Seeds

Securidaca longipedunculata Fresen, a medicinal tree indigenous to tropical Africa, faces threats due to root overharvesting and limited occurrence. This study assessed the extent of variation in the morphological traits and germination of seeds collected from populations located across the Sudano-Sahelian and Sudanian climatic zones in Burkina Faso. A total of 1600 mature fruits across the two climatic zones were characterized in their morphology. Seed germination tests were conducted with material collected across climatic zones, using six physical and chemical pre-treatments and two substrates. Descriptive statistics and analyses of variance were used to process the data generated. The morphological data showed significant variations in fruit and nut traits across the populations sampled, which may reflect a significant underlying genetic diversity, as expected in wild plants. Samples from the Sudano-Sahelian zone exhibited larger fruits (11.87 ± 1.38 mm) containing heavier (0.12 ± 0.04 g) and larger (5.64 ± 1.02 mm) nuts. Seeds sown on river sand exhibited the highest mean germination percentage (35.24 ± 17.73%) and germination speed (0.40 ± 0.36 seedlings per day). Seed wing and coat removal resulted in the highest mean germination percentages (respectively, 36.5 ± 19% and 35.5 ± 16%). These results suggest the existence of some barriers to germination in S. longipedunculata seeds. For seedling production, preferably heavier fruits should be collected and sowing carried out on river sand after wing or coat removal. Full article

The Euphorbiaceae is a large, diverse, and cosmopolitan family of monoecious or dioecious trees, shrubs, herbs, and lianas. Their name comes from Euphorbia, one of the largest genera in the Angiosperms, with close to 2000 species and a complex taxonomy. Many of their members have an economic interest in multiple applications, including pharmaceutical, nutritional, and others. The seeds of the Euphorbiaceae develop in schizocarps and have a diversity of shapes that have proven useful for species identification and classification. Nevertheless, analytical quantitative methods can be the subject of further development for the application of seed morphology in the taxonomy of this family. With this objective, measurements of size (area, perimeter, length, and width) and shape (circularity, aspect ratio, roundness, and solidity) in seed images of 230 species representative of the main taxonomic groups of Euphorbiaceae are presented, and curvature analysis is applied to 19 species. Seed images corresponding to many species of this family present a tetragonal pattern with a curvature peak in the apical pole and three in the basal pole. The results of the curvature analysis are discussed in relation to other morphological properties, revealing new aspects of seed morphology of taxonomic application. Full article

This study examined the prevalence of seed-borne fungi in polyethylene plastic-packaged soybean seeds stored in a genebank and identified factors influencing their incidence. Twenty-four seed lots were sampled from the collection stored at 10 °C in the World Vegetable Center genebank in Arusha, Tanzania. The seeds used were those regenerated and harvested in 2015, 2016, and 2017. A seed health test was conducted for sterilized seeds on potato dextrose agar, sterilized seeds on top of the paper, and unsterilized seeds on top of the paper. Seven-year-old sterilized seeds plated on top of the paper exhibited the highest germination percentage (74 ± 7.09%) and lowest fungal incidence (7.00 ± 4.41%). Conversely, seven-year-old unsterilized seeds plated on top of the paper had the lowest germination (22.00 ± 6.97%) and highest fungal incidence (79.00 ± 8.31%). Older seed lots showed significantly higher equilibrium seed moisture content (Eqmc), though seed age had no significant influence on germination percentage or fungal incidence. Seed germination percentage showed a significant negative relationship with Eqmc, though Eqmc had no significant effect on fungal incidence. Meanwhile, germination percentage showed a significant negative relationship with fungal incidence. Six fungi isolates were identified using their morphological features from soybean seed samples: Absidia glauca, Aspergillus niger, Fusarium spp., Mucor hiemalis, Pestalotiopsis versicolor, and Sordaria macrospora. It is concluded that high fungal incidence negatively affects seed germination but is not significantly correlated with seed moisture content. The dry and cold storage conditions in the genebank, while effective in extending seed longevity, can unintentionally allow seed-borne mycoflora to persist. Although fungi may not actively proliferate under these conditions, they may do so when favorable conditions are restored, such as during germination tests, and consequently may compromise seed viability. Therefore, this study emphasizes the importance of increased systematic seed health checks before storage in genebanks to ensure optimal seed quality, and the replacement of all polyethylene plastic bags to aluminium foil packaging. Full article

