Total Germination Research Articles

The addition of nano zero-valent iron during compost maturation effectively removes intracellular and extracellular antibiotic resistance genes by reducing the abundance of potential host bacteria

Applying compost to soil may lead to the spread of antibiotic resistance genes (ARGs) in the environment. Therefore, removing ARGs from compost is critical. In this study, for the first time, nano zero-valent iron (nZVI) was added to compost during the maturation stage to remove ARGs. After adding 1 g/kg of nZVI, the abundance of total intracellular and total extracellular ARGs was decreased by 97.62% and 99.60%, and that of total intracellular and total extracellular mobile genetic elements (MGEs) was decreased by 92.39% and 99.31%, respectively. A Mantel test and network analysis indicated that the reduction in potential host bacteria and intI1 after nZVI treatment promoted the removal of intracellular and extracellular ARGs. The addition of nZVI during composting reduced the horizontal transfer of ARGs and improve the total nitrogen and germination index of compost, allowing it to meet the requirements for organic fertilizers.

Influence of silicon doped biochar on germination and defense mechanisms of pea (Pisum sativum L.) under copper and salinity stresses

Soil pollution is an increasing environmental problem in all developing countries. Salinity and heavy metal stress increase the oxidative stress in plants and lead to the increased production of reactive oxygen species, decreases the production of anti-oxidant enzymes and decreases the rate of plant growth. In the current study, pea plants were grown in the botanical garden GCU, Lahore under stress of salinity and copper. In second stage, these plants were given the treatments of silicon nanoparticles and silicon nano-doped biochar. The salinity and copper effects were observed on different parameters of plant growth. Silicon nanoparticles and silicon-doped biochar proved to be the most effective in improving seedling fresh weight (70%) shoot length (68%), vitality index (82%), germination percentage (16%), seed vigor index (38%), and chlorophyll content (46%) under salinity and copper stress. Biochar, on the other hand, effectively improved root length (37%), total seedling length (55%), germination index (10%), and catalase (21%). Silicon nanoparticles and biochar proved to be most effective in decreasing total phenolics (11%) and total protein content (13%). Therefore, it is concluded that the application of Si-NPs and silicon-doped biochar can enhance plants resistance against saline-sodic and metal contaminated soil and can mitigate these stresses.

Do Not Keep It in the Dark: How Shading and Other On-farm Management Decisions Influence Seed Production and Quality of Asclepias tuberosa L.

Demand for butterfly milkweed (Asclepias tuberosa L.) has increased in recent years. However, seed production practices are not well-defined. We partnered with a wildflower seed producer to investigate the effects of weed barrier cloth, plot shading, mature follicle harvest timing, and dry–cold stratification on seed production and germination. Weed cloth had no impact on seed production. However, shading decreased the number of seeds produced by 1.2- to 9.6-fold. Seeds harvested in July and August showed 2.9- and 2.3-fold improvements in total germination and more uniform and rapid germination compared with September-collected seeds. Conversely, seeds exposed to dry–cold stratification displayed a 3.0-fold reduction in the germination rate compared with nonstratified seeds. Our results indicate that the production system significantly impacts seed production and quality of A. tuberosa. Seed producers can use weed barrier cloth to facilitate seed collection from shattering follicles and suppress weeds without a considerable loss of seed production. However, plants should not be grown under conditions of additional shade. Furthermore, high-quality A. tuberosa seeds can be collected earlier in the year, but they should not be subjected to dry–cold stratification.

After-ripening effect combined with drying methods on seed quality of aubergine seed lots harvested at different maturity stages

Desiccant is a hygroscopic substance that induces or sustains a state of desiccation in its vicinity. The most common desiccant is silica and other common desiccants include activated charcoal, bentonite, calcium sulphate, calcium chloride and zeolites. Our experiment's aim was to see different drying methods (KNO3 (% 90,79 ​± ​0,83 RH), NaCl (%74,87 ​± ​0,12 RH), CaCl (≅%45 RH)) and after-ripening period affect on seed quality in five aubergine maturity stages as determined by days after anthesis (DAA) (55-60-70-80-90 DAA) in two subsequent years of 2018–2019. The results demonstrate that the harvest days and drying treatments of aubergine seeds are considered on the basis of statistically obtained output parameters; total germination, mean germination-emergence time, seedling fresh and dry weight values were found to be significant at the 1% level (p ​< ​0.01). Given the field conditions under which we conducted our research, 70–80 days after anthesis in the first year and 90 days in the second year after anthesis in the Kemer27 cultivar were found to be suitable for seed harvesting. Besides that aubergine seeds (90 day harvest) second drying+after ripening and second drying treatments gave the highest CAT level, second drying ​+ ​after ripening and control groups gave the highest APX activity and control group gave the highest SOD activity. In general, drying treatment is advantageous in aubergine species and according to the harvest periods in all species, frist drying ​+ ​after ripening groups came to the fore. All enzyme results in aubergine were statistically significant according to the harvest day∗after ripening∗drying interaction.

