Growth Of Seedlings Research Articles

Phytotoxicity and accumulation of PFHxS in Australian native grasses of arid regions: implications for ecological risk assessment.

In Canadian boreal forests, clearcutting has traditionally been the main harvest treatment, resulting in relatively uniform, even-aged stand structures. With the shift to ecosystem-based management, partial harvest is proposed as an alternative that helps to maintain complex stand structures. Few studies have assessed the combined effects of edaphic conditions and competition on regeneration survival and growth. Our objective was to assess how different harvest intensities influence the role of edaphic conditions and interspecific competition in the height growth of white spruce ( Picea glauca [Moench] Voss) and balsam fir ( Abies balsamea (L.) Mill) seedlings. Edaphic condition parameters included nitrogen (N) and phosphorus (P) concentrations, pH and cation exchange capacity (CEC). Competition indices were angular height (AH) and vegetation cover. Our results showed that in the clearcut treatment, P concentration explained 23.4% of balsam fir and 23.9% of white spruce seedling growth, while AH accounted for 27.9% of balsam fir growth. In the partial cut treatment, the studied parameters explained poorly the variability in seedling growth, likely due to a limited number of measured variables. In the unharvested stands, both pH and AH explained most of balsam fir and white spruce seedlings growth. Overall, growth requirements varied more between harvest treatments than between species.

Vertical nursery systems offer promising solutions for stable, year-round lisianthus [Eustoma grandiflorum (Raf.) Shinn.] seedling production. Artificial lighting remains the largest contributor to energy consumption in the operations, underscoring the need to optimize both the light spectra and daily light integral (DLI). Five light-emitting diode (LED) spectral combinations including combinations of red, blue, and far-red light were tested while natural sunlight served as the control. Seedlings grown under the spectral combination of red:blue:far-red at a ratio of 1:1:0.2 exhibited superior shoot and root biomass, larger leaf area, greater stem diameter, higher seedling index, enhanced photon yield (PY), and an improved success rate in mechanical transplantation compared with those associated with other spectral treatments. Far-red supplementation reduced photosynthetic parameters, the net assimilation rate, transpiration rate, electron transport rate, effective quantum yield of photosystem II, and photochemical quenching coefficient. However, it promoted normal shoot elongation after transplantation. In contrast, plants grown under only red and blue light had shortened internodes. Seedling growth exhibited a positive quadratic response to increasing DLI (from 5.18 to 12.96 mol·m−2·d−1). Most growth parameters peaked at a DLI of approximately 10 mol·m−2·d−1, whereas PY reached its maximum efficiency of 2.3 g·mol−1 photosynthetic photon flux density at a lower DLI of approximately 5.6 to 6.1 mol·m−2·d−1. These findings provide data-driven insights regarding optimizing LED spectra and DLI to enhance the growth of lisianthus seedlings in vertical nurseries.

Sustainable application of rare earth elements (lanthanum and cerium) to enhance growth and nutrient uptake in Paramichelia baillonii seedlings via hormonal regulation

Influence of thermo-oxidatively aged mulch debris on the seedling emergence of field pea (Pisum sativum var. arvense L.) seeds.

BackgroundDrought stress significantly inhibits melon seedling growth and ultimately reduces fruit yield. Consequently, identifying drought-resistant germplasms, elucidating the physiological and biochemical mechanisms underlying plant drought responses, and establishing reliable drought resistance evaluation indices are critical objectives for advancing drought-resistant breeding of melon.ResultsThis study measured 30 growth, physiological, and biochemical indices of melon seedlings under drought conditions. By integrating correlation analysis, cluster analysis, and regression analysis, the drought resistance of 15 melon germplasm resources were evaluated, and key drought resistance indices were identified. The results demonstrated that drought stress significantly reduced the dry and fresh weight, total root length, root surface area, root volume, root tips, and forks of melon seedlings, but significantly increased the root-shoot ratio of plants. Additionally, drought stress significantly reduced leaf relative water content (RWC), increased pigment content (chlorophyll a, chlorophyll b, carotene, and total pigment) and regulatory substance content (soluble sugar and γ-aminobutyric acid, GABA). Furthermore, drought stress elevated the levels of hydrogen peroxide (H2O2), malondialdehyde (MDA), and oxidized glutathione (GSSG), while reducing superoxide anion (O2·−−) and GSH/GSSG, indicating oxidative stress in melon seedlings. Using D-value cluster analysis, the 15 melon germplasms were classified into 5 categories: strongly drought-resistant group (17Y1 and 17Y11), drought-resistant group (GT3, 23G36, YJM, 23G33 and 23G37), moderately drought-resistant group (GT4, 22P8 and GT1), drought-sensitive group (YD, TN and LB946), and highly drought-sensitive group (22P7 and 22G40). Stepwise regression analysis identified the following indices as objective evaluation criteria for melon seedling drought resistance: drought injury index (DI), chlorophyll a content, relative electrical conductivity (REC), and betaine content.ConclusionsTaken together, this study screened 2 strongly drought-resistant melon materials, 5 drought-resistant materials, 3 moderately drought-resistant materials, 3 drought-sensitive materials and 2 highly drought-sensitive materials. At the same time, drought injury index (DI), chlorophyll a content, relative electrical conductivity (REC), and betaine content were selected as the drought resistance indices of melon. These findings lay a theoretical foundation for melon drought resistance breeding.