The most important product of the lentil crop (Lens culinaris Medik) is the seeds. The main seed characteristics are their size, color, and the cooking time required to make them edible. Cultivar, location of cultivation, and their interaction are the primary factors of raw or cooked seed characteristics. The study examined the impact of five different lentil cultivars (Dimitra, Elpida, Thessalia, Samos, and 03-24L), as influenced by the cultivation environment in four different zones or nine different locations in Central-Northern Greece, on cooking time. The optimal cooking time (OCT) was calculated by cooking the seeds for 0–60 min to determine the percentage of cooked seeds using the penetration test. OCT was associated with the characteristics of both raw (mass of 1000 seeds, external color, and the percentage of mature/immature seeds) and cooked (color and organoleptic characteristics of the cooking media as well as mass increase and hardness and organoleptic characteristics of the seeds) seeds for 30 min. Depending on location, each cultivar had a different mass of 1000 seeds; Elpida had the highest mass (63.9 g), and Dimitra had the lowest (33.1 g). This was linked to OCT, which was among the highest (57.5 min) for Elpida, lowest (49 min) for Dimitra, and intermediate for Thessalia, Samos, or 03-24L. The average OCT was 55.9 min for all samples. The seed from the five locations with the shortest OCT was considered appropriate for human consumption. Two locations yielded seeds with intermediate OCT, while the other two produced the highest OCT; these were recommended for processing or propagation. In this study, the cultivar factor had a greater effect on raw seed characteristics, while the location factor had a greater effect on cooked seed characteristics and OCT than either the location, the cultivar factor, or the cultivar x location interaction. Full article

Seed germination is a complex process involving imbibition, activation and subsequent growth. In addition to re-establishing metabolic activity, water uptake helps stabilize macromolecules and biochemical reactions, resulting in radicle protrusion. Factors affecting water uptake include seed composition, water availability and seed coat permeability. Water entry sites vary with species and occur primarily through the hilum, micropyle or lens. In addition, seed size influences water uptake, where larger seeds are usually less permeable. The seed coat plays a significant role in regulating the water absorption process. Several seed coat characteristics, including color, thickness and differences in the anatomical structure, such as the presence of pores, cuticles and radicle pockets, alter water permeability. Similarly, the presence of either physical or physiological seed dormancy negatively affects water uptake. This review emphasizes that understanding seed characteristics, such as size, shape and seed coat permeability, and their relationships is essential for breeding and selecting seeds with desirable traits, as they directly influence water uptake, leading to improved germination and growth. Full article

Seedling establishment is often a critical bottleneck in the revegetation of mine tailings and similar substrates. Biochar and deactivated yeast are potential sustainable materials that could be used in this context as seed coatings to aid in seedling establishment. We conducted a greenhouse study on biochar and deactivated yeast use as seed coatings, assessing germination, establishment, and early growth of white clover (Trifolium repens) and purple prairie clover (Dalea purpurea). Coated seeds were applied to a mine tailing, a coarse granitic sand, and potting soil mix substrates; seedling establishment and growth were monitored over 75 days. Biochar coatings enhanced the seedling establishment of Trifolium, with biochar and biochar plus yeast coatings giving the best results. In some cases, these effects persisted throughout the experiment: biochar coatings resulted in a ~fivefold increase in Trifolium biomass at harvest for plants in the potting soil mix but had neutral effects on sand or tailings. Biochar seed coatings also enhanced Dalea germination in some cases, but the benefits did not persist. Our results indicate that biochar-based seed coatings can have lasting effects on plant growth well beyond germination but also emphasize highly species-specific responses that highlight the need for further study. Full article

The plant seed-borne microbiome comprises microorganisms vertically inherited from the mother plant. This microbiome is often linked to early-life protection and seedling growth promotion. Herein, we compare the seed-borne bacteriomes of a commercial hybrid (Santa Helena) and a landrace maize variety (Sol da Manhã). The landrace variety displays a more diverse seed-borne microbiome, featuring a variety of taxa across samples with an average Shannon’s diversity index of 1.12 compared to 0.45 in the hybrid variety. The landrace variety also showed a greater alpha diversity of 165.8, in contrast to 144.1 in the hybrid. Although both microbiomes lack a functional nitrogen fixation apparatus, we found a remarkably distinct presence of genes associated with phytohormone production and phosphate solubilization, particularly in the landrace variety. In addition, we recovered 18 metagenome-assembled genomes (MAGs), including four from potentially novel species. Collectively, our results allow for a better understanding of the contrasting diversity between maize varieties. The higher potential for phytohormone production in landraces, the absence of nif genes in both varieties, and the identification of core microbiome taxa offer valuable insights into how microbial communities impact plant health and development. This knowledge could pave the way for more sustainable and innovative agricultural practices in crop management. Full article

