Uniform Germination Research Articles

Stratification of apple seeds in the context of ROS metabolism.

Apple (Malus domestica Borkh.) seeds exhibit deep embryonic dormancy. Uniform germination of isolated apple embryos is observed after 40-day-long cold stratification of the seeds. Stratification treatment modifies the level of reactive oxygen species (ROS), which are regarded as key regulators of seed dormancy. In this study, axes of embryos isolated from seeds stratified for 7, 14, 21, and 40 days differing in dormancy depth were used. After one week of stratification, the increased polyamine oxidase activity enables ROS generation, which is followed by an upregulation of the NADPH oxidase gene expression. Catalase activity increased after 14 days of stratification, suggesting the requirement to maintain ROS concentrations at an optimal level already in the early phase of dormancy removal. When cold stratification was prolonged, accompanied by a significant increase in ROS level, ROS scavenging by catalase was supported by elevated phenolic compounds content. Then, peroxidase activity was also the highest. As ROS-induced phenylalanine (Phe) oxidation leads to the formation of meta-tyrosine (m-Tyr) - a potentially toxic component, the levels of these amino acids were examined. The fluctuation in m-Tyr content indicates the existence of mechanisms in the tissue for the disposal of this compound. Finally, its presence may be mitigated by an increase in Phe levels. Maintaining oxidised RNA at elevated levels from the 14th day of stratification may be crucial for seed dormancy removal, ensuring translation regulation as metabolism resumes. We concluded that dormancy removal of apple seeds by stratification requires a time-dependent sequence of biochemical events reflecting ROS metabolism alterations.

INFLUÊNCIA DOS ADUBOS EM SULCOS NA GERMINAÇÃO DE SEMENTES DE FEIJÃO

Agriculture faces significant challenges in increasing food production, reducing environmental impacts, and ensuring food security. This study evaluated the effect of fertilizer depth in relation to seed placement on the germination of common bean (Phaseolus vulgaris). The experiment was conducted in Palminópolis, Goiás, using four treatments: T1 (no fertilizer), T2 (fertilizer with the seed), T3 (fertilizer 2 cm below the seed), and T4 (fertilizer 4 cm below the seed). Germination rate and speed were assessed. Results indicated that T4 showed the best performance, with uniform germination and no vigor loss, while T2 negatively impacted germination due to the osmotic effect of the fertilizer. Improper fertilization can hinder germination, emphasizing the need for correct depth placement to avoid losses.

NaCl salt stress and PEG water stress differentially affect germination and early seedling growth of two sesame (Sesamum indicum L.) cultivars

Drought stress and salt stress are serious challenges to crop productivity in the arid lands. This work investigates the impact of NaCl-salt stress and PEG-water stress on germination and embryo growth of two sesame (Sesamum indicum L.) cultivars: Sohag 1 (Sohg) and Shandaweel 3 (Shnd). Seed dimensions, volume and weight were measured. The red Sohg seeds were larger with oblong appearance and lower density relative to the white Shnd seeds. Seeds were germinated in isosmotic solutions of NaCl and PEG-6000 at 0, − 0.103, − 0.205, − 0.410 and − 0.615 MPa. The time-based parameters (velocity, uniformity and synchrony of germination) were more reliable measures of germination efficiency than the final germination percentage. The impact of PEG was more severe than that of NaCl particularly on Sohg. The peak of daily germination was lowered and delayed under stress. The genotypic variability in germinability became evident under stress in favor of Shnd. Radicle length–a reliable measure of seedling growth–was subjected to stronger impact of NaCl than PEG. Although Na+ mobilization from seeds to embryos was indifferent in the two cultivars in PEG solutions, Shnd seedlings exhibited higher Na+ uptake from NaCl solutions. Whereas K+ mobilization was restricted by NaCl only in Sohg, it was hastened by PEG equally in the two cultivars. The stress-vulnerable Sohg recovered from stress with higher magnitude than did Shnd, particularly from the more stressing osmoticum (PEG). The indices of germination recovery were highest in PEG-pretreated Sohg while the biomass of recovered seedlings was highest in NaCl-pretreated Sohg.

