Higher Germination Rate Research Articles

Cinética de secagem e qualidade fisiológica de sementes de jiló

ABSTRACT The drying process is paramount for maintaining seed quality, where the temperature during this process directly influences germination and vigor, especially for vegetable species harvested with high moisture content. This research aimed to determine and model the drying curves of S. aethiopicum (cultivar Tinguá-verde-claro) seeds at temperatures of 35, 38, 41, and 44 ºC, as well as to evaluate the physiological quality of the seeds after drying. A completely randomized design was used, with four drying temperatures (35, 38, 41, and 44 ºC) and four replicates. Nine mathematical models were fitted using the non-linear regression analysis by the Gauss-Newton method, and the goodness of fit was assessed based on the magnitude of the coefficient of determination (R2), chi-square test (χ2), relative mean error (P), and estimated mean error (SE). Seed quality was evaluated by germination test (G), electrical conductivity (EC), and accelerated aging (AA). The Modified Midilli model best represents the drying curves of S. aethiopicum seeds at the studied temperatures. Seeds with higher germination and vigor, meaning lower electrical conductivity values and higher germination rates after accelerated aging, are achieved through drying at 35 and 38 ºC.

Optimizing beet seed germination via dielectric barrier discharge plasma parameters

This study explores the synergistic effects of gas composition and electric field modulation on beetroot seed germination using dielectric barrier discharge (DBD) plasma. The investigation initially focuses on the impact of air plasma exposure on germination parameters, varying both voltage and treatment duration. Subsequently, the study examines how different gas compositions (argon, nitrogen, oxygen, and carbon dioxide) affect germination outcomes under optimal air plasma conditions. Results indicate that plasma treatment significantly enhances germination rates and seedling growth relative to untreated controls. Notably, plasma exposure alters seed surface morphology and chemistry, increasing roughness, porosity, and hydrophilicity due to the formation of new polar functional groups. The highest germination rate (a 54.84 % increase) and germination index (a 40.11 % increase) were observed at the lowest voltage and shortest duration, whereas higher voltages and prolonged exposure reduced germination, likely due to oxidative stress. Among the tested gas environments, air plasma was most effective in enhancing water uptake and electrical conductivity, while oxygen plasma resulted in the highest germination index and marked improvements in root and shoot length. Conversely, carbon dioxide plasma treatment exhibited inhibitory effects on both germination and subsequent growth metrics. The results highlight the potential of DBD plasma technology to enhance agricultural productivity by optimizing seed germination and early growth. The study emphasizes the importance of precise parameter tuning, particularly gas composition and plasma exposure conditions, to maximize benefits while minimizing adverse effects, offering a refined approach to seed priming in agricultural practices.

Study of the efficacy of five growing media for nursery production of an endangered species, Afzelia africana Smith ex Pers in Côte d'Ivoire

Afzelia africana Smith ex Pers is an endangered plant species listed on the International Union for Conservation of Nature (IUCN) Red List. The low level of natural regeneration of this species requires it to be reproduced in a controlled environment in order to reconstitute its population by providing good quality seedlings. As the growing medium is an important factor in the quality of the seedlings, the influence of the substrates soil + wood chip compost, soil + poultry droppings, soil + rice straw compost, soil + cocoa pod husk compost and soil on the germination and growth of Afzelia africana in the nursery was evaluated through a completely randomised design. The soil + wood chips compost performed best, with a high germination rate (76.7%). It enabled the production of taller seedlings (15.6 cm; p = 0.004), with larger collar diameters (4.4 mm; p = 0.001), higher total dry matter (2.25 g.plant-1; p = 0.005) and higher root dry matter (2.25 g.plant-1; p = 0.005). The mixture of three parts soil + one part poultry droppings was toxic for the seedlings, resulting in 60.6% mortality. The use of growing media containing a mixture of soil and wood chips compost is effective for the production of vigorous seedlings. This compost can be recommended for nursery production of Afzelia africana.

