Seed Germination Percentage Research Articles

Prevalence of Seed-Borne Fungi on Soybean (Glycine max L. Merr.) Seeds Stored Under Medium-Term Cold Room Facilities: Implications for Genebanks

This study examined the prevalence of seed-borne fungi in polyethylene plastic-packaged soybean seeds stored in a genebank and identified factors influencing their incidence. Twenty-four seed lots were sampled from the collection stored at 10 °C in the World Vegetable Center genebank in Arusha, Tanzania. The seeds used were those regenerated and harvested in 2015, 2016, and 2017. A seed health test was conducted for sterilized seeds on potato dextrose agar, sterilized seeds on top of the paper, and unsterilized seeds on top of the paper. Seven-year-old sterilized seeds plated on top of the paper exhibited the highest germination percentage (74 ± 7.09%) and lowest fungal incidence (7.00 ± 4.41%). Conversely, seven-year-old unsterilized seeds plated on top of the paper had the lowest germination (22.00 ± 6.97%) and highest fungal incidence (79.00 ± 8.31%). Older seed lots showed significantly higher equilibrium seed moisture content (Eqmc), though seed age had no significant influence on germination percentage or fungal incidence. Seed germination percentage showed a significant negative relationship with Eqmc, though Eqmc had no significant effect on fungal incidence. Meanwhile, germination percentage showed a significant negative relationship with fungal incidence. Six fungi isolates were identified using their morphological features from soybean seed samples: Absidia glauca, Aspergillus niger, Fusarium spp., Mucor hiemalis, Pestalotiopsis versicolor, and Sordaria macrospora. It is concluded that high fungal incidence negatively affects seed germination but is not significantly correlated with seed moisture content. The dry and cold storage conditions in the genebank, while effective in extending seed longevity, can unintentionally allow seed-borne mycoflora to persist. Although fungi may not actively proliferate under these conditions, they may do so when favorable conditions are restored, such as during germination tests, and consequently may compromise seed viability. Therefore, this study emphasizes the importance of increased systematic seed health checks before storage in genebanks to ensure optimal seed quality, and the replacement of all polyethylene plastic bags to aluminium foil packaging.

Allelopathic Effects of Vachellia nubica, Vachellia tortilis and Hyphaene compressa on Germination and Seedling Growth of Prosopis juliflora

Background: Prosopis juliflora (Sw.) DC is an invasive species negatively impacting plant ecology and livelihoods in introduced areas. Native tree species may produce allelochemicals that can inhibit growth of invasive species, resulting in a natural management technique. Aim: This study aimed to determine allelopathic effect of three native tree species (V. tortilis, V. nubica, and H. compressa) on seed germination and early seedling growth of P. juliflora to identify the tree species that can be used to suppress P. juliflora invasion as part of its management strategy. Methodology: Crude Leaf and root extracts of the native trees at 0%, 1%, 2.5%, 5%, and 10% concentrations were prepared. P. juliflora seeds were subjected to 24 crude extract treatments and a control in a completely randomized design in Petri dishes. The seeds were uniformly moistened with 10 ml extracts daily in a germination chamber for 14 days, and germination counts were done after every 2 days. Shoot and root length and wet weight were measured after 14 days. The data were subjected to three-way ANOVA and means separated by Tukey. Results: Prosopis seed coats treated with V. tortilis and V. nubica leaf extracts turned darkish before germination while germination of seeds in 10% leaf extracts of V. nubica aborted. Seed germination percentage in 10% leaf extracts of V. tortilis (30%) and V. nubica (23%) were the lowest compared to control (90%). P. juliflora seedlings under 5% V. nubica and 10% V. tortilis died before the experiment period. Depending on crude extract concentrations, percent inhibition on germination characteristics were; percent germination (21-74%), wet weight (6-49%), plumule length (10-47%), and radicle length (7-86%) of germinating P. juliflora. Conclusion: The native tree species studied have allelopathic effects on the germination of P. juliflora and thus can be promoted to suppress invasiveness of P. juliflora.

