Average Germination Research Articles

Enhancing Germination Efficiency of Dragon Fruit (Hylocereus spp.) Seeds under Varied Climatic Conditions in East Nimar, Madhya Pradesh, India

The current study sought to identify optimal pre-treatment approaches for increasing seed germination percentage and vigor. Regardless of the therapies. The experiment was set up in randomized block design (RBD), with three replications. The nursery experiment was carried out in 2024 at the School of Agriculture Science, Dr. C.V. Raman University in Khandwa, Madhya Pradesh. Dragon fruit seeds from seven treatments were pretreated with various pretreatments, viz. T1 Darkness + water soaking 12 hours; T2 Darkness + water soaking 24 hours; T3 Continuous light (24 hours) + water soaking 12 hours. T4 Continuous light (24h) + water soaking for 24 hours, T5 Alternating light (12h light/12h dark) + water soaking for 12 hours T6 alternating light (12h light/12h dark) + water soaking for 24 hours, T7 Control (without pretreatment) to examine the impacts on germination %, germination value, mean germination time, and seedling vigour index. Seeds pre-treated with T-6 Alternating light (12h light/12h dark) + water soaking 24 hours had the highest average germination percentage (94.66%), while control had the lowest germination percentage (78.66%) when compared to other pre-treatments among all treatments, and the highest average mean germination value (9.57), while T7 Control had the lowest mean germination value (6.71). Seeds were pre-treated with T7 control recorded average highest mean germination time 21.21 days, while T6 Alternating light (12h light/12h dark) + water soaking 24 hours showed lowest mean germination time as compared to other pre-treatments among all treatments, When compared to other pre-treatments, T7 control had the lowest mean seedling vigor index (694.09) across all treatments.

Seedling Production of Retrophyllum rospigliosii in Nurseries and Potential Reforestation Areas Using Modeling Techniques

The success of reforestation and restoration projects depends on several factors, with proper seedling management and the selection of an appropriate planting area being crucial. In Peru, the populations of Retrophyllum rospigliosii (Pilg.) C.N.Page (Ulcumano) have been decreasing due to intensive logging of one of the most valuable woods in South America’s tropical forests. There are few studies that unify the production of plants through seeds in nurseries and the identification of suitable areas to place the plants produced. Our study has two components. The first aimed to optimize the plant production process through an experiment that evaluated the effects of three doses of controlled-release fertilizer (CRF) (4.2, 8.4, and 12.6 g/L) and two container sizes (115 and 180 cc) on the morphological quality of seedlings in the nursery. The second component involved identifying potential reforestation areas using ecological niche modeling, based on climatic and edaphic variables. The results indicated that the 4.2 g/L CRF treatment for both container sizes had a significant positive effect on seedling growth. The average germination rate was 85% at 120 days. At six months after seedling transplantation, treatments of 4.2 g/L CRF in 115 cc and 180 cc containers were shown to have the best positive effect on morphological variables of seedlings, with a root collar diameter of 3.76 mm and a height of 13.25 cm. Regarding the potential niche models, an area of 6321.97 km2 with ideal conditions for reforestation with R. rospigliosii was estimated, with the departments of Huánuco, Pasco, Junín, and Cusco showing the highest potential. Based on this, it is estimated that over three million plants are needed for large-scale reforestation projects. Integrating silvicultural studies with niche models is a valuable tool for supporting reforestation and ecosystem restoration projects.

Determination of pre-harvest sprouting tolerance and quality traits of the bread wheat landraces

