Non-primed Seeds Research Articles

Evaluation of Two Different Methods of Fulvic Acid Application (Seed Priming and Foliar Spray) on Growth, Yield, and Nutritional Quality of Pea (Pisum sativum L.)

Pea is a commercially significant legume that is widely utilized worldwide and has a elevated amount of nutrition and bioactive components. Its consumption is attributed to a number of health benefits and its potential as a functional food. Fulvic acid can be used as a bio-stimulant to promote plant growth and increase nutrient availability and uptake. A field experiment was designed during two subsequent cropping seasons (i.e., 2022–23 and 2023–24) to evaluate the impact of two methods of fulvic acid application of seed priming and foliar spray on the growth, yield, antioxidant content, and nutritional value of pea (Pisum sativum L.) plants. The seeds were primed with fulvic acid at 1.5, 3 g L−1, and water, while a foliar spray of fulvic acid with the same doses was performed on the seedlings of non-primed seeds. The results obtained exhibited that the seed priming technique with fulvic acid outperformed the fulvic acid foliar applications. The increase in the fulvic acid dose to 3 g L−1 in both application techniques exhibited the highest plant growth, heaviest fresh and dry weights, and highest green seed yield. The maximum growth parameters were recorded after the foliar spray treatment at a dose of 3 g L−1, as it led to improvement in the growth parameters, leaf pigments, and total carbohydrates. The highest number of seeds per pod, number of pods per plant, 100-seed weight, and seed yield were obtained by the seed priming technique. From the results obtained, it may be concluded that the application of fulvic acid at 3 g L−1 via the seed priming technique is beneficial for enhancing the productivity of peas.

Bacteria as potential biocontrol agents for managing purple witchweed (Striga hermonthica) in grain sorghum

Abstract Purple witchweed [Striga hermonthica (Delile) Benth.], a highly destructive parasitic weed, poses a significant threat to sorghum [Sorghum bicolor (L.) Moench] cultivation. This hemiparasitic plant intrudes its root system into the host plant, leading to substantial yield losses, particularly in susceptible genotypes. In the pursuit of eco-friendly solutions, the biocontrol approach has gained attention as a potential management strategy for Striga. In this study, 13 bacterial strains belonging to the genera Bacillus, Gluconobacter, Pseudomonas, and Streptomyces were investigated in vitro for their efficiency in controlling the early-stage development of Striga. Among the tested strains, Streptomyces morookaensis NRRL B-12429 demonstrated significant inhibition of Striga seed germination and radicle elongation at 54.36% and 61.84%, respectively, when applied to preconditioned seeds with a synthetic germination stimulant. The effect of S. morookaensis on the inhibition of Striga seed germination was more pronounced in the presence of the host plant, sorghum, at 62.35%. However, biopriming of sorghum seeds with S. morookaensis did not enhance the inhibitory effects on Striga seed germination but resulted in a greater reduction in radicle elongation at 74.64% compared with non-primed seeds. Additionally, the biopriming with S. morookaensis promoted the growth of shoots and roots of germinating sorghum, regardless of the presence of Striga seeds. These findings highlight the potential of S. morookaensis strain NRRL B-12429 as a viable candidate for biocontrol agent applications in sorghum cultivation. Further exploration and investigation of its biocontrol capabilities can provide valuable insights for sustainable management practices against Striga infestations.

Enhancing growth and yield attributes through bio priming approach in direct seeded rice