Standardization of Protocol for Production of Synthetic Seed of Brahmi (Bacopa monnieri) and Assessment of their Longevity under Differential Storage Condition

Brahmi [Bacopa monnieri (L) Pennel] is an important medicinal small succulent, medicinal herb belongs to the family ‘Scrophulariaceae’ which is commonly known as Jala Brahmi or Nira-Brahmi. National Medicinal Plants Board (NMPB), estimated an annual demand of Bacopa in 2004-2005 was 6621.8 tonnes, with a 7% annual growth rate. Micropropagation techniques and production of synthetic seeds can be a breakthrough to overcome the low availability of Brahmi propagating materials. So, the present study was conducted to standardize the protocol for preparation of synthetic seeds of Brahmi using nodal segment. The experiment was conducted with five treatments by using combinations of different concentrations of sodium alginate and calcium chloride and preparing two types of synthetic seeds (single layer and double layer). Further the longevity of both single layer and double layered synthetic seeds was studied under two different storage temperatures at 25°C (ambient condition) and 4°C (refrigerator) up to 40 days by inoculating them in two different types of media. The result showed no significant effect of concentrations of gelling agent and complexing agent on the germination percentage of synthetic seeds. The number of shoots per synthetic seed varied from 22.00 to 29.35 with 100% germination and maximum shoots/synthetic seed and shoot length was obtained by using T5 (single layered with MS media, 3% sodium alginate and 2.5% calcium chloride). Maximum number of days of storage can be observed in the single layer synthetic seeds when stored at 4°C along with media followed by double layer synthetic seeds when stored at 4°C along with media. However, seeds stored on vermiculite got dried up in the initial days of storage. Germination was found to be higher in seeds stored at 4°C when compared to seeds stored at 25°C. The study as a whole elucidated the opportunity for the use of synthetic seed as an alternative to traditional propagation system for Brahmi.

Salinity Studies in Quinoa (Quinoa Chenipodoum Willd) from Haditha Desert, Western of Iraq

The present studies were conducted to determine the effect of various concentrations of NaCl salinity on germination and growth of four genotypes of Quinoa Chenopodium Willd, namely G1 (KVL-SR2), G2 (Q-21), G3 (Q-37), and G4 (Regalona), exposed to 0, 60, 120, and 300 mM NaCl. The study was conducted at the Center of Desert Research, Egypt, and the experiment was carried out in the Plant Physiology Laboratory of the Center of Desert Studies. Seeds were treated with four different levels of NaCl concentration: 0, 60, 120, and 300 mM. The experiment followed a Completely Randomized Design with three replications. The germination experiment aimed to determine the effect of NaCl salinity on seed germination percentage. Seeds were placed in autoclaved petri dishes lined with two layers of filter paper, with fifty seeds per dish. Seeds were treated with 0, 60, 120, and 300 mM NaCl solutions (5 mL). The petri dishes were kept in the laboratory at temperatures ranging from 25°C to 28°C for four weeks. Water loss from the petri dishes due to evaporation was monitored using control petri dishes, and water was added every 24 hours as needed. A pot experiment was conducted using plastic pots containing 1700 grams of fine-sieved soil. Seeds of the aforementioned genotypes were sown in 500 grams of soil, separated from the rest of the pot's soil by a polythene sheet. Plants were watered on alternate days and subjected to salinity treatment 25 days after sowing. Fifty milliliters of nutrient solution (N ratio of 6:4) were also added to the salt solution per pot. The salt solution was applied to the 1200 grams of soil in the pot, and after complete absorption, the polythene sheet separating the soil containing plantlets was removed, allowing the roots of the seedlings to grow into the saline soil in the lower half of the pot. Thinning was done after one week, maintaining five plants per pot. The plants were harvested one month after the salinity treatment. It was observed that the germination percentage decreased as the salinity level increased. G1 was tolerant, while G4 was salt-sensitive compared to the other genotypes. Plant height, number of leaves, and number of nodes per plant decreased with increasing salt concentration. G3 was least affected, followed by G2, G1, and G4. Fresh weight, dry weight, and percentage water content of the plants also significantly decreased with increased salinity. The distribution of Na+ ions in various plant parts showed a high concentration in the roots, stem, leaf blade, and leaf sheath of all genotypes. The highest concentration of Na+ ions was found in the leaf sheath of all genotypes, followed by the stem, root, and leaf blade, with high water content even under the highest salt levels. An effective partition of Na+ and Cl- ions in the leaf sheath and the transport of K+ to the physiologically important leaf blade were observed in G1, while other genotypes did not exhibit this efficiency. The specific ion effect of NaCl on the total N status of plants was most pronounced in G1, followed by G2 and G3, while G4 maintained optimal N levels in the root and leaf blade. The tolerant genotype G1 could be utilized for rehabilitation in salt-affected areas.

