Seed Germination Test Research Articles

Anaerobic Digestion of Olive Mill Wastewater in the Presence of Biochar

Biological treatments focused on stabilizing and detoxifying olive mill wastewater facilitate agronomic reuse for irrigation and fertilization. Anaerobic digestion is particularly attractive in view of energy recovery, but is severely hampered by the microbial toxicity of olive mill wastewater. In this work, the addition of biochar to the digestion mixture was studied to improve the stability and efficiency of the anaerobic process. Kinetics and yields of biogas production were evaluated in batch digestion tests with biochar concentrations ranging from 0 to 45 g L−1. The addition of biochar reduced sensibly the lag phase for methanogenesis and increased the maximum rate of biogas generation. Final yields of hydrogen and methane were not affected. Upon addition of biochar, soluble COD removal increased from 66% up to 84%, and phenolics removal increased from 50% up to 95%. Digestate phytotoxicity, as measured by seed germination tests, was reduced compared to raw wastewater. Addition of biochar further reduced phytotoxicity and, furthermore, a stimulatory effect was observed for a twenty-fold dilution. In conclusion, biochar addition enhances the anaerobic digestion of olive mill wastewaters by effectively reducing methanogenesis inhibition and digestate phytotoxicity, thus improving energy and biomass recovery.

The Effect of Initial Carbon to Nitrogen Ratio on Kitchen Waste Composting Maturity

A home electrical composter has arisen as a popular tool to expedite the lengthy composting process. It has been conveniently selected as a compost producer in kitchen households and is especially favoured in urbanized settings. The generated composts from the electrical composter, however, are still found to be immature and would require additional curing. The quality of the compost can be improved by investigating the initial carbon-to-nitrogen ratio (C/N ratio) of kitchen waste. It is, therefore, the aim of this paper to determine the optimum initial C/N ratio by preparing two primary samples: with and without soil. Samples of 10:1, 15:1, 20:1, 25:1, 30:1, and 35:1 C/N ratios were fed into the electrical composter and allowed to cure for 4 weeks. The six main samples were further divided into sub-samples for replications. The phytotoxicity levels and maturity of the produced compost were assessed in terms of the germination index (GI), using a seed germination test. In addition, statistical analyses using box plots and T-distributed Stochastic Neighbour Embedding (T-SNE) were carried out to observe the root growths’ variability and to deduce any significant clusters amongst the samples. The results have shown that samples with and without soil performed better with C/N ratios of 10:1 and 25:1 and with GI values of 16.2 and 31.8, respectively. The results also indicate the presence of a substantial level of phytotoxins within the samples, even after four weeks of curing.

Exudate Flavonoids of Primula veris Leaves and Their Inhibitory Activity on Lolium perrene Seed Germination

In the present study exudate flavonoids from P. veris leaves were identified and their potential as inhibitors on L. perrene seed germination was evaluated. Leaves of P. veris were collected from natural population. Leaf exudate was obtained by dipping whole leaves into acetone for 2--3 min. Chemical composition of the exudate was analysed by GC/MS. The seed germination test was done in Petri dishes. Flavonoid aglycones were found as main components of the exudate (over 50% of all compounds). Unsubstituted flavone, 2'-methoxyflavone, 3'-methoxyflavone, 3',4'-dimethoxyflavone, 2',5'-dimethoxyflavone, 5,6,2',6'- tetramethoxyflavone were identified. Complete inhibition on Lolium perenne seed germination and root elongation by aqueous solution of the exudate at concentration 7 mg/mL was found. This is the first report about inhibitory activity of P. veris leaf exudate on seed germination.

Harnessing fungicide potential of hydrothermal liquefaction water from livestock manure: A new vision of integrated crop-livestock system

