Seed Germination Responses Research Articles

Seed germination response of the invasive Haloxylon persicum in Tunisia

Seed germination response of the invasive Haloxylon persicum in Tunisia

Differential germination responses of plump and shriveled seeds to environmental factors and storage conditions in Tamarix laxa Willd.

Tamarix laxa Willd. is a vital shrub widely distributed in arid and semi-arid regions. It serves as an excellent species for sand-fixing afforestation in saline-alkali and sandy desert lands and has medicinal properties for wind-dispelling and detoxifying. This plant produces two types of seeds: plump and shriveled. However, the effect of seed plumpness on germination has not been extensively studied. In this research, we found that 42% of the seeds in T. laxa were plump, and 58% were shriveled. We then investigated how different temperatures, light conditions, salt concentrations, and storage methods affect the germination of these seeds. Shriveled seeds were significantly smaller and had a lower germination percentage compared to plump seeds. T. laxa seeds exhibited a broad adaptability to temperature. Plump seeds showed over 90% germination at three different temperatures, whereas shriveled seeds had a 57% germination percentage at 15/30oC. Continuous darkness significantly reduced the germination percentage for both seed types. Although T. laxa seeds displayed some salt tolerance, high salt concentrations (0.6mol/L NaCl) markedly decreased their germination percentage. Freshly mature seeds initially had a 99% germination percentage. However, seeds stored at room temperature for 90 days nearly lost their viability. In contrast, seeds stored at -18 oC for 180 days maintained a germination percentage above 80%. Low-temperature storage effectively delayed the short-term loss of seed vitality. This study offers comprehensive insights into T. laxa seed germination, providing valuable information for desert restoration efforts.

Seed Germination Responses to Temperature and Osmotic Stress Conditions in Brachiaria Forage Grasses

Seed Germination Responses to Temperature and Osmotic Stress Conditions in Brachiaria Forage Grasses

Interannual Variability in Seed Germination Response to Heat Shock in Cistus ladanifer

Mediterranean climates, characterised by hot and dry summers, have predictable fire regimes, and many species with physical seed dormancy (PY) thrive after wildfires. While it is well known that PY is released after heat shock in these species, intraspecific variation in seed response to heat is less understood. This research explores, for the first time, the variability in the traits of Cistus ladanifer seeds from the same central Spain population over eight years. It examines seed germination and viability under different heat shocks and the relationships among seed traits and climatic variables. While the response to heat shock remained constant over the years studied, achieving the highest germination percentages after heat shock at 100 °C, seed germination varied between years, and environmental conditions affected seed traits. Seed moisture content was negatively correlated with the maximum summer temperatures, and seed viability was positively related to annual precipitation. Germination at 100 °C was lower in warmer years as more seeds did not break their PY. In conclusion, despite the fact that PY appears to be genetically determined, it also depends on the environmental conditions experienced by the mother plant. This interannual phenotypic variability may help Cistus ladanifer to cope with the increasingly unpredictable conditions imposed by climate change.

Tomato Seed Treatment and Germination Responses to Selected Plant Extracts

Tomato Seed Treatment and Germination Responses to Selected Plant Extracts

Differential Seed germination Responses of Ashwagandha Seed Collected at Different Time Period

Differential Seed germination Responses of Ashwagandha Seed Collected at Different Time Period

Seed dormancy types and germination response of 15 plant species in temperate montane peatlands.

Despite their crucial role in determining the fate of seeds, the type and breaking mode of seed dormancy in peatland plants in temperate Asia with a continental monsoon climate are rarely known. Fifteen common peatland plant species were used to test their seed germination response to various dormancy-breaking treatments, including dry storage (D), gibberellin acid soaking (GA), cold stratification (CS), warm followed cold stratification (WCS), GA soaking + cold stratification (GA + CS) and GA soaking + warm followed cold stratification (GA + WCS). Germination experiment, viability and imbibition test, and morphological observation of embryos were conducted. Of the 15 species, nine showed physiological dormancy (PD), with non-deep PD being the dominant type. Four species, Angelica pubescens, Cicuta virosa, Iris laevigata, and Iris setosa exhibited morphophysiological dormancy. Two species, Lycopus uniflorus and Spiraea salicifolia, demonstrated nondormancy. Overall, the effect hierarchy of dormancy-breaking is: CS > GA > WCS > GA + CS > D > GA + WCS. Principal component analysis demonstrated that seed traits, including embryo length: seed length ratio, seed size, and monocot/eudicot divergence, are more likely to influence seed dormancy than environmental factors. Our study suggests that nearly 90% of the tested peatland plant species in the Changbai Mountains demonstrated seed dormancy, and seed traits (e.g. embryo-to-seed ratio and seed size) and abiotic environmental factors (e.g. pH and temperature seasonality) are related to germination behavior, suggesting seed dormancy being a common adaptation strategy for the peatland plants in the temperate montane environment.