Streptomyces fradiae Mitigates the Impact of Potato Virus Y by Inducing Systemic Resistance in Two Egyptian Potato (Solanum tuberosum L.) Cultivars

In this study, the impact of culture media filtrate of QD3 actinobacterial isolate on two potato cultivars, Spunta and Diamond, infected with potato virus Y (PVY) was investigated. Various parameters, including infection percentage, PVY virus infectivity, disease severity scoring, PVY optical density, photosynthetic and defense-related biochemical markers, enzymatic profiling, phenolic compounds, proline content, salicylic acid levels, and growth and yield parameters, were assessed to elucidate the potential of the QD3 actinobacterial isolate culture filtrate in mitigating PVY-induced damage. The physiological and biochemical characteristics of the QD3 actinobacterial isolate, including its salinity tolerance, pH preferences, and metabolic traits, were investigated. Molecular identification via 16S rRNA gene sequencing confirmed its classification as Streptomyces fradiae QD3, and it was deposited in GenBank with the gene accession number MN160630. Distinct responses between Spunta and Diamond cultivars, with Spunta displaying greater resistance to PVY infection. Notably, pre-infection foliar application of the QD3 filtrate significantly reduced disease symptoms and virus infection in both cultivars. For post-PVY infection, the QD3 filtrate effectively mitigated disease severity and the PVY optical density. Furthermore, the QD3 filtrate positively influenced photosynthetic pigments, enzymatic antioxidant activities, and key biochemical components associated with plant defense mechanisms. Gas chromatography‒mass spectrometry (GC‒MS) analysis revealed palmitic acid (hexadecanoic acid, methyl ester) and oleic acid (9-octadecanoic acid, methyl ester) as the most prominent compounds, with retention times of 23.23 min and 26.41 min, representing 53.27% and 23.25%, respectively, of the total peak area as primary unsaturated fatty acids and demonstrating antiviral effects against plant viruses. Cytotoxicity assays on normal human skin fibroblasts (HSFs) revealed the safety of QD3 metabolites, with low discernible toxicity at high concentrations, reinforcing their potential as safe and effective interventions. The phytotoxicity results indicate that all the seeds presented high germination rates of approximately 95–98%, suggesting that the treatment conditions had no phytotoxic effect on the Brassica oleracea (broccoli) seeds, Lactuca sativa (lettuce) seeds, and Eruca sativa (arugula or rocket) seeds. Overall, the results of this study suggest that the S. fradiae filtrate has promising anti-PVY properties, influencing various physiological, biochemical, and molecular aspects in potato cultivars. These findings provide valuable insights into potential strategies for managing PVY infections in potato crops, emphasizing the importance of Streptomyces-derived interventions in enhancing plant health and crop protection.

Nuclear DNA Markers to Distinguish between Salix caprea, Salix gracilistyla, and Their Interspecific Hybrids

The Salix genus of the Salicaceae family has advantages such as rapid initial growth, a high germination rate, and asexual reproduction; therefore, it is used as a short-rotation energy crop for biomass production. The National Institute of Forest Science created new interspecific hybrid cultivars with superior biomass production by artificially interbreeding Salix caprea L. and Salix gracilistyla Miq. Identifying these hybrids during the seedling stage is challenging because their separate reproductive and vegetative growth stages necessitate prolonged observation of their morphological characteristics. Consequently, a reliable identification method is required to overcome these limitations. This study aimed to develop nuclear DNA markers to distinguish between S. caprea, S. gracilistyla, and their interspecific hybrids. An evaluation of 35 nuclear simple-sequence repeat (nSSR) markers in the Salix genus revealed two markers that distinguish these parent species and their hybrids. A sequence analysis confirmed the presence of insertion-deletion (InDel) regions within the nSSR markers that differed between S. caprea and S. gracilistyla. To effectively identify hybrids, a primer set comprising the InDel region, which exhibited only interspecies differences and no intraspecies differences, was developed. The results of this study will facilitate the genetic resource management of interspecific hybrids between S. caprea and S. gracilistyla, thus allowing for early identification and improved management of hybrids.