Sowing pregerminated and primed rice seeds was found to be advantageous in shortening the numbers of emergence, heading, and maturity days. Reduction in the maturity period of rice by 14.1 days is a significant phonological achievement. Therefore, to ensure the benefits of seed enhancing techniques on seed yield and yield components of rice (Oryza sativa L.),field experiment was conducted in Split Plot Design with four replications using PMK(R)4 with fourteen different seed biopriming liquid microbial cultures and its combinations. The results showed that the seeds soaked in equal volume of liquid microbial cultures Azospirillum+ Phosphobacteria 20% for 18hrs recorded maximum plant height at 45(29.2cm), 90DAS(105.2 cm) and harvest stages (113.3 cm). The leaf area index(10), number of productive tillers, panicle length(36.3 cm), number of spikelets per panicle (106) and panicle weight were maximum in co-inoculated priming treatment Azospirillum + Phosphobacteria and Azospirillum+ Phosphobacteria+ Silicate Solublizing Bacteria followed by Azosprillium 20% for 18hrs and minimum with non-primed seeds. Combined application of Azospirillum + Phosphobacteria was found to be most effective treatment in improving seed yield per plot(6.6g), seed yield per hectare and 1000 seed weight (24.72 g) over non-primed seeds.

Melatonin Priming Promotes Crop Seed Germination and Seedling Establishment Under Flooding Stress by Mediating ABA, GA, and ROS Cascades.

Both seed germination and subsequent seedling establishment are key checkpoints during the life cycle of seed plants, yet flooding stress markedly inhibits both processes, leading to economic losses from agricultural production. Here, we report that melatonin (MT) seed priming treatment enhances the performance of seeds from several crops, including soybean, wheat, maize, and alfalfa, under flooding stress. Transcriptome analysis revealed that MT priming promotes seed germination and seedling establishment associated with changes in abscisic acid (ABA), gibberellin (GA), and reactive oxygen species (ROS) biosynthesis and signaling pathways. Real-time quantitative RT-PCR (qRT-PCR) analysis confirmed that MT priming increases the expression levels of GA biosynthesis genes, ABA catabolism genes, and ROS biosynthesis genes while decreasing the expression of positive ABA regulatory genes. Further, measurements of ABA and GA concentrations are consistent with these trends. Following MT priming, quantification of ROS metabolism-related enzyme activities and the concentrations of H2O2 and superoxide anions (O2 -) after MT priming were consistent with the results of transcriptome analysis and qRT-PCR. Finally, exogenous application of GA, fluridone (an ABA biosynthesis inhibitor), or H2O2 partially rescued the poor germination of non-primed seeds under flooding stress. Collectively, this study uncovers the application and molecular mechanisms underlying MT priming in modulating crop seed vigor under flooding stress.

Synchrotron tomography of magnetoprimed soybean plant root system architecture grown in arsenic-polluted soil.

The present study evaluated the repercussions of magnetopriming on the root system architecture of soybean plants subjected to arsenic toxicity using synchrotron radiation source based micro-computed tomography (SR-µCT). This will be used evey where as abbreviation for the technique for three-dimensional imaging. Seeds of soybean were exposed to the static magnetic field (SMF) of strength (200 mT) for 1h prior to sowing. Magnetoprimed and non-primed seeds were grown for 1 month in a soil-sand mixture containing four different levels of sodium arsenate (0, 5, 10, and 50 mg As kg-1 soil). The results showed that arsenic adversely affects the root growth in non-primed plants by reducing their root length, root biomass, root hair, size and number of root nodules, where the damaging effect of As was observed maximum at higher concentrations (10 and 50 mg As kg-1 soil). However, a significant improvement in root morphology was detected in magnetoprimed plants where SMF pretreatment enhanced the root length, root biomass, pore diameter of cortical cells, root hair formation, lateral roots branching, and size of root nodules and girth of primary roots. Qualitative analysis of x-ray micro-CT images showed that arsenic toxicity damaged the epidermal and cortical layers of the root as well as reduced the pore diameter of the cortical cells. However, the diameter of cortical cells pores in magnetoprimed plants was observed higher as compared to plants emerged from non-primed seeds at all level of As toxicity. Thus, the study suggested that magnetopriming has the potential to attenuate the toxic effect of As and could be employed as a pre-sowing treatment to reduce the phytotoxic effects of metal ions in plants by improving root architecture and root tolerance index. This study is the very first exploration of the potential benefits of magnetopriming in mitigating the toxicity of metals (As) in plant roots utilizing the micro-CT technique.

