Germination Capacity Of Seeds Research Articles

Exploring the effects of metallic toxicity on the seed germination and initial growth of Lavandula stoechas L. and Myrtus communis L.: Towards promoting the dissemination of aromatic plants in contaminated lands

The high accumulation of heavy metals (HMs) in soils is becoming a major ecological concern worldwide that negatively impacts all living organisms. Therefore, sustainable solutions are urgently needed to withstand these challenging circumstances and to maintain natural ecosystem functionality. Among the relevant solutions is to select well-adapted plant species and embed them in revegetation operations for degraded areas. In this study, the effects of different concentrations (0, 200, 400, and 600 mg L–1) of cadmium (Cd), chromium (Cr), nickel (Ni), and lead (Pd) on the seed germination capacity and initial growth performance of two valuable aromatic plants (Lavandula stoechas L. and Myrtus communis L.) were tested. The germination of seeds was greatest in the control treatment (0 mg L–1), while amplifying HM stress restricted germination. The results obtained showed that seeds of L. stoechas were unable to germinate in the presence of high doses of Cd (400 and 600 mg L–1) and Ni (600 mg mg L–1), and subsequently featuring increasing tolerance thresholds in the following order: Pb > Cr > Ni > Cd. Regardless of the HM used, M. communis seeds germinated at all concentrations, and germination increased in the following pattern of HM resistance: Cd > Ni > Cr > Pb. Seedlings of L. stoechas displayed better resistance to Ni and Pb, while M. communis seedlings were most strongly affected by Ni. Overall, the hypocotyl was typically more susceptible to different metal elements than the radicle. The ability of seeds to effectively emerge in a broad range of HM solutions indicates that both species can further establish and propagate in contaminated soils.

Bioprospects of pink pigmented facultative methylotrophs (PPFMs)

PurposeThe purpose of this article is to provide information about interactions between pink-pigmented facultative methylotroph (PPFM) organisms and plants, their molecular mechanisms of methylotrophic metabolism, application of PPFMs in agriculture, biotechnology and bioremediation and also to explore lacuna in PPFMs research and direction for future research.Design/methodology/approachResearch findings on PPFM organisms as potent plant growth promoting organisms are discussed in the light of reports published by various workers. Unexplored field of PPFM research are detected and their application as a new group of biofertilizer that also help host plants to overcome draught stress in poorly irrigated crop field is suggested.FindingsPPFMs are used as plant growth promoters for improved crop yield, seed germination capacity, resistance against pathogens and tolerance against drought stress. Anti-oxidant and UV resistant properties of PPFM pigments protect the host plants from strong sunshine. PPFMs have excellent draught ameliorating capacity.Originality/valueTo meet the ever increasing world population, more and more barren, less irrigated land has to be utilized for agriculture and horticulture purpose and use of PPFM group of organisms due to their draught ameliorating properties in addition to their plant growth promoting characters will be extremely useful. PPFMs are also promising candidates for the production of various industrially and medicinally important enzymes and other value-added products. Wider application of this ecofriendly group of bacteria will reduce crop production cost thus improving economy of the farmers and will be a greener alternative of hazardous chemical fertilizers and fungicides.Graphicalabstract:

Insecticidal activity of crude olive pomace oils from Kabylia (Algeria) against the infestation of Rhyzopertha dominica (F.) and Sitophilus oryzae (L.) in stored wheat grains

The insecticidal effect of four crude olive pomace oils extracted from pomace collected from four localities of Kabylia, refined olive pomace oil and extra virgin olive oil were assessed under laboratory conditions for the control of adults of Rhyzopertha dominica (Fabricius, 1792) (Coleoptera: Bostrychidae)) and Sitophilus oryzae (Linnaeus, 1763) (Coleoptera: Curculionidae). The doses used ranged from 0.1 to 0.4 ml/25 g of durum and soft wheat seeds. In addition, the quality indices and the fatty acid composition of these oils were evaluated. The results show that the legal quality indices were well within the legal limits for crude olive-pomace oil (COP), refined pomace oil (ROP) and extra-virgin olive oil (EVO) categories. The effectiveness of these vegetable oils is highly dependent on the insect species, the dose rate, the exposure time and the type of oil tested The main fatty acids from all samples tested, were oleic (61.89–79.25%), palmitic (8.34–15.71%) and linoleic (8.17–16.52%) acids. For both species and substrates tested, mortality is dose and time of exposure dependent. The highest dose (0.4 ml/25 g) causes ≥ 63.75% mortality, after 24 h of exposure. Comparison of LD50 (ml/25 g) indicates that olive oil was generally more toxic than crude and refined pomace oils, for both insects and substrates, values varies from 0.005 to 0.189. The most sensitive insect was S. oryzae for most vegetable oils tested. Likewise, oils significantly reduced the F1 offspring of both insects and seed weight losses. No progeny were observed in the two pests at the highest dose, and therefore no weight loss was recorded. The results also revealed that the six oils affect the germination capacity of durum and soft wheat seeds when the dosage is increased. The results collected remain encouraging for the recommendation of natural substances as part of integrated pest management programmes against insect pests of stored grains.