Internal transport (endozoochory) and external transport (epizoochory) by migratory waterbirds are key mechanisms of long-distance dispersal for seeds and other diaspores of plants lacking a fleshy fruit. Beginning with Darwin in 1859, we review how opinions about the relative importance of epizoochory and endozoochory have changed repeatedly over time and how this allows us to reassess our modern understanding of plant dispersal. Darwin was mistaken in asserting that diaspores cannot survive passage through the gut of waterbirds or other granivorous birds. This “digestion myth” led him to underestimate endozoochory and overstate the importance of epizoochory, an approach which is echoed throughout the literature until the present day. Darwin also focused on aquatic plants, yet it is now clear that waterbirds are also major vectors of terrestrial plants. Based on their empirical observations and experiments, other less influential scientists (notably Hesselman in 1897, Guppy in 1906 and Proctor in the 1960s) argued that endozoochory is the more important mechanism for waterbirds. Modern field and experimental studies demonstrate the dominant role for endozoochory. Unfortunately, avian endozoochory of dry-fruited plants continues to be ignored as a dispersal mechanism by many plant ecologists, which we attribute to Darwin’s continuing influence. However, this endozoochory has major implications for plant biogeography and requires wider recognition and research. Full article

Alstroemeria spp. and carnation (Dianthus caryophyllus L.) have considerable and increasing economic importance in the floriculture market, therefore breeders carry out intense breeding programs to select new superior varieties. However, poor germination of hybrid seeds remains a bottleneck. Based on this assumption, seed pre-treatments and in vitro germination protocols, using different germination substrates, were applied in Alstroemeria spp. and carnation to improve germinability. Seed viability was tested using the 2,3,5-triphenyl tetrazolium chloride (TTC) test, and resulted in 91.10% ± 2.33 and 86.66% ± 3.85 in Alstroemeria and carnation, respectively. In Alstroemeria, pre-treatment with potassium nitrate (KNO₃) in combination with modified ½ Murashige and Skoog (MS) medium ensured high germination uniformity combined with high germination percentage, showing significantly higher values than the control. In carnation, a suitable seed sterilization procedure was set up (up to 95.8% sterility); treatments with gibberellic acid (GA₃) and KNO₃ did not influence germination percentage compared to the control. A high multiplication rate of seedling lines was obtained on hormone-free MS medium. Full article

The use of microbial seed priming may be a promising tool to improve the first stages of seed germination of several herbaceous species. In tomatoes (Solanum lycopersicum L.), enhanced germination and vigor, and biotic and abiotic stress control, with a reduction in chemicals, have been reported. In this study, seeds from two Italian tomato varieties (Canestrino di Lucca and Pisanello) were primed with seven different strains of plant growth-promoting rhizobacteria (PGPB) belonging to Azospirillum baldaniorum, A. brasilense, Methylobacterium symbioticum, Bacillus amyloliquefaciens, B. licheniformis, and B. subtilis. They were selected for their ability to produce auxin. The germination test was carried out on treated seeds and the germination percentage was calculated. The obtained seedlings were transplanted and kept in greenhouse conditions. After 60 d, fresh and dry weight, root number, and length of plantlets were recorded. A general and significant improvement in the growth parameters was observed in the treated plants. All microbial strains proved to be indolacetic acid (IAA) producers using the Salkowsky method. A positive relationship between root number and length, and amount of IAA was found. The overall results suggest that the microbial priming of tomato seed could be useful for advancing organic farming, sustainable agriculture, and environmental protection. Full article

The rapid growth of the cannabis industry necessitates accurate and efficient methods for detecting and classifying cannabis seed varieties, which is crucial for quality control, regulatory compliance, and genetic research. This study presents a deep learning approach to automate the detection and classification of 17 different cannabis seed varieties, addressing the limitations of manual inspection processes. Leveraging a unique dataset of 3319 high-resolution seed images, we employ self-supervised bounding box annotation using the Grounding DINO model. Our research evaluates two prominent object detection models, Faster R-CNN and RetinaNet, with different backbone architectures (ResNet50, ResNet101, and ResNeXt101). Extensive experiments reveal that RetinaNet with a ResNet101 backbone achieves the highest strict mean average precision (mAP) of 0.9458 at IoU 0.5–0.95. At the same time, Faster R-CNN with ResNet50 excels at the relaxed 0.5 IoU threshold (0.9428 mAP) and maintains superior recall. Notably, the ResNeXt101 backbone, despite its complexity, shows slightly lower performance across most metrics than ResNet architectures. In terms of inference speed, the Faster R-CNN with a ResNeXt101 backbone demonstrates the fastest processing at 17.5 frames per second. This comprehensive evaluation, including performance-speed trade-offs and per-class detection analysis, highlights the potential of deep learning for automating cannabis seed analysis. Our findings address challenges in seed purity, consistency, and regulatory adherence within the cannabis agricultural domain, paving the way for improved productivity and quality control in the industry. Full article

