Seedling Traits Research Articles

Cocopeat supplementation negates lunar soil simulant-induced baneful phenotypic and biochemical changes in crop seedlings

Lunar exploration has captivated significant attention in recent times through programs such as Artemis. To establish long-term sustenance on the moon, astronauts have to grow their food on-site. While a key substrate for plant production – lunar regolith can induce baneful effects, supplementation with organic amendments could alleviate this inherent toxicity and significantly improve plant growth. In the present study, we examined the suitability of cocopeat (CP) as an amendment to ISRO's lunar soil simulant (LSS), LSS-ISAC-1. We assessed the germination and seedling growth response of four crops—wheat, tomato, groundnut, and cotton to LSS and Cocopeat supplementation. As anticipated, all four crops grew very well on earth soil (ES) and CP per se compared to the LSS. However, due to acidic pH, low electric conductivity (EC), and severe nutrient deficiency in LSS, we observed significantly low germination, stunted seedling growth, and altered associated oxidative stress indicators. To mitigate these pernicious effects, LSS supplemented with varied CP proportions – 3.125, 6.25, 12.50, 25, 50, and 100 %. The resultant data revealed that LSS supplemented with 6.25 % CP in wheat and tomato; 3.125 % CP in groundnut, and 25 % CP in cotton significantly improved phenotypic and biochemical traits in seedlings. Collectively, this study suggests the utility of CP as a novel augmenting agent to boost ISRU strategy for crop growth in moon regolith.

Anthropogenic soil as an environmental material, as exemplified with improved growth of rice seedlings

Herein, the feasibility of artificial black soil (ABS) derived from hydrothermal humification-hydrothermal carbonization (HTH-HTC) for restructuration of weak soil was verified. This study breaks through the long history of soil formation and evolution, and obtains reconstructed anthropogenic soil (AS) system which only takes one month, for the further application of rice seedlings. HTH-HTC derived by-products are slightly acidic, which facilitates the effective nutrient uptake and prevention of wilt diseases for acid-loving rice seedlings. AS mainly consists of the inherent components retained from weak soil such as SiO2 and minerals, and exogenous components such as artificial humic substances and hydrochar, as introduced by hydrothermal humification processes. Results exhibit that AS has high contents of ammonium nitrogen, organic matter, organic carbon, and abundant porous structure for nutrient transport and water holding, especially, the community diversity and richness of microbial system gets the expected recovery and new beneficial bacteria (such as Caballeronia calidae) or fungi (such as Humicola) appear. Positive effects of AS on agronomic traits in rice seedlings are quantified. As a general result, this study supports the application of AS in sustainable agriculture, and provides a novel strategy to tackle the already-omnipresent land degradation by anthropogenic misuse and larger scale accidents.

Effect and Cytotoxic Influence of High Concentrations of Manganese on the Phenotypic Variation of different Chickpea (Cicer arietinum L.) Seedlings

This study explores the phenotypic responses of diverse chickpea (Cicer arietinum L.) germplasms to heavy metal (Mn) stress, emphasizing seedling traits vital for plant establishment and growth. Chickpea seeds obtained from Acharya Narendra Deva University of Agriculture and Technology underwent meticulous examination and were stressed with manganese (Mn) supplementation at 200 µM Mn. Germination assays were meticulously conducted under controlled conditions, with data recorded over a 14-day span. Statistical analysis uncovered significant variations among germplasms concerning traits such as seed volume, germination percentage, 100-seed weight, speed of germination, field emergence, shoot and root lengths, seedling length, and vigour index-I. Correlation analysis delineated intricate interrelationships between these traits under heavy metal (Mn) stress. Notably, ICCV 92944 emerged as a superior variety, showcasing rapid germination, vigorous seedling growth, and remarkable stress tolerance. Other promising genotypes include HC 3, BG 267, and SBD 377. These findings offer valuable insights for breeding programs aimed at cultivating stress-tolerant chickpea varieties, thereby contributing to sustainable crop production in contaminated environments.