Test For Germination of Cocoa Seeds (Theobroma cacao L.) Using Different Storage Lengths

Cocoa is one of the plantation commodities that has quite an important role in Indonesia's economic activities. Based on data from the International Cocoa Organization (ICCO) in 2021 and 2022, Indonesia is ranked 7th as the largest cocoa-producing country in the world. Apart from increasingly open export opportunities, the domestic cocoa bean market is still quite large. One of the problems in preparing high-quality seeds is seed storage time. Seeds that are stored will experience deterioration or decline in quality with signs of decreased quality, low viability and vigor, poor planting, and reduced yields. This research aims to determine the extent to which cocoa seeds are able to germinate well if stored for a certain time so that they can become a benchmark for seed users for sowing. The research approach was carried out qualitatively using mathematical methods. Data is analyzed and displayed in table form. Treatment 0 seeds were planted immediately. Treatment 1 seed was stored for 1 week, treatment 2 seeds were stored for 2 weeks, treatment 3 seeds were stored for 3 weeks, and treatment 4 seeds were stored for 4 weeks. The research results on the germination capacity of cocoa seeds with different storage periods showed that the best treatment was for seeds planted directly in the nursery, with water content 35.7%, germination time 12.3 days, germination capacity of 97.56%.

Targeted mutagenesis of BnTTG1 homologues generated yellow-seeded rapeseed with increased oil content and seed germination under abiotic stress

Yellow seed is one desirable trait with great potential to improve seed oil quality and yield. The present study surveys the redundant role of BnTTG1 genes in the proanthocyanidins (PA) biosynthesis, oil content and abiotic stress resistance. Stable yellow seed mutants were generated after mutating BnTTG1 by CRISPR/Cas9 genome editing system. Yellow seed phenotype could be obtained only when both functional homologues of BnTTG1 were simultaneously knocked out. Homozygous mutants of BnTTG1 homologues showed decreased thickness and PA accumulation in seed coat. Transcriptome and qRT-PCR analysis indicated that BnTTG1 mutation inhibited the expression of genes involved in phenylpropanoid and flavonoid biosynthetic pathways. Increased seed oil content and alteration of fatty acid (FA) composition were observed in homozygous mutants of BnTTG1 with enriched expression of genes involved in FA biosynthesis pathway. In addition, target mutation of BnTTG1 accelerated seed germination rate under salt and cold stresses. Enhanced seed germination capacity in BnTTG1 mutants was correlated with the change of expression level of ABA responsive genes. Overall, this study elucidated the redundant role of BnTTG1 in regulating seed coat color and established an efficient approach for generating yellow-seeded oilseed rape genetic resources with increase oil content, modified FA composition and resistance to multiple abiotic stresses.

Impact of eco-physiological factors on the weed seed germination and emergence: A review on its role in weed management

Dormancy is a typical feature of many weed seed populations, which makes forecasting the time and magnitude of weed emergence difficult. The mean minimum temperatures required for undergoing germination of different weed seeds varies considerably depending on the place of their origin as well as the season on which the plants grow. For instance, the temperature requirement for the germination of summer weeds was observed to be 40% higher than for the winter weeds. Decreasing the water potential from 0 Mpa (mega pascal) to -1.0 Mpa tends to reduce the germination capacity of many weed seeds with some seeds totally failing to germinate at -1.0 Mpa (Chloris truncate, Retama raetam). The effects of planting depth on seed germination and seedling growth of Aframomum citratum on varied soil types indicated that sowing depth greatly influenced the plant's cumulative germination percentage and early growth. The seeds of Sysimbrium officinale (L.), a summer annual species, displayed greater sensitivity to nitrates and lost dormancy throughout the winter. The germination of Thlaspi arvense was also discovered to be stimulated by nitrate only in the presence of light. Tilling the surface of soil has a positive impact in the weed seed germination, however if the tillage depth increases more than 9cm, it tends to lower down the germination of several weed species. However, weed seeds of Bernard grass are among the exceptions in which they germinate better at a shallow depth (2cm). The nature and the thickness of the mulching component influence the germination of weed seeds. Thicker mulches and mulching materials like pearl millet resulted in a greater suppression of the weed seed germination due to an increased allelopathic effects.