The research assessed the current state of the Mongolian pine forests and revealed the features of their restoration after logging and fires. It was found that the number of Pinus sylvestris L. undergrowth in the cuttings is 15–18 times less than under the canopy of undisturbed stands. Noticeable changes in the cuttings are also observed in the ground cover. So, 5–8 years after harvesting the stand, part of the taiga forest species of the grass-shrub layer disappears in the cuttings and steppe and forest-meadow plant species appear. Changed environmental conditions, intensively developing ground cover and frequently recurring grass-roots fires in cuttings prevent the emergence of seedlings and the formation of undergrowth of the main forest-forming species. The pyrogenic factor is the main anthropogenic factor preventing the natural restoration of forests after their disturbance. Dendrochronological analysis of pine wood samples indicates that fires in the studied area occurred in the past with an average frequency of about 14 years. In the last 20–25 years, during the period of uncontrolled exploitation of forests, forest communities have been exposed to fires once every 7–9 years, and in some tracts much more often. The Scots pine is successfully renewed on burning grounds. The amount of viable undergrowth ranges from 3 to 10 thousand, pcs./ ha. In case of repeated fires in these areas, pine undergrowth and living ground cover are damaged or completely destroyed, shoots in the amount of 4–5 thousand pcs/ha or more appear in places of burnt litter. The age of the undergrowth of the scots pine in the burning is determined, for the most part, by the prescription of the last fire. Haphazard logging of stands and forest fires are most often powerful exogenous factors affecting the formation and development of pine forests in Mongolia.

This study identified 39 SNPs significantly associated with RSR and ST traits, associating to 36 functional genes responding to salt stress, through the joint analysis of GWAS and transcriptome under salt stress in cotton seedlings. These findings offered a molecular foundation for improving salt tolerance of cotton. Improving the survival rate of cotton seedlings under salt stress is a crucial breeding objective for the future. In this study, the GWAS of relative seedling emergence rate (RSR) and salt tolerance grade (ST) traits were operated on salt-stressed cotton seedlings of 373 upland cotton core collections, and identified 39 significantly associated SNPs comprised of 283 genes. Transcriptome sequencing of 18 samples from salt-tolerant and -sensitive variety groups screened out 11,624 long non-coding RNAs (lncRNAs) and 70,478 mRNAs from cotton seedlings under salt stress, including 453 differentially expressed lncRNAs and 6009 mRNAs. Joint analysis of GWAS and differentially expressed mRNAs revealed 36 salt responsive genes significantly associated with RSR and ST traits. VIGS assay further verified that Gh_D07G0886 negatively regulated and Gh_A13G0145 positively regulated the salt tolerance of cotton seedlings, which was consistent with their expression patterns in response to salt stress. These findings offered molecular foundation for improving salt tolerance of cotton.

High temperature stress poses a significant threat to the normal growth of maize seedlings, and key heat-resistant gene mining is the molecular basis for breeding new heat-resistant maize varieties. Through transcriptome sequencing of heat-tolerant hybrid ZD819 and its parental lines (ZD819-F, ZD819-M) under high-temperature stress, we identified 12 HSF (Heat shock transcription factors, HSFs) transcription factors from 12,442 differentially expressed genes. The results indicate that the maize hybrid ZD819 has stronger heat tolerance compared to its parent varieties (ZD819-F, ZD819-M). Transcriptome data identified 12 HSFs transcription factors, among which ZmHSF10 had the highest differential expression fold of 1279.40 before and after high-temperature treatment. The heat tolerance function of ZmHSF10 was studied by creating Arabidopsis thaliana materials overexpressing ZmHSF10 and obtaining ZmHSF10 silenced maize materials using VIGS technology. Genetic experiments have shown that overexpression of ZmHSF10 can stabilize the cell membrane stability of Arabidopsis plants under high temperature stress and improve their survival rate under high temperature treatment. Reducing the expression level of ZmHSF10 leads to a decrease in chlorophyll content, poor cell membrane stability, and lower relative water content in maize leaves under high temperature stress. These results preliminarily demonstrate that ZmHSF10 plays an important role in regulating heat tolerance in plants, providing genetic resources for enhancing heat tolerance in maize seedlings.