Influence of priming treatments on seed germination and growth characteristics of Moringa oleifera seedlings under laboratory and greenhouse conditions

Seed priming is the treatment of seeds with various priming substances to improve germination and seedling quality, and plant growth. The procedure entails advancing the seed to an equivalent stage of the germination process to achieve rapid and uniform emergence when planted, which is required in the case of Moringa oleifera to reduce the damage of ageing seeds, stimulate their performance, and overcome uneven germination rate due to seedcoat hardening, that leads to wide variation in terms of commercial qualities in the planting field. Therefore, a series of seed priming experiments were conducted to determine the optimal methods of priming treatments that maximise Moringa oleifera total germination, germination rate, and seedling vigour. Moringa oleifera seeds were treated with hydropriming, osmopriming (KNO3), and nutripriming (SeedActivator) for 4, 8, and 12 hrs. Germinability was improved by priming treatments. Results indicated that the highest germination percentage was recorded on seeds subjected to hydropriming (63.25%), followed by nutripriming (61.75%) and osmopriming (60%) with the exact duration of 4 hrs soaking time. All pre-germination treatments have significantly early mean germination days (MGT) compared to the unprimed seeds. In the seed pouch study, seeds treated with hydropriming for 4 hrs had shown the best results to improve roots growth in total root length (cm), root volume (cm3 ), the number of forks, and the number of crossings with 240.52 cm vs. 163.64 cm, 0.47 cm3 vs. 0.29 cm3 , 517.80 vs. 271.47 and 59.20 vs. 28.53 respectively when compared to unprimed seeds. The positive effect of priming can also be seen in the seedling growth of M. oleifera grown in a pot with two different growing media.

In Vitro Assessment of Salinity Stress Impact on Early Growth in Ten Certified Palestinian Barley Cultivars (Hordeum vulgare L.) Potentially Suitable for Cultivation on Former Quarry Substrates

Salinity is a major constraint for crop health and productivity, particularly on arid, semiarid, and otherwise marginal soils, such as quarry residue. Quarries are a main pillar of national income in Palestine but have a long-lasting toll on the environment. We examined barley (Hordeum vulgare L.), another pillar of the Palestinian economy and one of the most important crops in the world, in this regard for its tolerance to salinity stress. This study is the first to evaluate the impact of salinity (50, 85, 120, and 175 mM NaCl) on seed germination, early growth stage, and morpho-anatomy on ten pre-selected certified Palestinian barley cultivars (Baladi, Improved Baladi, Rihan, ICARDA 1, ICARDA 15, ACSAD 68, ACSAD 176, ACSAD 1417, ACSAD 1732, and ACSAD 1744) to assess their potential for a successful growth start under adverse saline conditions. In addition, soil samples from quarries in Hebron governorate were randomly selected and tested for salinity level, electrical conductivity, and total of soluble salts for a first rough overview of options for applying our results, since local data are often scarce or outdated. The examined soil samples reached electrical conductivity (EC) ranges of 1.81 × 10−4–9.071 × 10−4 dS m−1, which are below the normal EC (11–57 × 10−4 dS m−1). This result may contraindicate the hypothesis that quarry lands always suffer from salinity stress. Cultivars such as ACSAD 68 and Icarda 15 proved very sensitive to higher salinity stress with high G50 (time point when 50% of seeds have germinated) at 4.4 d, with 120 mM NaCl (ACSAD 68) or incalculable amounts (Icarda 15) and just 50 and 20% total germination, respectively. Concentrations of 175 mM NaCl were found in ACSAD 176 and Improved Baladi (no G50, 37 and 30% germination, respectively). Some cultivars showed a moderate to high resilience to salinity, such as ICARDA I, ACSAD 1417, and ACSAD 1744, which reached &gt; 80% seed germination at 120 mM NaCl and &gt;60% at 175 mM NaCl, and G50 within 1.5–2.2 days; the most resilient was ACSAD 1732 with G50 &lt; 2 days and germination still &gt;80% at 175 mM NaCl. This is strongly supported by the monitored growth parameters. In conclusion, ACSAD1732 and Icarda 1 cultivars are highly recommended for cultivation in areas of low precipitation and high salt accumulation. In addition, the land and/or soil of quarries, their landfills, and nearby areas in Palestine may be fit for barley cultivation with recommended cultivars regarding salinity stress.

