Seeds

Guilandina bonduc L. is a pantropical coastal shrub with varied fruits and seeds, capable of germinating under saline stress. This study aimed to morphologically characterize the fruits and seeds of the species, correlate these characteristics, and evaluate the tolerance of seedlings to salt according to seed mass. Physical variables (length, width, thickness, and weight) were analyzed, and Spearman’s correlation was applied. Germination was tested with light seeds (<1.55 g) and heavy seeds (≥1.55 g) under five levels of salt stress, in a 2 × 5 factorial design. G. bonduc can produce seeds with variations in mass and size that are not necessarily related to fruit size. The reduction in osmotic potential resulted in lower seed germination and vigor; even so, the species demonstrated tolerance to salt stress, maintaining germination rates above 50% even under conditions of −1.0 MPa, regardless of seed mass. Lighter seeds germinate more quickly and uniformly, while heavier seeds produce more vigorous seedlings, especially in the absence of salinity, and are therefore more suitable for seedling production. These results indicate that G. bonduc has potential for revegetation of saline areas, being useful in adaptation to climate change due to its tolerance to saline stress and the relationship between seed mass and seedling vigor. Full article

Aegopodium podagraria (A. podagraria) L. is a perennial herb valued for its medicinal properties but exhibits poor germination and inconsistent growth under conventional cultivation. To overcome these limitations and enhance its functional potential, this study investigated the effects of various LED light spectra on the plant’s physiological and antioxidant responses under controlled indoor conditions. Six light treatments were applied, consisting of different red (R) and blue (B) light ratios (R100, R80:B20, R60:B40, R40:B60, and B100), along with a white-light control. Red-dominant treatments, particularly R80:B20, not only improved germination traits but also significantly promoted shoot growth and biomass accumulation. In contrast, higher proportions of blue light generally inhibited germination performance and reduced growth-related parameters compared to the white-light control. Antioxidant activity was also modulated by light quality: R80:B20 induced the highest levels of total phenolics, ferric reducing antioxidant power, and vitamin C, whereas R40:B60 maximized flavonoid content and DPPH radical scavenging activity. These results suggest that optimizing the red-to-blue light ratio can effectively enhance both the cultivation performance and biofunctional quality of A. podagraria in controlled environments. Full article

With the aim of developing an efficient propagation method for the exploitation of Thymelaea hirsuta and T. artonraira ssp. tartonraira in the xeriscaping and pharmaceutical industry, the effects of the following were examined on the in vitro germination of their seeds: (i) pretreatment (mechanical and chemical scarification or immersion in hot water; (ii) incubation temperature (5–30 °C); (iii) incubation light conditions (16 h photoperiod or continuous darkness); (iv) storage period at room temperature and darkness (up to 24 months). Seeds collected for two years from the same wild plants in Greece were surface-sterilized with a 15% commercial bleach solution for 15 min after the abovementioned treatments and placed for germination in Petri dishes containing a half-strength MS medium in growth chambers. The rate and final percentage of germination were recorded. For both species, scarification after immersion in concentrated H₂SO₄, preferably for 20 min, was necessary for seed germination, which indicates coat dormancy. Higher germination percentages were observed at temperatures of 10–20 °C, under continuous darkness for T. hirsuta (79–100%) and regardless of photoperiod for T. tartonraira (73–90%). Long storage reduced germination of only T. tartonraira (54–68% at optimum temperatures, 23 months after harvest), while T. hirsuta seeds stored for 5 months germinated at significantly lower percentages (40% maximum) compared to seeds stored for 9–24 months, revealing a dry after-ripening process. Seeds of both species harvested at different years showed stable behavior in terms of germination. For both species, an effective seed propagation protocol suitable for their exploitation as ornamental and landscape plants was developed. Full article