Seed Dormancy and Germination Responses to Different Temperatures of Leptochloa chinensis (L.) Nees: A Case Study with 242 Populations Collected from Rice Fields in East China

Leptochloa chinensis (L.) Nees is a troublesome rice weed. We collected 242 L. chinensis populations from rice fields in eastern China and studied the duration of seed dormancy and the seed germination ability at different temperatures. All L. chinensis populations studied exhibited seed dormancy. The periods required to reach 50% germination under optimal conditions were 31–235 days, with an average of 96 days. None of the populations germinated at 15 °C. Under constant temperatures of 20, 25, 30, and 35 °C, the average germination percentages of 242 populations were 0%, 71%, 79%, and 60% at 2 days after treatment (DAT), and were 56%, 84%, 88%, and 88% at 14 DAT, respectively. The duration of seed dormancy, as well as the germination ability of seeds, were significantly (p < 0.05) influenced by the agricultural region and the longitude and latitude of the collection locations. Under constant temperatures of 20 to 35 °C, the average germination percentages of seeds collected from transplanted rice fields were significantly higher than those collected from direct-seeded fields. This is the first study on seed germination biology of L. chinensis with multiple populations systematically collected from rice fields on a regional scale.

Effect of alternating temperature regimes on seed germination of guar [Cyamopsis tetragonoloba (L.) Taub.

Guar [Cyamopsis tetragonoloba (L.) Taub.] 2n=14, is an annual crop that belongs to the Fabaceae family and has a spring–summer growth cycle. This species has been assuming increasing importance among agro-industrial crops due to the high galactomannan content of its seeds for which a multitude of food and non-food applications have been developed. Guar is a viable rotation crop for growers in Mediterranean areas and can result in diversification in crop production systems. The effects of four alternating day/night temperature regimens on C. tetragonoloba seed germination were tested: (T1) 23/15 °C, (T2) 21/13 °C, (T3) 19/ 11 °C, and (T4) 17/09 °C with a 16/08 h light/dark photoperiod, respectively. Seeds from two guar cultivars (RGC-0936 and RGC-1066) were used. Treatments consisted of four replicates of 50 seeds each, arranged in a split-plot design with temperatures as the main plot and cultivars as the subplot. The results showed that lower temperatures reduced guar seed germination. The highest germination percentages were obtained at the 21/13 °C and 23/15 °C temperature regimens, while a significant drop in germination percentage occurred for the 19/11 °C treatment, and the lowest germination percentages were observed at 17/09 °C. No statistically significant differences were found between the two cultivars studied for seed germination percentages. The interaction effects among the different alternative temperature regimes on seed germination and guar cultivars were not statistically significantly different. The values obtained at the 21/13 °C temperature treatment allow us to conclude that this regimen is the minimum acceptable combination of temperatures to program the sowing date.

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.

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.

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.

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.

Influence of exogenous 24-epibrassinolide on improving carotenoid content, antioxidant capacity and gene expression in germinated maize seeds.