Assessing the potential of mosquito larval rearing water for enhanced tomato seedling establishment

Vigorous seedlings guarantee satisfactory production in the forward stages of the vegetation period. This study aimed to evaluate the impact of bio-based rearing water of two mosquito species (Culiseta sp. and Culex sp.) on tomato germination, emergence, and seedling quality. For this purpose, two distinct larval-rearing waters (LRW)(with diverse larval densities), and fry food-applied water were used as bio-priming agents. The findings revealed that using bio-based rearing water could enhance the vigor of tomato seeds. All Culex sp. derived LRWs had a shorter mean germination time than the control group. One Culex sp. derived larval rearing water treatment resulted in the shortest mean germination time (4.35 days), whereas one Culiseta sp. derived larval rearing water treatment resulted in the longest (6.20 days). There were no statistically significant differences in stem length but significant differences in plant length. Plant length was shorter in larval rearing water and fry food-applied water than in the control. The stem diameters of plants primed with larval rearing water were generally wider than the control. According to analyses of the plant length, stem length, and stem diameter measurements, the larval rearing water and fry food-applied water treatments may have had a reductive influence on plant length but provided significant support for thicker seedlings, which are more beneficial for seedlings. Other germination and growth characteristics (vigor index of germination, emergence percentage, mean time of emergence, vigor index of emergence, plant length, stem length, leaf width, leaf length, stem fresh weight, stem dry weight, root dry weight) did not show significant variation among treatments. Using larval rearing water as a bio-priming agent in agriculture offers several benefits. Larval rearing water enhances seed germination and vigor due to its possibly rich nutrient content and bioactive compounds, promoting faster and more uniform germination. It is an eco-friendly and cost-effective alternative to chemical treatments, supporting sustainable agricultural practices.

Genome‐Wide Association Study Revealed the Genetics of Seed Vigour Traits in Rice (Oryza sativa L.)

ABSTRACTA crucial phenotypic attribute for breeding rice for direct seeded condition is rapid uniform germination and build‐up of biomass during the initial period of seedling establishment. Seed vigour constitutes such traits that have gained potential to meet the requirements of breeding for direct seeded rice. In the present study, a set of 295 markers, including 215 candidate gene‐derived markers covering all chromosome, was used to discover the casual alleles for eight rice seed vigour‐related traits. Using a mixed linear model, the study identified 99 significant associations for seed vigour traits. Many associated markers originated from diverse candidate genes in rice. Notably, alleles from genes like RSR1, OsSRS3 and OsSWEET15 exhibited pleiotropic effects, influencing multiple seed vigour traits. This discovery underscores the potential of certain genes to impact various facets of seed vigour simultaneously. The new candidate gene markers associated with seed vigour traits may be utilized to incorporate variable alleles for seed vigour traits through marker‐assisted breeding programmes. Markers identified to be closely associated with more than one trait have significant application in the simultaneous improvement of multiple traits.

Current state and open issues of priming onion seeds

Relevance. In the context of climate change, onion cultivation has become a challenge and innovative solutions are needed to support breeders and seed producers as well as farmers, starting with critical issues of seed quality. Seed priming successfully improves seed viability, which leads to rapid and uniform germination and emergence of onion seedlings.Results. Priming onion seeds can improve viability, especially under unfavorable conditions such as low/high temperatures, reduced water availability and salinity. It is a simple, low-cost and low-risk intervention that can be a useful technology for farmers and have a positive impact on their livelihoods by increasing the rate of seed germination, increasing the rate of plant development, reducing harvest time and increasing yields. Although this method is common for radish, tomato, carrot and cabbage seeds, this method is less popular for onions. This review provides an up-to-date picture of the scientific and technological advances that have contributed to increasing seed germination and vigor in onion plants to date. For large-scale commercial use, optimal priming methods and conditions tailored to different varieties or seed lots will require further extensive experimental work. It cannot be denied that seed priming technology is characterized by ease of operation, low cost and high practical value in industrial and market contexts. It can be foreseen that this technology will have wider prospects in agricultural production and green building. In addition, seed priming can effectively restore or enhance seed viability and ensure successful retention of germplasm resources and subsequent development, especially for onion seeds that rapidly lose viability.