In this study, pre-harvest sprouting tolerance and some quality characteristics of some wheat landraces and modern varieties in Turkey were determined. In Eskişehir, Karaman and Samsun locations of Turkey, 126 genotypes were tested in the 2014-2015 growing seasons, and 48 genotypes were tested in the 2015-2016 and 2016-2017 growing seasons in two-replication experiments. Data regarding germination index, protein content, sedimentation volume and falling number of genotypes were observed. Physical properties of grain, the number of days to spike, and plant height were also investigated. The difference between genotypes was found to be statistically significant for all traits. We found the germination index of the genotypes varied between 0.19 and 0.70 for the 2015-2016 and 2016-2017 growing seasons, respectively. The average germination index value of red kernel genotypes is lower than white kernel genotypes. The landraces from Turkiye included in the research were taller and harvested lately. In comparison, modern genotypes are in the first place regarding sedimentation volume. The landraces had higher protein content but lower protein qualities than modern cultivars. The grain hardness of landraces was lower than that of modern cultivars in the three years. We found positive relationships between the germination index, grain filling time, thousand-grain weight, and grain color. Protein content, sedimentation volume, falling number, and grain hardness are negatively and significantly related to the germination index. The results showed that white kernel Clark's Cream and red kernel Karakılçık (1) genotypes could be used as gene sources for pre-harvest sprouting tolerance breeding in bread wheat.

Multiplication and development in the nursery of Pterocarpus erinaceus, an endangered agroforestry species in Cote d'Ivoire

Pterocarpus erinaceus is a multi-purpose species threatened with extinction. The present study aims to contribute to the improvement of multiplication and nursery growth of Pterocarpus erinaceus hulled seeds. To this end, four pre-treatments were applied to Pterocarpus erinaceus hulled seeds to lift their dormancy in order to facilitate germination of the species. These were: untreated seeds as Control (To), soaking in ordinary water for 24 h (T1), soaking in hot water at 60°C (T2) and soaking in sulfuric acid (H2SO4) for 20 min (T3). Germination parameters such as germination rate, germination time and average germination time were evaluated. Growth in height, diameter, number of leaves and root length were determined. Germination data and growth parameters were collected. Analyses showed that soaking shelled seeds in ordinary water for 24 h was the best treatment, with a germination rate of 43%. Pre-treatment of the seeds with sulfuric acid for 20 min showed the lowest germination rate (1%), due to the sensitivity of the seeds. Furthermore, these pre-treatments had no effect on seedling growth in the nursery. Those interested in producing Pterocarpus erinaceus seedlings are advised to soak shelled seeds in ordinary water for 24 hours to ensure better germination in the nursery.

Morphophysiological variation, vigor test, and influence of light and temperature on the germination of four cultivars of Glycine max (L.) Merrill

Soybean (Glycine max. (L.) Merrill) is a crop whose productivity depends on the quality of the seeds used. In this context, the objective of this study was to characterize the seeds physically, evaluate viability using tetrazolium, identify physiological vigor through an electrical conductivity test, and determine the influence of temperature and photoperiod on the germination of four cultivars (Ultra, Olimpo, Extrema and Foco). 200 seeds were used, measuring size, weight of a thousand seeds, moisture content, and fresh mass. In tetrazolium (1%), 100 seeds were soaked for 4 h at 25°C. For electrical conductivity, 50 seeds were submerged on 75 mL of deionized water at 25°C for periods of 4, 8, 12, 16, 20 and 24 h. In the germination process, the treatments (four replications of 50 seeds) were incubated (B.O.D.) at temperatures of 25°C, 27°C, 30°C and 35°C, under photoperiods of 12 and 14 h. The experimental design adopted was completely randomized for all experiments, and the means were subjected to analysis of variance and Tukey's test at 5% probability. The Ultra cultivar presented perimeter (38.21±3.72 mm), length of 9.98±0.24 mm, and width of 7.94±0.27 mm. The cultivars presented viability above 90%. For electrical conductivity, the 12 h period was effective for identifying vigor. The Ultra cultivar (25°C and 12 h of photoperiod) achieved 77% germination, 10 germinated seeds per day, an average germination time of 4 days and 43 germinated seeds by the third day.