Carotenoids have various physiological functions, such as immune regulation and cancer prevention. Germination could further improve the content of carotenoids in maize seeds. In this study, yellow maize seeds (Suyu 29) were soaked and germinated with different concentrations of 24-epibrassinolide. The changes of germination percentage, sprout length, bioactive components, antioxidant capacity and carotenoid content of the maize seeds were analyzed. Additionally, the relative expression of key genes in the carotenoid synthesis pathway was investigated. The results showed that the sprout length, germination percentage, soluble protein, free amino acids, proline, endogenous abscisic acid, vitamin C, total phenolics and carotenoids displayed a significant increasing trend compared with the control group (P < 0.05). The activity of superoxide dismutase and peroxidase increased by 55.1% and 58.5% versus the control group, and the antioxidant capacity of 2,2-diphenyl-1-picrylhydrazyl, 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and ferric reducing antioxidant power was 19.8%, 13.4% and 44.1% higher than that of the control group (P < 0.05). Compared with the control group, the expression of genes was significantly up-regulated (P < 0.05). Under the treatment of 0.1 mg L-1 of 24-epibrassinolide, carotenoid content reached the highest value. The carotenoids showed a positive correspondence with antioxidant enzyme activity, antioxidant capacity and total phenolics content (P < 0.05). This study showed that 0.1 mg L-1 of exogenous 24-epibrassinolide promoted the accumulation of carotenoids and improved the antioxidant capacity and the quality of germinated maize seeds. It could provide a method for the development of germinated maize products enriched in carotenoids. © 2024 Society of Chemical Industry.

Combined vigour tests to estimate relative seedling emergence in the field and germination after storage in sweet corn seed lots

This study was carried out to test whether the radicle emergence (RE), cold (CT) and accelerated ageing (AAT) tests and their combinations of CT+RE and AAT+RE can be used to rank sweet corn seed lots according to field seedling emergence and germination after storage. Seed samples for eight hybrid seed lots were stored hermetically over 12 months at 20°C with 9.9-10.2% seed moisture. RE was counted between 32 and 72 hours, AAT was carried out at 41 ± 1°C and 100% RH for 72 hours, and CT at 5°C over two days. RE count was performed after AAT (AAT+RE) and CT (CT+RE). Seedling emergence was tested in two field sowings, in April and May 2022. The vigour test results were correlated with both seedling emergence percentages in the field and germination after storage. Both normal germination after CT (r = 0.73−0.94, P &lt; 0.05−0.001) and AAT+RE72h (r = 0.71−0.84, P &lt; 0.05−0.01) were significantly related to both parameters. The RE test was significantly related to seedling emergence, but not to any post-storage data. The normal seed germination percentage was found to be significant in only one case (sowing 2). Seed vigour in sweet corn seeds and its importance in relation to seedling emergence and seed storage are discussed.

Simulated Herbicide Drift Effects on Seed Germination, Seedling Emergence, and Seedling Growth of Native Plants of the Northern Great Plains.

Small concentrations of herbicide, such as those found in drift, can affect nontarget plants at different life-history stages including seed germination and seedling emergence as well as seedling growth. Fragmented landscapes, such as those in the northern Great Plains, lead to increased proximity of ecological restoration sites to agricultural lands using herbicides. Germination, emergence, and growth are crucial life-history stages leading to ecological restoration success, but these stages are sensitive to impacts from external factors such as herbicide exposure. A lab germination experiment and a greenhouse emergence experiment were performed to examine the effect of herbicides (2,4-dichlorophenoxyacetic acid [2,4-D], atrazine, and trifluralin) on species used in ecological restorations in the northern Great Plains. Seed germination, seedling emergence, and seedling growth of many study species decreased with exposure to herbicides at different concentrations representative of herbicide drift. At concentrations as low as 0.1% recommended application rate 2,4-D elicited broad effects on final seed germination percentage and germination rate. Atrazine affected seedling emergence and growth for a number of study species at concentrations as low as 10% recommended application rate. Trifluralin affected germination, emergence, and growth of the fewest number of study species. The information gained from these experiments can be used to inform restoration practitioners of best practices and recommended species to use when implementing ecological restoration adjacent to agricultural lands. Environ Toxicol Chem 2024;43:2387-2397. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

A Survey of Fruit Quality Properties, Growth, and Yield of Several Melon Varieties (&lt;i&gt;Cucumis melo&lt;/i&gt; L.) Using Fertigation Approach

Melons, &lt;i&gt;Cucumis melo&lt;/i&gt; L., belongs to the family Cucurbitaceae. They are popular for their sweet, juicy fruit flesh with pleasant aroma. These melons are packed with numerous essential nutrients for the human body. In this study, the fruit quality properties, growth, and yield of nine different melon varieties were compared via a fertigation approach to deduce the best melon variety to be planted by melon farmers. Quantitative and qualitative traits of all nine melon varieties were collected and compared. As a result, it was discovered that the Japanese Rock Melon F1 Hybrid is an all-rounder best melon variety, with the highest seed germination percentage and fruiting percentage. On the other hand, the Sweet Green Melon F1 can also be considered the second-best choice, but the only downside is that the germination rate is significantly lower compared to others, at merely 37%. Hopefully, this study can serve as a foundation for developing a more comprehensive database for melon varieties to aid melon farmers in decision-making and further improve the industry’s yield.