Effect of Ultrasound Conditions on Germination and Drying Characteristics of Bengal Gram (Cicer arietinum L.) and Determination of Physicochemical and Functional Properties of Flours

ABSTRACTThis study aims to investigate the effect of ultrasound conditions on the germination kinetics and drying characteristics of a germinated Bengal gram at different drying temperatures. Ultrasound treatment was given to the Bengal gram seeds at two different conditions, that is, before (US) and after soaking (SU), which was then followed by germination. This study also determines mass transfer parameters at drying temperatures of 45°C, 55°C, and 65°C and assesses the influence on the physicofunctional characteristics of a germinated Bengal gram. The germination rate behavior was effectively predicted using a zero‐order kinetic model with the highest R2 value of 0.7974–0.8857 in each nontreated (S) and treated (SU, US) Bengal gram seed, respectively. This study showed that the ultrasound treatment effectively enhanced the germination rate in both conditions, and the highest germination rate was found in pretreated ultrasound Bengal gram samples. The logarithmic thin layer drying model, with the highest average R2 of 0.9954 and the lowest average RMSE value of 0.0160, is the best‐fitted model to predict the changes in moisture ratio in both treated and nontreated conditions. The moisture diffusivity values at drying temperatures ranging from 45°C to 65°C were found in treated (US, SU) and nontreated (S) germinated samples ranging from 3.34 × 10−8 to 4.03 × 10−8 m2/s, 1.30 × 10−8 to 2.01 × 10−8 m2/s, and 6.6 × 10−9 to 8.06 × 10−9 m2/s, respectively. The protein content increased in the ultrasound‐treated sample between 12.37% and 13.50%. The solubility ranged from 8% to 10.36% throughout the treated and nontreated germinated Bengal gram flour. This study provides a unified approach to utilizing ultrasound‐treated germinated Bengal gram seeds as an alternative option to develop a functional product with better nutritional and functional properties.

Pennisetum glaucum in reducing ecotoxicity in soil with tebuthiuron, thiamethoxam and vinasse

The purpose of this study was to evaluate the ecotoxicological effects on soils containing associations of the herbicide tebuthiuron (TBT), the insecticide thiamethoxam (TMX), vinasse (VIN), and millet (Pennisetum glaucum) cultivation. We conducted the experiment under greenhouse conditions using a completely randomized design with five replications. Treatments consisted in soil application of tebuthiuron (1000 g ha-1 a. i), thiamethoxam (330 g ha-1 a. i), vinasse (113 m3 ha-1) with or without P. glaucum cultivation. The monitoring extended to 50 days after sowing (DAS) and evaluated the ecotoxicological potential from Lactuca sativa seeds as test-organism. Seed germination and root development determined the germination index (GI) concerning the negative control, which was prepared with water. Thus, P. glaucum highlighted a beneficial influence on soil health, thereby mitigating the ecotoxicological effects of TBT and TMX. Results emphasized the importance of the timing in soil sample collection, where early collections after plant seeding result in higher germination rates and rapid soil health improvements. Furthermore, vinasse reduced the ecotoxicological impact of pesticides and TBT presence presented harmful effects to test-organism. The interaction between P. glaucum growth period and soil sampling had a profound impact on ecotoxicity bioassays, which highlighted the importance of early intervention. Therefore, P. glaucum and vinasse can be valuable components in effective phytoremediation strategies, pointing towards future research and enhancement of approaches for sustainable treatment strategies of agricultural soils with pesticides.