Comparative Phenotypic and Transcriptomic Analyses Provide Novel Insights into the Molecular Mechanism of Seed Germination in Response to Low Temperature Stress in Alfalfa.

Low temperature is the most common abiotic factor that usually occurs during the seed germination of alfalfa (Medicago sativa L.). However, the potential regulatory mechanisms involved in alfalfa seed germination under low temperature stress are still ambiguous. Therefore, to determine the relevant key genes and pathways, the phenotypic and transcriptomic analyses of low-temperature sensitive (Instict) and low-temperature tolerant (Sardi10) alfalfa were conducted at 6 and 15 h of seed germination under normal (20 °C) and low (10 °C) temperature conditions. Germination phenotypic results showed that Sardi10 had the strongest germination ability under low temperatures, which was manifested by the higher germination-related indicators. Further transcriptome analysis indicated that differentially expressed genes were mainly enriched in galactose metabolism and carbon metabolism pathways, which were the most commonly enriched in two alfalfa genotypes. Additionally, fatty acid metabolism and glutathione metabolism pathways were preferably enriched in Sardi10 alfalfa. The Weighted Gene Co-Expression Network Analysis (WGCNA) suggested that genes were closely related to galactose metabolism, fatty acid metabolism, and glutathione metabolism in Sardi10 alfalfa at the module with the highest correlation (6 h of germination under low temperature). Finally, qRT-PCR analysis further validated the related genes involved in the above pathways, which might play crucial roles in regulating seed germination of alfalfa under low temperature conditions. These findings provide new insights into the molecular mechanisms of seed germination underlying the low temperature stress in alfalfa.

Transcriptome Profiling Reveals the Response of Seed Germination of Peganum harmala to Drought Stress.

Peganum harmala L. is a perennial herbaceous plant that plays critical roles in protecting the ecological environment in arid, semi-arid, and desert areas. Although the seed germination characteristics of P. harmala in response to environmental factors (i.e., drought, temperature, and salt) have been investigated, the response mechanism of seed germination to drought conditions has not yet been revealed. In this study, the changes in the physiological characteristics and transcriptional profiles in seed germination were examined under different polyethylene glycol (PEG) concentrations (0-25%). The results show that the seed germination rate was significantly inhibited with an increase in the PEG concentration. Totals of 3726 and 10,481 differentially expressed genes (DEGs) were, respectively, generated at 5% and 25% PEG vs. the control (C), with 1642 co-expressed DEGs, such as drought stress (15), stress response (175), and primary metabolism (261). The relative expression levels (RELs) of the key genes regulating seed germination in response to drought stress were in accordance with the physiological changes. These findings will pave the way to increase the seed germination rate of P. harmala in drought conditions.

Effect of Water Deficit and Burial Depth on The Germination of Periploca angustifolia

Abstract Periploca angustifolia (Labill.) is a multipurpose xerophytic shrub in the Apocynaceae, which is widely disturbed in arid zones. This shrub is often used in programs for the rehabilitation of degraded areas, so it is essential to investigate the impact of environmental factors (drought, burial depth) on seed germination patterns. During 20 days, germination responses of seeds were determined over a wide range of constant temperatures (25 °C), polyethylene glycol PEG-6000 solutions of different osmotic potentials (0 to -1.6 MPa), and burial depths (1–8 cm). The highest germination percentages (99%) were obtained under control conditions without PEG, and increasing osmotic pressure progressively inhibited seed germination, which was about 2% at -1.6 MPa. When seeds were buried deep, there was a significant decrease in seedling emergence percentage and rate. Seedlings of P. angustifolia emerged well at depths of 1–2 cm with the highest emergence percentage of 74 and 69%, respectively. They could not emerge when the sand burial depth was higher than 4 cm.