Genetic and Physiological Insights into Salt Resistance in Rice through Analysis of Germination, Seedling Traits, and QTL Identification.

Understanding the genetic basis of salt resistance in crops is crucial for agricultural productivity. This study investigates the phenotypic and genetic basis of salt stress response in rice (Oryza sativa L.), focusing on germination and seedling traits. Under salt stress conditions, significant differences were observed in seed germination and seedling traits between parental LH99 (Indica rice LuHui 99) and SN265 (japonica rice ShenNong 265). Transgressive segregation was evident within the RIL population, indicating complex genetic interactions. Nine QTLs were detected at germination and seedling stages under salt stress, namely qSGE5 and qSGE7 for seed germination energy (SGE); qSGP7 for seed germination percentage (SGP); qSSH7, qSSH9-1, and qSSH9-2 for seeding height (SSH); qSRN6 for root number (SRN); and qSDW6 and qSDW9 for dry weight (SDW). Among them, qSSH9-1 and qSDW9 were localized in the same interval, derived from the salt-resistant parent SN265. PCA revealed distinct trait patterns under salt stress, captured by six PCs explaining 81.12% of the total variance. PC composite scores were used to localize a QTL associated with early salt resistance in rice qESC9, which was located in the same interval as qSSH9-1 and qSDW9, and was subsequently unified under the name qESC9, an important QTL for early-growth salt tolerance in rice. Correlation analysis also confirmed a relationship between alleles of qESC9 and the resistance to salt, underscoring the critical role this locus plays in the determination of overall salt tolerance in rice. Physiological analyses of extreme phenotype lines highlighted the importance of ion exclusion mechanisms in salt-resistant lines, while salt-susceptible lines exhibited elevated oxidative stress and impaired antioxidant defense, contributing to cellular damage. This comprehensive analysis sheds light on the genetic and physiological mechanisms underlying salt stress response in rice, providing valuable insights for breeding programs aimed at enhancing salt resistance in rice.

Ethylene Is Crucial in Abscisic Acid-Mediated Modulation of Seed Vigor, Growth, and Photosynthesis of Salt-Treated Mustard.

The current study explored the differential interaction between ethylene (ET) and abscisic acid (ABA) in relation to salt stress in mustard (Brassica juncea L.) plants. Significant reductions in seed germination, growth, and photosynthesis were observed with 100 mmol NaCl. Among the cultivars tested, the Pusa Vijay cultivar was noted as ET-sensitive. Pusa Vijay responded maximally to an application of 2.0 mmol ethephon (Eth; 2-chloethyl phosphonic acid-ethylene source), and exhibited the greatest growth, photosynthesis, activity of 1-aminocyclopropane carboxylic acid (ACC) synthase (ACS), and ET evolution. Notably, Eth (2.0 mmol) more significantly improved the seed germination percentage, germination and vigor index, amylase activity, and reduced H2O2 content under salt stress, while ABA (25 µmol) had negative effects. Moreover, the individual application of Eth and ABA on Pusa Vijay under both optimal and salt-stressed conditions increased the growth and photosynthetic attributes, nitrogen (N) and sulfur (S) assimilation, and antioxidant defense machinery. The addition of aminoethoxyvinylglycine (0.01 µmol AVG, ET biosynthesis inhibitor) to ABA + NaCl-treated plants further added to the effects of ABA on parameters related to seed germination and resulted in less effectiveness of growth and photosynthesis. In contrast, the effects of Eth were seen with the addition of fluoridone (25 µmol Flu, ABA biosynthesis inhibitor) to Eth + NaCl. Thus, it can be suggested that ET is crucial for alleviating salt-induced inhibition in seed germination, growth, and photosynthesis, while ABA collaborated with ET to offer protection by regulating nutrient assimilation and enhancing antioxidant metabolism. These findings provide insight into the complex regulatory processes involved in ET-ABA interaction, enhancing our understanding of plant growth and development and the mitigation of salt stress in mustard. It opens pathways for developing hormonal-based strategies to improve crop productivity and resilience, ultimately benefiting agricultural practices amidst a challenging environment.

