, the results of the study demonstrated that seed priming with chitosan nanoparticles can reduce the negative effects of drought stress on guar seedlings. In addition, application of 200 ppm of this substance was the most suitable treatments that improve most quantitative and qualitative indices of guar. Keywords: Enzymatic activity, Nano particles, Priming, Seed structure.

Evaluating the Effectiveness of Organic Seed Priming Formulations on Germination and Seedling Growth in Acid Lime (Citrus aurantifolia Swingle) cv. Kagzi

The primary objective of this research was to evaluating the effectiveness of organic seed priming formulations on germination and seedling growth in acid lime cv. Kagzi at CCS Haryana Agricultural University, Hisar, during the period 2020-2021. The study comprised six distinct treatments of organic formulations, including beejamrit, cow urine (50% and 100%), cow dung, cow dung slurry, and control (without soaking). The seeds were soaked for a duration of 24 hours. The experiment was conducted using a completely randomized design with three replications. The study findings revealed that the control (without soaking) exhibited the highest germination percentage (45.17) and germination rate (2.38), followed closely by the beejamrit. Furthermore, the beejamrit treatment demonstrated remarkable seedling growth at 180 days after sowing, with the highest values recorded for seedling diameter (3.23 mm), seedling shoot length (36.90 cm), fresh shoot weight (3.26 g), fresh root weight (1.26 g), tap root length (37.57 cm), and survival percentage (91.50). Cow dung slurry also exhibited notable performance in terms of seedling growth parameters at 180 days after sowing with the beejamrit. Cow dung slurry showcased the highest number of secondary roots (50.00), number of leaves per seedling (31.67), leaf chlorophyll content (33.80 SPAD), and nitrogen content (1.52%), closely followed by the beejamrit treatment. Accelerating the rate of germination and growth of lime seedlings has become a top concern for nurserymen and scientists on a national level to reduce expenditures and time for seedling maintenance. For overcoming such types of problems at the nursery stage, contributing to more resilient and sustainable farming practices using organic seed priming is a good alternative against chemical seed priming.

Isolation, morphological characterization, and screening virulence of Beauveria bassiana and Metarhizium robertsii fungal isolates on Galleria mellonella

Background Entomopathogenic fungi exists naturally in plants as an asymptote and have the potential to reduce the population of insect pests through indirect interactions. This study was conducted to detect and characterize the endophytic fungi Beauveria bassiana and Metarhizium robertsii from the rhizosphere soil of tomato plants and their virulence effect on Galleria melonella. Methods From the rhizosphere soil of 40 tomato fields, three Beauveria bassiana and seven Metarhizium robertsii isolates were isolated using the galleria bait method. All fungi isolate were morphologically characterized by their colony color, shape, and surface texture. Isolates with the highest percentages of germination, conidial yield, and radial growth were selected, and their virulence was evaluated on second instar larvae of Galleria melonella under laboratory conditions. Results In this study, Beauveria bassiana showed white colony color and aseptate hyphae, whereas Metarhizium robertsii showed dark green to light green colony color and septate hyphal structures. Maximum spore production and conidial length were obtained by Beauveria bassiana isolate APPRC-27 with 2.67x107 spores ml-1 and 3.24 µm, respectively. Colony radial growth rates ranged from 1.73 to 3.24 mm day-1. The results revealed that the highest mortality rate of Galleria melonella (100%) was obtained by Metarhizium robertsii isolates K-61 and K-102 at a concentration of 1x108 conidial ml-1 at 7 days post-inoculation. The lowest mortality rate was registered by Metarhizium robertsii isolate RST-11. Conclusions In the present study, isolates that produced the most spores and had the highest germination rates were the most virulent to Galleria mellonella second instar larvae. Therefore, virulent entomopathogenic fungi, Beauveria bassiana and Metarhizium robertsii, are promising bioagents for the control of insect pests.

The Efficiency of Seed Priming with Dead Sea Water for Improving Germination and Early Seedling Growth of Wheat (Triticum aestivum L.) under Salinity

<p>Salinity is considered the most critical environmental factor which negatively affects the germination and growth of plants. In this study, the potential of using Dead Sea water (DS) as a seed priming agent for the mitigation of the adverse effects of salinity on seed germination and growth performance of wheat (<em>Triticum aestivum</em> L.) was investigated. Germination of wheat seeds primed with different doses of DS; 0%, 5%, 10%, 15%, and 20% were evaluated under different saline conditions (0, 100, 200, and 300 mM NaCl). High salinity (300 mM NaCl) remarkably inhibited germination attributes and reduced seedling length. However, seeds primed with DS exhibited improved germination parameters and seedling growth. Among the different DS concentrations used, the 10% DS priming achieved the highest increase in final germination percentage tolerance, germination index, relative germination salt tolerance, and seedling length. The increased tolerance to salinity was associated with improved water imbibition, α-amylase activity, antioxidant capacity and osmotic homeostasis correlated with high proline and soluble sugar levels. In addition, DS priming increased the membrane stability index, and reduced malondialdehyde content and K<sup>+</sup> leakage besides lowering Na<sup>+</sup>/K<sup>+</sup> ratio. Overall, priming with DS could be a promising strategy for minimizing the damaging effects of salinity in wheat.</p>

Allelopathic potential of invasive alien plant species, Xanthium strumarium L., water and methanol extracts on germination and seedling growth of Guizotia abyssinica (L.f.) Cass., and Linum usitatissimum L.