Assessing of sugar beet Seed adaptation under salt and drought stress conditions with coating technology based on Fuzzy inference system

Sustainability in crop production is highly dependent on favorable indicators of germination and seedling establishment. In this research seed coating different treatments data prepared and membership function defined in fuzzy inference system then used rule editor tool for determining parameters weight for achieved the best coating treatment in salinity and drought stress conditions. Seed coating formulations were investigated in laboratory and greenhouse experiments for their potential to increase maximum germination, germination rate, germination uniformity, and seedling growth of sugar beet seeds. Sugar beet seeds were coated with different compounds and combinations, including micro- (Fe, Zn, Cu, Mn, Co, Mo) and macro- (N, P, K) nutrients, humic acid, gibberellic acid, kaolin, and chitosan. Coated and non-coated sugar beet seeds were evaluated for germination and seedling growth after 10 and 21 days, respectively. In total, 30 different treatments were used to assess the effects of seed coating treatments. In laboratory experiments, sugar beet seeds were placed on paper in Petri dishes and maintained in a germinator at 25 °C. Sodium chloride and polyethylene glycol 8000 were used to apply salinity and drought stresses at three levels each and achieve the results of seed coatings on reducing the effects of salinity and drought stresses. To determine the indices related to emergence and establishment, cultivation trays were utilized with four replications for each treatment. The trays were kept inside a greenhouse. Coating treatments significantly improved total germination percentage, germination rate, seedling growth, and uniformity compared with the non-treated controls. In all treatments, polyvinylpyrrolidone was utilized as a binder. The best treatment with respect to germination and seedling growth indices was number 21 (micro and macronutrients, humic acid, gibberellic acid) in salinity and drought stress conditions. The results by fuzzy inference system illustrated that micronutrients, humic acid, and gibberellic acid create the best seed coating for sugar beet seeds, especially when combined at the specified amounts.

Effects of Corm Treatment with Cold Plasma and Electromagnetic Field on Growth and Production of Saffron Metabolites in Crocus sativus.

Crocus sativus L. is a widely cultivated traditional plant for obtaining dried red stigmas known as "saffron," the most expensive spice in the world. The response of C. sativus to pre-sowing processing of corms with cold plasma (CP, 3 and 5 min), vacuum (3 min), and electromagnetic field (EMF, 5 min) was assessed to verify how such treatments affect plant performance and the quality and yield of herbal raw materials. The results show that applied physical stressors did not affect the viability of corms but caused stressor-dependent changes in the kinetics of sprouting, growth parameters, leaf trichome density, and secondary metabolite content in stigmas. The effect of CP treatment on plant growth and metabolite content was negative, but all stressors significantly (by 42-74%) increased the number of leaf trichomes. CP3 treatment significantly decreased the length and dry weight of flowers by 43% and 60%, respectively, while EMF treatment increased the length of flowers by 27%. However, longer CP treatment (5 min) delayed germination. Vacuum treatment improved the uniformity of germination by 28% but caused smaller changes in the content of stigma compounds compared with CP and EMF. Twenty-six compounds were identified in total in Crocus stigma samples by the HPLC-DAD method, including 23 crocins, rutin, picrocrocin, and safranal. Processing of Crocus corms with EMF showed the greatest efficiency in increasing the production of secondary metabolites in saffron. EMF increased the content of marker compounds in stigmas (crocin 4: from 8.95 to 431.17 mg/g; crocin 3: from 6.27 to 164.86 mg/g; picrocrocin: from 0.4 to 1.0 mg/g), although the observed effects on growth were neutral or slightly positive. The obtained findings indicate that treatment of C. sativus corms with EMF has the potential application for increasing the quality of saffron by enhancing the amounts of biologically active compounds.

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.

Evaluation of memory drought stress effects on storage compounds seedlings of cotton (Gossypium hirsutum) and in-silico analysis of glutathione reductase