Seed germination is the initial step in a plant’s life cycle; it is precisely regulated by many factors at the molecular and biological levels. Reversible protein phosphorylation, which is regulated by protein kinases and protein phosphatases, plays a key role in hormone signal transduction, energy metabolism, stress response, and plant growth and development, including seed germination. This review provides a comprehensive elucidation of the coordinated regulatory mechanisms mediated by kinases and phosphatases during seed germination, with particular emphasis on their dynamic interplay and reciprocal modulation within biological signaling networks. Through the systematic integration of current research findings, we mechanistically dissect the sophisticated phosphorylation–dephosphorylation circuitry that governs metabolic activation, hormonal signaling transduction, and cellular homeostasis in germinating seeds. Furthermore, we propose a novel conceptual framework that delineates the spatiotemporal cooperation between these opposing enzymatic activities in regulating dormancy release and developmental transitions. The current challenges in the field of seed germination research are critically examined, and potential future investigative trajectories are outlined, aiming to establish a robust theoretical framework for elucidating the molecular mechanisms underlying seed dormancy regulation, as well as translating these findings into innovative agricultural production practices. Full article

Seed germination, a pivotal stage in the plant life cycle, profoundly impacts crop growth and establishment. However, fluctuating environmental conditions like drought, salinity, severe temperatures, and heavy metal toxicity impede seed germination rates and seedling vigor. Seed priming is a pre-sowing seed treatment that involves the controlled hydration of seeds, proven to improve germination rate and stress resilience. It initiates pre-germinative metabolism, including enzyme activity, antioxidant accumulation, hormone modulation, and cellular repair, without radicle emergence. Recent advancements in seed priming, encompassing the application of nanoparticles, phytohormones, and beneficial microbes, have significantly broadened its potential. Despite its proven benefits, challenges such as reduced seed longevity post-priming and variability in species-specific responses remain. This paper revisits the principles and methodologies of seed priming, highlighting its physiological, biochemical, and molecular mechanisms that enhance germination under stress conditions. Additionally, it addresses current challenges and future research directions for optimizing seed priming as a low-cost, eco-friendly approach to improve crop establishment under adverse environments, thereby supporting resilient and sustainable agriculture. Full article

Seed microbes play crucial roles in plant health, but studying their diversity is challenging due to host DNA contamination. This study aimed to optimise methodologies for investigating seed microbiomes across diverse plant species, focusing on the efficacy of peptide nucleic acid (PNA) clamps to reduce host DNA amplification. We tested PNA clamps on three plant species: Melaleuca quinquenervia (tree), Microlaena stipoides, and Themeda triandra (grasses). The effectiveness of PNA clamps was assessed through in silico analysis, axenic tissue culture, and metabarcoding techniques. In silico analysis confirmed the specificity of PNA clamps to the 16S rRNA gene V4 region of chloroplasts in the grass species. Axenic tissue culture experiments showed that applying PNA clamps at both 1 µM and 0.25 µM concentrations significantly reduced plant DNA amplification. Metabarcoding analyses further confirmed that PNA clamps effectively suppressed host DNA, enhancing microbial diversity estimates across all three species while preserving core microbial taxa. The efficacy of the clamps varied among host species, with T. triandra exhibiting the highest blocking efficacy, and chloroplast clamps outperforming mitochondrial ones. This study demonstrates that PNA clamps are a useful for improving seed endophyte metabarcoding datasets, although they require optimisation for some plant species. This knowledge will contribute to enhancing our understanding of seed microbiome diversity and its ecological implications. Full article

Solid-state ¹³C NMR spectroscopy using cross-polarization magic-angle spinning is a highly valuable technique for the semi-quantitative analysis of complex solid matrices. One of its key advantages is that it does not require any manipulation of the matrix, such as extractions or other treatments, which is particularly important for preserving the integrity of unstable secondary metabolites. Glucosinolates (β-thioglucoside-N-hydrosulphates) are crucial secondary metabolites specific to Brassica species, and many of them are known to be highly unstable. In this study, we evaluated solid-state nuclear magnetic resonance spectroscopy as an alternative method for the identification and quantification of total glucosinolates in the seeds of Sisymbrium officinale, Brassica napus, Sinapis alba, Brassica nigra, and Moringa oleifera. The results obtained with this method showed good agreement with those from conventional chemical analyses of the seed material. Although, based on a limited number of samples, this preliminary study suggests that the proposed approach could be a useful alternative for quantifying total glucosinolate content in seeds. Full article