Seed Dormancy and Germination Responses to Different Temperatures of Leptochloa chinensis (L.) Nees: A Case Study with 242 Populations Collected from Rice Fields in East China

Leptochloa chinensis (L.) Nees is a troublesome rice weed. We collected 242 L. chinensis populations from rice fields in eastern China and studied the duration of seed dormancy and the seed germination ability at different temperatures. All L. chinensis populations studied exhibited seed dormancy. The periods required to reach 50% germination under optimal conditions were 31–235 days, with an average of 96 days. None of the populations germinated at 15 °C. Under constant temperatures of 20, 25, 30, and 35 °C, the average germination percentages of 242 populations were 0%, 71%, 79%, and 60% at 2 days after treatment (DAT), and were 56%, 84%, 88%, and 88% at 14 DAT, respectively. The duration of seed dormancy, as well as the germination ability of seeds, were significantly (p < 0.05) influenced by the agricultural region and the longitude and latitude of the collection locations. Under constant temperatures of 20 to 35 °C, the average germination percentages of seeds collected from transplanted rice fields were significantly higher than those collected from direct-seeded fields. This is the first study on seed germination biology of L. chinensis with multiple populations systematically collected from rice fields on a regional scale.

Mechanism of betterment towards growth and induction of defense in rice (Oryza sativa L.) by biopriming with bacterial endophytes isolated from wild rice

Utilizing beneficial microorganisms associated with plants, particularly endophytes, is becoming more and more prevalent since it supports the physiological health and evolutionary adaption of the host. The range of enhanced endophytic bacteria found in wild rice makes it a promising resource for sustainable agriculture. Current study focused on benefits of bacterial endophytes isolated from tissues of wild rice plants' roots, stems, and leaves for managing the health and development of rice (Oryza sativa L.) plants. Bacterial endophytes were characterized using 16 S rRNA. Treatments with Priestia megaterium (NRRI EB 1) and Priestia aryabhattai (NRRI EB 2) outperformed the other isolates in rice growth enhancement activities significantly. The biocontrol efficacy of bacterial endophytes was tested against Xanthomonas oryzae pv. oryzae and Rhizoctonia solani and percentage of inhibition was higher in NRRI EB 1 by 79.32–80.83 % and in NRRI EB 2 by 79.69–80.45 %. Bio-priming the seeds with specific endophytic bacterial strains led to a decrease in average germination time, an increase in seedling vigor, and total chlorophyll content. Additionally, they generated greater amounts of soluble phosphate (40.91–83.70 μg/mL) and indole acetic acid (28.10–60.18 μg/mL), which are in the midst of encouraging more plant development. Higher expressions of defense enzymes in comparison to the control, including catalase (>220 % in root and shoot), peroxidase (>200 % in shoot and root), and superoxide dismutase (>150 % in shoot and root) illustrates the rice crop's resilience to withstand stress. The activity of the mentioned enzymes was further validated through the activation of corresponding defense genes such as DEFENSIN (>2-fold), PAL (>3-fold), PR-3 (>2-fold), POX (>2-fold) and LOX (>1-fold) in relation to the untreated plants. The possibility exists to extract advantageous endophytic bacteria from wild rice species, potentially rewilding the microbiome of cultivated rice cultivars and fostering their deployment.

Viability and storage of Myrceugenia euosma (O. Berg) D. Legrand and Siphoneugena reitzii D. Legrand (Myrtaceae) pollen

This study evaluated aspects of the pollen viability of the species Myrceugenia euosma (O. Berg) D. Legrand and Siphoneugena reitzii D. Legrand (Myrtaceae), both native trees with ornamental, medicinal and industrial potential. The study used different concentrations of sucrose to determine pollen viability in vitro and through colorimetric tests with specific dyes (Lugol, carmine acetic, and tetrazolium chloride – TTC – 0.1 and 0.05%). The two species also had their pollen stored for 30 and 90 days in freezers, refrigerators, and natural environments to check the best method for preserving their viability. The results showed that the highest average germination of M. euosma pollen was in a culture medium containing 30% sucrose. After 30 and 90 days of storage, pollen viability was significantly reduced, having preserved part of its potential only in the freezer. The pollen of S. reitzii had a higher average germination rate in a medium with 20% sucrose, but also showed a reduction in viability after 30 and 90 days of storage. The colorimetric tests showed that the pollen of both species responded to the dyes. However, the viability of Lugol and carmine acetic was considered to be overestimated in relation to the in vitro germination tests. Tetrazolium at 0.1% proved to be an alternative for checking the viability of S. reitzii pollen. It can be concluded that different concentrations of sucrose affect germination, and that storing pollen at a low temperature can preserve some of its viability in the short term.