Evaluation of Different Geographic Provenances of Silver Fir (Abies alba) as Seed Sources, Based on Seed Traits and Germination

The evaluation of the diversity of silver fir (Abies alba Mill.) populations and the reproductive traits of the trees are of great importance for the conservation of genetic resources and forest management. Therefore, important reproductive characteristics of A. alba from seven Romanian provenances, considered as different geographical populations, were evaluated. Significant differences between the provenances were observed for the female cones, seed morphology, and germination. Due to the relatively low germination of silver fir seeds, germination tests were conducted to identify treatments that can stimulate the germination capacity. Thus, the seed germination capacity was determined using four different stimulation treatments and the data were compared with those of untreated seeds, designed as the control. Considerable differences were recorded not only depending on the seed provenances, but also regarding the treatments applied to stimulate germination (Atonik biostimulator, scarification, acetone, H2SO4). The biostimulator seed treatment gave the highest germination percentage, while sulfuric acid caused the lowest germination. The research also revealed that not all the forest seed sources provide high-quality reproductive material. Furthermore, for some of the seed resources, even the germination stimulation treatments did not result in adequate germination. The findings are pertinent and valuable for identifying suitable forest populations as seed sources, as well as for their use in silver fir reforestation programs.

The effect of prolonged stratification and shading on the emergence of Pseudotsuga menziesii (Mirb.) Franco seedlings

The Douglas fir has been cultivated in Europe since the mid-19th century, but its artificial regeneration leads to a low yield of seedlings. It could be improved by prolonged pre-sowing treatment (cold stratification of seeds) or the early shading of sowings, so that their effect on five Douglas fir seed lots and their emergence and growth of seedlings were analysed. One lot came from the USA; four lots came from the Czech Republic. The germination capacity and germination rate were analysed for seed without pre-sowing treatment and seed after 21-day and 49-day stratification. The emergence rate was tested for variants of the 21-day and the 49-day stratification (shaded and unshaded treatment) and for autumn sowing (unshaded treatment). The results show that the maximal germination capacity of full seeds is achieved after the 21-day stratification. The prolonged 49-day stratification increases the germination rate, especially in seed lots with lower vitality. The biggest seedlings, in terms of length and biomass of the above-ground part and the biomass of the root system, emerged from seeds sown in autumn. The combination of the 49-day stratification of seeds and the 3-week shading after spring sowing can accelerate seedling emergence and increase the emergence rate of seedlings; seedlings achieve more biomass and length of the above-ground part, the root system compared to unshaded seedlings or seedlings emerged from 21-day stratified seeds. Comparable or better results were achieved from autumn sowing.

The chances in the redox priming of nondormant recalcitrant seeds by spermidine.

The problems posed by seed sensitivity to desiccation and aging have motivated the development of various techniques for mitigating their detrimental effects. The redox priming of seeds in antioxidant solution to improve their postharvest performance is one of the approaches. Spermidine (Spd) was tested as an invigorating solution on nondormant recalcitrant (desiccation sensitive) seeds of the silver maple (Acer saccharinum L.). The treatment resulted in an 8-10% increase in germination capacity in seeds subjected to mild and severe desiccation, while in aged seeds stored for six months, no significant change was observed. The cellular redox milieu, genetic stability, mitochondrial structure and function were investigated to provide information about the cellular targets of Spd activity. Spd improved the antioxidative capacity, especially the activity of catalase, and cellular membrane stability, protected genome integrity from oxidative damage and increased the efficiency of mitochondria. However, it also elicited a hydrogen peroxide burst. Therefore, it seems that redox priming in nondormant seeds that are highly sensitive to desiccation, although positively affected desiccated seed performance, may not be a simple solution to reinvigorate stored seeds with a low-efficiency antioxidant system.