Microclimatic effects of tree shelters on the early establishment and resilience of seeded acorns vs. outplanted seedlings

Little is known about the effects of tree shelters on the early response of oak seedlings produced by acorn seeding. In this paper, we explore the effects on holm oak (Quercus ilex L. subsp. ballota (Desf.) Samp.) seedlings of the microenvironment created by the tree shelters and the restoration method (seeding vs. outplanting) in terms of emergence, survival, growth, and resilience after harvesting. For this purpose, seedling height [H], root collar diameter [RCD], number of leaves, and aerial biomass were monitored. We made two sowings of acorns in February 2017 and February 2018, together with a seedling outplanting in February 2018 in a common garden site in semiarid SE Spain. In total, 600 acorns were randomly sowed and 300 nursery-grown seedlings were outplanted and studied until 2022. Mother tree and initial acorn mass were also monitored as additional variables in the analyses. Tree shelters consisted of closed plastic Tubes, Mixed tubes, Cork shelters, Tiles, and a Control with no shelter. Emergence rate was positively influenced by the Tube shelter (86%) as compared to the Control (64%), and especially by the initial acorn mass. By contrast, mother tree or year of sowing seemed to have no effect. The survival rate for the emerged acorns (88%) was statistically similar to that of outplanted seedlings (91%), and was unaffected by mother tree, tree shelter, or acorn mass. In terms of growth, the slenderness ratio (H:RCD) was considerably higher in seedlings from directly seeded acorns than for those that were outplanted. With the exception of Tile, all the shelters showed a higher slenderness ratio than the Control, especially the Tube shelter, which also showed a lower number of leaves and a lower aboveground dry biomass than the Control, Cork, and Tile shelters. Virtually no interactions were observed between the mother tree and the tree shelter. At harvesting, all the growth-related parameters were still strongly dependent on the acorn mass and the initial seedling features recorded after the first growing season. Resprouting rate and growth were also highly dependent on the acorn mass and the plant features at the beginning of the experiment and at harvesting. In summary, we did not find evidence to support tree shelters to improve the microclimate of holm oak seedlings both seeded or outplanted. Direct acorn seeding can be as successful as outplanting of nursery-grown seedlings. Selection of heavy acorns from mothers with a high germination and emergence rate is highly advisable.

An innovative formulation to improve spent coffee characteristics as soil fertilizer: Nutrient, chemical characterization and effects on plant germination

Spent coffee grounds (SCG) possess high organic content and various essential nutrients. However, their direct use as a fertilizer is limited due to high acidity, phenolic content, and C/N ratio. Therefore, in this study, SCG-based fertilizer (SCGf) was developed by mixing the raw SCG (SCGr) and zein through a granulation process and was compared with the SCGr. According to the obtained results, in SCGf, a reduction in the C/N ratio from 22.9 to 10.9, improved flowability from fair to good, an increase in the concentration of elements (N, C, S), nutrients (ash, fats, proteins), macrominerals (Ca, Mg, P, K, Na), microminerals (Cu, Fe, Mn, Zn), total polyphenolic content (TPC), total flavonoid content (TFC), and antioxidant activities (AOA) was noted. Additionally, a decrease in total organic acids, total chlorogenic acids, and was also observed in SCGf. Regarding phytotoxicity test results obtained by using Sinapis alba, Sorghum saccharatum, and Lepidium sativum and treating them with 2.5%, 5%, and 10% of SCGf and SCGr, better germination was observed for SCGf in S. alba (5%, 10%), L. sativum (2.5%, 5%). However, in L. sativum, 5% of SCGr and 10% of both SCGr and SCGf completely inhibited seed germination. For S. saccharatum, higher germination rates were observed for SCGf (2.5%, 10%), and at 5%, a comparable effect of both SCGf and SCGr was noted. SCGf gave the longest root length at all concentrations in all plants except for 2.5% in S. alba. In conclusion, this study addresses the effective use of SCG for sustainable agriculture while mitigating environmental impacts.