Evaluation of Propiophenone, 4-Methylacetophenone and 2',4'-Dimethylacetophenone as Phytotoxic Compounds of Labdanum Oil from Cistus ladanifer L.

This is the first study to evaluate the phytotoxic activity of three phenolic compounds present in the essential oil of the labdanum of Cistus ladanifer, an allelopathic species of the Mediterranean ecosystem. Propiophenone, 4'-methylacetophenone, and 2',4'-dimethylacetophenone slightly inhibit total germination and radicle growth of Lactuca sativa, and they strongly delay germination and reduce hypocotyl size. On the other hand, the inhibition effect of these compounds on Allium cepa was stronger on total germination than on germination rate, and radicle length compared to hypocotyl size. The position and number of methyl groups will affect the efficacy of the derivative. 2',4'-dimethylacetophenone was the most phytotoxic compound. The activity of the compounds depended on their concentration and presented hormetic effects. In L. sativa, on paper, propiophenone presented greater inhibition of hypocotyl size at greater concentrations, with IC50 = 0.1 mM, whereas 4'-methylacetophenone obtained IC50 = 0.4 mM for germination rate. When the mixture of the three compounds was applied, in L. sativa, on paper, the inhibition effect on total germination and the germination rate was significantly greater compared to the effect of the compounds when they were applied separately; moreover, the mixture inhibited radicle growth, whereas propiophenone and 4'-methylacetophenone did not exert such effect when applied separately. The activity of the pure compounds and that of the mixture also changed based on the substrate used. When the trial was conducted in soil, the separate compounds delayed the germination of the A. cepa to a greater extent compared to the trial on paper, although they stimulated seedling growth. In soil, L. sativa against 4'-methylacetophenone also showed the opposite effect at low concentrations (0.1 mM), with stimulation of germination rate, whereas propiophenone and 4'-methylacetophenone presented a slightly increased effect.

Effect of sulfur on pollen germination of Clemenules mandarin and Nova tangelo.

This study aims to elucidate whether sulfur can inhibit citrus pollination by affecting pollen grains. For this, four sulfur-based products (inorganic sulfur, water dispersible granular sulfur, ammonium sulfate, copper sulfate) were tested to evaluate their effect on pollen germination and pollen tube growth of two citrus varieties: Clemenules mandarin (Citrus clementina) and Nova tangelo (Citrus clementina x [Citrus paradisi x Citrus reticulata]). Pollen grains were extracted from the flowers of these two varieties and subsequently placed in Petri dishes with modified BK (boron and potassium) germination medium with six concentrations of the sulfur-based products (0.2, 2, 20, 200, 2,000, 20,000 mg l-1). All the dishes were incubated and the pollen germination rate was calculated. All the sulfur products showed progressive pollen germination inhibition with a rising sulfur concentration. CTC50 (50% cytotoxicity inhibition) was around 20 mg l-1, with significant differences among treatments. Total pollen germination inhibition took place at 20,000 mg l-1. These results demonstrate that sulfur application can affect citrus pollination.

Fine Bubbles Utilization to Increase Germination Rate of Oil Palm (Elaeis guineensis L. Jacq) Seeds

The current method to break oil palm seed dormancy is the dry heat method which requires approximately 90 days for seeds to germinate with an average germination percentage. Therefore, hastening the process with a higher ratio of germinated seeds becomes necessary. This experiment aims to hasten and increase germination percentage by applying fine bubble water during the dormancy-breaking process. A seed lot derived from one bunch as replication is divided into two sets where fiber plugs from one of the sets are removed while the other set remains intact. Each set was re-divided into six experimental units soaked with tap water or fine bubble water for 1 to 3 days. The result showed that applying fine bubble water provided a better germination rate than tap water treatments. However, the total germination percentage between all treatments does not differ significantly. The germination peak of oil palm seed in the fine bubble water treatments occurred on the 26 th day, 8 days faster than in the tap water treatments. The occurrence showed the potential use of fine bubble water application during dormancy breaking using the dry heat method.