Hydrothermal liquefaction (HTL) can turn livestock manure into biocrude oil, but the aqueous phase (HTL-AP) attracts increasing concerns owing to its large amount and high toxicity. In this regard, a novel integrated crop-livestock system paradigm was proposed where HTL-AP from livestock manure was used as fungicide for phytopathogen control. To verify this strategy, Alternaria solani was employed as indicator phytopathogen, whereas cow manure (CM) and swine manure (SM) were used as the feedstock to obtain fungicide compounds via hydrothermal liquefaction (HTL). Results showed that the minimum inhibition concentration (MIC) of two HTL-APs was about 12%, where the main active compounds probably were phenols and nitrogenous compounds. The fungicide application would increase the manure carrying capacity by over 10%. Further observation revealed that HTL-AP exhibited inhibition through multiple pathways such as changing the mycelial morphology and cell membrane structure, resulting in metabolic disorders via impacting the generation of H2O2, ATP, reducing sugar and protein. The synergistic interaction among pathways was finally analyzed. Then, the effect of HTL-AP on seed-borne fungi control was evaluated via 36 groups of seed germination tests. For all that, this study provides new insights into the valorization of HTL-AP form livestock manure via unlocking its potential as sustainable fungicide constituents for phytopathogen control, further contributes to green development of current integrated crop-livestock system.

Effects of Temperature, pH, and Salinity on Seed Germination of Acinos alpinus subsp. Meridionalis and FTIR Analysis of Molecular Composition Changes

This study aimed to determine the impact of three abiotic factors (Temperature, pH, and salinity) on the metabolic activities (macromolecules) and germination rate of Acinos alpinus subsp. Meridionalis (Satureja) seeds. In vitro, seed germination tests were performed in an aqueous medium. They were monitored as a function of time at different levels of temperature, NaCl concentration, and pH. The best germination rate (85.3%) was achieved at 15 °C and pH = 7. However, the germination was nil at a higher temperature (more than 25 °C), acidic pH (pH < 3.5), and higher NaCl concentration (more than >7.5 g L−1). Fourier transform infrared spectroscopy (FTIR) analysis showed an important variability of the chemical composition of germinated seeds. Indeed, the comparison of the absorbance peaks of chemical compounds in the treatments versus the control revealed significant differences in their concentrations and structures, which may justify why seeds fail to germinate under some extreme abiotic conditions. The results of this study are expected to serve as a guide for the protocols to be adopted in the ex situ conservation of this species.

Using Time-to-Event Model in Seed Germination Test to Evaluate Maturity during Cow Dung Composting

Maturity is a matter of concern for the utilization of livestock manures after composting because of the phytotoxicity of immature compost. The seed germination test is widely used for evaluating the maturity of compost. However, the process of seed germination was not studied by establishing a model for evaluating the maturity. Here, we established a time-to-event model for the data of germination proportion over time in a seed germination test with cow dung compost at different composting times. Results show that the profile of the seed germination proportion over time for Chinese cabbage (Brassica rapa L.) and garden cress (Lepidium sativum L.) were both well described by the model. Seed germination was delayed in composts at the early stage of composting from parameter t50 (half germination time) of the model. Parameter t50 was significantly negatively related to radicle length (RL), which indicated that there is an organic relationship between seed germination (i.e., radicle emergence) and radicle elongation. In conclusion, the immature compost can hinder seed radicle elongation by delaying seed germination.

Physiological Alterations and Nondestructive Test Methods of Crop Seed Vigor: A Comprehensive Review

Seed vigor is one of the essential contents of agricultural research. The decline of seed vigor is described as an inevitable process. Recent studies have shown that the oxidative damage caused by reactive oxygen species (ROS) is the main reason for the destruction of various chemicals in seeds and eventually evolves into seed death. The traditional vigor tests, such as the seed germination test and TTC staining, are commonly used to assess seed vigor. However, these methods often need a large number of experimental samples, which will bring a waste of seed resources. At present, many new methods that are fast and nondestructive to seeds, such as vibrational spectroscopic techniques, have been used to test seed vigor and have achieved convincing results. This paper is aimed at analyzing the microchanges of seed-vigor decline, summarizing the performance of current seed-vigor test methods, and hoping to provide a new idea for the nondestructive testing of a single seed vigor by combining the physiological alterations of seeds with chemometrics algorithms.

Efficacy of Saccharothrix algeriensis NRRL B-24137 to suppress Fusarium oxysporum f.sp. vasinfectum induced wilt disease in cotton.