ENHANCING GERMINATION AND SEEDLING VIGOR IN NIGELLA SATIVA: THE IMPACT OF NANO IRON OXIDE AND PHOSPHORUS PRIMING

Nigella sativa, commonly known as black cumin, is known for its health benefits due to its rich content of compounds like thymoquinone. This study explored the effects of various seed priming methods on Nigella sativa seeds, including control (unprimed), distilled water, nano iron oxide (Fe₂O₃), phosphorus (P), and a combination of Fe₂O₃ and P. We assessed how these treatments influenced several key aspects of seed germination: germination rate (GR), mean germination time (MGT), germination index (GI), coefficient of velocity of germination (CVG), and vigor index (VI).Our results showed that seeds treated with Fe₂O₃ nanoparticles had the highest germination rate at 93.5% and germinated faster than seeds from other treatments. This suggests that Fe₂O₃ nanoparticles effectively speed up the germination process. However, despite the improved germination rate, the seeds treated with Fe₂O₃ did not exhibit the highest seedling vigor; the control seeds had the highest vigor index, indicating that while Fe₂O₃ accelerates germination, it does not enhance seedling health as much as the untreated seeds. Additionally, there were no significant differences in the germination index and coefficient of velocity of germination between the treatments, suggesting these parameters were less influenced by the priming methods.In summary, nano-priming with Fe₂O₃ is effective for speeding up seed germination but does not necessarily improve seedling vigor. These findings provide valuable insights into how different priming techniques can be optimized to enhance seed performance and plant growth under various conditions.

Study on Maturity Indices and Effect of Growing Substrates on Seed Germination of Litsea glutinosa

Aim: Litsea glutinosa is a multipurpose, fast-growing tree widely exploited due to its multipurpose utilisation. Species reported low seed viability, hence generally propagated through vegetative methods. We studied the maturity indices of fruits and seeds to determine the optimal collection stage. Studied the effect of different growing substrates and Gibberellic acid (GA3) treatment on the germination percent (GP), mean germination time (MGT), germination value (GV), peak value (PV), and germination index (GI). Study Design: Study was conducted at Forest Tree Seed Laboratory, ICFRE-FRI. The change in fruit colour from green, dark brown purple, and dark blue stages was compared with the seed parameters, germination percent, mean germination time, germination value, etc. to obtain the most suitable stage for fruit and seed maturity. Seed germination experiment was conducted in Complete Randomized Design with four replications of 25 seeds for each treatment. Seeds were sown directly on different germination substrates, such as filter paper, sand, and vermiculite, without treatment and also with 0.05% GA3 pretreatment. Seeds were kept in the seed germinator at 25±1ºC with a 24-hour photoperiod and high relative humidity (RH > 90%). Results: The highest germination rate was observed in vermiculite with GA3 soaking . i.e., 80±3.26%, followed by vermiculite 68±8.64%. The lowest germination percent of 5±4.08% was observed in seeds plated on filter paper with GA3 soaking. No germination was recorded in the seeds plated on the filter paper. Conclusion: Most suitable germination medium to maximise the germination of L. glutinosa seed is vermiculite. Furthermore, the pretreatment of seeds in GA3 (0.05%) for 24 hours and sowing in vermiculite improves overall performance with respect to GP, MGT, GV, PV, and GI. In the context of maturity indices, the dark blue stage with a moisture content of around 50% is the right stage for the collection of seeds of the species. This stage is characterised by high GP, GV, and low MGT values as compared to other growth stages.

Propagation and growth of Paspalum carajasense: a threatened Amazonian canga grass