Seed germination is a crucial phase where a plant embryo transitions from dormancy to active growth, emerging as a seedling. This intricate process is highly susceptible to environmental cues, particularly abiotic stress factors including drought, salinity, and temperature extremes, which can profoundly influence both germination success and subsequent plant development. Among the various cellular components that modulate plant responses to these stresses, Rho of Plants (ROP) emerges as a pivotal regulator. Under abiotic stress, ROP signaling components integrate with the core abscisic acid (ABA) signaling pathway by regulating gene transcription and protein stability, modulating subcellular localization, converting protein activity, and engaging in competitive interactions. This review summarizes recent findings on roles of ROP signaling in regulating plant adaptive responses to abiotic stress, whilst explores potential involvement of ROPs in seed germination. This review summarizes the effects of ROP proteins and their effectors, such as GEF, on the seed germination process. It preliminarily elucidates the crosstalk mechanisms between these proteins and the ABA signaling pathway, thereby gaining a deeper understanding of the role of ROP signaling in regulating plant adaptive responses to abiotic stresses. Full article

Populus alba clone ‘Villafranca’ (white poplar), highly suitable for biomass production and ecosystem restoration, is a model system for molecular and physiological studies, but no reports are available concerning seed quality. Although clonal propagation is the preferred approach for commercial purposes, attention should be given to face genetic variability losses in the existing germplasm. To address this challenge, new populations should be developed starting from seeds, overcoming the issues of low germinability and viability during storage. This study proposes to develop tailored treatments to improve the germination of long-term stored white poplar seeds. Priming and soaking protocols, based on the use of water or spermidine (Spd, 50 and 100 μM), were tested. Treatment efficacy was assessed based on germination parameters, reactive oxygen species (ROS) profiles, and the expression patterns of genes with key roles in early seed germination. Soaking with 100 μM Spd for 4 h significantly enhanced germination percentage and speed. Low ROS levels were evidenced in the Spd-treated seeds, compared to water-soaked seeds. High expression of genes involved in desiccation tolerance acquisition, polyamine biosynthesis, and antioxidant defense was observed only in dry seeds. The results are discussed in view of the potential protective role of Spd. Full article

Seed science is the comprehensive study of seeds. It encompasses their biology, production, technology, genetics, physiology, ecology, and applications in agriculture and conservation. Seed science has undergone transformative advancements through the integration of microbial technologies, with beneficial microorganisms emerging as critical tools for enhancing germination, seedling vigor, and crop resilience. Research demonstrates that microbial treatments improve nutrient uptake, hormonal regulation, and stress tolerance while establishing early symbiotic relationships with plants. This review synthesizes recent advances in understanding the roles of beneficial microbes in seed science, focusing on their impact on seed germination, seedling growth, and plant health. We explore the composition and transmission of seed microbiomes, highlighting the vertical transfer of microbes from parent plants to seeds and the influence of environmental factors on microbial community structure. The review also discusses innovative approaches to seed microbiome engineering. Particular attention is given to seed biopriming with plant growth-promoting bacteria (PGPB), which has shown significant potential in improving germination rates, seedling vigor, and crop productivity. Specific microbial strains, such as Trichoderma species and Pseudomonas fluorescens, are discussed with emphasis on their mechanisms of action in enhancing plant performance. The review also addresses the impact of breeding on seed microbiomes and explores emerging research directions, including the development of tailored microbial inoculants and the investigation of intracellular seed bacteria. By synthesizing these findings, this review aims to provide a comprehensive summary of the current state of seed microbiome research and its implications in seed science for sustainable agriculture. Full article