Indigo (Indigo suffruticosa Mill.) seed germination to improve commercial viability

Indigo suffruticosa Mill., commonly known as Guatemalan indigo or anil indigo, is being investigated as a regenerative rotational crop that is used to produce natural plant-based dyes in the USA. The fashion and textile industry currently rely on harmful synthetic dyes to color fabric. To improve the viability of Indigo and to minimize production costs, methods to improve Indigo seed germination rates will benefit the quality, crop yields, and enable large scale field plantings.This study was initiated to develop a methodology of treating seeds to increase seed germination rates of Guatemalan Indigo and decrease fungal seed pathogens. All studies were conducted on the currently available commercial Indigo varieties. Sterilization and germination methods included: ethanol and bleach sterilization, mechanical scarification (coffee grinder, belt sander), gibberellic acid, dry heat, freezing, distilled water soaking, and boiling water. Each treatment was replicated four times for each of the various times and temperatures tested. The dry heat method at 80°C for 30 min resulted in the highest average germination rate of 83 %. Trials demonstrated that the dry heat method was the only treatment that resulted in higher germination rates than control treatment with an average of only 64 % germination. Dry heat at 90°C across all time intervals (30 min, 1 h, and 2 h) showed no results higher than 34 % germination. Pre-treating seed with 10 min soak in 10 % bleach resulted in complete control of surface pathogens with no decrease in seed germination. The boiling water method for 30 sec also lead to higher germination rates but may prove too difficult in larger volumes. Other methods of sterilization, gibberellic acid, freezing, mechanical scarification, and long-term soaking resulted in average germination percentages equal to or less than the control of no treatment. The dry heat method should be applied 2 h before planting. Applying a 10 min bleach sterilization step and dry heat treatment will greatly improve germination of Indigo and will allow for a commercially viable protocol to be created. This will allow natural indigo to compete with inexpensive synthetic dyes, enabling producers to direct seed indigo rather than costly transplant production.

The Effect of Grass Juices on The Agricultural Properties of Legumes Grown in Different Root Media

The consumption of grass juices obtained from cereals for health purposes is increasing day by day. For this purpose, research on different plant solutions has gained momentum. In our study, barley (Hordeum vulgare L.) and oat (Avena sativa L.) grass juices grown in hydroponic conditions were used. Obtained grass juices were applied to pea and lupine seeds in 100% soil (control), 100% pumice, 100% perlite, 100% tea waste and 100% cocopeat substrate. Germination percentage, germination rate, average daily germination, peak value, germination value, root dry and fresh weight, stem dry and fresh weight, root and stem length, plant yield, grass yield, plant yield seed rate, macro and micro (N, P, K, Ca, Mg, Fe, Cu, Zn and Mn) mineral substance contents were investigated pea and lupine. Grass juices were obtained by mowing barley and oat seeds sown in 30 × 50 × 7 cm plastic tubs in ten days and passing them through a juicer. Pea and lupine 25 seeds, which were placed in each pot, were grown in different root media (100% soil, 100% cocopeat, 100% pumice, 100% perlite, and 100% tea waste) under in vitro conditions. 150 ml of water (control), barley grass juice, oat grass juice and barley + oat grass juice were applied to the seeds according to their subjects. The experiment was carried out in 400 pots with 10 replications x 2 species x 4 treatments x 5 media, according to the factorial fully randomised design. As a result of the research, germination physiology (germination percentage, germination rate, average daily germination, peak value and germination value), mineral substance content (N, P, K, Ca, Mg, Fe, Cu, Zn and Mn), growth and yield parameters at (root dry and wet weight, stem dry and wet weight, root and stem length, plant yield, grass yield, plant yield seed rate) barley grass juice application was found to be more effective than other applications after control. In all parameters examined in the research, it was determined that the five different medias used as growing media followed the order of soil>cocopeat>pumice>perlite>tea waste, and after the control and the best growing medium was cocopeat.