Mechanised non-contact, non-destructive imaging methodologies have revolutionised plant phenotyping, increasing throughput well beyond what was possible using traditional manual methods. Quantifying the variation in post-harvest material such as seeds and fruits, usually the economically important part of the crop, can be critical for commercial quality assessment as well as breeding and research. Therefore, reliable methods that gather metrics of interest, quickly and efficiently, are of widespread interest across sectors. This study focuses on evaluating the phenotyping capabilities of the Cgrain Value™, a novel grain imaging machine designed for quality and purity assessment and used primarily in commercial cereal production and processing. The performance of the Cgrain Value™ in its generation of high-throughput quantitative phenotypic data is compared with a well-established machine, MARVIN, assessing repeatability and reproducibility across a range of metrics. The findings highlight the potential of the Cgrain Value™, and some shortcomings, to provide detailed three-dimensional size, shape, and colour information rapidly, offering insights into oat grain morphology that could enhance genome-wide association studies and inform the breeding efforts in oat improvement programmes. Full article

The Sideritis genus includes over 150 species primarily found in the Mediterranean basin, including the S. clandestina subsp. pelopponesiaca from the Peloponnese and S. scardica from North and Central Greece. In vitro seed germination has proven effective for conserving and amplifying the genetic diversity of endangered species such as Sideritis. This study aimed to optimize in vitro germination and seedling growth of S. scardica and S. clandestina subsp. pelopponesiaca under different lighting conditions at 22 °C, including white fluorescent lamps (WFL-BG-40) and LEDs (LED-BGYOR-40, LED-BR-40, LED-BR-80, LED-BR-120) all under a 16-h light/8-h dark photoperiod (WFL: white fluorescent light, B:blue, G:green, Y:yellow, O:orange, R:red, 40–80–120 μmol m⁻² s⁻¹), along with a 24-h dark treatment. The results indicated that LED-BR-80 combined with 250 mg L⁻¹ GA₃ in the MS medium promoted best germination (40%, day 55) and shoot proliferation in S. clandestina subsp. pelopponesiaca. Conversely, 5-year-old cold stratified S. scardica seeds showed higher germination rates (80%) and robust seedling growth under LED-BGYOR-40 with 250 mg L⁻¹ GA₃, particularly thriving in LED-BR-120 for increased shoot height and root number. This is the first report of the efficacy of LED technology in optimizing in vitro conditions for Sideritis species, crucial for their conservation and sustainable commercial cultivation. Full article

Soybean breeding programs targeting tofu quality must evaluate their performance within zones of adaptation. A comprehensive study was carried out to examine soybean breeding lines from three maturity groups (MGs; MG0, MG00, and MG000) from 2018 to 2022. Several agronomic, chemical composition and tofu-related quality traits were evaluated, and the associations among traits were investigated. The results showed that genotypes in MG0 yielded higher and matured later, which confirmed that the selection of targeted genotypes for a specific maturity group was successful. Non-imbibed “stone seeds”, an important quality trait for tofu processors, were higher in MG000 lines. Tofu texture using both GDL and MgCl₂ coagulants was positively associated, indicating one coagulant might be enough for screening purposes. The MG by traits biplot showed very clear MG clustering for all genotypes tested from 2018 to 2022, signifying that the MG has a more pronounced effect on the investigated traits than the environmental effects seen in different years, regardless of the MG. Most tofu-related traits were higher and showed stronger associations in MG0 lines compared to the lines in earlier MGs, indicating a need for future effort in shorter season MGs. Overall, this study provided useful information for selecting soybean lines for tofu end-use application targeting specific MGs. Full article

Seedling growth is one of the most important stages for the establishment of natural and artificial regeneration. For the first time, the initial growth and biomass allocation of seedlings germinated from cryostored seeds of Parkia nitida were analyzed. P. nitida is an economically and ecologically important timber tree species distributed in Central and South America. Cryostored seeds germinated quickly after priming by scarifying a part of the seedcoat with emery paper, reaching a germination percentage of 94%. Thirteen weeks after germination, the seedlings grew to a height of 16.5 to 60.0 cm. The results of our study, under different day/night alternating culture temperatures, showed that culture temperature had a direct correlation with seedling growth, total biomass allocation, and biomass partitioning. The greatest growth (height, diameter, and number of node sections) and greatest biomass allocation (leaf, stem, and root weight) were recorded under alternating temperatures of 30/25 °C, and these decreased with decreasing culture temperatures to 25/20 °C and 20/15 °C. Shoot:Root (S:R) ratios also decreased with decreasing culture temperatures, but a statistically significant difference (p < 0.05) was only observed between 20/15 °C and 30/25 °C. However, significant differences were not observed in Photosynthetic:Non-photosynthetic organ ratios among the different alternating culture temperatures. This study provides fundamental information for the production of good-quality seedlings of the fast-growing tropical trees of the legume family. Full article