Ultrasonic treatment can improve maize seed germination and abiotic stress resistance

Constant-frequency ultrasonic treatment helped to improve seed germination. However, variable-frequency ultrasonic treatment on maize seed germination were rarely reported. In this study, maize seeds were exposed to 20–40 kHz ultrasonic for 40 s. The germination percentage and radicle length of maize seeds increased by 10.4% and 230.5%. Ultrasonic treatment also significantly increased the acid protease, α-amylase, and β-amylase contents by 96.4%, 73.8%, and 49.1%, respectively. Transcriptome analysis showed that 11,475 differentially expressed genes (DEGs) were found in the ultrasonic treatment and control groups, including 5,695 upregulated and 5,780 downregulated. Metabolic pathways and transcription factors (TFs) were significantly enriched among DEGs after ultrasonic treatment. This included metabolism and genetic information processing, that is, ribosome, proteasome, and pyruvate metabolism, sesquiterpenoid, triterpenoid, and phenylpropanoid biosynthesis, and oxidative phosphorylation, as well as transcription factors in the NAC, MYB, bHLH, WRKY, AP2, bZIP, and ARF families. Variable-frequency ultrasonic treatment increased auxin, gibberellin, and salicylic acid by 5.5%, 37.3%, and 28.9%, respectively. Abscisic acid significantly decreased by 33.2%. The related DEGs were upregulated and downregulated to varying degrees. Seed germination under the abiotic stress conditions of salt stress (NaCl solution), drought (PEG solution), and waterlogging (water-saturated sand bed) under ultrasonic treatment were promoted, radicle length was significantly increased by 30.2%, 30.5%, and 27.3%, respectively; and germination percentage by 14.8%, 20.1%, and 21.6%, respectively. These findings provide new insight into the mechanisms through ultrasonic to promote maize seed germination.

Enhancement of Drought Tolerance and Plant Growth in Tomato by Trichoderma harzianum Seed Treatment

The proficiencies of soil microorganisms to drought tolerance have been known for many years, but their use as crop inoculants was not explored in agriculture commercially. One possibility to increase the drought tolerance is to use beneficial microorganisms as seed treatment. This study was conducted to investigate the effect of Trichoderma harzianum on the growth and development of Tomato (Solanum lycopersicum L.) plant under water stress condition. Trichoderma harzianum is applied to the seeds by treating seeds with Trichoderma harzianum before sowing. Parameters including germination percentage, chlorophyll content, leaf area, number of leaves, plant height, root length, plant fresh and dry weight and yield were recorded in all the treatments along with the untreated control. Tomato seeds treated with Trichoderma harzianum had higher seed germination percentage and chlorophyll content 95.50%, (2.41%), 42.59 SAPAD units (13.83%) respectively than untreated seed. Maximum leaf area and number of leaves 11.71 cm² (19.40%), 190.75 (15.43%) respectively recorded in the plants of Trichoderma harzianum treated seeds in water stress condition as compared to untreated seeds. Under extreme water stress condition plant height and root length of tomato plant increased significantly 98.25 cm, (19.45%), 41.25 cm (42.24%) respectively in Trichoderma harzianum treated seeds as compare to untreated seed. Also, Trichoderma harzianum seed treatment in tomato showed a significantly higher plant fresh and dry weight 189.43 g (8.65%) and 31.98 g (47.57%) respectively in drought condition as compared to untreated seeds. Trichoderma harzianum seed treatment played critical role in drought condition by increasing yield 731.25 g/plant (27.62%) increase over untreated seeds. Taken together, the study recommends that in drought condition for enhanced tomato growth Trichoderma harzianum should be used as eco-friendly solutions by seed treatment.

Evaluation of the Impact of Chemical Mutagens on the Phenological and Biochemical Characteristics of Two Varieties of Soybean (Glycine max L.).