Influencia del parental masculino sobre el poder germinativo de semillas de palma aceitera

The National Institute of Agricultural Research (INIAP) uses female parentals (Dura -Deli) and male parentals (Pisifera) from different origins to obtain the hybrid INIAP -Tenera of oil palm (Elaeis guineensis Jacq). The objective was to evaluate the influence of the male parental on the germination of African oil palm seeds. Seeds from 20 bunches, resulting from the crossing of 10 Dura plants with pollen from two Pisifera plants, were subjected to the germination process. The process involved eight days of imbibition 1, 80 days of heating, 24 hours of drying, four days of imbibition 2, and six hours of drying. One hundred seeds per treatment and per repetition were evaluated using a completely randomized design, assisted by Tukey's test at 5%. The results showed that seeds from Dura plants D1, D8, and D9 crossed with the male parental P1 achieved a higher percentage of optimal germination and statistical differences compared to seeds from the same Dura plants crossed with Pisifera P2. Of the 10 Duraprogenitors studied, seven (D1, D3, D4, D5, D8, D9, D10) crossed with Pisifera P1 achieved an average optimal germination rate above 50%, while only two of the Dura plants (D3 and D5) evaluated and crossed with Pisifera P2 achieved an optimal germination rate equal to or above 50%. This demonstrated that the germination of Tenera seeds (Dura x Pisifera) of African oil palm is highly related to the male parental use.

Chemical and Mechanical Scarification as Techniques for Overcoming Dormance in Red Tent Seeds (Adenanthera pavonina L.)

Purpose: Evaluate chemical and mechanical scarification techniques, as methods for overcoming dormancy in red vine seeds. Theoretical Framework: Based on scientific articles found on search engines and books in the field of seeds, types of forest seeds, types of dormancy in forest seeds and techniques for overcoming dormancy. In order to support the explanation of how techniques for overcoming dormancy are related to the rate and time of germination of red seed seeds, and how germination time can subsequently affect the quantity of seedlings produced, as well as their initial growth. Method: The experiment was installed to test the following treatments: T0 – without scarification; T1 – mechanical scarification; T2 chemical scarification with 80% H2SO4 for half an hour; T3 – chemical scarification with 80% H2SO4 for one hour; T4 – chemical scarification with 0.4% KNO3 for half an hour; T5 – chemical scarification with 0.4% KNO3 for one hour. The design used was completely randomized, with six treatments, five replications and 20 seeds in each replication. At the end of 30 days, counting from the beginning of germination, the following variables were evaluated: germination speed index (IVG), average germination time (TMG), germination percentage (G) and germination speed index (IVG). Results and Conclusion: The most efficient methods for germinating the red tent seeds were mechanical scarification with sandpaper and immersion in 0.4% KNO3 for half an hour. However, mechanical scarification would be the most easily used and least expensive method for producing seedlings in nurseries. Research Implications: These results indicate that the mechanical scarification technique is an efficient method for overcoming the dormancy of the red tent, which is integumentary. Understanding the most efficient and effective techniques for overcoming dormancy in seeds of species that present this characteristic is important to allow, within the nursery, germination to occur quickly and uniformly. Consequently, making it possible to obtain seedlings with more uniform sizes, even though these are produced from seeds. Originality/Value: A high germination rate and uniform initial growth are important factors within the nursery, especially if it is of a commercial nature, but also for the restoration of areas, because it allows seedlings to be obtained in less time.

The GA and ABA signaling is required for hydrogen-mediated seed germination in wax gourd