GA3 and BAP phytohormone seed priming enhances germination and PEG induced drought stress tolerance in soybean by triggering the expression of osmolytes, antioxidant enzymes and related genes at the early seedling growth stages

Drought stress strongly affects seed germination and seedling development during the early stages of plant growth in soybean (Glycine max L.). Seed priming with phytohormone (PH) is known to regulate various physiological and biochemical processes that govern plant growth and yield under optimal and stress conditions. In the present study, the effects of seed priming with Gibberellic acid (GA3) (0.28 mM), 6-Benzyl aminopurine (BAP) (20 mM) and Methyl Jasmonate (MJ) (2.5 mM) was studied during germination and at early seedling growth stages in JS-335 (drought sensitive) and MAUS-71 (moderately drought tolerant) soybean varieties under PFG induced drought stress conditions. The seed priming effects were studied in terms of germination percentage and rate (Timson Index), accumulation of osmolytes (proline and glycine betaine), antioxidant enzymes activity (superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT)), and the relative expression of genes viz., Cu/Zn-superoxide dismutase copper chaperone (SOD-CCS) , iron-superoxide dismutase (SODB2) , betaine aldehyde dehydrogenase (BADH2) and dehydration-responsive element binding protein (DREB2A). The germination percentage of non-primed soybean seeds decreased under drought stress but significantly increased upon GA3 and BAP priming. Interestingly, seed priming with MJ completely inhibited the germination in both the varieties. GA3 and BAP seed priming increased proline and glycine betaine accumulation under PEG induced drought stress in both the soybean varieties. The results showed that the activities of SOD, APX and CAT were significantly enhanced in the leaves of seedlings raised from GA3 and BAP-primed seeds, as compared to the non-primed seeds under the drought stress conditions. Isozyme profiling of SOD and APX revealed that the GA3 and BAP seed priming treatments enhanced the drought-inducible expression of SOD isozymes rather than inducing novel isoforms. In case of APX isozymes, GA3 seed priming appears to preserve APX isozyme diversity in both varieties, and BAP seed priming elevated the expression of APX isoforms in both soybean varieties under the drought conditions. In response to the drought stress, relative expression of the genes associated with superoxide dismutase and glycine betaine viz., SOD CCS, SODB2, BADH2 and DREB2A was markedly upregulated in the leaves of seedlings raised from the GA3 and BAP primed seeds in both the soybean varieties. The global correlation analysis designated that the osmolyte Proline, antioxidant enzyme APX and CAT, and SOD CCS, SODB2, BADH2 and DREB2A genes were potent regulator for drought stress tolerance mechanism in soybean. This study illuminates the intricate interplay of GA3 and BAP hormonal seed priming during the germination and early seedling stages in soybean plants under the drought stress. This finding emphasizes the critical consideration of genotype specific reactions to the hormonal seed priming under PEG induced drought stress conditions.

Salicylic Acid and Calcium Chloride Seed Priming: A Prominent Frontier in Inducing Mineral Nutrition Balance and Antioxidant System Capacity to Enhance the Tolerance of Barley Plants to Salinity.

The current investigation aims to underline the impact of salicylic acid or calcium chloride seed pre-treatments on mineral status and oxidative stress markers, namely levels of electrolyte leakage (EL) and lipid peroxidation levels, measured as thiobarbituric reactive substances (TBARS), and the activity of some antioxidant enzymes in roots and leaves of plants in two barley species grown under various salt treatments. Overall, our results revealed that salinity inhibits essential nutrient absorption such as iron, calcium, magnesium and potassium and stimulates the absorption of sodium. Also, this environmental constraint induced oxidative stress in plants in comparison with the control conditions. This state of oxidative stress is reflected by an increase in TBARS content as well as the stimulation of EL values. In addition, salinity induced disturbances in the activity of antioxidant enzymes, which were mainly dependent on the applied salt concentration and the species. In addition, Hordeum marinum maintained high antioxidant enzyme activity and low levels of oxidative stress parameters, which reinforces its salt-tolerant character. Importantly, salicylic acid or calcium chloride seed priming alleviated the mineral imbalance and the oxidative damage induced by salinity. Moreover, seed priming improves iron, calcium magnesium and potassium content and limitsthe accumulation of sodium. Also, both treatments not only decrease TBARS levels and limit EL, but they also stimulate the antioxidant enzyme activities in the leaves and roots of the stressed plants as compared with stressed plants grown from non-primed seeds. Interestingly, the beneficial effects of the mentioned treatments were more notable on Hordeum vulgare species.