Promoting effect of Manila clam Ruditapes philippinarum (Adams & Reeve, 1850) on the establishment of eelgrass Zostera marina L. seedlings

It is necessary to restore the declined eelgrass Zostera marina L. beds which have multiple functions. The utilization of seedlings to recover eelgrass beds can maintain the genetic eelgrass diversity; however, the seedling establishment rate that is affected by many habitat factors is very low. Manila clam Ruditapes philippinarum (Adams & Reeve, 1850) transform habitats through several ways. Thus, it is inferred that the clam affects the establishment of eelgrass seedlings in multiple ways, and the seedling establishment rate of eelgrass might not simply increase or decrease under the presence of clams. To verify this hypothesis, a five-month clam-mediated seedling establishment experiment was conducted. The contents of total nitrogen (TN) and exchangeable ammonia NH4-N (Ex-NH) in sediment increased as the clam body size increased, and TN decreased with the increase in clam abundance. There was a positive relationship between the content of organic matter in sediment (OM) and the interaction of body size and abundance of clam. The emergence rate of germinated seeds and the seedling establishment rate increased with increasing clam biomass. They were positively correlated with the interaction of OM and Ex-NH. The seedling establishment rate was negatively correlated with the interaction of water content in sediment (W) and medium diameter of sediment (Ø50), OM and TN. The presence of clams affected the height, chlorophyll b content and superoxide dismutase (SOD) activity of seedlings. The clam body size affected the SOD activity of seedlings by influencing Ex-NH. Thus, the habitat modification of clams with moderate biomass improves the establishment and traits of seedlings in multiple ways. The seedling establishment mediated by Manila clam is useful for eelgrass bed restoration.

Identification of Novel QTL for Seedling Root Architectural Traits in the D Genome of Natural and Resynthetic Allohexaploid Wheat

Root architectural traits at the seedling stage have been demonstrated to be crucial for the efficient uptake of nutrients and drought tolerance in wheat. To dissect the genetic basis of these traits from the D genome, 182 recombinant inbred lines (RILs) derived from the common wheat TAA10 crossed with resynthesized allohexaploid wheat XX329 possessed similar AABB genomes were used for QTL mapping of five root traits in hydroponic-cultured seedlings, including lateral root number (LRN), seminal root number (SRN), root hair length (RHL), root diameter (RD), and total root volume (TRV). A total of seven QTLs were identified for the five root traits, with six possible novel QTLs for LRN, RHL, RD and TRV, accounting for 4.98–12.17% of phenotypic variation. One QTL (QLrn.qau-5D.2), controlling lateral root number, was fine mapped an approximate 5.0-Mb interval harboring 80 annotated genes, including five auxin-related genes. We further validated that QLrn.qau-5D.2 in NILTAA10 significantly enhanced yield-related traits, such as plant height, spike length, spike compactness, tiller number per plant and grain yield per plant, as comparison with NILXX329. Collectively, these results provide vital insights for fine-mapping QTLs associated with LRN, SRN, RHL, RD and TRV and facilitate the root morphologic designs for enhancing yield performance.

Comparative analysis of differential gene expression reveals novel insights into the heteroblastic foliage functional traits of Pinus massoniana seedlings

Pinus massoniana needles, rich in medicinal polysaccharides and flavonoids, undergo heteroblastic foliage, transitioning from primary needles (PN) to secondary needles (SN) during growth, resulting in altered functional traits. Despite its significance, the molecular regulatory mechanisms governing these traits remain unclear. This study employs Iso-Seq and RNA-Seq analyses to explore differentially expressed genes (DEGs) associated with functional traits throughout the main growth season of heteroblastic foliage. Co-expression network analysis identified 34 hub genes and 17 key transcription factors (TFs) influencing light-harvesting antenna, photosystem I and II, crucial in photosynthesis regulation. Additionally, 14 genes involved in polysaccharide metabolism pathways, synthesizing sucrose, glucose, UDP sugars, and xylan, along with four genes in flavonoid biosynthesis pathways, regulating p-coumaroyl-CoA, quercetin, galangin, and myricetin production, exhibited differential expression between PN and SN. Further analysis unveils a highly interconnected network among these genes, forming a pivotal cascade of TFs and DEGs. Therefore, heteroblastic changes significantly impact needle functional traits, potentially affecting the pharmacological properties of PN and SN. Thus, these genomic insights into understanding the molecular-level differences of heteroblastic foliage, thereby establishing a foundation for advancements in the pharmaceutical industry related to needle-derived products.