In breeding programs, stress memory in plants can develop drought stress tolerance. Memory stress, as an approach, can keep stress data by activating tolerance mechanisms. This research was conducted to evaluate some physiologically effective mechanisms in inducing memory drought stress in the seeds that were exposed to water stress three times in four treatments including rainfed, 33%, 66%, and 100% of field capacity (FC). After the production of the seeds, the third-generation seeds were placed under different irrigation treatments, seed and seedling traits, starch to carbohydrate ratio in seed, protein concentration and glutathione reductase were investigatied in a factorial format based on a randomized complete block design with three replications. Results showed that percentage of changes from the lowest to the highest value for traits including seed vigor, seed endosperm weight, seed coat weight, accelerated aging, cold test, seedling biomass and seedling length were 25, 37, 65, 65, 55, 77, 55, 65 and 79, respectively and germination uniformity was 3.9 times higher than the lowest amount. According to the deterioration percentage, seed vigor and the percentage of seed germination in cold test data, it can be reported that seed production by 100% FC was not appropriate for rainfed plots. However, considering the the appropriate results in the percentage of germination for a cold test, germination uniformity percentage, and the lowest accelerated aging seeds, seed production under the rainfed conditions with 33% FC watering can be recommended. In-silico analysis was coducted on Glutathione reductase (GR) enzymes in Gossypium hirsutum. It is clear that GR has a Redox-active site and NADPH binding, and it interacts with Glutathione S transferase (GST). So, memory drought stress through inducing physiological drought tolerance mechanisms such as starch-to-carbohydrate ratio and GR can determine the suitable pattern for seed production for rainfed and low rainfall regions in a breeding program. Our study thus illustrated that seed reprduction under 33% FC equipped cotton with the tolerance against under draught stress from the seedling stage. This process is done through activating glutathione reductase and balancing the ratio of starch to carbohydrates concentration.

Physiological Responses of Different Aged Rice Seeds to Osmopriming with PEG 6000

The objective of this research was to compare the quality of different aged rice seed after priming. The rice seeds were deteriorated by accelerated aging method at 44 °C and relative humidity 100 %, in different periods for 0 (without accelerated aging), 1, 2, 3, and 4 days. Then, the germination of rice seeds of different ages were induced by soaking in 30% of PEG 6000 solution at room temperature for 24 hours. After that, the rice seeds were dried in a hot air oven at 35 °C for 10 hours until the moisture content was close to the initial moisture. Finally, these treated rice seeds were examined for the seed quality of various characteristics such as seed germination rate (planted in the laboratory and field conditions), germination index, speed of germination, and electrical conductivity of solution used for soaking seeds. The results showed that the electrical conductivity of all different aged seeds decreased after priming. For the field of germination and germination uniformity, it was found that the seeds with different rates of deterioration showed different responses to the priming. Aged seeds with germination rates of 12 and 33 percent germination were able to induce germination rate by 27 and 48 percent, respectively, while aged seeds with higher deterioration rate had a decreased response.

Assessment of sensor-based automatic smart watering unit for paddy nurseries under Indian perspective

A sensor-based automatic watering unit was developed to irrigate the paddy seedling trays. The watering unit comprised six flat spray nozzles with a direct current (DC) water pump and flow sensor, and these were kept at the top of the conveyor frame, which was actuated by a DC water pump with a solenoid valve to drop the water in trays. The actuation of the DC solenoid valve was controlled by a limit switch fitted to the conveyor frame, which sensed the moving trays on the conveyor. The performance of the developed unit was evaluated, and process optimization was performed using the Inscribed Central Composite Design in Response Surface Methodology. The effect of main operating parameters- chain conveyor speed (0.123, 0.196, and 0.27 m/s), spray operating pressure (1.5, 3.0, and 4.5 kg/cm2), and spray height (10,30 and 50 cm) on the performance of the sensor-based automatic watering unit was studied in terms of the amount of water spray requirement and coefficient of water spray uniformity in trays. The responses of the unit at its optimal parameter operation (spray operating pressure 4.5 kg/cm2, spray height 10 cm, and chain conveyor speed 0.14 m/s) were found to be 1.31 L/tray as the amount of water spray requirement and 92.41 % as the coefficient of water spray uniformity of the unit. Hence, it can be an efficient substitute with significantly less power consumption 41 W with a higher working capacity of 780 trays/h for watering into the paddy tray nursery. The developed sensor-based automatic smart watering unit saves irrigation water per square area of 68.90 %, 76.13 %, and 82.31 % compared to existing drip, sprinkler, and flood irrigation methods in mat-type paddy nurseries. The developed sensor-based automatic smart watering unit saves the watering cost INR 11,567.16 (140.02 USD) per hectare, reducing cost by 63.7 % compared to manual watering in the mat-type nursery preparation. Thus, an automatic smart watering unit in a paddy tray nursery offers consistent and uniform watering from an Indian perspective, promoting uniform germination, crop growth, and establishment. It conserves water by ensuring the right amount of water is applied at the right time, avoiding overwatering or under-watering.

