Highest Germination Percentage Research Articles

Is the endemic Phoenix canariensis H. Wildpret an orthodox species? Implications for its conservation

ABSTRACT Seed banks (gene banks) have become essential for the conservation of genetic biodiversity in natural ecosystems. Seed preservation is especially important for threatened species, since seeds are the primary genetic material used to reintroduce plant species. Knowledge of the desiccation tolerance of each species is relevant for selecting the best method for ex situ conservation, but it is not always available. Currently, the categorisation of the seed storage behaviour of the Phoenix species as orthodox, recalcitrant or intermediate, remains uncertain. This study uses four accessions of the endemic species from Canary Island Phoenix canariensis H. Wildpret, with storage times ranging between 2 and 28 years. Germination tests were carried out to measure seed viability over time, desiccation tolerance and the possible impact of seed storage on viability. The germination results differed for seeds after 192 days in a greenhouse. Accessions stored in the seed bank at −20°C and 15%RH for 17 years showed a high germination percentage (72%). In contrast, accessions stored under unsuitable conditions showed a 0% germination. These results indicate the orthodox seed storage behaviour of P. canariensis. In addition, it supports the good state of conservation of the material stored in the Seed Bank of the Botanical Garden Viera y Clavijo and the reliability of the temperature and humidity conditions in which the seeds of P. canariensis have been stored. In addition, the results are relevant in order to manage the conservation of this endemic species from the Canary Islands.

Effects of planting window on grain yield and oil yield under rainfed sunflower (Helianthus annuus L.) in Kilwa District, Lindi, Tanzania

This study evaluated the effects of planting windows on grain yield and oil yield of three sunflower varieties (Hysun33, Record, and K/Fedha) across two locations in 2023. The two factors (varieties and planting windows) were laid out in a split plot arrangement and fitted into randomized complete block design in three replicates. The first planting window (PW1) occurred in late January, the second (PW2) in mid-February, and the third (PW3) in early March. Weather parameters evaluated included minimum and maximum temperatures, average monthly rainfall and rainfall during the growth period. The weather data revealed trends of decreasing minimum and maximum temperatures, as well as fluctuating average rainfall over the period. Total rainfall did not significantly differ between the three planting windows (PW1, PW2, PW3). However, there was significant variation in rainfall amounts at different phenological stages between planting windows (P = 0.001). Grain yield and oil yield were highest in PW3 (1.50 t/ha and 360.2 L, respectively), as well as for the Hysun33 variety (0.92 t/ha and 22.95 L, respectively). High grain and oil yields were influenced by high germination and survival percentages, high rainfall during leaf development and stem elongation, flowering time and interactions between planting window, variety, and locations. Study showed that PW3 and HYsun33 offers the most favorable options for optimal sunflower production in Kilwa District. However, multi-environment trials, repeated over several seasons is recommended to explore the influence of environmental variables. The results may also prompt a revision of the sunflower planting calendar for the southern zone.

Comparative evaluation of biochar produced from laboratory waste media using different thermochemical methods and its potential in plant growth promoting properties

The disposal of laboratory waste, especially microbiology media, is a growing concern due to its potential environmental impact. In this study, the conversion of laboratory waste, specifically nutrient agar media, into biochar using three different pyrolysis methods: conventional tube pyrolysis, biomass gasification, and microwave-assisted pyrolysis has been explored. Microwave pyrolysis of biomass resulted in higher biochar yield (63.85%) than conventional pyrolysis (58.16%) and gasification (32.18%). The obtained biochar has been subjected to different analytical techniques to understand the comparative differences in characteristics. Conventional pyrolysis yields the most negative zeta potential (−27.5 mV), whereas biomass gasification results in −16.7 mV, and microwave-derived biochar produces −7.5 mV to −4.8 mV, indicating diverse colloidal stability, anionic character, and potential for tailored soil applications. In plant growth experiments, the application of conventionally pyrolyzed biochar demonstrated superior performance, with the highest germination percentage (84.62%) and significantly longer shoot lengths ( p < 0.001) revealing its potential environmental benefits. In summary, the research has broad implications, ranging from waste management and biochar production efficiency to potential applications in soil improvement and environmental remediation. Further, it contributes to the ongoing efforts to develop sustainable solutions for waste disposal and environmental conservation.