A previous study demonstrated that spontaneous forest recovery can result in the development of functional mixed forests in post-mining areas. A critical step in this process is the establishment of climax woody species in the understory of pioneer trees. In this case study, we utilise repeated sampling to evaluate the establishment, initial survival, and growth of pedunculate oak (Quercus robur) and European beech (Fagus sylvatica) seedlings, and to newly assess Norway spruce (Picea abies) during unassisted forest recovery on a post-mining site after coal mining near Sokolov in North Bohemia. Detailed mapping of beech and oak seedlings was conducted in 2009 and 2012 (i.e., 14 and 11 years after the site was reclaimed). Now, we have resurveyed these seedlings, which has allowed us to evaluate their survival and growth. We have also mapped spruce seedlings and estimated their age from annual branch whorls. In the original study, most seedlings were found on the northern site near the edge of the post-mining area and the surrounding landscape, which serve as seed sources. Beech shows the best survival and growth on the northern site, where the greatest number of new seedlings also appear. In contrast, oaks demonstrate much higher mortality than beech overall, with the highest mortality observed on the northern site and the highest survival on the southern site, where most of the new seedlings also appeared. Interestingly, however, surviving oaks grew faster on the northern site. Across microtopography, seedlings of all three tree species were most frequent on the slopes of micro-undulations. Beech individuals were taller in depressions, whereas oaks did not consistently demonstrate a size advantage across microhabitats. Spruce colonised vigorously and was the most abundant of the three species across microhabitats. Age-frequency analyses suggest an annual mortality rate of 3%–9%. Browsing damage was observed on 19% of beech seedlings and 9% of oak seedlings. The study shows that pioneer tree stands are suitable nursing sites for studied climax tree species, which can colonise these sites several kilometres away from mature trees, and their establishment involves a complex interplay between distance to seed source and local microclimatic conditions. Our resurvey indicates that later successional stages may increasingly be shaped by shade-tolerant beech and spruce under the developing canopy.

Among the prominent diseases in rice farming is damping-off, linked to the soilborne fungus Rhizoctonia solani. The pathogen attacks emerging seedlings, leading to tissue damage, reduced vigor, seedling mortality, and ultimately lower plant stands, which may reduce crop yield. Environmental conditions that delay seedling emergence can increase disease severity by extending the window of opportunity for R. solani to infect rice seedlings. This report assesses the efficacy of seed treatments for managing R. solani seedling disease in rice fields in Arkansas. The trial was carried out in 2024 in the Rice Research & Extension Center in Stuttgart, AR, on the Clearfield rice (Oryza sativa L.) variety ‘CL163’. Results from this trial will provide up-to-date information to rice growers for selecting effective seed treatment combinations to manage R. solani seedling diseases.

Growth medium is an important factor in the germination and early growth of cocoa plants. In view of this, a pot experiment was conducted in the screen house of Crop Production Technology department to evaluate the effect of organic-enriched growth media on germination and early growth of cocoa seedlings over a period of one month. The treatments were Control (Top soil only), Top soil + Sawdust, Top soil + Poultry Manure, Top soil + Cow Dung, Top soil + Swine Dung, Top soil + Sawdust + Poultry Manure, Top soil + Sawdust + Cow Dung and Top soil + Sawdust + Swine Dung. The treatments were replicated 10 times and arranged in a completely randomized design. The treatment mixture (Top soil + Sawdust) was done at 3:1, while the organic manures were applied at 10 tons/ha (equivalent to 50 g per pot). Data collected were germination percentage, plant height, stem diameter, number of leaves and leaf area. The collected data were subjected to analysis of variance and significant means were compared using Duncan’s Multiple Range Test at 5% probability. The application of organic manures enhanced the growth performance of cocoa plant, and Top soil + Sawdust was significantly higher compared to other treatments. Top soil + Poultry manure, Top soil + Sawdust and Top soil + Cow dung had the highest significant germination percentages (90%, 89% and 88%) and, produced the highest significant plant height (25.00 cm, 24.00 cm, 23.00 cm), number of leaves (10.50, 10.20, 10.00), leaf area (55.00 cm2, 53.00 cm2, 52.50 cm2) and stem diameter (1.80 cm, 1.78 cm, 1.75 cm) respectively compared to other treatments. The addition of organic manures to the growth substrates improved the germination and early growth of cocoa seedlings. The use of Top soil enriched with poultry manure was recommended for improved early growth of cocoa plant.