Linking Seed Traits and Germination Responses in Caribbean Seasonally Dry Tropical Forest Species.

Understanding the relationships between seed traits and germination responses is crucial for assessing natural regeneration, particularly in threatened ecosystems like the seasonally dry tropical forest (SDTF). This study explored links between seed traits (mass, volume, moisture content, and dispersal type), germination responses (germinability, germination speed (v¯), time to 50% of germination (T50), synchrony, and photoblastism), and physical dormancy (PY) in 65 SDTF species under experimental laboratory conditions. We found that species with smaller seeds (low mass and volume) had higher v¯ and reached T50 faster than species with larger seeds. For moisture content, species with lower moisture content had higher germinability and reached the T50 faster than seeds with high moisture content. Abiotic dispersed species germinated faster and reached the T50 in fewer days. Most of the SDTF species (60%) did not present PY, and the presence of PY was associated with seeds with lower moisture content. As for photoblastism (germination sensitivity to light), we classified the species into three ecological categories: generalists (42 species, non-photoblastic), heliophytes (18 species, positive photoblastic, germination inhibited by darkness), and sciadophytes (5 species, negative photoblastic, light inhibited germination). This study intends to be a baseline for the study of seed ecophysiology in the SDTF.

Various treatments to overcome dormancy of jernang rattan seeds (Daemonorops didymophylla Becc.)

Jernang rattan is a resin known as “dragon’s blood” and belongs to e family arecaceae. Its uses vary, including being a source of supply for the ceramics, jewelry, glass, textile, and pharmaceutical industries. This study is to determine the germination response of rattan jernang seeds (Daemonorops didymophylla Becc.) in various treatments of dormancy of rattan jernang seeds. The research was conducted in Silangit, Siborongborong District, North Tapanuli Regency, starting from April 2023 to July 2023. The study used a non-factorial Randomized Block Design (RBD). The treatment factors are: P0 (seeds without treatment / control), P1 (soaking seeds with ordinary water 24 hours), P2 (scarification of seeds / sanding), P3 (soaking seeds with KNO3 0.5% 24 hours) and P4 (soaking seeds with coconut water 24 hours). The parameters observed are growth potential, germination test includes the percentage of normal sprouts and the percentage of dead sprouts. The conclusions were obtained soaking treatment of rattan jernang seeds in 0.5% KNO3 solution for 24 hours had a very real effect on on the percentage of germination, the percentage of normal sprouts and the percentage of dead sprouts.

Assessing Seed Germination Response of Parasitic Plant Striga hermonthica with Small-Molecule Probes.

Seed germination of a parasitic plant Striga hermonthica is elicited by strigolactones which are exuded from roots of host plants. Here, we describe a high-throughput germination assay and a method for visualizing in vivo strigolactone receptor functions with a fluorogenic probe.

Same, same, but different: dissimilarities in the hydrothermal germination performance of range-restricted endemics emerge despite microclimatic similarities.

Seed germination responses for most narrow-range endemic species are poorly understood, imperilling their conservation management in the face of warming and drying terrestrial ecosystems. We quantified the realized microclimatic niches and the hydrothermal germination thresholds in four threatened taxa (Tetratheca erubescens, Tetratheca harperi, Tetratheca paynterae subsp. paynterae and Tetratheca aphylla subsp. aphylla) that are restricted to individual Banded Ironstone Formations in Western Australia. While T. aphylla subsp. aphylla largely failed to germinate in our trials, all other species demonstrated extended hydrothermal time accumulation (186-500°CMPadays), cool minimum temperatures (7.8-8.5°C), but broad base water potential thresholds (-2.46 to -5.41MPa) under which germination occurred. These slow germination dynamics are suggestive of cool and wet winter months, where soil moisture is retained to a greater capacity in local microsites where these species occur, rather than the warmer and drier conditions in the surrounding arid environment. Hydrothermal time-to-event modelling showed that each species occupied unique hydrothermal germination niches, which correspond with the microclimatic differences the species are exposed to. Our results provide a baseline understanding for environmental and germination thresholds that govern the recruitment, and ultimately the population structure and persistence, of these short-range endemic plants. In addition, our results can aid future conservation, as well as restoration actions such as translocation to bolster population numbers and to mitigate against losses due to anthropogenic disturbance and global environmental change.