Bornean tropical forests recovering from logging at risk of regeneration failure.

Active restoration through silvicultural treatments (enrichment planting, cutting climbers and liberation thinning) is considered an important intervention in logged forests. However, its ability to enhance regeneration is key for long-term recovery of logged forests, which remains poorly understood, particularly for the production and survival of seedlings in subsequent generations. To understand the long-term impacts of logging and restoration we tracked the diversity, survival and traits of seedlings that germinated immediately after a mast fruiting in North Borneo in unlogged and logged forests 30-35 years after logging. We monitored 5119 seedlings from germination for ~1.5 years across a mixed landscape of unlogged forests (ULs), naturally regenerating logged forests (NR) and actively restored logged forests via rehabilitative silvicultural treatments (AR), 15-27 years after restoration. We measured 14 leaf, root and biomass allocation traits on 399 seedlings from 15 species. Soon after fruiting, UL and AR forests had higher seedling densities than NR forest, but survival was the lowest in AR forests in the first 6 months. Community composition differed among forest types; AR and NR forests had lower species richness and lower evenness than UL forests by 5-6 months post-mast but did not differ between them. Differences in community composition altered community-weighted mean trait values across forest types, with higher root biomass allocation in NR relative to UL forest. Traits influenced mortality ~3 months post-mast, with more acquisitive traits and relative aboveground investment favoured in AR forests relative to UL forests. Our findings of reduced seedling survival and diversity suggest long time lags in post-logging recruitment, particularly for some taxa. Active restoration of logged forests recovers initial seedling production, but elevated mortality in AR forests lowers the efficacy of active restoration to enhance recruitment or diversity of seedling communities. This suggests current active restoration practices may fail to overcome barriers to regeneration in logged forests, which may drive long-term changes in future forest plant communities.

Survival, growth, and functional traits of tropical wet forest tree seedlings across an experimental soil moisture gradient in Puerto Rico.

Droughts are predicted to become more frequent and intense in many tropical regions, which may cause shifts in plant community composition. Especially in diverse tropical communities, understanding how traits mediate demographic responses to drought can help provide insight into the effects of climate change on these ecosystems. To understand tropical tree responses to reduced soil moisture, we grew seedlings of eight species across an experimental soil moisture gradient at the Luquillo Experimental Forest, Puerto Rico. We quantified survival and growth over an 8-month period and characterized demographic responses in terms of tolerance to low soil moisture-defined as survival and growth rates under low soil moisture conditions-and sensitivity to variation in soil moisture-defined as more pronounced changes in demographic rates across the observed range of soil moisture. We then compared demographic responses with interspecific variation in a suite of 11 (root, stem, and leaf) functional traits, measured on individuals that survived the experiment. Lower soil moisture was associated with reduced survival and growth but traits mediated species-specific responses. Species with relatively conservative traits (e.g., high leaf mass per area), had higher survival at low soil moisture whereas species with more extensive root systems were more sensitive to soil moisture, in that they exhibited more pronounced changes in growth across the experimental soil moisture gradient. Our results suggest that increasing drought will favor species with more conservative traits that confer greater survival in low soil moisture conditions.