Enhancing Bean (Phaseolus vulgaris L.) Resilience: Unveiling the Role of Halopriming against Saltwater Stress

Common bean (Phaseolus vulgaris L.), one of the most important cultivated legumes, requires a high level of water. It is included among the most sensitive species to climate change; drought and salinity cause a reduction in photosynthesis, metabolic and enzymatic alterations, and oxidative stress. To improve crop tolerance to salt, seed priming and acclimation can be useful tools. To test the salt tolerance of beans, a preliminary screening was undertaken on four cultivars of P. vulgaris (Black Turtle, Cargamanto, Bola Roja, Borlotto) by exposing the seeds to different levels of salinity. The salt-sensitive cultivar Borlotto was chosen for experimental greenhouse trials to study the effects of halopriming and acclimation. Primed and non-primed seeds were sown in non-saline soil and acclimated for 2 weeks; then, the plants were watered with non-saline and saline solutions for 4 weeks. At the end of this growth period, the primed plants showed a marked increase in salt stress tolerance, improving the chlorophyll content, phenolic compounds, and many enzymes’ activities, in turn reducing the effect of salt on growth and fruit production compared to the non-primed controls. In conclusion, halopriming can be considered a useful tool to enhance salinity tolerance in beans and other salt-sensitive crops.

Seed Priming with Nanoencapsulated Gibberellic Acid Triggers Beneficial Morphophysiological and Biochemical Responses of Tomato Plants under Different Water Conditions

Water deficit (WD) promotes great losses in agriculture, and the development of new sustainable technologies to mitigate the effects of this stress on plants is essential. This study aimed to evaluate the morphophysiological and biochemical alterations induced by the priming of tomato seeds with different formulations in plants under field capacity and WD conditions. In the first experiment, the treatments consisted of nanoparticles of alginate/chitosan and chitosan/tripolyphosphate containing gibberellic acid (GA3) in different concentrations (0.5, 5, and 50 µg mL−1 GA3), in addition to control with deionized water. The alginate/chitosan (5 µg mL−1 GA3) provided the greatest gains in plant growth under field capacity. In addition, under WD this treatment reduced damage to photosystem II (−14%), stomatal conductance (−13%), and water loss (−38%) and increased the instantaneous carboxylation efficiency (+24%) and intrinsic water use efficiency (+12%). In the second experiment, the treatments were alginate/chitosan nanoparticles containing GA3 (NPGA3 5 µg mL−1), free GA3 (GA3 5 µg mL−1), nanoparticles without GA3 (NP), deionized water (WATER), and non-primed seeds (CONT). Under WD, GA3 and CONT maintained plant growth and lost water rapidly, reducing stomatal conductance (−87%) and net photosynthesis (−69%). In contrast, NPGA3 decreased leaf area (−44%) and increased root-to-shoot ratio (+39%) when compared to GA3, reducing water loss (−28%). Activation of protective mechanisms (e.g., superoxide dismutase and catalase activities) by WATER, NPGA3, and NP treatments also resulted in lower susceptibility to WD compared to CONT and GA3. The results highlight the positive effect of seed priming on plant response to WD, which was enhanced by the use of nanoencapsulated GA3.

An insight into seed priming response of Crotalaria ochroleuca and Crotalaria spectabilis during storage.