Mutagenic effectiveness and efficiency are the most important factors determining the success of mutation breeding, a coherent tool for quickly enhancing diversity in crops. This study was carried out at Lovely Professional University's agricultural research farm in Punjab, India, during the year 2023. The experimental design followed a randomized complete block design (RCBD) with three replications. The experiment aimed to assess the effect of three chemical mutagens, sodium azide (SA), ethyl methyl sulphonates (EMSs), and methyl methane sulfonate (MMS), at three different concentrations (0.2%, 0.4%, and 0.6%), in SL958 and SL744 soybean varieties to select the mutant exhibiting the highest yield. The data were collected and analysed using a two-way ANOVA test through SPSS software (version 22), and the means were separated using Duncan's multiple range test (DMRT) at the 5% level of significance. Between the two varieties, the highest seed germination percentage (76.0% seedlings/plot) was recorded in SL958 (0.4% SA), while the lowest (30.33% seedlings/plot) was observed in 0.6% MMS as compared to the control (53% and 76% in SL744 and SL958 at 10 days after sowing, respectively). Several weeks after sowing, the average plant height was observed to be higher (37.84 ± 1.32 cm) in SL958 (0.4% SA) and lower (20.58 ± 0.30 cm) in SL744 (0.6% SA), as compared to the controls (SL958: 26.09 ± 0.62 cm and SL744: 27.48 ± 0.74 cm). The average leaf count was the highest (234.33 ± 3.09 tetrafoliate leaves/plant) in SL958 (0.4% SA) while it was the lowest (87 leaves/plant) in 0.6% MMS as compared to the control (SL744 180.00 ± 1.63 and SL958 160.73 ± 1.05). The highest total leaf areas recorded in the SL958 and SL744 M1plants were 3625.8 ± 1.43 cm2 and 2311.03 ± 3.65 cm2, respectively. Seeds of the SL958 variety treated with 0.4% SA resulted in the development of tetrafoliate leaves with a broad leaf base and the maximum yield (277.55 ± 1.37 pods/plant) compared to the narrow pentafoliate leaves obtained through the treatment with EMS. Meanwhile, in the SL744 variety, the same treatment led to tetrafoliate leaves with a comparatively lower yield of 206.54 ± 23.47 pods/plant as compared to the control (SL744 164.33 ± 8.58 and SL958 229.86 ± 0.96). The highest protein content (47.04 ± 0.87% TSP) was recorded in the SL958 (0.4% SA) M2 seeds followed by a content of 46.14 ± 0.64% TSP in the SL744 (0.4% SA) M2 seeds, whereas the lowest content (38.13 ± 0.81% TSP) was found in SL958 (0.6% MMS). Similar observations were recorded for the lipid and fibre content. The 0.4% SA treatment in SL958 proved to be efficient in generating the highest leaf area (tetrafoliate leaves) and a reasonable yield of M1 (the first generation after mutation) plants.

Various presowing treatments for enhancing Melia dubia (Cav.) seed germination, seedling development, and vigor index

Melia dubia (Cav.) is one of the most promising agroforestry multipurpose tree species. However, there is a shortage of this quality planting material due to its low germination ability. Our study assessed six different presowing treatments, namely, soaking in tap water for 24 h, soaking in a cow dung slurry for 7 days (CDS), scarification with 50 % H2SO4 for 5 min, soaking in 200 ppm gibberellic acid (GA3) for 24 h, and soaking in CDS + H2SO4, GA3 + H2SO4 or the control (no application), for enhancing seed germination and growth in Melia dubia during 2019–20 in the Indo-Gangetic Plains region. STAR version 2.0.1 was used to analyze the observed data using one-way ANOVA. The results of this study showed that different treatments substantially impacted the germination and growth of Melia dubia. Compared with those of untreated seeds (control), the germination percentage of seeds treated with cow dung slurry significantly increased by 49 %, the biomass percentage significantly increased by 25 %, and the vigor index significantly increased by 79 %. In conclusion, our study revealed that treating Melia dubia seeds with cow dung slurry for a period of 7 days enhances germination and seedling growth and is also cost-effective for nursery managers and farmers due to the absence of associated costs.