Cross‐Generational Effect of Water Deficit Priming on Physiology of Peanut Plants Under Water Stress

ABSTRACTWater deficit priming through regulated deficit irrigation has been shown to be beneficial for peanut cultivation, leading to improved water‐use efficiency during the crop cycle and enhanced stress acclimation. The effects of priming using water deficit can be heritable, but little is known about stress priming effects on the physiology and growth of successive generations undergoing water stress. Two experiments were conducted to assess cross‐generational priming by determining physiological and growth responses of offspring of primed and non‐primed peanut plants of two genotypes, COC‐041 and New Mexico Valencia C (NMV‐C), both previously found to be strongly responsive to priming. Seeds were collected from parental plants subjected to mild water stress by regulated deficit irrigation (primed) or adequate irrigation (non‐primed). These seeds were then planted, and the offspring were monitored for physiological and growth responses to water stress, including on a whole‐plant basis using a high‐throughput physiological phenotyping platform and on individual leaves by periodic single‐leaf measurements. Measurements included whole‐plant transpiration (plant‐Tr), root water uptake, leaf transpiration, stomatal conductance and net CO2 assimilation (leaf‐Tr, leaf‐gs, and leaf‐A), leaf water and osmotic potential (leaf‐Ψw and leaf‐Ψo), leaf osmotic adjustment, leaf relative water content (leaf‐RWC) and cumulative plant‐Tr. Offspring of both genotypes from primed parent plants had faster early establishment, with more uniform germination, and more rapid initial seedling growth compared to offspring from non‐primed parent plants. Although offspring of both non‐primed and primed plants of both genotypes exhibited a significant reduction of plant‐Tr, gas exchange, leaf‐Ψw, leaf‐Ψo, and leaf‐RWC when exposed to water stress, offspring of primed plants showed increased water use efficiency through reduced leaf‐gs, leaf‐Tr and plant‐Tr while maintaining leaf‐A under water stress. Despite offspring of both primed and non‐primed plants being susceptible to severe water stress, offspring of primed plants exhibited overall enhanced water use efficiency, leading to greater dry biomass production per gram of transpired water and a trend of less growth reduction due to water stress compared to offspring of non‐primed plants, especially for the genotype COC‐041. This study shows the potential of water deficit priming to promote cross‐generational changes in physiological function under limited water availability, by enhancing crop stress acclimation in the next plant generation.

Quantifying the influence of seed priming on germination and growth traits of Bitter gourd (Momordica charantia L.) varieties

The uniform and quick germination of seeds is crucial for better growth, yield and quality traits of vegetable crops. Likewise, the seeds of the bitter gourd have a thick and hard seed coat, germination and field emergence are always problematic for this crop. One of the best, economical, readily available,method for reducing seed dormancy and promoting germination is pre-sowing seed treatment. Therefore, a field trail was conducted at Horticultural Garden, Sindh Agriculture University, Tandojam to explore the efficacy of seed primimg on bitter gourd germination and growth attributes. The experiment was run in a Randomized Complete Block Design (RCBD), consisted of two varieties, Karan and Jaunpur-I, and two priming sources, zinc solutions (0.1%, 0.3%, 0.5%, and 0.7% w/v) and distilled water. The seeds were primed for 24 hours. Additionally, the untreated seeds were used as control. The results revealed that seed priming treatments significantly influenced bitter gourd's growth traits (P<0.05), except for pH, TSS, ash, and moisture. Moreover, increasing zinc concentrations were associated with a decreasing pattern in seed germination and growth-related attributes. The optimal results were achieved with 0.1% zinc priming, showed 90% seed germination, minimum flowering time (44.33days), fresh fruit weight (152.57g), fruit length (18.54cm), fruit diameter (18.7cm), and fruit plant-1(39.17). Notably, all parameters, except seed germination percentage, aligned closely with results obtained from distilled water priming. The varietal comparison revealed non-significant differences in most parameters except fresh fruit weight and pH, while the interaction between bittergourd varieties and seed priming treatments significantly influenced fruit length and fruits plant-1. The study concluded that seed priming with the lowest concentration of 0.1% zinc effectively enhanced bittergourd germination and growth attributes. However, for optimal growth, zinc priming at 0.1% could be replaced by priming in distilled water.

Research advances on the hard seededness trait of soybean and the underlying regulatory mechanisms.