The proper establishment of plants is essential for the efficient use of resources such as water and light. Besides, even after seed storage and sowing the uniform establishment of plants is essential for their success. Crotalaria ochroleuca and Crotalaria spectabilis are important medicinal plants with poor seed germination rate, occasionally. The effects of seed priming in both C. ochroleuca and C. spectabilis were evaluated in seed performance even after seeds storage for up 90-days. Experimental assays were performed in a randomized design with gibberellic acid (GA3, 100 ppm), polyethylene glycol (PEG 6000, -0.2 MPa) and PEG (-0.2 MPa) + GA3 (100 ppm) solutions during seed priming in four replicates. Seeds not submitted to priming treatments constituted control. Seeds physiological performance were evaluated immediately and even after 30, 60 and 90-days seed dry-storage. The data obtained in each experiment were submitted to variance analysis (ANOVA) adopting a confidence level of 95%. The effects of seed priming with PEG and GA3 during seed ageing were significant for germination variables of C. ochroleuca and C. spectabilis. During dry storage, seed viability of both species gradually decreased and the first symptoms were delayed seed germination, especially more evident for C. ochroleuca, even in primed or non-primed seeds. Afterwards, C. ochroleuca seeds previously GA3 primed had higher results of root protrusion (86%), hypocotyls elongation (76%) and complete seedlings (75%) than non-primed seeds (control). These findings shown a good potential of hormopriming to attenuate damage during the seed aging of C. ochroleuca.

Comprehensive Metal-Based Nanopriming for Improving Seed Germination and Initial Growth of Field Pea (Pisum sativum L.)

Nanopriming is a newly developed seed technology that improves seed germination, initial plant growth, and crop yield by enabling plants to withstand a variety of abiotic stresses. The objective of this study was to evaluate the effectiveness of comprehensive metal-based (Co, Mn, Cu, Fe, Zn, Mo, and Se) nanopriming as compared to hydro- and non-primed seeds of three different pea cultivars in a germination test. Seed priming with nanoparticles (NPs) improved field pea quality via significant increase in germination energy (cv. E-244), final germination (cv. E-244, cv. Dukat), shoot length (cv. E-244, cv. Partner), root length (cv. E-244, cv. Dukat, cv. Partner), fresh shoot weight (cv. Partner), dry shoot weight (cv. Partner), seedling vigor index (cv. E-244, cv. Partner), and chlorophyll content (cv. Dukat, cv. Partner), as compared to both hydropriming and the control. Moreover, nanopriming led to significant improvements in shoot length, fresh shoot length, dry shoot length, seedling vigor index (cv. Dukat), and dry root weight (cv. E-244) as compared to the control only. In general, the highest effect on the examined parameters was achieved by nanopriming, indicating that this treatment may be utilized to raise field pea quality performance. To optimize the method, it is necessary to conduct extensive laboratory and field trials.

Morphological and biochemical changes with hormone and hydro- priming applications in safflower (Carthamus tinctorius L.) seedlings under salinity stress conditions

In this study, the ameliorative effects of hydro- and hormopriming applications against salt stress of safflower seeds during germination and seedling development stage were investigated. Primed (hydropriming (0, 1, 2 and 3 days) with distilled water and hormopriming for 24 hours (0, 50, 100 and 150 mg L-1 with kinetin) and nonprimed seeds were sown under control (no salt) and salt stress (0, 50, 100 and 150 mM NaCl) conditions. When priming applications under salt stress are compared with the control, germination percentage (GP), seedling lenght (SL), root length (RL), seedling fresh weight (SFW), root fresh weight (RFW), leaf relative water content (RWC), elctrolyte leakeage (EL) parameters reducing the effects of stress, however, it was determined that caused an increase in carotenoid (Car), superoxide dismutase (SOD), total phenolic compounds (TPC) parameters. Besides this, it has an inhibitory effect on the increase in proline (Pro) and malondialdehyde (MDA) content. According to the correlation analysis, significant positive correlation was determined in all parameters. A significant positive correlation was determined for hydropriming GP with SL, RL, SFW, RFW, and for hormopriming with SL, RL, SFW, RFW, total Chl, RWC and GP. According to the PCA analysis, the parameters examined in both applications it is seen that they are divided into four different groups. In conclusion, this study priming applications are compared with each other, it has been determined that hormopriming is more effective in reducing the effects of stress than hydropriming.