Comparative effects of NaCl and Na2SO4 on germination and early seedling stages of the halophyte Carthamus tinctorius L.

Salinity is one of the primary environmental problems limiting the agricultural productivity and affecting soil physicochemical properties, especially on arid and semi-arid areas. Hence, early screening of salt-tolerant species is a promising strategy for the recovery of salt affected lands. Safflower (Carthamus tinctorius L.), is a medicinal plant used as a laxative, pain relieving, antipyretic and an antitoxin against poisoning. It provides an interesting perspective in becoming a salt-tolerant and high-value crop at saline conditions. In this regard, the aim of the present investigation was to evaluate the effect of salt stress on the germination and early seedling stages of safflower. A laboratory experiment was carried out in a phytotron at a temperature of 25 °C and in the dark for 7 days. The seeds were germinated in Petri dishes treated with various concentrations 0 (control) to 600 mM of NaCl and Na2SO4, with 4 repetitions. The presented results indicate that increasing salinity delayed the beginning of germination and gradually reduced germination percentages. At salt levels beyond 400 mM Na2SO4 and 500 mM NaCl germination was completely inhibited. The germination stress tolerance index displayed that seed germination of safflower was restricted more with Na2SO4 compared to NaCl. Ungerminated seeds in high salt treatments (≥ 300 mM Na2SO4 and ≥ 400 mM NaCl) when transferred to distilled water recovered and kept their ability to germinate. Although, total germination percentages progressively decreased with increasing salinity levels, suggesting that the adverse impact of these treatments were osmotic effect and specific ion toxicity. In addition, increasing salinity concentrations led to a significant decrease in the seedling vigor index by means of reduced radicle and hypocotyl growth irrespective of the salt agents applied. These findings suggest that safflower may be considered as a promising species for saline soil rehabilitation and by consequence for ecological balance improvement.

Uticaj fitopatogenih gljiva na parametre kvaliteta semena boranije u periodu 2018-2022

Green beans are among the most essential legumes because of their nutritional value. However, the production of green beans in Serbia suffers major decline due to significantly reduced yields, as well as the sown areas. Diseases caused by phytopathogenic fungi not only reduce yield and have the negative impact on total germination and seed quality of green beans, but also some phytopathogenic fungi can produce mycotoxins, adversely affecting human health. In this paper, the quality parameters of two green bean varieties (GB1 and GB2) were monitored for quality traits over a period of five years on the territory of Smederevska Palanka. The energy germination and total germination were the highest in the first observed year and amounted to 63% and 88% for GB1, respectively. For GB2 the energy germination and total germination (2018) were 71% and 75%, respectively. A significant decline in total germination was determined in 2020. and amounted to 75% for GB1 and 67% for GB2( p&lt;0.05). The lowest energy germination and total germination were obtained in the last observed year (2022) in both genotypes and statistically increased infection with Alternaria sp. and Fusarium sp. The presence of Alternaria sp. was detected for GB1 and GB2 in the range of 2-3% (2018); Fusarium sp. was 3%. In the last observed year, the presence of other fungi was determined, apropos a higher percentage of diseased seeds with Alternaria sp. and Fusarium sp. (5-6%). Other phytopathogenic fungi were detected in both genotypes: Aspergillus sp. (1-3%), Penicillium sp. (1-4%), Rhizopus sp. (1-3%) and Rhizoctonia solani (2-3%). The moisture was 8.5-10.9 for both genotypes and did not differ statistically between varieties (p&gt;0.05). The impact of phytopathogenic fungi on green beans was reflected in the reduction of total germination, and therefore in seed quality and yield. The priority of future research is the application of biotreatments that will contribute to seed protection and improve total germination, and thus the yield in the field.