Soybean is one of the world's most economically significant crops and is widely utilized as an essential source of vegetable protein and edible oil. Cultivated soybean is domesticated from its annual counterpart, wild soybean, which is considered valuable germplasm for soybean breeding. However, wild soybean accessions generally produce seeds with impermeable coats, a trait known as hard seededness (HS), which is beneficial for long-term seed survival but is undesirable for the uniform water absorption and germination of seeds, thus limiting the utilization of wild soybeans in breeding. In addition, moderate HS can isolate the embryo from the surrounding environment and is thus beneficial for long-term seed storage and germplasm preservation. The HS trait is primarily associated with the structure and chemical composition of the seed coat. Moreover, its development is also influenced by various environmental conditions, such as water and temperature. Genetic analysis has revealed that HS of soybean is a complex quantitative trait controlled by multiple genes or minor quantitative trait loci (QTL), with many QTLs and several causal genes currently identified. Investigating the physiological and molecular mechanisms underlying this trait is crucial for soybean breeding, production, and food processing. For this article, the literature was reviewed and condensed to create a well-rounded picture of the current understanding of internal and external factors, QTLs, causal genes, and the regulatory mechanisms related to the HS of soybean, with the aim of providing reference for future research and utilization of this trait.

Is pearl millet (Pennisetum glaucum) a good plant species for ecotoxicological tests?

Various plant species can be selected for environmental testing, including pearl millet (Pennisetum glaucum (L.) R. Br), a globally significant cereal crop. This study aims to assess millet's suitability as a species for ecotoxicological tests, examining (1) germination and initial development dynamics, (2) the minimum seed quantity for reliable sampling, (3) optimal experimental design with replication numbers, (4) suitability of positive control, and (5) the effectiveness of the protocol in evaluating toxic effects of environmental pollutants. Millet exhibited rapid and uniform germination as well as consistent initial seedling development. To establish the minimum number of seeds required for reliable experimentation, germination, and seedling growth were compared across plots containing 10, 25, and 50 seeds. Consequently, 10 seeds per plot were chosen for subsequent experiments to reduce labor and costs while maintaining reliability. To validate the selected experimental design, and to establish a positive control for assays, aluminum was used as a toxic element at concentrations ranging from 10-2 to 10-6 M. While aluminum did not affect the final percentage of germinated seeds, it did exhibit an impact on the Germination Speed Index (GSI). Significant differences in root and aerial growth, and with fresh weight, were observed. The 10-3M concentration was chosen as the positive control as the 10-2 concentration showed extreme toxicity. To assess the applicability of the established protocol in determining the toxic effects of environmental pollutants, millet roots were exposed to the toxic agents atrazine, cadmium, methyl methane sulfonate (MMS), and Spent pot liner (SPL). Millet demonstrated sensitivity and efficiency in response to these tests. In conclusion, millet proves to be an effective species for the toxicological risk assessment of environmental pollutants.

A genome-wide association study uncovers a ZmRap2.7-ZCN9/ZCN10 module to regulate ABA signalling and seed vigour in maize.

Seed vigour, including rapid, uniform germination and robust seedling establishment under various field conditions, is becoming an increasingly essential agronomic trait for achieving high yield in crops. However, little is known about this important seed quality trait. In this study, we performed a genome-wide association study to identify a key transcription factor ZmRap2.7, which regulates seed vigour through transcriptionally repressing expressions of three ABA signalling genes ZmPYL3, ZmPP2C and ZmABI5 and two phosphatidylethanolamine-binding genes ZCN9 and ZCN10. In addition, ZCN9 and ZCN10 proteins could interact with ZmPYL3, ZmPP2C and ZmABI5 proteins, and loss-of-function of ZmRap2.7 and overexpression of ZCN9 and ZCN10 reduced ABA sensitivity and seed vigour, suggesting a complex regulatory network for regulation of ABA signalling mediated seed vigour. Finally, we showed that four SNPs in ZmRap2.7 coding region influenced its transcriptionally binding activity to the downstream gene promoters. Together with previously identified functional variants within and surrounding ZmRap2.7, we concluded that the distinct allelic variations of ZmRap2.7 were obtained independently during maize domestication and improvement, and responded separately for the diversities of seed vigour, flowering time and brace root development. These results provide novel genes, a new regulatory network and an evolutional mechanism for understanding the molecular mechanism of seed vigour.