BackgroundHydrogen gas (H2), a novel and beneficial gaseous molecule, plays a significant role in plant growth and development processes. Hydrogen-rich water (HRW) is regarded as a safe and easily available way to study the physiological effects of H2 on plants. Several recent research has shown that HRW attenuates stress-induced seed germination inhibition; however, the underlying modes of HRW on seed germination remain obscure under non-stress condition.ResultsIn this current study, we investigated the possible roles of gibberellin (GA) and abscisic acid (ABA) in HRW-regulated seed germination in wax gourd (Benincasa hispida) through pharmacological, physiological, and transcriptome approaches. The results showed that HRW application at an optimal dose (50% HRW) significantly promoted seed germination and shortened the average germination time (AGT). Subsequent results suggested that 50% HRW treatment stimulated GA production by regulating GA biosynthesis genes (BhiGA3ox, BhiGA2ox, and BhiKAO), whereas it had no effect on the content of ABA and the expression of its biosynthesis (BhiNCED6) and catabolism genes (BhiCYP707A2) but decreased the expression of ABA receptor gene (BhiPYL). In addition, inhibition of GA production by paclobutrazol (PAC) could block the HRW-mediated germination. Treatment with ABA could hinder HRW-mediated seed germination and the ABA biosynthesis inhibitor sodium tungstate (ST) could recover the function of HRW. Furthermore, RNA-seq analysis revealed that, in the presence of GA or ABA, an abundance of genes involved in GA, ABA, and ethylene signal sensing and transduction might involve in HRW-regulated germination.ConclusionsThis study portrays insights into the mechanism of HRW-mediated seed germination, suggesting that HRW can regulate the balance between GA and ABA to mediate seed germination through ethylene signals in wax gourd.

Production of Seedlings of Corymbia citriodora Inoculated with Endophytic Bacteria

This study aimed to evaluate the effect of inoculants of endophytic bacteria producing indoleacetic acid (IAA) on the physiological quality of seeds and the production of seedlings of Corymbia citriodora (Hook.) KD Hill & LAS Johnson. In the physiological quality test of the seeds, the treatments used were individual inoculation with Priestia megaterium, Exiguobacterium sibiricum, Pantoea vagans strain 45URP4-1, and Bacillus sp.; joint effect of the four strains (mix); inoculation only with the carrier (cassava starch and activated charcoal); carrier with 1.0 μg mL−1 of IAA; and non-inoculated control without IAA and without a carrier. In the production of seedlings in a greenhouse, the treatments were the same, except for the mix, which was replaced by P. vagans strain 7URP1-6 (Pvs7), as inoculation with the mix increased the number of abnormal seedlings. In the physiological quality test of seeds, seeds inoculated with the bacteria individually did not have the physiological quality impaired and the carrier created a microenvironment around the seeds, benefiting germination percentage, germination speed index, average germination time, and average germination speed. In the greenhouse, seedlings inoculated with Pvs7, P. megaterium and E. sibiricum were taller, with a larger stem diameter and dry mass of shoot, roots, and total. Seeds inoculated with E. sibiricum had higher averages for height, chlorophyll b content, and shoot and total dry mass, as well as a greater ability to colonize the rhizosphere and roots of C. citriodora, resulting in the production of higher-quality seedlings. Inoculation of seeds of C. citriodora with endophytic bacteria proved to be a promising alternative for plant development.

Pollen thermotolerance of a widespread plant, Lotus corniculatus, in response to climate warming: possible local adaptation of populations from different elevations.

One of the most vulnerable phases in the plant life cycle is sexual reproduction, which depends on effective pollen transfer, but also on the thermotolerance of pollen grains. Pollen thermotolerance is temperature-dependent and may be reduced by increasing temperature associated with global warming. A growing body of research has focused on the effect of increased temperature on pollen thermotolerance in crops to understand the possible impact of temperature extremes on yield. Yet, little is known about the effects of temperature on pollen thermotolerance of wild plant species. To fill this gap, we selected Lotus corniculatus s.l. (Fabaceae), a species common to many European habitats and conducted laboratory experiments to test its pollen thermotolerance in response to artificial increase in temperature. To test for possible local adaptation of pollen thermal tolerance, we compared data from six lowland (389-451 m a.s.l.) and six highland (841-1,030 m a.s.l.) populations. We observed pollen germination in vitro at 15 °C, 25 °C, 30 °C, and 40 °C. While lowland plants maintained a stable germination percentage across a broad temperature range (15-30 °C) and exhibited reduced germination only at extremely high temperatures (40 °C), highland plants experienced reduced germination even at 30 °C-temperatures commonly exceeded in lowlands during warm summers. This suggests that lowland populations of L. corniculatus may be locally adapted to higher temperature for pollen germination. On the other hand, pollen tube length decreased with increasing temperature in a similar way in lowland and highland plants. The overall average pollen germination percentage significantly differed between lowland and highland populations, with highland populations displaying higher germination percentage. On the other hand, the average pollen tube length was slightly smaller in highland populations. In conclusion, we found that pollen thermotolerance of L. corniculatus is reduced at high temperature and that the germination of pollen from plant populations growing at higher elevations is more sensitive to increased temperature, which suggests possible local adaptation of pollen thermotolerance.