Changes in the Root Architecture of Oil Palm Seedlings in Response to Nitrogen Starvation

Oil palm (Elaeis guineensis) is a widely cultivated crop known for its high oil yield. It is cultivated extensively across tropical regions, notably in Southeast Asia, Africa, and Latin America. It plays a vital role in global vegetable oil supply, meeting approximately 35% of the world’s demand. However, the expansion of oil palm plantations often involves the utilization of degraded soils where nutrient availability, particularly nitrogen, is limited, posing challenges to plant growth and productivity. Roots are crucial in responding to nitrogen deficiency by adjusting their growth and distribution; however, research on root system distribution patterns in oil palm still needs to be completed. This study analyzes the root system architecture using RhizoVision Explorer, a 2D root image processing software while assessing its relationship with nitrogen availability across two commercial cultivars: Deli × La Mé of African oil palm (Elaeis guineensis) and the interspecific hybrid O×G Coari × La Mé. Our findings reveal significant associations between eight root traits in oil palm seedlings and treatments with and without nitrogen availability. Notably, total root morphology (length, surface area, and volume), rotation angle, solidity, and hole characteristics decreased under nitrogen deprivation, whereas surface angle frequency increased. We highlight the variability of these traits across cultivars, suggesting genetic dependence and potential utility in breeding programs. Moreover, interactions observed in primary root morphology and hole size indicate greater differences between control and nitrogen-treated groups in C × LM than in D × LM cultivars. On the other hand, cultivar differences, regardless of nitrogen availability, influenced lateral root morphology, while nitrogen availability, irrespective of cultivar, affected inclined angle frequency. Significant differences were observed in growth and development parameters such as root and shoot biomass, root-to-shoot ratio, and leaf emission numbers between nitrogen-optimal and nitrogen-starved conditions. Nitrogen significantly affects root architecture and plant growth in oil palm, particularly in the C × LM cultivar during the nursery stage.

Ecophysiological traits of seedlings from different accessions of Stipa tenacissima along a climatic gradient

Predicting the future impact of climate change on Stipa tenacissima steppes is of paramount importance to prevent desertification. From this perspective, we selected seven populations, covering a rainfall range from 100 to 600 mm/year at the sites of seed collection, and we grew the seedlings at the same site. Gas exchange measurements of CO2, light response curves, chlorophyll content and isotopic analysis were investigated. Thala and Valencia populations displayed a contrasted gas exchange response. Both populations were subjected to A-Ci curve analysis. No significant difference was detected between these two different populations in the maximum rate of carboxylation (Vcmax) and the maximum rate of electron transport (Jmax). Stipa tenacissima exhibited a variable response in relation to different light intensities. Photosynthesis and chlorophyll fluorescence parameters proved to be significantly different among populations in response to light intensities. All populations exhibited similar chlorophyll content. The isotopic analysis highlighted a different carbon and nitrogen isotopic composition (δ13C and δ15N) and carbon content © among populations. Mesic populations presented a higher gas exchange activity and light response. The xeric populations performed a photosynthesis adjustment along with minimizing chlorophyll content. Under climate change, S. tenacissima limits productivity, which may lead to desertification.

Comparison of the genetic basis of salt tolerance at germination, seedling, and reproductive stages in an introgression line population of rice.

Salinity is a major limitation for rice farming due to climate change. Since salt stress adversely impact rice plants at germination, seedling, and reproductive stages resulting in poor crop establishment and reduced grain yield, enhancing salt tolerance at these vulnerable growth stages will enhance rice productivity in salinity prone areas. An introgression line (ILs) population from a cross between a high yielding cultivar 'Cheniere' and a salt tolerant donor 'TCCP' was evaluated to map quantitative trait loci (QTLs) for traits associated with salt tolerance at germination, seedling, and reproductive stages. Using a genotyping-by-sequencing based high density SNP linkage map, a total of 7, 16, and 30 QTLs were identified for five germination traits, seven seedling traits, and ten reproductive traits, respectively. There was overlapping of QTLs for some traits at different stages indicating the pleiotropic effects of these QTLs or clustering of linked genes. Candidate genes identified for salt tolerance were OsSDIR1 and SERF for the seedling stage, WRKY55 and OsUBC for the reproductive stage, and MYB family transcription factors for all three stages. Gene ontology analysis revealed significant GO terms related to nucleotide binding, protein binding, protein kinase activity, antiporter activity, active transmembrane transporter activity, calcium-binding protein, and F- box protein interaction domain containing protein. The colocalized QTLs for traits at different growth stages would be helpful to improve multiple traits simultaneously using marker-assisted selection. The salt tolerant ILs have the potential to be released as varieties or as pre-breeding lines for developing salt tolerant rice varieties.