Effect of saline concentrations and humidity percentage on alfalfa va-rieties (Medicago sativa L.) from the Mexicali Valley, Mexico.

Objective: The aim of this experiment was to identify alfalfa varieties resistant to salt and drought stress in Mexicali Valley Mexico. Design/methodology/approach: Four alfalfa (M. sativa L.) varieties were used: Cuf-101 C, FD9, Pioneer and Cuf-101 P. Drought stress resistance was evaluated using four different percentages of commercial peat moss substrate (100%, 50%, 25%, and 15%), and saline stress resistance was evaluated by applying four concentrations of NaCl (0 mM, 50 mM, 100 mM, and 200 Mm.The variables evaluated in each treatment were: plant height, number of leaves and root length. The data obtained were subjected to an analysis of variance using the SAS statistical package version 9.0 with an α=0.5. Results: Alfalfa variety Cuf-101 had a good adaptation to both stresses with an average height of 11.28 cm and an average number of leaves of 3.54. Seed germination of alfalfa varieties (M. sativa L.) subjected to salt stress were affected even at the lowest NaCl concentration. Conclusions: The alfalfa variety with the highest germination percentage in all NaCl concentrations was Cuf-101 C with 91.17%.

Quality aspects of paddy grain and seed dried in HSTU mobile grain and seed dryer integrated with a dual heating system

Proper drying and excellence of dried grain and seed are the key concerns of millers, farmers and seed growers. The performance of a new Hajee Mohammad Danesh Science and Technology University (HSTU) mobile grain and seed dryer (HMD) integrated with dual heating system was assessed regarding the quality of dried seed and grain. The HMD was found to be capable of drying 720±10 kg paddy in a batch and drying period varied between 7 to 8 h at drying air temperatures of 65 oC. Paddy seeds of BRRI Dhan 49 and BRRI Dhan 89 were dried at 40 oC and the drying time required 9 to 10 h and 14 to 16 h in Aman and Boro season, respectively. Head rice yield and milling recovery varied from 59.50±0.16% to 61.61±0.54% and 74.95±0.09% to 75.70±0.59% for paddy dried in HMD. In addition, higher germination percentage (GP) of BRRI Dhan 49 varieties was found in Aman season that ranged from 86% to 88% which was dried in HMD in contrary to GP of paddy seeds dried under the sun. Moreover, higher GP was found from BRRI Dhan 89 varieties dried by HMD in Boro season. Also, the vigor index of HMD dried paddy seeds was more than the sun dried samples in both seasons. In conclusion, HMD integrated with a dual heating system is recommended for using at farm level as an alternative drying process for rapid and efficient handling of high-moisture grain and seed in Bangladesh and other subtropical nations in adverse climate.

Analysis of Drought Stress Effect on Inpari Germination: Survival Method

Drought stress using mannitol can inhibit the germination of rice variety seeds. These studies typically produce time-to-event data and censored observation. Survival analysis techniques are valuable for accounting for these non-germination events, as they describe how germination probability changes over time based on the likelihood of seed development. Until now, there have not been survival studies regarding rice germination affected by drought stress in Indonesia. Thus, we investigated the germination probability of three rice varieties (Inpari 19, Inpari 32, and Inpari 49) under drought stress using survival analysis. The seeds were germinated in 0%, 2%, 4%, 6%, and 8% concentrations of mannitol and evaluated daily over 14 days. Our results demonstrated that higher mannitol concentrations significantly decreased the germination percentage and delayed germination time. The survival rates varied significantly between different mannitol concentrations, highlighting the adverse effects of drought stress. However, there was no significant difference in the probability of seed germination among the varieties treated with 2% mannitol. Among the varieties studied, Inpari 19 is more likely to be drought-resistant compared to Inpari 32 and Inpari 49. It is based on the highest germination percentage, shortest germination time, and highest probability of germination compared.