Fusarium cotton wilt is a devastating disease of the cotton crop throughout the world, caused by Fusarium oxysporum f.sp. vasinfectum (FOV). Chemical control has many side effects, so, biological controls have been widely used for the management of Fusarium wilt. This study aimed to investigate the possible use of an actinomycetes Saccharothrix algeriensis (SA) NRRL B-24137 to control FOV. To access in-vitro anti-Fusarium ability of SA NRRL B-24137, dual culture assay, spore germination and seed germination tests were carried out. Following in-vitro investigations, several pot tests in a greenhouse environment were used to evaluate the biological control potential of SA NRRL B-24137 against FOV. Dual culture assay and spore germination revealed that SA NRRL B-24137 showed significant anti-Fusarium activity.During spore germination 87.77% inhibition of spore germination were observed. In pot experiments, SA NRRL B-24137 primed cotton seeds resulted in a 74.0% reduction in disease incidence. In soil there was a significant reduction in FOV spores in the presence of SA NRRL B-24137. Positive correlation was also observed on different concentrations of SA NRRL B-24137 towards FOV reduction. The results of this study showed that SA NRRL B-24137 has the potential to be employed as a biocontrol agent against Fusarium cotton wilt, improving cotton growth characteristics and yield.

Ultrasound‐assisted photo‐Fenton process for treatment of pulp and paper mill wastewater and reduction of phytotoxicity

AbstractThe efficiency of classical Fenton (CF) and modified Fenton (MF) as well as photo‐Fenton processes in real wastewater treatment of pulp and paper (P&P) mill was investigated in this study. The chemical oxygen demand (COD) was chosen as the reference measurement for evaluating the treatment's efficiency. After determining the optimum parameters for each process, the effect of adding ultrasound (US) on improving treatment efficiency was examined. In addition, kinetic study and phytotoxicity analysis were conducted under optimum conditions for all processes. With pH 4, reaction time 50 min, 1.2 g/L Fe2+ and 8 g/L H2O2 dosages, the best removal efficiency (RE) of COD was determined to be 82.18% in CF process, and this rate rose to 90.1% when US was added. The best RE in MF process was 84.16% with the application of UV‐C, pH 4, reaction time 50 min, 1 g/L Fe0 and 8 g/L H2O2 doses, although it increased to 93.4% when US was applied. The greatest results in the seed germination test were achieved in US processes with 100% of germination percentage (GP) for spinach and tomato and 90% for cress. In the economic evaluation, when conducting the treatment without US, the estimated relative cost decreased in a 15 and 16%, for CF/UV‐C and CF processes respectively, whereas the CF process was 64% cheaper than the MF process in all applications. The US contributed to enhanced water treatment efficiency by having a significant synergistic impact on Fenton applications. Hence, the combination of photo‐Fenton and ultrasound to treat effluent from P&P mills proved to be an effective and promising technique.

Studies on Pesticide Resistant Phosphate Solubilizing Bacteria from Grape Yard Soil

Dimethoate, a widely used organophosphate insecticide and acaricide to grape plants, is readily absorbed and distributed throughout plant tissues. The present work was based on isolation and studies on pesticide resistant phosphate solubilizing bacteria from grape yard soil. The Minimum inhibitory concentration [MIC] of normal garden microflora was observed to be 0.8% of dimethoate. The total of 6 pesticide resistant phosphate solubilizing bacteria [PP1, PP2, PP3, PP4, PP5, and PP6] were isolated from grape yard soil on Katznelson’s and Bose agar. Colony characteristics, morphological characteristics, motility, sporulation and capsulation of isolates were studied. Biochemical characteristics including carbohydrate utilization, H2S production and enzyme activities were studied. Agricultural importance of the isolates with respect to indole acetic acid production, nitrogen fixation, cellulose degradation, antagonistic effects on Azotobacter spp. and Rhizobium spp. were also studied. The pesticide tolerance was checked and seed germination test were performed. The effect of each isolate and mixed cultures on plant growth of moth bean seeds was studied. From the results, the isolate PP3 was found to be most important agriculturally producing indole acetic acid. The mixed culture also improved shoot and root growth. Further studies in this context are in process.

Effect of different concentrations of bioslurry on the germination and production of tomato seedlings (Solanum lycopersicum L.)