Facilitating comparable research in seedling functional ecology

Abstract Ecologists have worked to ascribe function to the variation found in plant populations, communities and ecosystems across environments for at least the past century. The vast body of research in functional ecology has drastically improved understanding of how individuals respond to their environment, communities are assembled and ecosystems function. However, with limited exceptions, few studies have quantified differences in plant function during the earliest stages of the plant life cycle, and fewer have tested how this early variability shapes populations, communities and ecosystems. Drawing from the literature and our collective experience, we describe the current state of knowledge in seedling functional ecology and provide examples of how this subdiscipline can enrich our fundamental understanding of plant function across levels of organisation. To inspire progressive work in this area, we also outline key considerations involved in seedling functional research (who, what, when, where and how to measure seedling traits) and identify remaining challenges and gaps in understanding around methodological approaches. Within this conceptual synthesis, we highlight three critical areas in seedling ecology for future research to target. First, given wide variation in the definition of a ‘seedling’, we provide a standard definition based on seed reserve dependence while emphasising the need to measure ontogenetic variation more clearly both within and following the seedling stage. Second, studies demonstrate that seedlings can be studied in multiple media (e.g. soil, agar, filter paper) and conditions (e.g. field, greenhouse, laboratory). We recommend that researchers select methods based on explicit goals, yet follow standard guidelines to reduce methodological noise across studies. Third, research is critically needed to assess the implications of different methodologies on trait measurement and compatibility across studies. By highlighting the importance of seedling functional ecology and suggesting pathways to address key challenges, we aim to inspire future research that generates useful and comparable data on seedling functional ecology. This work is critical to explain variation within and among populations, communities and ecosystems and integrate this most vulnerable stage of plant life into ecological frameworks.

Environmental effects on genetic variance are likely to constrain adaptation in novel environments.

Adaptive plasticity allows populations to cope with environmental variation but is expected to fail as conditions become unfamiliar. In novel conditions, populations may instead rely on rapid adaptation to increase fitness and avoid extinction. Adaptation should be fastest when both plasticity and selection occur in directions of the multivariate phenotype that contain abundant genetic variation. However, tests of this prediction from field experiments are rare. Here, we quantify how additive genetic variance in a multivariate phenotype changes across an elevational gradient, and test whether plasticity and selection align with genetic variation. We do so using two closely related, but ecologically distinct, sister species of Sicilian daisy (Senecio, Asteraceae) adapted to high and low elevations on Mt. Etna. Using a quantitative genetic breeding design, we generated and then reciprocally planted c. 19,000 seeds of both species, across an elevational gradient spanning each species' native elevation, and then quantified mortality and five leaf traits of emergent seedlings. We found that genetic variance in leaf traits changed more across elevations than between species. The high-elevation species at novel lower elevations showed changes in the distribution of genetic variance among the leaf traits, which reduced the amount of genetic variance in the directions of selection and the native phenotype. By contrast, the low-elevation species mainly showed changes in the amount of genetic variance at the novel high elevation, and genetic variance was concentrated in the direction of the native phenotype. For both species, leaf trait plasticity across elevations was in a direction of the multivariate phenotype that contained a moderate amount of genetic variance. Together, these data suggest that where plasticity is adaptive, selection on genetic variance for an initially plastic response could promote adaptation. However, large environmental effects on genetic variance are likely to reduce adaptive potential in novel environments.