Growth and Productivity of Cowpea (Vigna unguiculata L.) in Response to Seed Priming and Different Levels of Phosphorus

Acidic soil generally has lower availability of phosphorus. Grain legumes respond positively to higher levels of phosphorus in acidic soil. Seed priming also enhances growth of the crops by activating various metabolic processes in plants. A field experiment was carried out to determine the influence of seed priming and phosphorus levels on growth and productivity of cowpea at Bhojad, Chitwan, Nepal. The experiment plot was laid out in two factorial randomized complete block design with three replications and the planting was done in spring season of 2022. The treatment consisted of two levels of seed priming (no priming and priming with 0.2 % Ca (NO3)2 for 24 hours) and four levels of P2O5 (20,30,40 and 60 kg ha-1). The variations in different parameters of cowpea due to seed priming were significant (P < 0.05). Primed seed produced the highest grain yield (1.25 t ha-1), which was followed by non-primed seeds (1.16 t ha-1). Similar significant (p<0.001) differences in yield and yield-attributing (no. of grains/pods, test weight, biological yield, grain yield and harvest index) traits were found at different levels of P2O5, with the highest grain yield (1.44 t ha-1) was obtained when applied with 40 kg P2O5 ha-1. Significant (p<0.001) variations in grain yield were found as a result of the interaction between priming and P2O5 levels. The combination of priming and 40 kg P2O5 ha-1 produced the highest grain yield (1.51 t ha-1). The results showed that the use of primed seed with 40 kg P2O5 ha-1 would be beneficial for the farmers in the Terai region of Nepal.

Planting methods influence revegetation success of native species in an arid environment

In Kuwait, declining native vegetation cover due to prevailing arid conditions and severe anthropogenic disturbances necessitated undertaking revegetation programs. Seed sowing and outplanting of nursery-grown seedlings are the two major plant establishment methods commonly used all around the world. However, the success of plant establishment methods may vary between the species as well as between the methods. Therefore, we compared the effect of sowing of primed or non-primed seeds and outplanting of nursery-grown seedlings on field performance of four dominant native desert species of Kuwait: Vachellia pachyceras, Rhanterium epapposum, Farsetia aegyptia, and Haloxylon salicornicum for 22 months to find the best method for revegetation in arid conditions. A significant species and treatment interaction effect was observed in all plant parameters except plot volume index. Direct sowing of hydro-primed seeds appeared to be the most effective method for establishment and growth of V. pachyceras. In contrast, outplanting of nursery-grown seedlings showed better performance under the field conditions in H. salicornicum and F. aegyptia. These results suggest that direct sowing of primed seeds can also be used effectively along with seedling outplanting for the revegetation of arid lands.

Seed Priming with Exogenous Amino Acids Improves Germination Rates and Enhances Photosynthetic Pigments of Onion Seedlings (Allium cepa L.)