Germination Capacity of Helianthus annuus Less Seeds on Soil Media Contaminated by Waste

Used oil waste is often dumped on the ground around the workshop, causing soil pollution which can reduce the function of the soil. The most difficult contaminants in used oil waste to decompose are hydrocarbon compounds, which are highly toxic, polycyclic aromatic hydrocarbons (PAHs). The concentration of oil hydrocarbon contaminants in a sample is determined by measuring the total petroleum hydrocarbon (TPH) concentration. This study was conducted to determine the germination ability of Helianthus anuus, Less seeds on soil media contaminated with waste oil at different concentrations of Total Petroleum Hydrocarbon (TPH). The results showed that the concentration of TPH in the media could inhibit the speed of seed germination. Treatment with low concentration of TPH 2.7% in the media increased % germination, shoot and root length and sprout biomass compared to the medium/intermediate (8.00%) and high (12.26%) TPH treatments and controls. However, there was no significant difference between all treatments regarding germination time and shoot length, although in the low TPH treatment (2.70%) there was a tendency for germination time to be faster than the other treatments, as well as to shoot length which was longer than the other treatments. The higher TPH concentration in the media can inhibit germination time, germination percentage, shoot and root length and biomass. Morphological observations of the growth of sprouts showed an inhibition of root hair formation along with the high TPH content in the media, but all treatments did not affect the growth of the shoots.

Effect of Presowing Magnetic Field Stimulation on the Seed Germination and Growth of Phaseolus vulgaris L. Plants

Background: The problem of the influence of magnetic fields (FMs) on the growth and development of common bean plants is still far from being fully explained due to its complicated physical nature and the geometry of the seeds. FMs can practically penetrate through living organisms. Aim: The present work aimed to determine the effect of the presowing FM stimulation of common bean seeds on plant growth and development elements. Material and Methods: The present study was based on a field experiment carried out between the years 2015 and 2017 in Żyznów (N 49°81′, E 21°84′, 239 m above sea level). The experiment was carried out using three repetitions of the randomized block method. The experimental factor was the amount of exposure to FM seed stimulation: (I) 15 s, (II) 30 seconds, and (III) the control object without seed stimulation. The plant material of the study was a common bean: cv. Gold Saxa. Results: The biostimulation of the sources with an FM improved the germination energy, strength, and capacity of the seeds. The presowing FM stimulation of the common bean seeds favourably affected the fresh weight of the first and fifth leaves but did not affect their dry weight. The leaves’ collection dates measured the new first and fifth plates and their dry weight content. The collection dates of the leaves determined the level of the fresh weight of the first and fifth leaves and the content of their dry weight. Conclusions: The biostimulation of the seeds with the FM contributed to a higher germination capacity, energy, and strength of the common bean seeds. The highest level of the leaves’ fresh weight was achieved during full flowering, and the highest dry matter content of the leaves was found in the phase of pod setting.

Germination of Lolium perenne and Medicago Species under the Conditions of Drought and Silicon Application as Well as Variable pH and Medicago sativa Root Extracts

Drought and allelopathic conditions impact the germination of seeds of grass and legume species used in mixtures on grassland. This study evaluated the effects of drought and Medicago sativa root extracts at different pH levels on the germination and characteristics of seedlings of Lolium perenne and selected Medicago species. Two experiments were carried out: the first explored the effects of drought induced by PEG solutions (0.0, -0.3, and -0.6 MPa) under silicon (Si) application; the second studied the influence of Medicago sativa root extracts (12 and 24 g/100 mL H2O) and variable pH solutions (control, 5.0, and 6.5) on seed germination. Germination was carried out on Petri dishes for individual species and in two-species mixtures. The drought conditions did not affect the germination capacity of seeds, but it increased the dry weight of the seedlings of the tested species. The application of silicon decreased the root length of the seedlings of all species, independent of the germination conditions. The higher concentration of M. sativa root extract combined with the studied pH solutions had an inhibitive impact on the germination capacity of L. perenne. Our findings revealed that the lower concentration of M. sativa root extract had a beneficial effect on the morphological features (length of roots and leaves, fresh and dry weight) of the seedlings when germination was carried out separately for both species. In the mixture, the effect was especially marked for L. perenne (only in terms of the root length and fresh weight of seedlings). The applied root extracts in combination with the acidic pH conditions limited the germination capacity and growth of the seedlings of L. perenne the most when germination was performed separately. It was concluded from this study that silicon application did not improve the germination capacity of seeds under drought conditions, whereas the germination of L. perenne seeds in a mixture with M. sativa mitigated the negative allelopathic effects of M. sativa root extracts on the seed germination capacity and morphological features of seedlings of L. perenne.