Paspalum carajasense, an endemic and endangered annual grass found in the canga ecosystems of Serra dos Carajás, Brazil, lacks adequate propagation and conservation data. We assessed its germination and growth in various substrates to support conservation and mineland rehabilitation purposes. Seed germination tests involved soaking in water for 24 h and two KNO3 concentrations (2.5% and 5.0%). Seedlings were grown for 100 days on canga topsoil, mining waste substrate, and a commercial organic substrate. Mining substrates received 0%, 50%, and 100% of Carajás revegetation nutrients due to low fertility. Paspalum carajasense can be sexually propagated and pregermination treatments did not increase germination rates (14%). Seedlings were able to grow in all substrates and showed zero mortality. Plants in fertilized substrates showed similar growth to that on canga topsoil, with significant changes in root and leaf traits. In organic substrates, plants accumulated a larger amount of biomass and produced substantial amounts of seeds with higher germination rates, supporting the feasibility of ex situ cultivation. Therefore, our study provides essential information for the propagation and ex situ cultivation of a rare species of canga ecosystems and highlights the possibility of reconciling the conservation of P. carajasense with mineland rehabilitation.

Isolation, morphological characterization, and screening virulence of Beauveria bassiana and Metarhizium robertsii fungal isolates on Galleria mellonella

Background Entomopathogenic fungi exists naturally in plants as an asymptote and have the potential to reduce the population of insect pests through indirect interactions. This study was conducted to detect and characterize the endophytic fungi Beauveria bassiana and Metarhizium robertsii from the rhizosphere soil of tomato plants and their virulence effect on Galleria melonella. Methods From the rhizosphere soil of 40 tomato fields, three Beauveria bassiana and seven Metarhizium robertsii isolates were isolated using the galleria bait method. All fungi isolate were morphologically characterized by their colony color, shape, and surface texture. Isolates with the highest percentages of germination, conidial yield, and radial growth were selected, and their virulence was evaluated on second instar larvae of Galleria melonella under laboratory conditions. Results In this study, Beauveria bassiana showed white colony color and aseptate hyphae, whereas Metarhizium robertsii showed dark green to light green colony color and septate hyphal structures. Maximum spore production and conidial length were obtained by Beauveria bassiana isolate APPRC-27 with 2.67x107 spores ml-1 and 3.24 µm, respectively. Colony radial growth rates ranged from 1.73 to 3.24 mm day-1. The results revealed that the highest mortality rate of Galleria melonella (100%) was obtained by Metarhizium robertsii isolates K-61 and K-102 at a concentration of 1x108 conidial ml-1 at 7 days post-inoculation. The lowest mortality rate was registered by Metarhizium robertsii isolate RST-11. Conclusions In the present study, isolates that produced the most spores and had the highest germination rates were the most virulent to Galleria mellonella second instar larvae. Therefore, virulent entomopathogenic fungi, Beauveria bassiana and Metarhizium robertsii, are promising bioagents for the control of insect pests.

The transcription factor TabZIP156 acts as a positive regulator in response to drought tolerance in Arabidopsis and wheat (Triticum aestivum L.)

Drought stress strongly restricts the growth, development, and yield of wheat worldwide. Among the various transcription factors (TFs) involved in the wheat drought response, the specific functions of many basic leucine zipper (bZIP) TFs related to drought tolerance are still not well understood. In this study, we focused on the bZIP TF TabZIP156 in wheat. Our analysis showed that TabZIP156 was highly expressed in both roots and leaves, and it responded to drought and abscisic acid (ABA) stress. Through subcellular localization and transactivation assays, we confirmed that TabZIP156 was located to the nucleus and functioned as a transcriptional activator. Overexpression of TabZIP156 in Arabidopsis enhanced drought tolerance, as evidenced by higher germination rate, longer root length, lower water loss rate, reduced ion leakage, increased proline accumulation, decreased levels of H2O2, O2− and MDA, and improved activities of POD, SOD, and CAT enzymes. Additionally, the expression of drought- and antioxidant-related genes were significantly upregulated in TabZIP156 transgenic Arabidopsis under drought stress. However, silencing TabZIP156 in wheat led to decreased proline content, increased accumulation of H2O2, O2− and MDA, reduced activities of antioxidant enzymes, and downregulation of many drought- and antioxidant-related genes under drought stress. Furthermore, the dual-luciferase assay demonstrated that TabZIP156 could activate the expression of TaP5CS, TaDREB1A, and TaPOD by binding to their promoters. Taken together, this study highlights the significant role of TabZIP156 in drought stress and provides valuable insights for its potential application in breeding drought-resistant wheat.