Effect of Seed Germination and Early Seedling Growth Response on Two Rice (Oryza sativa) Varieties Supplied with Different Types and Concentrations of Wastewater in Thailand

With increasing concerns over water scarcity, wastewater reclamation for agricultural irrigation has gained attention. However, the use of wastewater can have both positive and negative effects on crop growth. Seed germination and early seedling growth tests are considered to accurately represent crop growth population. This study aimed to evaluate the effect of different types and concentrations of wastewater on rice seed germination and early seedling growth. Two rice varieties, SIRAJ279 and MR219, were grown in wastewater from shrimp culture, domestic sources, and cement factories at five concentrations: 0 (control), 25, 50, 75, and 100%. Seed germination percentage and germination rate index were used to evaluate seed germination analysis, while the seedling length, seedling vigor index, seedling fresh weight, seedling dry weight, and phytotoxicity percentage were used to evaluate early seedling growth analysis. Results showed that the SIRAJ279 rice variety had overall better seed quality than MR219. Rice irrigated with shrimp culture and domestic wastewater showed better results in seed germination, germination rate index, seedling length, seedling vigor index, and seedling fresh weight than those irrigated with cement factory wastewater. However, no significant difference was observed in seedling dry weight. Additionally, increased wastewater concentration had a negative effect on seed and seedling results. Seedlings grown in wastewater with a concentration of 75-100% from cement factories had the highest phytotoxicity percentage (more than 30%). Therefore, it is recommended to dilute cement factory wastewater to 50% before using it for agricultural irrigation.

Assessment of Germination Response to Salinity Stress in Castor through the Hydrotime Model

Germination of castor seeds from five dwarf hybrid genotypes, compared to a ‘Local’ genotype selected by the University of Catania from a Tunisian population well adapted to the Mediterranean environment, was studied at five different salt levels (0, −0.3, −0.6, −0.9, and −1.2 MPa) in order to assess seed germination performance under stress conditions. The results confirmed that optimum moisture (0 MPa) ensured 100% of germination; on the contrary, salt concentration negatively influenced the final germination percentage (FGP) and radicle elongation, causing severe consequences for plant establishment. At a level of −1.2 MPa, no germination occurred, while a level of −0.3 MPa slightly affected the seed germination of the dwarf genotypes, which achieved 77.3% of germination, contrary to the ‘Local’ genotype, in which germination was kept stable. Higher levels of salt (−0.6 and −0.9 MPa) caused a linear decrease in FGP and radicle elongation. Overall, the dwarf hybrid ‘C1019’ performed better at higher salt impositions, as did ‘C857’, confirming these genotypes were the most tolerant among the dwarf hybrids. Conversely, ‘C1013’ turned out to be the most susceptible genotype, followed by ‘C1008’. On the other hand, the ‘Local’ castor genotype was the best-performing genotype at −0.3 MPa and the most tolerant genotype in terms of salt concentration and germination time, which were accurately predicted by the hydrotime model, validating it as a valid method of assessing the germination response of castor seeds to Ψ.

Impact of Environmental Conditions on Seed Germination of Glossy Buckthorn (Frangula alnus (Mill)) in Eastern Canada

Understanding seed characteristics, germination, and seedling establishment patterns is essential for formulating effective management strategies to control invasive species. Glossy buckthorn (Frangula alnus) is a shrub or small tree from Eurasia that has become invasive in North America, and which has negative impacts on plant communities and ecosystems. In this study, we analyzed the germination response of glossy buckthorn seeds to different temperatures (12, 14, 16, 18, 20, 24, and 28 °C), various stratification lengths (4 to 20 weeks), and scarification conditions to measure the impact on breaking seed dormancy, and the effect of light in triggering germination. Analysis using distinct time-to-event approaches, including the Kaplan–Meier estimator and Cox proportional hazard model, was employed to interpret germination data. Glossy buckthorn seeds exhibited physiological dormancy and required cold stratification to germinate. At 12 °C, only 14% of the seeds could germinate. At warmer temperatures, germination rates increased, reaching a peak of 70% at 20 °C. At 24 °C and 28 °C, germination declined, and seeds were probably induced into secondary dormancy. Scarified seeds had a higher probability of germination than non-scarified ones, even at the lowest temperatures. Darkness had a negative impact on germination at all tested temperatures. This study significantly advances our understanding of how temperature, light, stratification, and scarification impact glossy buckthorn seeds, elucidating the species’ seasonal germination patterns in North America. The results emphasize that glossy buckthorn utilizes seed banks as a primary strategy for invading and establishing in new habitats. The ungerminated seeds form persistent seed banks, ensuring F. alnus’ survival and bolstering its chances of successful establishment and invasion. As climate change drives temperature increases, it may affect seeds in the soil, altering stratification periods and consequently shifting the timing of germination.