Seed propagation is the primary means of reproducing many native and endemic species, including garberia [Garberia heterophylla (W. Bartram) Merrill & F. Harper]. This attractive pollinator plant, native to Florida, is scarcely found in nursery production and largely unknown to the gardening community. To better understand the seed biology of garberia, a series of experiments were conducted to evaluate the effects of population on seed viability and germination response to four seasonal temperatures, as well as the effects of time on seed storability. Initial seed viability was 49% and 60% for Central and North Florida populations, respectively. Seeds germinated readily, indicating non-dormancy, with significant effects of population and temperature observed. Overall, on day 28, a greater germination proportion was observed from seeds collected from North Florida than Central Florida across temperatures, except for winter (11/22 °C), where responses were similar. The greatest germination proportion for seeds collected from North Florida was observed at 15/27 °C (fall) and 19/29 °C (spring), whereas the greatest germination from Central Florida was observed at 11/22 °C (winter), with the steepest decline observed at summer temperatures (24/33 °C). Further, it was observed that garberia seeds are intolerant of long-term storage, losing viability as early as 3 months under conventional cold or room temperature storage and decreasing substantially more after 6 months. These findings contribute to the overall understanding of the seed biology of underutilized species such as garberia, key to the development of efficient and reliable propagation systems for our nursery industry. Full article

Acacia species are important trees in arid ecosystems due to their diverse ecological roles, such as providing vegetation cover, community structures, food resources for animals, soil stabilization, and erosion prevention. However, in the Arabian Peninsula, Acacia species are declining due to climate change, overgrazing, and fuelwood harvesting. This study evaluates the effectiveness of various pre-sowing treatments—sulfuric acid soaking and tap and hot water soaking—on breaking seed dormancy to enhance germination in nine Acacia species native to the Al-Baha region of Saudi Arabia. The key germination indicators assessed were the mean germination time (MGT), germination percentage (GP), and germination index (GI). Sulfuric acid treatments for 10–15 min reduced the MGT and increased the GP for A. etbaica, A. hamoulosa, and A. tortilis, while A. origena responded best to 1 min of hot water soaking. Conversely, A. asak, A. ehrenbergiana, and A. johnwoodii showed little to no germination improvement with treatment and A. oerfota and A. gerrardii showed no germination improvement, indicating the need for alternative methods. These findings indicate that the seed germination requirements vary within Acacia spp. from the same geographic region and similar climatic conditions. Further work is required for five of the species tested to develop better seed germination techniques, given the potential utility of Acacia spp., in ecological restoration and sustainable land management in arid regions. Full article

Crops are continually subjected to frequent and extreme changes in climate, such as high temperatures and soil water deficits. Many studies have shown the individual effects of these factors on plants, but their combined effects on reproductive growth and subsequent seed germinability have received little attention. In this study, we used canola (Brassica napus) plants and grew them through their lifecycle under two temperature regimes (20/10 °C and 24/14 °C, 16 h light/8 h dark) in controlled-environment growth chambers. Half of the plants were watered to field capacity (well-watered) and the other half at wilting point (water-stressed). During the reproductive stage, the flower, silique, and seed traits were measured. Higher temperatures decreased the petal width by 1.17 times but increased petal anthocyanins by 1.03 times. The water deficit decreased the silique length and total seed number by 1.21 and 1.32 times, respectively, but increased nectar sugar concentration by 1.28 times. The total volume of nectar was affected by the interaction of temperature and water. The nectar volume was lowest in the water-stressed plants under higher temperatures (2.66 ± 0.29 µL per flower) but highest in the well-watered plants under the same temperature regime (5.73 ± 0.37 µL per flower). In conclusion, the combined effects of temperature and water were less pronounced than the individual effects of these factors on canola reproductive yield. Full article