Response of seed germination, seedling growth and physiological characteristics to alkali stress in halophyte Suaeda liaotungensis.

Soil salinization has been considered as a major environmental threat to plant growth. Different types of salt in saline soil have different effects on germination and seedling growth. Effect of NaCl on germination and seedling establishment in Suaeda liaotungensis have been reported, but its response to alkali stress remains unclear. Our results showed that brown seeds had higher germination rate, however, black seeds had higher germination recovery percentage under alkali stress. Na2CO3 had stronger inhibitory effect on germination and seedling growth than NaHCO3. As the concentration of alkali stress increased, the ROS level of brown seeds gradually ascended, while that of black seeds decreased first and then ascended. MDA content of dimorphic seeds significantly increased under alkali stress. The trend of SOD, POD and CAT activity between dimorphic seeds was similar under the same type of alkali stress. Alkali stress enhanced proline content of dimorphic seeds, and dimorphic seeds in NaHCO3 solution had higher proline content than Na2CO3 solution. Moreover, radicle and shoot tolerance indexes of seedlings in NaHCO3 solution were significantly higher than that of Na2CO3 solution. Under strong alkali stress, seedlings in NaHCO3 solution had significantly lower ROS level and MDA content as well as higher antioxidant enzyme activity than Na2CO3 solution. This study comprehensively compared the morphological and physiological characteristics in germination and seedlings to better reveal the saline-alkali tolerance mechanisms in S. liaotungensis.

Germination ecology of Phytolacca americana L. in its invasive range

AbstractInvasive species are a worldwide problem, and the germination process is useful to understand the characteristics that allow alien species to be invasive and their projected response to global climate change. Phytolacca americana is one of the most invasive plants in Italy, and we tested, for different populations (from different altitudes) how light, temperature, and cold stratification affect seed germination. According to our analyses, P. americana produces an exceptionally high number of seeds that may potentially survive in soil for extended periods. Seeds subjected to cold stratification and exposed to warmer temperatures, both in light and darkness, exhibited faster germination, with a higher germination rate and a shorter T50. Seeds collected at the highest elevation (337 m a.s.l.) have germinated in all tested thermal conditions, albeit with a lower germination percentage and a longer T50 compared with seeds collected at lower elevations (5 and 50 m a.s.l.) and tested under warm and moderate temperatures. In general, P. americana seems to adapt to moderate‐warm temperatures (at low elevations) and moderate‐cool temperatures (at highest elevations) and appears to increase germination with seeds exposed to cold stratification. These results, in a scenario of climate change, show that the invasiveness of P. americana may increase in the future.

Microencapsulation of betacyanins accumulated calli, short-term cold storage, and retrieval of callus in Selenicereus undatus (Haw.) D.R. Hunt

The red color of dragon fruit pulp and peel is due to the accumulation of betacyanins. In the present study, callus cultures were established using in vitro germinated seedlings of the white dragon fruit plant (Selenicereus undatus). Murashige and Skoog (MS) medium with 6-benzylaminopurine (BAP) at 2.0 mg/L was used to induce red-colored friable callus (92.0 % response). The betacyanin accumulated calli were harvested and encapsulated using sodium alginate (NaC6H7O6) and calcium chloride (CaCl2). These synseeds were cold stored for 6 months at 4.0 °C temperature. The stored synseeds were germinated on 2.0 mg/L BAP in the medium. The highest germination rate (88 %) of synseeds was achieved with 3 % sodium alginate polymerized with 75 mM calcium chloride, resulting in firm, uniform, and round synseeds. The betacyanin-loaded synseeds could be stored, transported, and directly used as inoculums for the extensive proliferation of calli and cell cultures for the commercial production of betacyanin.