The objective of this study was to investigate the allelopathic impact of Xanthium strumarium on the seedling growth and germination of Guizotia abyssinica and Linum usitatissimum. Plant specimens and samples of Xanthium strumarium were collected from the Minjar-Shenkora district in Ethiopia. In the laboratory, a series of dilutions of extracts from the leaves and roots of Xanthium strumarium were prepared using distilled water and methanol (99.85%) as solvents. Twenty-five grams of root and leaf samples were soaked separately in 250 mL of the specified solvent to create the stock solution. The experiment was carried out using Petri dishes in a completely random manner, with three replications repeated twice. Various concentrations of the extracts (25, 50, 75, and 100%) were applied as treatments, while distilled water served as the control. Each petri dish contained 25 seeds of each test crop and 5 mL of the corresponding extract. The number of Linum usitatissimum and Guizotia abyssinica seeds germinating was recorded every 24 hours until 12 and 14 days, respectively. Both descriptive and inferential analyses were conducted. When Guizotia abyssinica and Linum usitatissimum seeds were treated with 100% concentrations of water extract from leaf samples, germination percentages were inhibited by 72 and 77.4%, respectively. In methanol extracts, the entire inhibition of germination was observed in both test plant species at ≥ 50% and ≥ 75% concentrations of leaf and root samples, respectively. Therefore, the inhibitory effect of water and methanol extracts showed a concentration-dependent pattern, with increasing concentrations resulting in greater inhibition. The inhibitory effect of leaf extracts was more pronounced compared to root extracts, suggesting the presence of herbicidal activities. Further phytochemical and molecular studies are recommended to identify the active compounds in Xanthium strumarium. Additionally, utilizing isolated allelopathic substances as a means of controlling invasive alien species is suggested.

Seed pretreatment using design of engineering approach for regulating <em>Humulus lupulus</em> seed germination in different media

Humulus lupulus, a plant of commercial benefit, has been widely explored for its therapeutic applications. Plant propagation via seeds is one of the major challenges due to seed dormancy and low germination. The physical dormancy of the seed caused by a hard seed coat makes seeds impervious to water. Different types of methods have been reported to break the seed dormancy. The present study emphasizes the optimized chemical method of seed pretreatment for regulating the germination efficiency in three different media namely, Murashige and Skoog (MS), Hoagland’s media and Leafy 200®. The study explores the interaction between two variables viz., acid treatment time and concentration of sulphuric acid, on germination of Humulus lupulus seeds using the Design of Experiment (DOE) approach. The results showed a higher germination rate in MS media and Leafy200® media (100%) seed germination percentage with respect to Hoagland’s media. The result demonstrates the synergistic role of seed pretreatment and media on the seed germination efficiency. The scanning electron microscopy (SEM) analysis of the seeds pretreated with acid revealed small perforations on the seed coat ranging between 5-15 µm. Furthermore, the elemental analysis of the seed coat surface by Energy Dispersive X-ray (EDX) revealed a substantial decrease in carbon and oxygen (%) and the presence of calcium, magnesium, and sulfur. The results indicate the acid hydrolysis of organic constituents on the seed surface enabling changes in seed porosity. Additionally, factors such as pretreatment and media play a pivotal role in regulating seed germination.

Physiological Indexes in Seed Germination and Seedling Growth of Rangpur Lime (Citrus limonia L. Osbeck) under Plant Growth Regulators

The propagation of citrus seedlings is accomplished through grafting, utilizing seeds for the production of rootstocks. The germination of certain seeds may be low and uneven, complicating the production of high-quality seedlings. The use of plant growth regulators (PGRs) is a viable alternative to improve the quality of seedling production, as these compounds can break dormancy, control the hydrolysis of reserves, induce cell division, and regulate permeability and protein functions. This study aimed to evaluate the germination of seeds and the growth of Rangpur lime (Citrus limonia L. Osbeck) seedlings under the influence of imbibition in solutions of gibberellic acid (GA3) and a combination of GA4+7 + 6Benzyladenine. The experiment was conducted under controlled laboratory and greenhouse conditions, using a completely randomized design in a 2 × 5 factorial scheme, with two types of plant regulators (GA3 and GA4+7 + 6BA) at five concentrations (0, 250, 500, 750, and 1000 mg L−1 a.i.). Quantitative and qualitative variables were evaluated, ranging from seed germination to seedling development and formation, including germination percentage and speed index, fresh and dry biomass of roots and shoots, enzymatic activity, and gas exchange. The results indicate that GA3 significantly accelerates the germination process of Rangpur lime cv. Santa Cruz seeds and promotes better seedling growth and development, resulting in vigorous seedlings. These findings demonstrate that the application of PGRs, particularly GA3, can substantially enhance the propagation efficiency of citrus rootstocks, offering a practical solution for improving the uniformity and quality of seedling production in commercial settings.