Tomato is one of the main horticultural products in Argentina. Its cultivation is intensive in the use of fertilizers and pesticides, which negatively impact the environment. The chemical fertilizers commonly used are, to some extent, gradually being replaced by liquid biofertilizers. A liquid biofertilizer (bioslurry) made from goat manure, fresh plant residues, and some mineral inputs was physicochemically characterized. To evaluate its effect on tomato (Solanum lycopersicum L.) performance, two trials were conducted between October and November 2020: a seed germination test with increasing bioslurry dilutions (0 to 15%); and another trial in a greenhouse located in Luján de Cuyo, Mendoza, to evaluate the effect of different doses of bioslurry (5, 10 and 15%), compared to a commercial fertilization plan for seedlings in plastic trays. The experimental design used was completely randomized plots in both cases. Bioslurry at concentrations above 5% negatively affected tomato seed germination. The biofertilizer achieved a nutritional effect on seedlings compared to the unfertilized control. However, this effect was inferior to the treatment with commercial fertilizers. It is advisable to initiate applications of bioslurry after seedlings have emerged. Further studies are needed on biofertilizer use concentrations, doses, application frequencies, and suitability for different crops. Also, to achieve the effect of a commercial fertilization program, it will be necessary to combine enriched bioslurry with other bio inputs that complement plant nutrition.

Fruit biometrics and maturity on the quality of Diospyros inconstans Jacq. Seeds

Abstract: This study aimed to evaluate the biometric characteristics of fruits and seeds of Diospyros inconstans Jacq., germination and formation of seedlings obtained from fruits at three maturity stages, subjected to different temperatures. Biometric data were obtained from 100 fruits and 100 seeds. The determining parameters in the biometry of the fruits were: length, width, mass and number of seeds/fruit and for the seeds: length, width, thickness and mass. In the germination test, a factorial scheme (3x4), three maturity stages (green, intermediate and reddish), and four temperatures (20, 25, 30 and 35 °C) were used. The analyzed variables were: germination, germination speed index (GSI), mean germination time (MGT), time to obtain 50% germination (t50), percentage of seedlings, length and dry mass of shoots and roots, and collar diameter. Fruits and seeds showed greater variation in the parameters fresh mass and number of seeds per fruit. The germination speed index was higher in seeds from reddish fruits, and seeds from green fruits originated better-developed seedlings. Temperatures of 25 and 30 °C are recommended for conducting the seed germination test at the three maturity stages.

Mining Sludge Utilization as Medium Growth for Revegetation Plants through Seed Germination Test

The limited topsoil stock is one of the post-mining reclamation problems that will directly impact the company’s business processes. One solution that can be considered to reduce production costs is the utilization of unused materials around the mine. The settling pond sludge contains nutrients and can be used as a growing medium for plants to replace topsoil. This study examined the potential utilization of settling pond sludge through germination and sprout viability tests. This study used a completely randomized design with four composting treatments, namely 0%, 25%, 50%, and 75%. The number of replications was ten times and applied to several species of revegetation plants, namely Acacia mangium, Senna siamea, Falcataria moluccana, and Albizia saman, so there were 160 experimental units in total. The results showed that the settling pond sludge has organic matter reserves and low nitrogen content but is rich in P and element reserves of P and K. The physical texture of settling pond sludge was still suitable as a medium for plant growth. The addition of compost as a mixture of settling pond media had a significant effect on germination and germination viability but had no significant effect on the parameters of the germination rate. The increase in compost composition in the settling pond media mixture positively affected germination and germination survival. Based on this research, it is known that settling pond sludge can be used as a medium for growing revegetation plants. In general, the media with the addition of 50% and 75% compost gave the best germination response and viability. Keywords: Compost, post-mining reclamation, revegetation, seed germination test, settling pond sludge

Ecotoxicity Study of Additives Composed of Zinc and Boron.