This paper presents a pilot project conducted by ISPRA and ARPA Campania to develop a monitoring protocol to detect the presence of genetically modified (GM) oilseed rape (Brassica napus) plants resulting from accidental seed dispersal during transportation from entry points to storage and processing facilities; the project has been implemented in Italy’s Campania region. The unintentional dispersal of GM oilseed rape seeds and the potential establishment of feral populations have been identified as environmental concerns in various countries, even when GM oilseed rape is imported solely for processing and not for cultivation. The project activities were designed, taking into account the characteristics of the Italian environment and infrastructures. Multiple sampling campaigns were conducted in autumn 2018, spring 2019, and autumn 2019 to validate the selected transects and assess the presence of Brassicaceae species, with a particular focus on oilseed rape. These efforts involved direct monitoring and sample collection along transport routes from the port of Salerno to seed companies in the provinces of Benevento and Caserta. Field observations and import data revealed a decrease in oilseed rape movement at the port of Salerno in the years preceding the survey, while seed companies near Benevento remained active sites for white mustard (Sinapis alba). The presence of S. alba and the simultaneous occurrence of oilseed rape and Raphanus raphanistrum—a species with high hybridization potential—support the hypothesis that seed companies may act as hotspots for accidental seed dispersal and that potential interspecific gene flow can occur. The study also validated the adopted sampling and molecular analysis methods, including DNA extraction and PCR, for the detection of the Cruciferin A (CruA) gene in all Brassica species collected. These findings highlight the need to strengthen post-marketing monitoring plans, even when GM rapeseed is imported solely for processing, to mitigate the potential risks associated with unintended gene flow. Full article

The taxonomic complexity of Phoenix palms in the Canary Islands, where multiple morphotypes representing at least four taxa currently exist, presents significant challenges for archaeobotanical identification. We developed a Bayesian probabilistic framework to identify archaeological Phoenix seeds within the context of genus-wide morphological diversity. Our analysis incorporated thousands of specimens including modern reference collections, archaeological materials from pre-Hispanic sites in Gran Canaria and La Gomera (3–16th centuries CE), and fossil remains. We recorded quantitative measurements and qualitative characteristics for each specimen. To understand taphonomic effects, we conducted experimental carbonization of modern P. canariensis seeds and documented the resulting morphological alterations. We performed a hierarchical cluster analysis using Ward’s minimum variance method and calculated taxonomic assignment probabilities for archaeological specimens using Bayesian inference, where likelihood was derived from taxon proportions within assigned clusters. The results indicated a high probability (0.69–1.00) that the archaeological specimens belong to P. canariensis var. canariensis, with no evidence for P. dactylifera presence. These findings provide critical insights into pre-Hispanic exploitation of Phoenix palms, particularly the endemic P. canariensis, which served as a vital resource, providing food, fiber, and construction materials. Our methodological approach offers a robust framework for addressing taxonomic uncertainty in archaeobotanical research while enhancing understanding of historical palm biogeography and resource use patterns in the Canary Islands. Full article

Annual grass weeds can provide significant competition to an establishing sown tropical perennial grass pasture. At least two years of grass weed control prior to sowing is required to reduce the weed seed bank. Pre-emergent herbicides used in summer cereals, such as atrazine or s-metolachlor with metcamifen seed safener, may reduce this preparation time. Two controlled-environment experiments were conducted to assess the potential for these pre-emergent herbicides to be used with several tropical perennial grasses. Experiment 1 tested the effect of metcamifen (400 g L⁻¹ a.i. at 0–2× label rate) on the emergence and vigor of Chloris gayana, Dichanthium aristatum, Digitaria eriantha and Panicum coloratum, with Sorghum bicolor as the control. Experiment 2 tested the effect of s-metolachlor (960 g ha⁻¹ a.i.) with metcamifen-treated or untreated seed, and atrazine (1800 g ha⁻¹ a.i.) on the emergence and early growth of the grasses. Metcamifen did not inhibit emergence or vigor of the grasses. Without metcamifen seed treatment, s-metolachlor reduced the growth of the tropical perennial grasses by 47–100%, while it had no such effect on S. bicolor. In contrast, there was no effect of atrazine on shoot yields of the grasses, nor of s-metolachlor when D. aristatum, D. eriantha and P. coloratum seed had been treated with metcamifen. The collective results indicate that the herbicide safener metcamifen does not reduce the viability of tropical perennial grass seed and provides some protection against s-metolachlor, albeit not complete protection at the rates used in our study. Atrazine did not affect emergence or early growth of the grasses. Full article