Influence of Xanthomonas euvesicatoria on quality parameters of pepper seed from Serbia

The present study focused on detecting bacteria of the Xanthomonas spp. complex (X. euvesicatoria, X. vesicatoria, X. perforans and X. gardneri) and examining their influence on certain quality parameters of pepper seed collected from the territory of Smederevska Palanka (Serbia). The analysis included 27 non-commercial pepper seed genotypes (including chili and sweet pepper) collected in 2021. Several parameters of the quality of analyzed pepper seed (germination energy, total germination, moisture and seed health) were determined. The results showed that out of a total of 27 analyzed samples of pepper seed, the presence of X. euvesicatoria was detected in 13 of them. The presence of X. vesicatoria, X. gardneri and X. perforans was not confirmed. Germination energy of infected seed was 52-84%, and of bacteria-free seed 63-90%; total germination of infected seed was 66-91%, and of bacteria-free seed 80-95%. Seed moisture of infected seed samples was 6.1-12%, and of bacteria-free seed 6.2-8.1%. These parameters did not show significant statistical difference (p&gt;0.05). The presence of seed-borne fungi Fusarium sp. accounted for up to 3% in 25 samples, while it was up to 6% in the remaining two; Alternaria sp. ranked from 1-4% in 25 samples, and up to 5% in only two samples. The results led to a conclusion that the bacterium X. euvesicatoria is the predominant pathogen of the Xanthomonas spp. complex, but it did not affect the quality parameters of the tested pepper seed.

Antioxidant activity, phytotoxicity and allelopathic potential of green walnut (Juglans regia L.) fruit extract

The potential allelopathic effect of a green walnut fruit extract on seed germination and early growth of three weed species (Chenopodium album, Amaranthus retroflexus, Daucus carota) was tested, as well as its phytotoxic effect on seed germination and early growth of maize (Zea mays). Another objective was to analyze the plant extract and assess its antioxidative activity. Antioxidative activity of the plant extract was evaluated based on its ability to neutralize DPPH (2,2-diphenyl-1-picrylhydrazyl) radical and capacity for iron reduction using the FRAP method. Inhibition of the evaluated parameters (total germination and seedling length) decreased proportionally with decreasing concentrations of extract solution of green walnut fruit. The parameters of seedling growth were also found to show greater susceptibility than total seed germination of all three of the tested weed species. Although the seed bioassay results indicated a high inhibitory effect on germination and early growth of the tested weeds, they also revealed phytotoxic activity during early growth of the cultivated Z. mays.

Nutrient types for explants in in-vitro propagation of mulberries and microcloning indicators of mother material

Uzbek hybrid (♀Oshima I2N2 (Morus bombycis Koidz.)× ♂SANIIsh-25 (Morus multicaulis Perr.)) obtained by crossing the mulberry tree, obtained by selection in vitro from Jarariq-9 variety Murasige Skug (MS), Woody Plant Medium (WPM) and Driver and Kuniyuki (DKW) medium were used to obtain and develop explants. The average germination time of the explant in the WPM (standard) main nutrient medium in Uzbekistan hybrid, day-7.3 MS-6.6 days, DKW-7.6 days, but opening from the explant in WPM-56.8, MS-51.06%; DKW was observed to be 73.13%. It was observed that total shoot germination was MS-74.73 %; WPM-71.46%; DKW-78.86 %. It is determined that the indicators of Jarariq-9 variety compared to the indicators of the Uzbekistan hybrid, the average germination time of the explant in the WPM (standard) main nutrient medium is 7.6 days, MS-8.33 days, DKW-8 days, bud opening from the explant is 76.2% in WPM, MS-53.5%; and, DKW-74.4%

The response of Nassella trichotoma (serrated tussock) seeds and seedlings to different levels of fire intensity