Variation in degree of intermediate complex morphophysiological dormancy in seeds of Bunium persicum (Apiaceae)

AbstractBunium persicum is an important medicinal plant, but the requirements for seed dormancy break and germination are not well known. Based on available information, we hypothesized that seeds have an underdeveloped embryo and physiological dormancy (PD), and hence morphophysiological dormancy (MPD), and that populations of this species may have different degrees of MPD which demand different germination requirements. In this study, we evaluated embryo growth in seeds from four B. persicum populations at different temperatures and tested germination at varying constant temperatures, with or without GA3 and cold stratification. Seeds from the four populations had a fully differentiated, small, linear but underdeveloped embryo. The initial embryo‐to‐seed length ratio was 0.14–0.17, but it increased to 0.71–0.75 before germination at 5°C. Little embryo growth occurred at 15°C and no growth occurred at 25°C. GA3 effectively increased germination percentages, replaced cold stratification, reduced the required period for cold stratification, and in combination with cold stratification increased the maximum temperature of germination. Therefore, seeds from the four populations have intermediate complex MPD. Additionally, the germination responses of seeds from the four populations to GA3, cold stratification, or both were different, suggesting variation in the degree of PD. Bunium persicum seeds developed in cool and wet conditions were more dormant than those developed under warm and dry conditions. Thus, we showed that different climates can affect the depth of PD in a species whose seeds have MPD, resulting in variation in the degree of intermediate complex MPD at the population level.

Unraveling Drought Tolerance and Sensitivity in Coffee Genotypes: Insights from Seed Traits, Germination, and Growth-Physiological Responses

The coffee plant is highly susceptible to drought, and different genotypes exhibit varying degrees of tolerance to low soil moisture. The goal of this work was to explore the interrelation between seed traits and germination events, growth patterns, and physiological responses of coffee genotypes, aiming to identify significant associations that may facilitate the selection of coffee genotypes exhibiting enhanced drought tolerance and yield potential. Two consecutive experiments were conducted to examine the impact of these factors. In the first experiment, germination performance was examined for three groups of coffee genotypes: relatively tolerant (Ca74140, Ca74112, and Ca74110), moderately sensitive (Ca74158, Ca74165, and CaJ-21), and sensitive (Ca754, CaJ-19, and CaGeisha). The subsequent experiment focused on the growth and physiological responses of two relatively tolerant (Ca74110 and Ca74112) and two sensitive (CaJ-19 and Ca754) genotypes under drought stress condition. The relatively tolerant genotypes showed quicker and more complete germination compared to other groups. This was associated with higher moisture content, higher seed surface area to volume ratio, and higher coefficient of velocity of germination, coefficient of variation of germination time, and germination index. Additionally, the relatively tolerant genotypes showed higher seedling vigor. The results of the second experiment demonstrated superior growth performance in relative tolerant genotypes compared to the sensitive groups. Young coffee plants belonging to relatively tolerant genotypes exhibited higher growth performance than the sensitive genotypes, with a net assimilation rate strongly correlated to relative water content, leaf number, stomatal conductance, and chlorophyll-a. In addition, a strong correlation was exhibited between the growth of young coffee plants and the surface area to volume ratio of the seeds, as well as the germination percentage. The seedling vigor index showed a strong correlation with net assimilation rate, chlorophyll content, seedling growth, and cell membrane stability. Furthermore, principal component analysis illustrated distinct clustering of genotypes based on their germination and growth-physiological performance. Overall, the findings of this study suggest that seed traits, germination, and post-germination events are integral factors in determining drought tolerance and sensitivity, as well as the growth and physiological responses of adult coffee plants.

Quantifying the seed germination responses of two linseeds (Linum usitatissimum) genotypes to temperature

Quantifying the seed germination responses of two linseeds (Linum usitatissimum) genotypes to temperature