Introduction. Biarum bovei Blume is a medicinal plant native to eastern Libya. Although its phytochemical profile has been partially documented, its allelopathic behavior toward cultivated species remains unexplored. Objectives. This study aimed to evaluate the allelopathic effects of incorporating crude leaf and tuber powder of B. bovei into soil on the growth and yield of two Lupinus albus L. varieties (sweet and bitter). Materials and Methods. The pot experiments were conducted during the 2023 growing season at Omar Al-Mukhtar University. Crude powder of B. bovei leaves and tubers was incorporated into pots at 0, 5, and 10 g/kg soil. Ten seeds of each lupine variety were sown per pot in a completely randomized design with three replicates. Morphological and biochemical parameters were measured after four months. Results. The crude powder significantly inhibited several morphological and biochemical traits (P < 0.05), including seedling emergence rate (from 100% to 25%), shoot length, root length, fresh weight per plant (from 6.4 g to 1.8 g), and photosynthetic pigments, notably chlorophyll a (from 1.66 to 0.48 mg/g). Phosphorus, iron, sodium, phenols, and alkaloids also decreased. In contrast, potassium, copper, total nitrogen, crude protein, and proline increased under treatment. The strongest inhibition was recorded with tuber powder at 10 g/kg, and the sweet variety was more sensitive. Conclusions. These findings suggest that B. bovei residues can negatively impact L. albus growth and productivity, particularly when derived from tubers. Further field studies are needed to assess potential implications for crop management.

Submerged aquatic macrophytes play a key role in stream ecosystems, but their recovery in historically degraded Flemish streams is often limited. This study investigates whether sediment contamination constrains natural macrophyte germination and early seedling establishment. To address this knowledge gap, we combined a controlled mesocosm experiment with an analysis of long-term monitoring data from Flemish streams. The mesocosms showed that higher levels of sediment contamination reduced seedling emergence, indicating that sediment quality can directly inhibit germination and early establishment. In addition, historical monitoring data revealed only a weak association between sediment quality and macrophyte occurrence, pointing to the importance of interacting drivers such as hydrology, light availability, and habitat structure. Together, these findings highlight sediment contamination as a context-dependent but relevant barrier to macrophyte recruitment, underscoring the need to integrate sediment quality into broader restoration planning for streams in Flanders and abroad.

Global temperature rise has become a critical challenge to agricultural sustainability, severely affecting crop growth, productivity, and survival. Human-induced climate change and greenhouse gas emissions cause heat stress, disrupting plant metabolism and physiology at all developmental stages from germination to harvest. Elevated temperatures during germination impair water uptake, enzyme activity, and energy metabolism, leading to poor or uneven seedling emergence. At key phases such as flowering and grain filling, heat stress limits photosynthesis and transpiration by inducing stomatal closure, restricting carbon dioxide intake, and reducing photosynthetic efficiency. The reproductive stage is particularly vulnerable to high temperatures, impairing pollen viability, preventing anther dehiscence, and reducing fertilization success. Membrane instability further accelerates chlorophyll degradation and leaf senescence. Heat stress also alters biochemical and hormonal balances by disrupting the synthesis and signaling of auxins, gibberellins, and abscisic acid (ABA). Elevated ABA promotes stomatal closure to enhance stress tolerance, while increased ethylene levels trigger premature leaf senescence and abscission. These hormonal shifts and oxidative stress hinder plant growth and reproduction, threatening global food security. Although plants employ adaptive mechanisms such as heat shock protein expression and stress-responsive gene regulation, current strategies remain inadequate, highlighting the urgent need for innovative approaches to improve crop resilience under rising temperatures.