Context Fire is an important disturbance regime in grassland communities, since it is responsible for stimulating the regeneration of many species and for maintaining levels of biodiversity. When invasive plants, such as Nassella trichotoma, establish and become widespread in a grassland community, these important fire events can be altered in intensity and frequency, which means that they are able to facilitate the establishment of the exotic species. Therefore, before fire can be recommended as a suitable control technique for invasive species, or alternatively to be integrated into grassland restoration programs, understanding the response of the seeds of exotic species to high temperatures, such as those experienced during a fire, should be well understood. Aims Our aim was to identify their response to a gradient of temperatures associated with different levels of fire intensity. We examined how increased duration of exposure affects their response, and whether seed age or seed moisture content affect the germination response of this species. Methods To gain a fuller understanding of the fire response of N. trichotoma’s seedbank, seeds were collected in 2016, 2017, 2018 and 2019 and then stored until the commencement of the experiments in 2020. Selected seeds were first subjected to an increasing temperature gradient (80°C, 100°C, 120°C, 140°C, and a control), and an increasing duration of exposure (of 1, 3, 6, and 9 min). In the second experiment, one population was selected to test these same temperatures and duration of exposure after the seeds were hydrated to 15%, 50%, or 95%. Last, seedlings were grown for 3 months under glasshouse conditions and then exposed to increasing temperatures (20°C, 60°C, 80°C, 100°C, and 120°C), and an increasing duration of exposure (3, 6, and 9 min). The seedlings were assessed 2 weeks after the heat exposure for signs of damage. Key results It was found that increased temperatures and duration of exposure had a subtle negative effect on germination parameters, including reduced total germination and increased time to 50% germination. The 140°C treatment was seen to be a significant threshold because it killed all the seeds at any duration of exposure. A significant difference among the ages of each seed lot was observed to be a factor on the tested germination metrics, with the oldest tested population (2016) demonstrating the highest germination percentage, uniformity, and rate. Seed germination percentage was significantly reduced for seeds hydrated to 95% compared with the control treatment, whereas no significant difference was observed for the seeds hydrated to 15% and 50%. For the heat treatment of the seedlings, damage to the leaves was observed in the 80°C, 100°C, and 120°C treatments, with some plants in the 120°C treatment experiencing extensive damage prior to resprouting. No seedlings were killed at the tested temperatures. Conclusions Results of this study indicated that fire may be a useful tool for reducing seedbank density by killing a high proportion of the seeds on the soil surface, or located within the top 1 cm of the soil profile, but not for seeds buried more deeply. Efficacy of fire on surface and shallow-buried seeds is improved with high seed moisture content; however, these seeds buried below this depth are still protected by the soil from the lethal effects of temperature. Implications Fire implemented before seed set could be used to effectively kill a large proportion of N. trichotoma seeds. However, for more comprehensive control, it is recommended that chemical treatment is integrated with the fire treatment to improve the overall control efficiency.

Allelopathic effect of weed extracts on seed germination of finger millet

Finger millet is a nutritious food grain crop with a fair amount of minerals like calcium and iron. Present investigation deals with the allelopathic effect of Parthenium hysterophorus and Lantana camara on germination and seedling vigour in finger millet. Seeds of the finger millet were subjected to different concentrations of leaf aqueous extracts of Parthenium hysterophorus and Lantana camara (4%, 6%, 8%, 10%, 25%, 50% and 75%) to find out allelopathic effects on Total germination percentage (GT), Plant height stress tolerance index (PHSI), Root length stress tolerance index (RLSI), Peak value (PV), Germination value (GV). Experimental results revealed that leaf extract of Parthenium showed profound allelopathic effect on seeds of the finger millet over to Lantana camera. The present study helps farmers to be aware with the lethal allelopathic effect of obnoxious weeds like Parthenium and Lantana.

Silicon increases seed weight and initial seedling growth of maize under non-stress conditions, and improves the index of velocity of germination under salt stress conditions

Salinity is one of the most critical factors affecting agriculture worldwide. The application of beneficial elements like silicon (Si) is one of the alternatives to mitigate its effects. In this research, we evaluated the effect of Si applied during seed imbibition on mitigating the negative effects caused by salinity during the germination and initial growth phases of maize (Zea mays L.) SB-308 seedlings. Seed pre-treatment during the imbibition was made with 0.0-, 1.5- and 3.0-mM Si. Afterwards, seeds that were imbibed were placed in plastic containers and treated with 0, 80, 160, and 240 mM NaCl. The evaluated concentrations of Si and NaCl gave rise to 12 treatments. Pre-treated seeds with 3 mM Si had an increase of weight after imbibition, 5.1% higher than the control. The treatments obtained from combining NaCl and Si levels did not affect the total and relative germination. The radicle length increased by 13.6% with 3 mM Si compared to the control. Conversely, it was lower with increasing salinity. These trends were observed in plant height. The interaction of the study factors produced an increase in the radicle length in the interval from 0 to 160 mM NaCl, when the Si dose was increased. However, there were no significant differences among equal levels of salinity without Si. It is concluded that Si increased the absorption of water during the imbibition and raised the index of velocity of germination under salinity, except in the dose 240 mM NaCl. Likewise, the pre-treatment of seeds with Si tends to increase radicle length under saline conditions.