Effects of manakin gut passage on germination of a neotropical melastome shrub (Melastomataceae)

AbstractGut passage is an important but understudied component of animal‐mediated seed dispersal that can impact germination and survival. Melastomataceae plants are abundant and ecologically important throughout the tropics, but studies have obtained contrasting results regarding effects of avian gut passage on melastome germination. We conducted a paired germination experiment to test how gut passage by four species of manakins—key avian dispersers of melastomes—affects germination of the pioneer melastome shrub Miconia rubescens. Manakin gut passage accelerated M. rubescens germination, with gut‐passed seeds germinating an average of 5.1 days earlier than controls, and percent germination of gut‐passed seeds was significantly higher at 20 and 40 days post‐planting. Interestingly, manakin species varied in their gut passage effects, with L. velutina having stronger overall germination effects than M. manacus. Within species, greater body mass was correlated with higher percent germination and shorter times to first germination. Within M. manacus, seeds passed by females had significantly shorter times to first germination than seeds passed by males. Because control seeds were manually depulped in the experiment, the observed gut passage effects are likely attributable to minor scarification of the seed coat during gut transit. Our results suggest manakin gut passage can have biologically meaningful impacts on melastome germination, and the magnitude of these effects can vary based on manakin species, mass, and sex. This study refines our understanding of the “quality” component of seed disperser effectiveness in an iconic dispersal mutualism, with implications for plant community composition and recovery of deforested neotropical ecosystems.Abstract in Spanish is available with online material.

Seed ecology of the arid zone invasive thistle; Centaurea melitensis L.: A study of the effects of seasonal temperature, pH, salinity and moisture stress

AbstractCentaurea melitensis L., known commonly as Malta thistle, is an aggressive and invasive weed species native to the Mediterranean region. This species now occupies a diverse range of ecosystems and climate types across the globe, including the semi‐arid zone of New South Wales, Australia. This semi‐arid climate differs dramatically from its native Mediterranean climate, therefore, we aimed to identify if local adaptations in the seed ecology for C. melitensis have developed. Seeds were collected from mature C. melitensis at Nanya Station, located within the Scotia region of NSW, and then transported to Federation University Australia, Mt. Helen, Victoria. Under laboratory conditions, mature seeds were tested for their germination responses to temperature (17/7, 25/15, 30/20, 35/25°C), photoperiod (12 h light and 12 h dark [L/D], 24 h dark [D]), salinity (0, 25, 50, 100, 150, 200, and 250 mM), osmotic potential (0, −0.1, −0.2, −0.4, −0.6, and −0.8 MPa), and pH (5, 6, 6.2, 7, 8, 9, and 10). The seeds achieved 100% germination in the 17/7°C treatment, with light not being a limiting factor. The seeds exposed to the 25/15°C (D) and 30/20°C (D) treatments also maintained high germination percentage, whilst germination was significantly reduced in the 35/25°C (D) treatment. The L/D photoperiod maintained a 77.5% germination rate at 35/25°C. Whilst increased salinity reduced seed germination from 97.5% in the control to 6% at 250 mM, this species nevertheless demonstrated resistance to osmotic stress with 23% germination observed at 0.8 MPa. Germination exceeded 90% at all of the soil pH treatments, although mean germination time was significantly reduced when seeds were treated with a solution of pH 10. Our results demonstrate that the C. melitensis seeds collected in Australia's semi‐arid zone demonstrated high germination plasticity and are capable of competitive germination in warmer and drier conditions compared to its native Mediterranean climate. Therefore, management efforts that prioritise restricting the spread of C. melitensis seeds into new environments, for example through practising correct sanitation protocols, coupled with the early detection and control of emerging populations will be critical for C. melitensis management in Australia.

Effect of Different Seed Treatment on Germination of Fishtail Palm (Caryota urens) under Naturally Ventilated Poly-house Conditions

An investigation was conducted to study the effect of different seed treatments comprising of mechanical scarification, chemical and plant growth regulator on germination of Fishtail palm (Caryota urens) seeds under naturally ventilated poly-house at sheth D. M. Polytechnic in Horticulture College, Anand Agricultural University, Vadodara during 2021 to 2023. There were total 12 treatments under study which was replicated trice and statistically analysed by completely randomized design at 90 days after sowing. The results revealed that treatment T12 i.e. seeds treated with GA3 1000 ppm for one day recorded significantly lesser days to initiation of germination (46.33 days) along with higher germination percentage (86.67 % and 85.00 %), germination rate index (5.90 %/day and 5.70 %/day) and germination index (255 and 243.67), coefficient of velocity of germination (6.18 and 6.02), timpson’s germination index (1275 and 1218), modified timpson germination index (42.50 and 40.61) and survival percentage (88.33 and 86.67) at 90 days after sowing during first and second year respectively. While, seed without any treatment kept in open condition treatment T1 showed poor performance in germination percentage as well as survival percentage. Thus, Fishtail palm (Caryota urens) seeds soaked in solution of 1000 ppm GA3 along with sowing them in polybags and kept under NVPH condition provides better germination and survival.