As a biostimulant, amino acids play crucial roles in enhancing plant growth and development. These roles, combined with the ability to be approved for organic usage, make amino acids a good choice for sustainable farming systems. This work investigates the effect of onion seed priming with different exogenous amino acids, specifically the impact of seed priming in enhancing a diverse range of morpho-physiological responses of onion seedlings. Here, we primed onion seeds (Cultivar Giza 6) with ten exogenous amino acids. Based on the growth parameters of onion seedlings, data showed that glutamine significantly improved the most studied parameters. Germination percentage (GP) ranged from 85% in Methionine (Met) to 98.5% in Proline (Pro) and Tryptophan (Try), with 10% over the control treatment. Glutamine (Glu) enhanced the vigor index (VI) of onion, giving the seeds a high ability to produce normal seedlings. The most extended root system (≥3.3 cm) was obtained from Glu, Glycine (Gly), Pro, and Try treatments. The maximum shoot length was obtained from treatments (Glu and Try) with more than 60% over control. Priming onion seeds with amino acids (AAs) increased chlorophyll contents compared with non-primed seeds. Glutamine and Threonine (Thr) had the highest results (122 and 127 μg/g fresh weight, respectively), while the Glu treatment registered the highest Carotene contents with 50% over the control treatment. Furthermore, the data illustrate that the principal component analysis-1 (PCA1) indicates 67.2% variability, and PCA2 indicates 14.8% variability. Strong positive correlations were observed between germination percentage, root length, shoot length, dry matter, chlorophyll a, and carotene. The study concluded that the primed onion seeds by glutamine, proline, and tryptophan had the best germination rates.

Quality of garden pea (Pisum sativum L.) primed seed

The objective of this study was to examine the effects of different priming treatments on seed quality and initial growth and development of garden pea. For this purpose, three garden pea cultivars, developed at the Institute of Field and Vegetable crops, Novi Sad were examined. The laboratory experiment was conducted under optimal conditions. Seeds were primed in water (hydropriming), 0.5% KNO3 solution, and -0.49 MPa PEG solution for 24 hours; non-primed seeds were controls. The results showed that the percentage of germination, shoot and root length, and mean germination rate significantly increased after the tested priming treatments, while the percentage of abnormal seedlings and mean germi?nation time were significantly decreased after the priming treatments compared to the control. The increase of fresh and dry seedling biomass was significant only in cv.1 and cv.2. Despite the genetic diversity of pea cultivars, the results indicated that the examined seed priming treatments enhanced seed quality and vigour of garden pea cultivars.

RNA Sequencing indicates gene expression changes in Silene sendtneri seeds after seed priming with silicic acid

To improve our understanding of the molecular mechanisms underlaying seed priming, RNA transcriptome analysis was performed using primed and non-primed seeds of Silene sendtneri. Seed priming was performed by submergence in 1% silicic acid for 24h at 4°C, followed by rinsing with sterilised water and desiccation to original moisture content. Silene sendtneri is a species with no sequenced genome and annotation of de novo assembly of transcriptome was done against several species. Gene ontology (GO) analysis indicated that genes related to heavy metal transporters and heat shock proteins are differentially expressed after priming with silicic acid. Within these gene categories, genes such as heavy metal-associated isoprenylated plant protein 26-like (log2fold -8.79) were downregulated, while others such as heavy metal ATPase 5 (log2fold 6.46), heat shock factor protein HSF30-like isoform X1 (log2fold 5.98) were upregulated.

Effect of Seed Priming on Germination and Seedling Parameters of Cucumber (Cucumis sativus L.) in Lamjung, Nepal.

Poor seed germination obstructs the early and uniform seedling emergence at the sub-optimal conditions which can be a major setback to early spring cucumber growers. Different seed priming methods ought to be efficient solutions for the problem. To standardize the best priming method, an experiment was laid out in a Completely randomized design at the Horticulture lab of IAAS, Lamjung Campus. The treatment consisted of demineralized distilled water (hydropriming), hormonal priming (GA3 100ppm and GA3 200 ppm), halopriming (NaCl 0.5% and KNO3 0.5%), and non-primed seeds as control. The seeds were soaked in the respective treatment for 24 hours and then dried to initial moisture content under shade conditions. Observation recorded significantly highest germination percentage in GA3 100ppm (19.25%) and hydro priming (19.25%). The lowest mean germination time was found in GA3 100ppm (4.19days) which was significantly at par with GA3 200ppm (4.33days) and hydro priming (4.48days). The germination energy was found highest in GA3 100ppm (39.58) followed by GA3 200ppm (33.65) and dry weight was recorded highest in hydropriming (0.0252g) followed by GA3 100ppm (0.0250g) whereas the highest root length was observed in KNO3 priming (12.955cm) which is statistically at par with hydropriming (11.42cm), GA3 200 ppm (10.872cm) and NaCl priming (10.42cm). The plumule length was observed highest in KNO3 (13.00cm) followed by NaCl (11.25cm). All primed seeds showed increased seedling vigor compared to the unprimed seeds. The study showed that applied treatment notably increased the germination characteristics and seedling stand.