Plant origin and trade-off between generative and vegetative reproduction determine germination behaviour of a dominant grass species along climatic gradients

An increasing number of studies explore the effects of climate change on plants; less studies have paid attention to germination. Even less is known on a trade-off between investment to generative and vegetative reproduction. To assess how conditions of plant origin, germination climate and seed mass affect species’ germination, we studied Festuca rubra originating from localities situated along a natural climatic grid with a factorial combination of temperatures and precipitations. Germination of seeds of different origin was tested in two temperature and two soil moisture regimes, simulating extremes of the climatic grid. To study the relationship between generative and vegetative reproduction, we used previous data on vegetative traits of the species originating from the same study system. Higher seed mass and warm germination temperature contributed to higher and faster germination. However, the effects of temperature and moisture interacted leading to low germination and high proportion of dormant seeds in warm, dry conditions. Seeds of plants originating from warm climate had higher germination than those from cold climate; the effects of original climate were partly due to differences in seed mass. Total germination negatively correlated with plant performance variables contributing to vegetative reproduction. Both conditions of plant origin and of germination determine species’ germination and the effect of plant origin can partly be explained by seed mass. We confirmed a trade-off between generative and vegetative reproduction indicating that, depending on the actual conditions, the species is able to modify investments to generative or vegetative reproduction.

Influence of delta-hexachlorocyclohexane (δ-HCH) to Phytophthora ×alni resistant Alnus glutinosa genotypes − Evaluation of physiological parameters and remediation potential

Hexachlorocyclohexanes (HCHs) are persistent organochlorine pesticides with the adverse effects on human health and the environment. The effect of delta-isomer of hexachlorocyclohexane (δ-HCH) on germination, growth parameters and physiological parameters was studied in different Alnus glutinosa (L.) Gaertn. progeny of resistant genotypes to pathogen Phytophthora ×alni. Two experiments were performed: a short-term experiment to determine the effect of δ-HCH on total germination (GT), germination energy (GE), speed of germination (SG), shoot length and biomass of seedlings, and a long-term experiment devoted to remediation aspects. In addition, changes in the hormonal system of alders were monitored in both cases. Significant differences were found between the treated and control group in most of the evaluated characteristics. Also, the content of studied phytohormones differs between groups. Furthermore, the obtained results indicate genetically determined variability in response to δ-HCH. Of the six tested, the Březové and Tuřany progeny seem to be suitable candidates for phytoremediation because of the adaptation to stress conditions or high remediation efficiency. The rest of tested progeny seems to be unsuitable due to higher mortality, lower remediation efficiency and higher levels of stress hormones resulting in significant decrease in biomass and plant height. Moreover, results indicate the role of the plant as a remediation accelerator, probably through released exudates, and a positive effect on the soil microbiome as the presence of plants increased the remediation efficiency by 20.85 – 35.89%. The obtained research findings may be helpful in better understanding the processes involved in removing these pesticides from the soil. Further research should be focused on rhizosphere microbiome, mechanism of in-plant isomerization and metabolites identification.

A fungicide dresser against fungal phyto-pathogens of narrow-leaf lupin

The laboratory and field study of the dresser Delete Pro SC (suspension concentrate) effectiveness against anthracnose agent and other lupin diseases was carried out in Bryansk region in 2019-2021. Seeds, seedlings and sowings of the narrow-leaf lupin of Vityaz variety were the objects for the research. In the laboratory the effectiveness of Delete Pro (piraclostrobine 200 g/l) was tested in three doses of use (0.5; 1.0 and 1.5 l/t). Biological effectiveness was estimated by the number of infected seedlings grown in paper-and- polyethylene rolls compared to the control (without treatment). The dose 1.5 l/t had the high biological effectiveness against anthracnose (99.4 %). The total germination and the number of seeds with strong seedlings made 99.6 % and 90.4 %, respectively. The length of the roots and hypocotyl of the seedlings reliably increased by 9.4 and 10.6 mm, respectively. In the field test the seeds were treated with 1.5 l/t Delete Pro a month before sowing. The effectiveness of the fungicide was compared to the control variant without treatment. The average dresser biological effectiveness against anthracnose seed infection was 94.3 % during tests years. By the stage of brilliant pod the infected pods number decreased to 3.2 compared to 21.1 % in the control. Fusarium infection decreased from 20.1 % in the control to 13.7 % in the variant; risoctonia solari infection decreased from 9.4 % to 3.0 %. The development of Botrytis blight on the pods decreased 2.8 times. The significant true (LSD05 = 0.82) increasing of seed germination made 13.3 % and survival of productive plants by the harvest period increased by 32.4 %. Due to the application of the fungicide dresser Delete Pro SC (1.5 l/ha), the significant seed yield rise was 0.75 t/ha (LSD05 = 0.03); the cost recovery was 5.11 rubles.