Effect of Phosphorus Levels on Early Seedlings of Rice (Oryza sativa) under Varying Moisture Stress Conditions

This study investigated the impact of moisture levels and phosphorus applications on different rice varieties. It aimed to: 1. Identify optimal rice varieties for specific moisture and phosphorus combinations. 2. Understand how moisture stress affects seed germination speed and root and shoot development. 3. Analyze the influence of increased phosphorus on root growth, especially under moisture stress. 4. Evaluate if additional NPK application enhances the positive effects of phosphorus. The meticulously controlled experiment, conducted within the International Rice Research Institute (IRRI)'s RGA facility from October to November 2023, utilized five rice varieties, three moisture levels (flooded, ideal, and Drought-like), and varying phosphorus levels. The findings revealed a positive correlation between phosphorus levels and root length across all rice varieties. This emphasizes the crucial role of phosphorus in promoting root development under challenging conditions. Notably, while increased phosphorus significantly enhanced root adhesion under flooding and aided seedling recovery, drought remained a significant barrier to root growth, regardless of phosphorus application. Interestingly, despite general genetic uniformity in germination and root-shoot parameters among the varieties, a clear positive correlation between phosphorus levels and root length was still observed. In conclusion, this study highlights the importance of phosphorus in strengthening root grip during floods, thereby aiding seedling recovery. However, it also emphasizes that drought remains a dominant factor hindering plant growth. The consistency observed across different rice varieties strengthens the findings, and the significant increase in root length with increased phosphorus application underscores its vital role in root development under challenging conditions. This study provides valuable insights for optimizing rice growth strategies by considering specific rice varieties, moisture levels, and phosphorus applications.

Low temperature and excess moisture affect seed germination of soybean (Glycine max L.) under controlled environments

Cold and excess moisture pose a serious threat to soybean production especially during seed germination in short-season environments. In this study, the effects of low temperature and excess moisture stress on seed germination were investigated in 187 soybean accessions originating from 18 countries. The experiment used a combination of three temperature conditions (i.e., 20 °C/14 °C, 14 °C/10 °C, and 10 °C/10 °C day/night) and two moisture levels (i.e., normal and excess). The seed germinability traits measured included germination rate (GR), germination index, germination time, germination uniformity, and coefficient of velocity of germination. Overall, GR was lowest in the 20 °C/14 °C + excess moisture and germination time was longest in the 10 °C/10 °C + excess moisture. When compared with 20 °C/14 °C + normal moisture treatment, GR at 10 °C/10 °C + excess moisture decreased by 38%; germination time increased by 20 days; seed viability decreased by 83%; germination uniformity decreased by 70%; germination speed decreased by 73%. Differences in GR, germination index, and germination velocity under different treatments were affected by temperature, moisture, and their interaction. Variation in germination time uniformity was determined by temperature, with no significant effects of moisture conditions and the interaction of temperature and moisture. It was shown that the temperature–excess moisture interaction led to a sharp decrease in seed germination. Two genotypes including PI 603147 and PI 507702 were identified with a GR over 90% at 10 °C/10 °C + excess moisture. This study generated new knowledge and data to further the understanding of genetic resistance to cold and excess moisture stress in soybean.

Germination test of maize (Zea mays L.) seeds in a NaCl solution

R bjective: To evaluate the germination behavior and to define the initial vigor of maize seeds. Methodology: The genetic material consisted of four batches of 20 hybrid seeds each (M-2014, SR-2014, SR-2012, and SR-2011), which were germinated in a NaCl solution (0, 5, 10, and 15 dS m-1) in a germination chamber. A randomized complete block experimental design was used, in which the seed batch and salinity level were the experimental units, with four repetitions each. Seeds with defined radicle and plumule were counted for evaluation. Results: As a result of the comparison of the three batches from the same environment (production site) and different years, the statistical analysis indicated that the longest-lived seeds have a lower germination percentage. Similarly, when batches from different production environments and the same year were compared, M-2014 obtained the highest average germination percentage (92.19%). When the maximum level of salinity (15 dS m-1) was evaluated, an average 41.25% loss in germination was observed. Conclusions: The test efficiently discriminated seed batches, based on speed and uniformity in NaCl-based germination, therefore providing acceptable results for the evaluation of the viability and vigor of a seed batch.