Bioactive compounds in plants, such as carrots, have been widely used for their benefits. In agriculture, their potential as biostimulants still needs to be investigated, especially for their possible antioxidant action in plants subjected to abiotic stresses, such as salinity. This work aimed to evaluate the elicitor potential of carrot extract in alleviating salt stress in rice plants. This study aimed to evaluate the elicitor potential of carrot extract in alleviating saline stress in the rice cultivars BRS Querência and BRS 358. Aqueous extracts of carrot roots at concentrations of 0% (water), 25%, 50%, and 100% were used to soak rice seeds for 48 h, which were then subjected to different concentrations of NaCl (0, 25, 75, and 150 mM). To determine the effect of carrot extract as an elicitor under saline stress conditions, the following tests were conducted: germination, seedling length, dry mass, and oxidative stress through the activity of antioxidant enzymes, superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), peroxide content, and lipid peroxidation (hydrogen peroxide H₂O₂ and malonaldehyde MDA). Carrot extract increased the germination rate and maintained germination even under increased salinity rates in both cultivars. The application of 25 mM NaCl also boosted germination rates, followed by a significant decrease due to increased salinity rates. Shoot and root lengths and dry mass parameters showed a linear decrease in response to increasing NaCl concentrations. The activities of superoxide dismutase (SOD), ascorbate peroxidase (APx), and catalase (CAT) enzymes tended to decrease as the concentration of carrot extract increased, whereas the opposite was observed with NaCl application. Based on the combined analysis of the evaluated parameters, carrot extract application under the tested conditions was efficient in mitigating oxidative stress caused by high salinity conditions. Full article

Kentucky bluegrass (KBG) has poor seed establishment in the fall when used as a perennial groundcover in corn production. This study was conducted to investigate the effect of various seed treatments and soil amendments on the establishment of KBG under drought and non-drought conditions, simulated in a growth chamber. The effect of seed treatments, soil amendments, and irrigation frequency on KBG germination and shoot dry weight were measured over 21 days in a controlled environment at 21 °C, 50% RH, and exposure to a constant red light. The treatments were the Hydroloc seed treatment, a lime soil amendment, the Pivot Bio seed treatment, an ammonium nitrate soil amendment, a gibberellic acid seed treatment, osmotic seed priming, and an untreated control. The layout was a randomized complete block design, with two irrigation frequencies (restricted and full irrigation) and four replications (blocks). The irrigation treatments were applied to whole plots and the seed treatments were applied to subplots. The entire experiment was repeated four times. Irrigation affected the germination of all the seed treatments, but the size of the effect depended on the seed treatment applied. The control and Hydroloc treatments did not have significantly different dry shoot weights, while all the other treatments had significantly different dry shoot weights when comparing the irrigation regimes. The Hydroloc treatment significantly outperformed all the other treatments in regard to the restricted and full irrigation regime. These results indicate that the Hydroloc seed treatment improves KBG germination and shoot dry weight in drought and non-drought conditions, promoting KBG establishment in a wide range of soil moisture conditions. Full article

Mineral malnutrition negatively impacts almost 30% of the world population and could result in anemia, blindness, and stunted growth. Seed traits involve nutritional, physical, and physiological characteristics that play a key role in achieving seed quality. Chickpea (Cicer arietinum), the second most important food legume crop worldwide, is characterized by its rich nutrient profile, fiber, and antioxidant content. However, seed quality traits composition and daily nutritional value in chickpea seeds remain largely unknown. The objectives of the current study were to determine the variability in concentrations of macro and micronutrients, oil, protein, their correlations, and daily nutritional values (% DV) in the seeds of 61 chickpea genotypes. The results demonstrate substantial variation among chickpea genotypes in most nutrients, protein, and oil content. Moreover, this study identifies 12 promising chickpea genotypes that indicate large nutrient content and potential usage in chickpea biofortification and breeding programs. Our results further show that consumption of 100 g chickpea seeds could provide 122% DV of manganese (Mn), 77% DV of copper (Cu), 43% DV of magnesium (Mg), 32% DV of phosphorus (P), 27% DV of zinc (Zn), 26% DV of iron (Fe), and 5% DV of calcium (Ca). Overall, these findings improve our understanding of chickpea seed nutrient content as well as global food security by combatting mineral malnutrition. Full article