The high use of additives containing zinc borate and their limited solubility in water both lead to its persistence and accumulation in biological systems. On the other hand, soluble forms of boron are easily available to plant roots and are taken up by plants. There are no ecotoxicological data available for zinc borate, the industrial utilization of which is widespread. Therefore, the potential toxicity of zinc borate and its dissociated compounds was evaluated. Based on two different ecotoxicology tests, their effect on plant growth was studied. Firstly, the impact on Lemna minor growth was investigated, including the effect on pigment content. Secondly, the inhibition of the root growth of higher plant species Sinapis alba (mustard), Lactuca sativa (lettuce) and Trifolium pretense (clover) was measured. The growth inhibition test on L. minor was more complex and sensitive compared to the plant seed germination test. Already low concentrations (10 mg/L) of ZnO, B2O3 and Zn3BO6 led to a decrease in frond growth and to an inhibition of the conversion of chlorophyll a to chlorophyll b. These results suggested that the stress caused by these additives caused damage to the photosynthetic apparatus. The highest inhibition of frond growth was detected in fronds treated with B2O3 (92-100%). In ZnO and Zn3BO6, the inhibition of frond growth was between 38 and 77%, with Zn3BO6 being slightly more toxic. In the seed germination test, the most sensitive species was lettuce, the growth of which was inhibited by 57, 83 and 53% in ZnO, B2O3 and Zn3BO6 treatments, respectively. However, the inhibitory effect on each plant was different. In lettuce and clover, the seed germination and root elongation decreased with increasing element concentrations. In contrast, in mustard, low concentrations of ZnO and Zn3BO6 supported the growth of roots. For that reason, more complex tests are essential to evaluate the additive toxicity in the environment.

Wheat straw‐derived bio‐based hydroponic polyurethane foams for plant growth

AbstractAgricultural waste is a renewable and sustainable resource that can be used as an alternative to petroleum for the production of chemicals and materials. In this study, liquefied wheat straw was used as bio‐polyols to prepare bio‐based hydroponic polyurethane (BHPU) foams. The effects of foam preparation variables, such as surfactants, catalysts, blowing agents and types of petroleum‐based polyols (PPG 400 and/or VORANOL 280) on the properties of BHPU foam were investigated through single‐factor experiments. Response surface methodology was applied to optimize the foam formula. The prepared BHPU foams with 40–50% (w/w) bio‐polyols had an open cell content of 70–96%, a water absorption capacity of 594–1085% (w/w) and a water absorption time of 6–140 s. The potential of using the prepared BHPU foam as a plant growing medium was evaluated via mechanical testing, cell morphology, thermal stability, UV weathering testing and Phaseolus vulgaris (Linn.) cultivar Prelude and Glycine max (Linn.) Merr. seed germination tests. The wheat straw‐derived BHPU foams demonstrated potential as a plant growth medium in horticulture. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.

Seed germination tests in Achillea genus from the Pirot County (Southeastern Serbia)

Conditions in Serbia are favorable for the successful cultivation of high-quality varieties of yarrow. The paper examines the germination of seeds of four species of the genus Achillea (A. clypeolata, A. coarctata, A. crithmifolia, A. millefolium), which grow wild in the Pirot County, in order to investigate their potential cultivation. The seeds were first placed in Krstić’s germinator for germination without prior stratification, where, apart from A. crithmifolia seeds, the seeds of the other species did not germinate. After maintaining the seeds for 24 h in a refrigerator, treatment with hot water and a 20% solution of bleach had a favorable effect on the seed germination of all four Achillea species, especially white-flowered yarrow (A. crithmifolia and A. millefolium). In particular, pouring hot water on A. crithmifolia increased the germination energy by 65% and seed germination for 43.8%, while the seed of A. millefolium, reach the germination energy increased 78% and germination 81%, so this type of seed treatment is recommended before sowing.

Vermicomposting of Lavender Waste: A Biological Laboratory Investigation

In the present work, lavender waste, a residue of the essential oil extract industry, was used to feed Eisenia andrei with mature horse manure at ratios of 0:100, 25:75, 50:50, 75:25 and 100:0 on dry weight basis. Vermicomposting was carried out for 70 days in laboratory conditions. Biological parameters such as population build-up, total biomass, mortality and cocoon production were observed and measured. Increasing concentrations of waste affected positively the growth and reproduction of worms in a significant way. The 100% lavender waste combination showed the best cocoon production and even tripled their biomass in the first week. A seed germination test was also made, where no evidence of toxicity was found. The germination index range was, in general terms, above 100. The results indicated that the earthworm E. andrei was able to transform lavender waste into compost and thus play a major role in industrial waste management and apply circular economy.