Molecular characterization of plant growth-promoting Trichoderma from Saudi Arabia.

Fungi in the genus Trichoderma are widespread in the environment, mainly in soils. They are used in agriculture because of their mycoparasitic potential; Trichoderma have the ability to increase plant health and provide protection against phytopathogens, making them desirable plant symbionts. We isolated, identified, and characterized Trichoderma from different regions of Saudi Arabia and evaluated the ability of Trichoderma to promote plant growth. Morphological and molecular characterization, along with phylogenetic studies, were utilized to differentiate between Trichoderma species isolated from soil samples in the Abha and Riyadh regions, Saudi Arabia. Then, plant growth-promoting traits of the isolated Trichoderma species were assessed. Eight Trichoderma isolates were characterized via morphological and molecular analysis; six (Trichoderma koningiopsis, Trichoderma lixii, Trichoderma koningii, Trichoderma harzianum, Trichoderma brevicompactum, and Trichoderma velutinum) were from Abha and two (T. lixii and T. harzianum) were from Riyadh. The isolated Trichoderma strains belonged to three different clades (Clade 1: Harzianum, Clade 2: Brevicompactum, and Clade 3: Viride). The Trichoderma isolates varied in plant growth-promoting traits. Seeds treated with most isolates exhibited a high percentage of germination, except seeds treated with the T3-T. koningii isolate. 100% germination was reported for seeds treated with the T4-T. harzianum and T6-T. brevicompactum isolates, while seeds treated with the T1-T. koniniopsis and T5-T. lixii isolates showed 91.1% and 90.9% germination, respectively. Seeds treated with the T8-T. velutinum, T2-T. lixii, and T7-T. harzianum isolates had germination rates of 84.1%, 82.2%, and 72.7%, respectively. The Trichoderma isolate T5-T. lixii stimulated tomato plant growth the most, followed by T7-T. harzianum, T8-T. velutinum, T4-T. harzianum, T1-T. koniniopsis, T2-T. lixii, and T6-T. brevicompactum; the least effective was T3-T. koningii. A maximum fresh weight of 669.33mg was observed for the T5-T. lixii-treated plants. The Abha region had a higher diversity of Trichoderma species than the Riyadh region, and most isolated Trichoderma spp. promoted tomato growth.

Impact of dielectric barrier discharge plasma and plasma-activated water on cotton seed germination and seedling growth

Unfavorable environmental conditions during planting can reduce seed germination and hinder seedling growth. To address this issue, manufacturers are exploring innovative and cost-effective methods, such as cold plasma discharge. This simple, low-cost, and efficient physical technique induces significant biological responses in seeds and plants without the use of traditional, environmentally hazardous chemicals. This study investigated the impact of dielectric barrier discharge (DBD) plasma and plasma-activated water (PAW), produced by gliding arc plasma, on the germination and seedling growth of My344 cotton seeds. The seeds were pre-treated with 80 W of DBD plasma for 0, 1, 2, and 3 min, and subsequently soaked for 90 min in PAW with varying pH levels of 5.82, 3.88, 3.63, and 3.38. The results showed that plasma treatment positively influenced seed germination and seedling growth. The highest germination percentage (98.89 %) was observed with 1 min of DBD treatment, followed by PAW priming at pH levels of 3.63 and 3.38. Additionally, a 3-min DBD treatment followed by soaking in PAW with a pH of 3.63 led to significant increases in stem length (76.76 %), root length (48.77 %), and wet weight (76.44 %). Furthermore, it was observed that the electrical conductivity of the seeds in all groups decreased significantly with increased PAW acidity. The physical and chemical effects of cold DBD plasma on the seed surface, as well as changes in hydrophilicity, were further examined using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and water contact angle imaging.