Tetrazolium viability test method for micro-seeds of the endangered plant Deinanthe caerulea

Deinanthe caerulea is a rare perennial herb endemic to China that has high medicinal and ornamental value. Seeds of D. caerulea are tiny with a thousand seed weight of only 200 mg. Thus, classical germination tests are difficult to apply in this species and a rapid and accurate method for determining seed viability becomes an important prerequisite for species conservation, introduction and domestication. When using the tetrazolium (TTC) topographical staining method, removing the seed coat for TTC penetration is not practical. Therefore, in this experiment, we tried a hypochlorite seed treatment before the TTC test for discolouring and improving permeability of the seed coat. For three different seed samples, we found that treatment with 1% sodium chlorite solution for 30 minutes was the best pre-treatment, followed by staining with a 0.5% TTC solution for five hours. Staining patterns of embryos can then be observed under a microscope without any further preparation of the seeds. Only completely stained embryos were classified as viable. Simultaneously, germination tests were performed at different temperature and light regimes. The best regime was alternating 25/15°C and constant light at 3000 lx. Average germination percentage of the three samples was 79.75%, whereas viability was 86.77%. The results showed that a hypochlorite treatment before TTC staining is a versatile method for improving practicability of viability testing in Deinanthe caerulea.

Determination of germination characteristics and salinity and drought tolerances of Mountain Swan (Atriplex nitens Schkuhr)

In this study, it was aimed to determine the appropriate seed germination temperature, salt tolerance, salinity and drought tolerance of seedlings in Mountain swan (Atriplex nitens). For this purpose, an experiment was established in 2021 in laboratory conditions according to the factorial experiment design in random plots and in greenhouse conditions according to the random plots experiment design with three replications. Firstly, 4 constant (10, 15, 20, 25, 30°C) and 2 variable (20/15, 25/15°C) temperatures were used in the refrigerated incubator. Total germination rates and average germination times of seeds with and without pericarp were determined. Secondly, 6 different salt concentrations (0, 100, 200, 300, 400 and 500 mM NaCl) were studied considering the optimum germination temperatures (25°C and 20/15°C). At the end of the study, germination rates (%), average germination times (days) and sensitivity indices (SI) were determined. In the last two stages, seedlings were subjected to 4 different salinity (0, 100, 200, 300, 400 and 500 mM NaCl) and 5 different drought (control, low, moderate, high and severe) tests under greenhouse conditions. At this stage, plant and root length, stem thickness, leaf area index (LAI), plant and root dry weight, root/plant ratio and tolerance percentage values were measured. As a result of the laboratory study, it was determined that seeds without pericarp had a better germination percentage than seeds with pericarp. The highest total and normal germination rates were obtained from 200 mM NaCl treatment at 20/15°C. Germination rate was determined from 0, 100 and 200 mM salt treatments at 25°C. These results showed that Atriplex nitens seeds could germinate in high salt concentrations and that their seedlings had high tolerance to drought and salinity.

Selecting Suitable Tree Species for Direct Seeding to Restore Forest Ecosystems in Northern Thailand