High density promotes the germination of the recalcitrant seeds of submerged macrophyte Vallisneria natans

Seed germination is a critical process in the seed life cycle, especially for annual submerged macrophytes Vallisneria natans which is a model species for the restoration of degraded shallow lakes. Fresh seeds of V. natans have a very high germination rate but with no significant responses to the aggregation effect; meanwhile, these recalcitrant seeds quickly lose seed viability under dry storage. This study aims to explore the response of seed germination of V. natans after dry storage to aggregation effect by several microcosm experiments. We observed that seed aggregation has a significant positive effect on germination, and among the seven experimental densities between 10 ∼ 640 seeds, higher seed densities resulted in significantly enhanced germination. In contrast, daily removal of germinated seeds led to a significant decrease in the overall germination rate, suggesting that germinated seeds may secrete chemicals that promote the germination of ungerminated seeds. However, further experiments indicated that ethylene and gibberellins had no noticeable impact on seed germination, which was consistent with additional experiment results from spectrophotometer and high-throughput targeted metabolomics. We concluded that the promoting effect of aggregation on the seed germination of V. natans may be an adaptation of this species to its natural habitat but detailed mechanisms warranted further study.

Assessment of Aseptic and Non-Aseptic Systems' Influence on Basil (Ocimum basilicum L.) Microplants.

Considering the current global climate and demographic conditions, combined with the growing demand for food diversification, the need for innovative functional foods that adhere to the principles of the circular economy is becoming clear. Therefore, this research aims to identify an appropriate cultivation system and growth substrate to maintain a high germination rate and produce basil aromatic microplants with superior quality traits that are entirely edible, together with the substrate. Microplants were grown in both aseptic (AS) and non-aseptic (NAS) systems. Both AS and NAS experiments were conducted in vitro using eco-innovative production technology. Moreover, various growth substrates were tested, such as perlite, agar, banana peel, peat, and their combinations. The analyses focused on the germination capacity, morphometric measurements, and biochemical analyses of the microplants. The results showed that the edible agar-based substrate, used in both AS and NAS, increased the germination capacity up to 95.00 ± 0.30%, while peat provided a germination capacity of only 12.07 ± 1.27% under AS conditions and 6.07 ± 0.35% under NAS conditions. Most biochemical analyses indicated that AS conditions are more suitable for basil microplant production, increasing the dry matter content, total phenolic content, total flavonoid content, and total antioxidant capacity compared to NAS conditions. These findings support the adoption of a new eco-innovative technology that provides organic basil microplants, which are fully usable along with the edible agar substrate.

A Comparative Study of the Influence of Soil and Non-Soil Factors on Seed Germination of Edible Salt-Tolerant Species

Cultivating edible salt-tolerant plants (halophytes) for human consumption is increasingly important due to climate change and soil salinization, and offers sustainable agricultural solutions. Optimizing seed germination, the crucial initial stage of crop growth, is essential for enhancing crop production. This study aimed to optimize the germination of edible halophytes under greenhouse conditions, focusing on select soil (salinity and substrate) and non-soil-related factors (chemical and mechanical treatments). The target species were selected for their commercial value and included Mesembryanthemum crystallinum L. (crystalline iceplant), Salicornia ramosissima J. Woods (sea asparagus), Medicago marina L. (sea medick), Ammophila arenaria (L.) Link (European beachgrass), Portulaca oleracea L. (common purslane), and Atriplex halimus L. (Mediterranean saltbush). Salinity negatively impacted germination rates (GRs) and delayed mean germination time (MGT) across species. P. oleracea had the highest GR (95.6%) in coco peat under freshwater irrigation, and the shortest MGT (5.2 days). A. halimus did not germinate under the tested conditions. Scarification with sulfuric acid improved the GR of M. marina by 42.2%, while scarification with ultrasounds improved the GR of A. arenaria by 35.5%. Our results indicate that the choice of substrate and the application of specific treatments like scarification can significantly improve the germination of certain halophyte species under variable saline conditions.