Biodegradation of high di-(2-Ethylhexyl) phthalate (DEHP) concentration by food waste composting and its toxicity assessment using seed germination test

Di-(2-ethylhexyl) phthalate (DEHP), a plasticizer derived from phthalate ester, is used as an additive in industrial products such as plastics, paints, and medical devices. However, DEHP is known as an endocrine-disrupting chemical, causing cancers and adverse effects on human health. This study evaluated DEHP biodegradation efficiency via food waste composting during 35 days of incubation. At high DEHP concentrations (2167 mg kg−1) in food waste compost mixture, the DEHP biodegradation efficiency was 99% after 35 days. The highest degradation efficiency was recorded at the thermophilic phase (day 3 - day 11) with the biodegradation rate reached 187 mg kg−1 day−1. DEHP was metabolized to dibutyl phthalate (DBP) and dimethyl phthalate (DMP) and would be oxidized to benzyl alcohol (BA) and mineralized into CO2 and water via various metabolisms. Finally, the compost's quality with residual DEHP was evaluated using Brassica chinensis L. seeds via 96 h of germination tests. The compost (at day 35) with a trace amount of DEHP as the end product showed no significant effect on the germination rate of Brassica chinensis L. seeds (88%) compared to that without DEHP (94%), indicating that the compost can be reused as fertilizer in agricultural applications. These results provide an improved understanding of the DEHP biodegradation via food waste composting without bioaugmentation and hence facilitating its green remediation and conversion into value-added products. Nevertheless, further studies are needed on DEHP biodegradation in large-scale food waste composting or industrial applications.

Study on the Selection of Processing Process and Parameters of Platycodon grandiflorum Seeds Assisted by Machine Vision Technology

Seed processing is an important means of improving seed quality. However, the traditional seed processing process and parameter adjustment are highly empirically dependent. In this study, machine vision technology was used to develop a seed processing method based on the rapid extraction of seeds’ material characteristics. Combined with the results of clarity analysis and the single seed germination test, the seed processing process and parameters were determined through data analysis. The results showed that several phenotypic features were significantly or highly significantly correlated with clarity, but fewer phenotypic features were correlated with viability. According to the probability density distribution of pure seeds and impurities in the features that were significantly correlated with seed clarity, the sorting parameters of length, width, R, G, and B were determined. When the combination of width (≥0.8 mm) + G (<75) was used for sorting, the recall of pure seeds was higher than 91%, and the precision was increased to 98.6%. Combined with the specific production reality, the preliminary determination of the Platycodon grandiflorum seed processing process was air separation—screen (round hole sieve)—color sorting. Then, four commercialized Platycodon grandiflorum seed lots were sorted by this process using corresponding parameters in the actual processing equipment. Subsequently, the seed clarity and germination percentage were significantly improved, and the seed quality qualification rate was increased from 25% to 75%. In summary, by using machine vision technology to quickly extract the material characteristics of the seeds, combined with correlation analysis, probability density distribution plots, single feature selection, and combination sorting comparisons, the appropriate processing process and corresponding sorting parameters for a specific seed lot can be determined, thus maximizing the seed quality.

Isolation and characterization of Rhizobium spp. and Bradyrhizobium spp. from legume nodules

Rhizobia topic has been re-focused in recent years because of new findings on their traits not only as nitrogen-fixing bacteria but also as plant growth-promoting rhizobacteria. When combing rhizobial strains with novel biological carriers (e.g., biochar) for inoculant production, it brings great potential for improving soil health in long-term. Appreciating this trend, this study is designed to isolate and characterize local rhizobial strains from legume fields using the conventional method with some modifications to increase efficiency in rhizobial identification. As a result, 17 rhizobial strains were isolated and classified biochemically that genetic identification outcome confirmed 10 strains belong to 07 different Rhizobium species as R. mayense, R. paknamense, R. pusense, R. miluonense, R. tropici, R. phaseoli, and R. multihospitium while the rest belong to 06 various Bradyrhizobium species as B. elkanii, B. centrosematis, B. guangxiense, B. liaoningense, B. yuanmingense, and B. arachidis. Thermal and saline tolerant tests together with seed germination tests also performed on these rhizobial strains to gain data on their responses to abiotic stresses. By comparing rice and mung bean GI values, we can assess the effectiveness of each rhizobial strains to help seeds at their early germination.