Relative position of seeds driven the seedling growth are mediated by root–leaf traits

Abstract Variations in plant traits are indicative of plant adaptations to forest environments, and studying their relationships with tree growth provides valuable insights into forest regeneration. The spatial arrangement of plant seeds within the forest litter or soil critically influences the variations of root–leaf traits, thereby affecting the adaptive strategies of emerging seedlings. However, our current understanding of the impacts of individual root–leaf traits on seedling growth in different relative position, and whether these traits together affect growth, remains limited. This study focuses on the dominant tree species, Castanopsis kawakamii, within the Sanming C. kawakamii Nature Reserve of China. The present experiment aimed to examine the variations in root–leaf traits of seedling, focus on the relative positions of seeds within different layers: beneath or above the litter layer, or within the bare soil layer (without litter). Our findings provided evidence supporting a coordinated relationship between root and leaf traits, wherein leaf traits varied in conjunction with root traits in the relative positions of seeds. Specifically, we observed that seedlings exhibited higher values for specific leaf area and average root diameter, while displaying lower root tissue density. The mixed model explained 86.1% of the variation in root–leaf traits, surpassing the variation explained by the relative positions. Furthermore, soil nitrogen acted as a mediator, regulating the relationship between seedling growth and root–leaf traits, specifically leaf dry matter content and root tissue density. Therefore, future studies should consider artificially manipulating tree species diversity based on root–leaf traits characteristics to promote forest recovery.

Effects of Decapitation, Water-Deficit Stress, and Pot Size on Morpho-Anatomy and Physiology of Pterocarpus indicus

The interacting effects of stem decapitation, water-deficit stress, and pot size on the growth, morpho-anatomical, and physiological traits of Pterocarpus indicus seedlings were analyzed in this study. Changes in root collar diameter (RCD), biomass allocation, number of leaflets (NL), mean leaf area, guard cell size, stomatal aperture size, phloem cap fiber (PCF) thickness, xylem vessel density (XVD), relative leaf water content (RWC), stomatal conductance (gsw), transpiration rate (E), fluorescence quantum yield, transpiration (E), photosynthesis (PN), and electron transport rate (ETR) of decapitated and undecapitated P. indicus seedlings in different pot sizes (small, medium, large) and watering regimes (every 2, 7, and 14 days) were analyzed. The decapitation × water-deficit stress × and pot size interaction did not affect growth and morpho-anatomical variables, but they did on most of the physiological traits. Decapitated seedlings watered every 14 days and planted in medium or large pots have lower gsw, PN, E, and RWC. While the RCD of large-potted and water-stressed (every 14 days) seedlings decreased, allocations to stem and fine roots increased. Moreover, the NL and PCF significantly decreased, while the ETR and XVD significantly increased in decapitated and water-stressed seedlings. Overall, the decapitation-watering interaction caused significant stress to P. indicus seedlings. Keywords: biomass allocations, decapitation, drought stress, multiple stress, xylem vessel density

Tamanho ótimo de parcela com mudas clonais de cafeeiro conilon LB1 produzidas em tubetes

ABSTRACT In experimental studies, achieving an optimal plot configuration holds significant importance. This study aimed to establish suitable experimental plot sizes for evaluating agronomic traits of clone LB1 conilon coffee seedlings grown in tubes. Both non-destructive and destructive traits were evaluated using seedlings obtained from a nursery, with each seedling allocated to basic experimental units. A completely randomized block design was used and various scenarios were generated based on combinations of treatments (3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35 and 40), replicates (3, 4, 5, 6 and 7) and levels of experimental precision (10, 20, 30 and 40 %). Convenient plot size recommendations were obtained for clone LB1 conilon coffee seedlings grown in tubes.