Unveiling wheat growth promotion potential of phosphate solubilizing Pantoea agglomerans PS1 and PS2 through genomic, physiological, and metagenomic characterizations.

Phosphorus is an abundant element in the earth's crust and is generally found as complex insoluble conjugates. Plants cannot assimilate insoluble phosphorus and require external supplementation as chemical fertilizers to achieve a good yield. Continuous use of fertilizers has impacted soil ecology, and a sustainable solution is needed to meet plant elemental requirements. Phosphate solubilizing microbes could enhance phosphorus bioavailability for better crop production and can be employed to attain sustainable agriculture practices. The current study unveils the biofertilizer potential of wheat rhizospheric bacteria through physiological, taxonomic, genomic, and microbiomics experimentations. Culture-dependent exploration identified phosphate-solubilizing PS1 and PS2 strains from the wheat rhizosphere. These isolates were rod-shaped, gram-negative, facultative anaerobic bacteria, having optimum growth at 37°C and pH 7. Phylogenetic and phylogenomic characterization revealed their taxonomic affiliation as Pantoea agglomerans subspecies PS1 & PS2. Both isolates exhibited good tolerance against saline (>10% NaCl (w/v), >11.0% KCl (w/v), and >6.0% LiCl (w/v)), oxidizing (>5.9% H2O2 (v/v)) conditions. PS1 and PS2 genomes harbor gene clusters for biofertilization features, root colonization, and stress tolerance. PS1 and PS2 showed nitrate reduction, phosphate solubilization, auxin production, and carbohydrate utilization properties. Treatment of seeds with PS1 and PS2 significantly enhanced seed germination percentage (p = 0.028 and p = 0.008, respectively), number of tillers (p = 0.0018), number of leaves (p = 0.0001), number of spikes (p = 0.0001) and grain production (p = 0.0001). Wheat rhizosphere microbiota characterizations indicated stable colonization of PS1 and PS2 strains in treated seeds at different feek stages. Pretreatment of seeds with both strains engineered the wheat rhizosphere microbiota by recruiting plant growth-promoting microbial groups. In vitro, In vivo, and microbiota characterization studies indicated the biofertilizer potential of Pantoea sp. PS1 & PS2 to enhance wheat crop production. The employment of these strains could fulfill plant nutrient requirements and be a substitute for chemical fertilizers for sustainable agriculture.

Production of pyrite-based catalysts supported on graphene oxide and zinc oxide to treat drug mixture via advanced oxidation processes.

Advanced oxidation processes (AOP) stood out as an efficient alternative for the treatment of organic contaminants. In this work, there were proposed syntheses of mixed catalysts of pyrite and graphene oxide and pyrite and zinc oxide to treat a mixture of the drugs atenolol and propranolol in aqueous solution through the photo-Fenton process with ultraviolet radiation. The efficiency of the methodologies used in the syntheses was confirmed through different characterization analyses. It was verified that the pyrite and zinc oxide catalyst led to the best contaminant degradation percentages with values equal to 88 and 84% for the groups monitored at the wavelengths (λ) of 217 and 281nm. The degradation kinetics presented a good fit to the kinetic model proposed by Chan and Chu (2003) with R2 equal to 0.99, indicating a pseudo-first-order degradation profile. Finally, toxicity tests were carried out with two types of seeds, watercress and cabbage, for the solution before and after treatment. The cabbage seeds showed a reduction in germination percentages for the samples after treatments, while no toxicity was observed for watercress ones. This highlights the importance of evaluating the implications caused by products in relation to different organisms representing the biota.

Apomictic seed formation and viability in Ilex paraguariensis A.St.-Hil. (Aquifoliaceae)

The objective of this study was to investigate fruit and seed formation in Ilex paraguariensis A.St.-Hil. without sexual reproduction in addition to evaluating their viability. This study was based on the hypothesis that the formation of apomictic fruit and seeds occurs, but the seeds are non-viable, contributing to the low germination percentage of the species. Five branches of 20 pistillate mother plants were bagged before anthesis (T1) and five immediately after fruit formation (TC). Once they reach maturity, the fruit were collected and counted. Their seeds were cut lengthwise and classified as intact (with embryo and endosperm) or non-intact (empty and/or deteriorated). The viability of intact seeds was evaluated with the tetrazolium test when they were classified as viable or non-viable. The data were submitted to the Kruskal-Wallis Test. The formation of viable fruit and seeds occurred in smaller numbers in T1, all statistically different from TC (p<0.05). Although in smaller quantities and with a statistical difference, the formation of viable fruit and seeds occurs without sexual reproduction, suggesting that the process responsible for their formation is the facultative apomixis. The higher percentage of viable fruit and seeds in TC is probably a result of the occurrence of both apomixis and sexual reproduction. The percentage of non-viable seeds does not differ between the two treatments, suggesting that apomixis may not be the cause of the low percentage of viable seeds and germination, requiring further studies to understand its causes.