Thiamine and Indole-3-Acetic Acid Induced Modulations in Physiological and Biochemical Characteristics of Maize (Zea mays L.) under Arsenic Stress

Arsenic (As) accumulation in plant tissues is an emerging threat to crop productivity and global food security. As-toxicity in soil is increasing at alarming rates through mining, pesticide applications and industrial revolution. Therefore, a novel study was conducted to disclose the role of vitamin B1 (thiamine) and Indole-3-acetic acid (IAA) in maize (Zea mays L.) against different As stress levels, i.e., 0, 50 and 100 mg/kg sodium arsenite (NaAsO2). Seeds of two contrasting maize varieties Akbar and Pearl were primed with different treatments, i.e., control (non-primed seeds), thiamine (250 ppm), IAA (30 µM) and a mixture of thiamine (250 ppm) + IAA (30 µM). Of both As stress levels (50, 100 mg/kg), a higher As stress level (100 mg/kg) imparts maximum negative impacts on maize growth by decreasing shoot and root nutrient ions—potassium (K), calcium (Ca), phosphorus (P), total phenolics, total soluble proteins—as compared to the control, while increases in catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), malondialdehyde MDA, hydrogen peroxide (H2O2), proline, total soluble sugars, free amino acids and ascorbic acid were recorded under As-stress as compared to control. The varietal differences showed that Pearl exhibited tolerance against As-stress as compared to Akbar. However, thiamine and IAA treated seeds of maize manifested remarkable enhancement in plant growth attributes with better chlorophyll, plant water status, enzymatic and non-enzymatic antioxidants activities under imposed As-stress. The growth and biomass significantly increased with priming treatments of thiamine and IAA under both As-stress levels of both varieties that suggests the role of these in As-stress tolerance. Overall, the performance order in improving growth under As-stress of thiamine and IAA treatments was thiamine + IAA > thiamine > IAA observed in both maize varieties.

Solid matrix priming improves cauliflower and broccoli seed germination and early growth under the suboptimal temperature conditions.

Seed priming is an effective method for imparting stress tolerance to plants. This study aimed to analyze the effects of solid matrix priming (SMP) on cauliflower and broccoli seed germination and early seedling growth under suboptimal temperature conditions. The SMP method used in this study included the following steps: (1) mixing seeds with vermiculite and water at a ratio of 2:3:2.5 (w/w/v) and incubating for 2 days in the dark at 20°C; (2) drying the SM-primed seed; (3) germinating the SM-primed and the nonprimed seeds at 10, 15, 20, and 25°C; (4) analyzing the antioxidant enzyme activities of SM-primed and nonprimed germinating broccoli and cauliflower seeds in the early germination stage at 10, 15, 20, and 25°C; and (5) testing the emergence of SM-primed and nonprimed control seeds in the early spring glasshouse. The results showed that the SMP improved seed germination vigor and early seedling growth and increased the activities of peroxidase and ascorbate peroxidase in the germinating cauliflower and broccoli seeds under the suboptimal temperature conditions in the early germination stage compared with nonprimed seeds. It was observed that the suboptimal temperature conditions (i.e., 10 and 15°C) suppressed SM-primed and nonprimed seed germination and early seedling growth of cauliflower and broccoli. Inside a greenhouse, the SMP improved the emergence of cauliflower and broccoli seeds during the early spring season. SMP is an effective method for improving seed germination and the emergence of cauliflower and broccoli under suboptimal temperature conditions.