To upscale restoration of tropical forest ecosystems, direct seeding—sowing seeds directly into the ground—is potentially a more cost-effective technique than tree planting. However, its success is limited by seed predation, the harshness of environmental conditions on restoration sites and particularly by a lack of information about suitable tree species. Therefore, this study tested the suitability of 23 native forest tree species for direct seeding, to restore a biodiversity-rich, upland, evergreen forest in northern Thailand. Three replicate seed batches of each species were sown randomly in two degraded sites and in a tree nursery under controlled conditions. Seed removal and germination were monitored weekly until no further germination had occurred for more than a month. Subsequently, seedling yield, growth and species performance score were also monitored at appropriate intervals. Nine months after sowing, seed removal differed significantly among species but was generally low, with a cross-species average of 3.4% (±0.5 SE). Seed size was negatively correlated with seed removal. Eight species failed to germinate. Seed germination percentage varied widely among species. Cross-species average germination of the 15 species that germinated was 25% (±6.2 SE). Two species (Adenanthera microsperma and Alangium kurzii) were ranked as having high germination (>50%), five species (Choerospondias axillaris, Spondias pinnata, Diospyros glandulosa, Melia azedarach and Phyllanthus emblica) had medium germination (20–50%) and eight species had low germination (<20%). Following the first dry season, two of the fifteen germinated species failed to establish. Germination and establishment were influenced by seed size, seed storage behavior and successional status. A. microsperma, S. pinnata and C. axillaris are recommended for direct seeding based on their high species performance index values. This study further concluded that selecting desiccation-tolerant seeds, particularly those with medium-to-large sizes, could increase the chances of successful seedling establishment.

Experimental Study of Vegetative Properties in Zeolite–Biochar-Improved Ecological Revetment Substrates

The vegetation of the ecological substrate plays a crucial role in restoring shoreline ecology. This study focused on using zeolite and biochar as substrate modifiers, specifically utilizing the Cynodon dactylon from Central China for vegetation. A pot vegetation experiment was carried out to compare the effects of different ratios of zeolite and biochar. The vegetation indices, including germination index, plant height, and coverage rate, were analyzed and discussed. The results revealed that zeolite primarily influenced the germination index of Cynodon dactylon, while biochar had a more significant impact on germination percentage, germination energy, plant height, and coverage rate. This study discovered that the seed germination effect of the improved substrate initially increased with zeolite content and then decreased. The average germination percentage was 63.96%. Conversely, it decreased with an increase in biochar content, resulting in an average germination percentage of 55.45%. Zeolite and biochar caused a decrease and increase in substrate pH by −0.11 and 0.4 on average, respectively. The germination of each substrate showed a negative correlation with pH. Additionally, the average coverage and plant height decreased with an increase in biochar content. However, the inclusion of 6% zeolite led to an increase in coverage and plant height. Specifically, the average plant height increased by 3.92 cm and the coverage by 7.48%. Our research identified the optimal ratio of zeolite and biochar as 6% zeolite and 0% biochar, showcasing good overall vegetative properties. These findings offer insights for further understanding the vegetative effects of zeolite–biochar-modified substrates and optimizing substrate schemes for ecological vegetation projects.

Salinity tolerance at the germination stage of Senegalese varieties of peanut, cowpea, millet and sorghum

Salinization continues to increase in semi-arid areas like Senegal where it limits seed germination, a crucial phase in a plant's cycle. Adaptation to salinization, one of the great challenges of modern agriculture, is possible through the use of halotolerant varieties which could be selected early during seed germination. The general objective of this study is to evaluate the effect of salinity on the germination of peanut, cowpea, millet and sorghum. The effect of NaCl (0, 40, 80 and 120 mM) was tested on seed germination for one week at 30°C in a culture chamber. The parameters evaluated are: the final percentage of germination (FG), the germination vigor index (GVI), the coefficient of velocity of germination (CVG), the percentage reduction in germination compared to the control (PRG) and the daily average germination (DAG). The FG, GVI and CVG of millet, cowpea, sorghum and peanut show significant differences (p<0.01) for each NaCl concentration. On the other hand, DAG and PRG give significant differences only at 80 mM and/or 120 mM NaCl. FG, CVG, DAG and GVI decreased with increasing salinity for all varieties unlike PRG. Cowpea (V4) are less sensitive to salinity than peanut (V3), which tolerate NaCl better than cereals. Millet (V5) is more resistant than sorghum (V7). The increase in NaCl led to a significant difference in germination. Cowpea (V4) would be more osmotolerant than peanut (V3) which is more tolerant than cereals such as millet (V5) and sorghum (V7) to salinity. These varieties would be the most recommended for successful cultivation in a saline environment.