Studying hypoxia in rice is particularly important because oxygen deficiency during germination severely limits seedling establishment. Understanding the molecular and physiological mechanisms underlying hypoxic tolerance is therefore crucial for improving rice yield stability under flooded or waterlogged conditions. Progress in developing rice cultivars that thrive under flooding and low oxygen (hypoxic) conditions has been limited over the past two decades due to a lack of tolerant plant varieties and a limited understanding of genetic mechanisms. This study evaluated hypoxia tolerance in the Cheongcheong Nagdong Double Haploid (CNDH) rice population, along with their parent lines, for hypoxia tolerance. Significant phenotypic differences were identified, with the Cheongcheong and CNDH lines CNDH13, CNDH35, and CNDH91 showing strong hypoxia tolerance, while Nagdong and CNDH lines CNDH14-2, CNDH43, and CNDH50-1 were susceptible to hypoxia. Root length was unaffected by hypoxia, while shoot length and fresh weight were key tolerance indicators. Comprehensive quantitative trait loci (QTL) analysis based on logarithm of the odds (LOD) scores above 3.0 identified three QTLs associated with hypoxia tolerance, indicating significant genetic control: qSL-8 and qSL-10 (shoot length) and qFW-2 (fresh weight). The gene expression analysis performed under hypoxic conditions highlighted that 35 candidate genes within these QTL regions exhibited differential regulation: Os02g0184200, Os08g0430200, Os08g0431900, and Os08g0432500 were upregulated, whereas Os08g0439100, Os10g0343400, Os10g0395400, and Os10g0405600 were downregulated in both resistant and susceptible lines. Os08g0431900 displayed significant expression changes correlating with hypoxia resistance. Phylogenetic and protein–protein interaction analyses revealed that Os08g0431900 is highly conserved and interacts with proteins involved in stress responses, suggesting that these proteins are crucial in hypoxia tolerance. These findings provide valuable insights into the genetic basis of hypoxia tolerance and identify key genes for future breeding programs to develop hypoxia-resistant rice varieties.

Natamycin is a polyene macrolide produced by Streptomyces spp. with broad-spectrum antifungal activity. Agro-industrial by-products are abundant and nutrient-rich resources that can be converted into sustainable bioproducts. This study aimed to investigate their application in natamycin production via solid-state fermentation (SSF) using Streptomyces lydicus JCK-6019, with the goal of developing a dual-function product with plant growth-promoting and biocontrol properties. Optimization results revealed that a substrate mixture of brown rice and sesame seed cake (2:1, w/w) supplemented with 3% (w/w) rice hull, 80% (v/w) initial moisture content, and 30% (v/w) inoculum size produced the highest natamycin yield (18.55 mg/gds) in 250 mL flasks at 28 °C on day 7. Scaling up to a 2.5 L system with 70% moisture and 15% inoculum size further increased the yield to 20.22 mg/gds on day 6. This SSF product significantly promoted cucumber seedling growth, increasing plant height, leaf width, and biomass. It also increased chlorophyll content by 147.40%, reduced malondialdehyde content by 36.72%, and enhanced antioxidant enzyme activities (polyphenol oxidase by 42.16% and peroxidase by 26.99%). The 300-fold diluted SSF product exhibited a control value of 90.91% against cucumber damping-off caused by Rhizoctonia solani, comparable to a commercial fungicide. Moreover, the SSF product exhibited high storage stability, retaining over 95% natamycin activity after 1 year of storage at 25 °C. This study showed a cost-effective and eco-friendly approach for natamycin production from agro-industrial by-products, highlighting its SSF product potential as a stable biofungicide and plant growth promoter in sustainable agriculture. © 2025 Society of Chemical Industry.

Objective: To know the effect of controlled release fertilizers on the growth and development components of Tabebuia rosea (Bertol.) Design/methodology/approach: In this research, a randomized block design with seven treatments and 50 replications was used. Three treatments will consist of substrate with different mixtures of Controlled Release Fertilizers (CRF) at three concentrations each of 4, 5 and 6 kg m-3 plus a Control (without fertilization). Results: The use of controlled release fertilizers such as Multicote™ Agri 8 and Basacote® Plus 9M demonstrated greater growth and development in macuilis seedlings on the components of plant height, basal stem diameter, aerial biomass, root biomass among others, of the seven treatments presented in this research, the concentrations at 5 and 6 kg m-3 proved to be the best nutritional alternative, which will result in a higher survival rate in the field. Limitations on study/implications: Due to the loss of undisturbed specimens, it is becoming increasingly difficult to find trees with seed production capabilities. Findings/conclusions: Multicote™ Agri 8 in concentrations of 5 and 6 kg m-3 is the best nutritional alternative for optimal growth and development. As far as I know, it is essential for reforestation in urban and rural areas of the region. In addition, for its floral beauty that is part of the culture of the state. Keywords: Macuilis, Growth, Development, Quality Indices.

Influence of sodium selenite concentrations on growth and selenium accumulation in tissue-cultured seedlings of Trichosanthes kirilowii Maxim

Overstory and understory interactions as key drivers of differential growth in tropical tree seedlings during the conversion from pure Araucaria angustifolia stands to mixed stands