Effect of alternating temperature regimes on seed germination of guar [Cyamopsis tetragonoloba (L.) Taub.

Guar [Cyamopsis tetragonoloba (L.) Taub.] 2n=14, is an annual crop that belongs to the Fabaceae family and has a spring–summer growth cycle. This species has been assuming increasing importance among agro-industrial crops due to the high galactomannan content of its seeds for which a multitude of food and non-food applications have been developed. Guar is a viable rotation crop for growers in Mediterranean areas and can result in diversification in crop production systems. The effects of four alternating day/night temperature regimens on C. tetragonoloba seed germination were tested: (T1) 23/15 °C, (T2) 21/13 °C, (T3) 19/ 11 °C, and (T4) 17/09 °C with a 16/08 h light/dark photoperiod, respectively. Seeds from two guar cultivars (RGC-0936 and RGC-1066) were used. Treatments consisted of four replicates of 50 seeds each, arranged in a split-plot design with temperatures as the main plot and cultivars as the subplot. The results showed that lower temperatures reduced guar seed germination. The highest germination percentages were obtained at the 21/13 °C and 23/15 °C temperature regimens, while a significant drop in germination percentage occurred for the 19/11 °C treatment, and the lowest germination percentages were observed at 17/09 °C. No statistically significant differences were found between the two cultivars studied for seed germination percentages. The interaction effects among the different alternative temperature regimes on seed germination and guar cultivars were not statistically significantly different. The values obtained at the 21/13 °C temperature treatment allow us to conclude that this regimen is the minimum acceptable combination of temperatures to program the sowing date.

Physiological quality of green corn seeds under water stress conditions

This study aimed to evaluate the physiological quality of green corn seeds subjected to water stress. The experimental design used was completely randomized, in a 2 x 5 factorial arrangement, consisting of two corn hybrids (AG1051 and BRS3046) and five osmotic potentials (0; -0.4; -0.8; -1.2 and – 1.6 MPa) simulated with aqueous solutions of polyethylene glycol 6000 (PEG 6000), with four replications of 50 seeds per treatment, totaling 40 experimental units. The analyzed variables were: water content, germination, root protrusion, final root protrusion, germination speed index, root length and coleoptile length. There was a significant effect of the interaction between hybrid factors and osmotic potentials for all analyzed variables, except for final root protrusion, which showed an isolated effect for the two factors studied. The results obtained indicated a higher percentage of germination and initial development of green corn seedlings for green corn seeds, hybrids AG1051 and BRS3046 at the osmotic potential of 0.0 MPa. The germination and vigor of green corn seeds decrease under water stress conditions from the osmotic potential of -0.4 MPa induced by PEG 6000, inhibiting the development of normal seedlings, affecting seed viability. Hybrid AG1051 presents superior germination and vigor compared to BRS3046.

Pre-Germinative Treatments and In Vitro Germination of Dianthus caryophyllus and Alstroemeria spp. Seeds

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.

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 Effects of Organic Fertilizers and NPK on Growth and Yields of Cowpea (Vigna unguiculata. L) in Kano Plains Kisumu, Kenya