Variation and trade-offs in fine root functional traits of seedlings of different mycorrhizal types in mixed broadleaf-Korean pine forests

Variation and trade-offs in fine root functional traits of seedlings of different mycorrhizal types in mixed broadleaf-Korean pine forests

Liquid organic matter from banana peel improves morpho-physiological traits of coffee seedlings

Due to its economic advantage, the Robusta coffee clones BP 308 and BP 939 are widely grown. Many factors affect coffee growth during the cultivation practice, especially in the availability of adequate nutrients at the nursery stages. Apart from inorganic fertilizer application, organic matter needs to be applied in the nursery stages to support plant growth, such as applying liquid organic matter (LOM) derived from banana peel waste. This study was conducted to find out how the LOM of banana peels affected the morphological and physiological responses of BP 308 and BP 939 clone Robusta coffee seedlings and what proper dosages of LOM were needed. The experiment was conducted at the Ciparanje Experimental Station, Faculty of Agriculture, Universitas Padjadjaran, Jatinangor from January to April 2022. This experiment used a randomized block design method consisting of 10 treatments and 3 repetitions. The treatments tested included 1.5 g of NPK inorganic fertilizer; 10 mL.L-1.plant-1 LOM ; 20 mL.L-1.plant-1 LOM; 30 mL. L-1.plant-1 LOM and 40 mL. L-1 .plant-1 LOM that was given to both clones, namely BP 308 and BP 939. The results of this experiment showed that there were differences in the effect of LOM between BP308 and BP939 on the morphological response such as an increase in plant height and leaf number, on the physiological response such as chlorophyll index and stomatal conductance at the 3 months after treatment (MAT). The BP939 was partly better in response to LOM of 10 mL.L-1.plant-1on plant height, the BP308 was partly better in stomatal conductance.

Evaluation of growth-promoting effect of 1-(2-(dodecyloxy)-2-oxoethyl)pyridin-1-ium chloride on wheat seedlings

Ester-functionalized long-chain pyridinium salt 1-(2-(dodecyloxy)-2-oxoethyl)pyridin-1-ium chloride (1b) has been synthesized. The influence of the substance on morpho-physiological traits of wheat seedlings (germination, shoot and root length and biomass, chlorophylls and carotenoids content, as well as flavonoid content) has been studied. The germination of seeds increased after their exposure to water solutions of pyridinium chloride 1b in the concentration range 0.001-0.1%. However, the concentration 0.1% has a negative effect on plant growth leading to reduced growth parameters in shoots and roots, plant mass, as well as pigments content. The exposure of wheat seeds to water solutions of pyridinium salt with lower concentrations (especially at 0.001%) significantly increased shoot and root length, as well as wet green mass in 7-day-old seedlings. At a concentration of 0.01%, the substance caused a significant increase of chlorophyll a, chlorophyll b, and carotenoids content thus revealing a positive effect on the photosynthetic apparatus of plant leaves. The flavonoid content in a green part of the plants also significantly increased which may indicate activating the plant defense system under mild stress conditions. The high growth-promoting effect of long-chain pyridinium chloride 1b on wheat plants, together with its broad range of antimicrobial activity and biodegradability, makes it an attractive product for various agrochemical applications

Effect Of Negative Temperature Shock On The Primary Rezistance Of Maize Hybrids

The paper presents the results of assessing the resistance of 14 maize hybrids to a negative temperature shock (NTS) of -4°C for 16 hours. The germination and growth seedlings parameters of maize hybrids were studied. Germination of maize seeds at optimal temperature of 26°C for 5 days was used as a control, and pretreatment of maize seeds with NTS followed by germination and subsequent growth at 26°C for 5 days was considered experimental. Pretreatment of maize seeds with NTS made it possible to identify and evaluate the primary resistance of each hybrid to stress, and according to the degree of constitutive frost resistance of each hybrid, the distribution and classification of the studied hybrids into 3 zones was carried out, including hybrids with high, medium and low frost resistance. Also, the effect of NTS on the morpho-physiological traits of the maize seedlings are shown.