Nigella sativa, also known as black cumin, is esteemed for its rich reservoir of health-benefitting phytoconstituents nestled within its seeds. The composition of its seeds can be influenced by factors such as genotype diversity and agricultural practices. Understanding these dynamics is important for maximizing the nutritional and medicinal attributes of the seeds. This study investigated how different genotypes, growing densities, and sowing times affect oil yield and phytoconstituents of Nigella seeds in Northern Australia. The aim was to find the optimal combination of these factors to maximize desirable compounds. Our findings revealed variability in oil yield and phytoconstituents among different genotypes, growing densities, and sowing times. No single genotype stood out as having elevated levels of all desired compounds. For instance, genotype AVTKS#5 had high total phenolic content (TPC) and antioxidant capacity, while AVTKS#8 and AVTKS#7 excelled in thymoquinone (TQ) and polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs), respectively. Planting density had a nuanced impact, with no significant effect on oil yield and CUPRAC values, but higher densities decreased TPC, FRAP, and TQ. Interestingly, seeds cultivated at 20 and 30 plants/m² had higher ratios of MUFAs/SFAs, PUFAs/SFAs, and (MUFAs + PUFAs)/SFAs, indicating the importance of planting density in shaping fatty acid profiles. Sowing times also had a noticeable effect, with late sowing leading to a decrease in oil yield from 19% to 14%. May-sown seeds had higher TPC, FRAP, CUPRAC, and fatty acid ratios, while TQ levels peaked in June-sown seeds. Our study highlighted positive correlations among TPC, FRAP, CUPRAC, and TQ, emphasizing their collective contribution to the nutritional and medicinal potency of Nigella seeds. Fatty acids, on the other hand, showed no significant correlation with these parameters, indicating independent regulation. In summary, our comprehensive analysis provides insights into the factors (genotype and agronomic practice) that shape the phytochemical profile of Nigella seeds, and suggests better genotype, planting density, and time of sowing for the cultivation and quality production. Full article

Seed germination (GS) and seedling growth are vital plant stages that can be affected by stresses such as drought and aging, which cause deterioration and reduce seed viability. With the aim of homogenizing and improving GS, priming treatments with biostimulants such as the antioxidant melatonin are commonly used in seeds. In this study, the effects of melatonin on germination and seedling growth in two different situations, i.e., aging seeds of rice, barley, and sorghum and under polyethylene glycol (PEG)-induced drought stress in sorghum, were studied. Aged seeds were primed for 7 days in different concentrations of melatonin, and drought stress seeds were primed for 24 h before PEG treatment for 7 days, and germination and initial growth parameters were monitored. Aging-seeds of rice and barley showed the maximum response in terms of germination percentage at 20 µM melatonin and 0.05 µM respectively; while aging-seeds of sorghum showed improvement in germination for practically all concentrations studied, even the highest tested at 50 µM. Regarding the effect of melatonin treatments on drought stress in sorghum seeds, all the studied parameters showed a significant attenuation of the adverse effects of drought stress, alleviating them, for all concentrations tested but especially at 200 µM melatonin. The results obtained confirm that priming seeds with melatonin under low germinability conditions relieves stress and improves both germination and seedling growth. Full article

Jatropha curcas L. (J. curcas), a shrub plant of the Euphorbiaceae family, has received enormous attention as a promising biofuel plant for the production of biodiesel and medical potential in ethnopharmacology. However, the tumor-promoter toxin phorbol esters present in J. curcas raise concerns for health and environmental risk as its large-scale cultivation limits the use of meal obtained after oil extraction for animal feed. Here, we determined the variation of phorbol ester profiles and contents in eight J. curcas tissues by high-performance liquid chromatography (HPLC) and found phorbol esters present in all parts of the plant except the seed shell. We showed tissue-specific patterns of accumulation of phorbol esters and associated terpenoids at the transcriptional level with high transcript levels in reproductive and young tissues. Genes involved in the same module of terpenoids biosynthesis were positively correlated. We further present diverse abiotic and biotic stresses that had different effects on the accumulation of transcripts in terpenoids shared and branched terpenoid pathways in plant seedlings. The fine-tuning of terpenoids biosynthesis may link with ecological functions in plants under extreme environments and defense against pathogens. Full article