Excessive use of inorganic mineral fertilizers as an agronomic practice has resulted in the depletion of soil organic matter of soils of many regions thereby rendering such soils infertile and unable to maintain sustainable production. The use of organic amendments provides the immediate strategy for compensating for soil carbon depletion thereby reducing land degradation. The purpose of this study was to evaluate the effects of six organic amendments on the growth and yield of Cowpea (Vigna unguiculata L) as compared to the conventional use of inorganic fertilizer NPK. The organic amendments were Boom Max, Ecoplanting, Evergrow, Dung slurry, Filter mud, and Market waste slurry applied to the soil at 8.33 t/ha against NPK (9:15:20) at 250 kg/ha. The experiment was laid in a RCBD. Data on growth and yields was collected on 10 tagged plants per plot. The results showed differences among treatments. Mature composts (Boom Max, Ecoplanting, and Evergow) resulted in a significantly (p< 0.05) higher germination percentage (53.49% on average) compared to that of Filter mud (41.50%) and the slurries (34.18% on average) while all the composts resulted in 25% higher number of branches on the average in season two as compared to the bio-slurries. In season three, Boom Max gave the highest germination percentage (41.02%) which was significantly higher than those of Evergrow (29.80 %), Filter mud and Dung slurry (27.18% on average) and NPK and Market waste slurry (5.64% on average) but not different from that of Ecoplanting. Five of the amendments had significantly better germination rates than NPK by an average of 20%. There were no significance differences (P≤0.05) in growth parameters between the mature composts and the NPK fertilizer, suggesting that the mature composts were equally efficient in nutrient supply to the crop as did the NPK fertilizer for plant growth. The application of organic amendments produced significant improvements in fresh leaf yields of the cowpea crop, with the highest yield recorded from the Boom Max applied plot (5781 kg on average), which was not different from others in seasons one and three but significantly different from that of NPK in season three. It can be concluded that depending on choice or type of amendment, organic manures are capable of producing similar or better results of crop growth and yields as the inorganic fertilizers.

Seed Priming and Biopriming in Two Squash Landraces (Cucurbita maxima Duchesne) from Tunisia: A Sustainable Strategy to Promote Germination and Alleviate Salt Stress.

In recent years, seed priming has gained interest, with researchers aiming to enhance seed germination and early growth, especially under abiotic stress conditions. In this study, seeds from two squash landraces (Cucurbita maxima Duchesne; i.e., Galaoui large seeds (Galaoui hereafter) and Batati green (Batati hereafter)) were subjected to different priming methods ((a) 0.3% and 0.4% KNO3 (halopriming); (b) 0.1% and 0.2% GA3 (hormopriming); (c) inoculation with Trichoderma spp. (T. harzianum, T. viride, and T. virens), Bacillus subtilis, and Pseudomonas fluorescens (biopriming) in order to promote germination parameters and seedling growth under salinity stress (0, 100, and 200 mM of NaCl). Our findings indicate the better performance of primed seeds compared to the untreated ones in terms of germination and seedling growth traits, although a varied response depending on the priming method and the landrace was observed. The highest germination percentage (GP) and the lowest mean germination time (MGT) were observed in 0.4% KNO3-primed seeds. The positive effects of 0.4% KNO3 were also depicted in all traits related to seedling growth and the seedling vigor index (SVI), indicating its effectiveness as a priming agent in squash seeds. Under salinity stress conditions, priming with 0.4% KNO3 significantly improved the germination and seedling growth traits for both landraces, while the application of 0.2% GA3 at high salinity significantly improved photosynthetic quantum yield (Fv/Fm ratio). Regarding the effects of biopriming in germination and seedling growth traits, our results indicate that T. harzianum and B. subtilis were the most effective bioagents in promoting germination and seedling growth in Galaoui and Batati seeds, respectively. In conclusion, our findings provide important information regarding the practice of using priming and biopriming agents to enhance the germination and seedling growth capacity of squash seeds, as well to mitigate the negative effects of salinity stress at the critical stages of germination and early growth.

Effect of D-mannitol and Gibberellic Acid on Physiological Parameters, Early Seedling Growth Characteristics, and Some of the Most Important Chemical Components of Barberry (Berberis vulgaris L.)

Background: One of the important medicinal plants and agricultural products in Asia, particularly in Iran, is barberry, and both salinity and drought can cause osmotic or ionic imbalance in plant cells. In order to study the impacts of D-Mannitol and gibberellic acid on seed germination, physiological parameters, early seedling growth characteristics, and some of the most important chemical ingredients of barberry, one experiment is designed. Methods: The experimental design was Completely Randomized Design (CRD) with three replicates, and drought stress was done by D-mannitol at various stress levels, namely, 0 MPa, 40 MPa, and 80 MPa, and the reaction of studied cultivar was assessed on the basis of experimental characteristics associated to germination and seedling growth, and Gibberellic acid treatments were 0 mgL-1, 300 mgL-1, 600 mgL-1, and 900 mgL-1. Results: The effects of D-mannitol were significant in germination percentage, germination rate, seedling vigor index, chlorophyll a, total chlorophyll, leaf dry weight and total sugar. Experimental treatments such as germination percentage, germination rate, and total chlorophyll were also influenced by the application of gibberellic acid. The interaction between D-mannitol and gibberellic acid had significant effect on peroxidase activity. The highest germination percentage, germination rate, seedling vigor index, catalase activity, peroxide activity, and Chlorophyll a were obtained for 0 MPa application of D-Mannitol, followed by usage of 40 MPa, and 80 Mpa, respectively. The maximum total chlorophyll, relative water content, and leaf dry weight were also related to control treatment (0 MPa D-Mannitol), while the higher values of proline content, carotenoids and total sugar were obtained for 80 MPa application of D-Mannitol. The maximum values of germination rate, germination percentage, seedling vigor index, peroxidase activity, and chlorophyll a were related to control treatment (0 mgL-1 gibberellic acid), and the highest CAT activity was related to the application of 300 mgL-1 gibberellic acid. The highest total chlorophyll content and relative water content were related to 0 mgL-1 gibberellic acid, while the maximum praline content and leaf dry weight were obtained for the application of 600 mgL-1 and 0 mgL-1 gibberellic acid. There was not any significant difference in carotenoids between gibberellic acid treatments, while the application of 900 mgL-1 gibberellic acid obtained the highest value of total sugar of barberry. Conclusion: Conclusively, on the basis of the results, the application of 80 MPa D-Mannitol and 600 mgL-1 could be recommended as they can increase the absorption of nutrients and water.

Sulfuric acid as a germination stimulator in forage soybean seeds (Neonotonia wightii)

Forage soybean (Neonotonia wightii) is a legume frequently used as a cover crop in field crops. However, as a species of the Phaseoloideae subfamily, it is characterized by the physical latency of the seed, which makes it difficult to obtain a high, homogeneous, and rapid germination. The aim of the present study was to determine which method of scarification stimulates the germination process to a greater extent. The following immersion times were evaluated: 5 to 20 minutes in 98% sulfuric acid, 24 hours in 5.4% sodium hypochlorite, water, and gibberellic acid [100 ppm], 15 minutes of treatment with sandpaper and the combination of these last two. They were distributed in a completely randomized experimental design, where eight treatments and a control were evaluated, with three replicates each and 200 seeds as experimental units, subjected to controlled conditions (germination chambers at constant temperatures and a relative humidity of 27 °C and 70%, respectively) during the spring of 2022. The results were favorable, a high germination percentage was obtained from seeds subjected to a 20-minute immersion time in sulfuric acid (90% germination and an average of six germinated seeds per day) and this was significantly higher than the rest, making it an effective method to break the physical latency of the seeds, as it removes the impermeable cover allowing inhibition and consequently the activation of the seed’s metabolism.

Differential effects of increasing temperature on the germination of five wild species with varying range sizes in a Carrara marble quarry

Assessing the performance of spontaneous plants in abandoned quarries under future environmental scenarios is important for successful restoration practises. Air warming is one of the most relevant ongoing climatic changes in the Mediterranean. We tested the effects of increasing temperature on the germination of five species spontaneously colonising the abandoned sectors of a Carrara marble quarry (Tuscany, central Italy). We selected five plant species with different widths of their distribution range, from local endemic to invasive alien: Santolina pinnata, Globularia incanescens, Hypericum coris, Helichrysum italicum, and Buddleja davidii. Seeds were collected in situ and their germination was tested in laboratory conditions at 10, 15, 20, 25, and 30 °C. The effects of temperature and species on germination percentage (GP) and mean germination time (MGT) were tested through two-way ANOVA. Increasing temperatures negatively affected the GP of S. pinnata and H. coris. G. incanescens performed better at intermediate temperatures, whilst H. italicum benefited from increasing temperatures. B. davidii showed a similar high GP under all the treatments. MGT decreased with increasing temperature for all the species, except for S. pinnata, which showed an increase of MGT with increasing temperature. We highlighted that, under future warmer climatic conditions, the two endemic species will be disadvantaged with respect to the species with a wider distribution range and the non-native species in the studied quarry. This evidence is relevant for restoration planning since seeding the two endemic species could be unsuccessful under future environmental scenarios, when H. italicum and B. davidii will be more competitive in the colonisation of the quarry.