Всхожесть семян хвойных интродуцентов в условиях Центрального Казахстана при различной стратификации и внесении в субстрат хвойного опада

This study observes the issues of the possible usage of wastes from timber industry in the sprouting of seeds of coniferous plants in the arid climate of Central Kazakhstan. Such treatment of coniferous seeds is easily implementable and cost-effective, compared to the other methods. However, the complex chemical composition of needle litter in the soil substrate has the multifactorial and controversial effects on such indicators as germination energy, seed germination capacity and rest energy. In addition, the article discusses the use of long-term natural seed stratification as an alternative method of planting seeds in forest nurseries. The other studies have shown that natural stratification has a more significant effect on the indicators of seed rest energy and germination energy. However, it should be said that these parameters mostly correlate with the generic assignment of the objects. Thus, representatives of the genera Picea and Abies have more significant rates of germination during spring stratification. Whereas, representatives of the genera Pinus and Pseudotsuga – with natural stratification. This may be the result of their ecological and biological adaptation. The conditions of Central Kazakhstan are characterized by a sharply continental climate, which includes not only a sharp climate change, but also a rather low snow cover and low temperatures. Under these conditions, the seeds of the genera Pinus and Pseudotsuga may have higher adaptive abilities, which may become a further subject of research. At the same time, it was determined that despite the rather convincing data obtained during autumn stratification, the highest results of seed germination in most experimental species were noted during spring stratification, including variation with the use of needle litter. Again, it is not entirely advisable to introduce the use of this method based only on the indicators of seed germination in arid conditions of Central Kazakhstan, since the favorable period for seed germination in this area is unstable from year to year. Thus, based on the results of the study, it was concluded that the most suitable method for germinating seeds of conifers, with some exceptions, is natural stratification. The use of needle litter affects insignificantly the rates of seed germination, and in some cases even suppresses this process.

Beneficial effects of silicon fertilizers on indicators of seed germination, grain yield of barley and soybean and silage corn biomass

The aim of the study was to determine the optimal doses and methods of the application of silicon fertilizer in barley, silage corn, and soybean under the climatic conditions of Ukraine. A series of laboratory and field experiments were carried out, as along with statistical and analytic data processing. The small-plot field experiment was conducted on chernozem podzolic soil at the NSC ?Institute for Soil Science and Agrochemistry Research named after O.N. Sokolovsky? (Kharkiv region, Forest-Steppe of Ukraine). The laboratory experiments were set up in Petri dishes using a preparative form of different concentrations (0%, 0.5%, 0.75% and 1.0%) of potassium silicate for their assessment of the germination indicators of barley and corn seeds. The significant stimulating effect of potassium silicate on the germination capacity and germination energy of barley and corn seeds was shown, and the optimal concentration of the solution for pre-sowing seed treatment was established. A high positive correlation was determined between the amount of SiO2 application and the yield of the studied crops (P < 0.01; R = 0,7479-0,8682). The optimal levels of the pre-sowing application of SiO2 into the soil were established to obtain maximum crop yields on chernozem podzolic soil (105 kg SiO2 ha-1 for barley, 92 kg SiO2ha-1 for silage corn, and 76 kg SiO2ha-1 for soybean). Also, for each of the studied crops, the most optimal methods of the application of silicon fertilizers were determined, which will improve their productivity on chernozem soils.

The Changes in Seed Germination Capacity, Seedling Growth, and Leaf Morphology of Ficus variegata Blume Influenced by Gamma-Ray Irradiation

Gamma irradiation treatments have commonly been applied to induce variation in plant genetic improvement programs. The improvement of nyawai (Ficus variegata Blume) is urgently needed mainly to break the seed dormancy, increase seedling growth, and induce variation for selecting desired traits. This research aimed to assess the effect of gamma irradiation doses on seed germination, seedling growth, and leaf morphology of Ficus variegate Blume. This experiment's irradiation doses ranged from 5-240 Gy and were applied to seeds with varying levels of vigor based on the artificial seed aging process. The data displayed a positive relationship between low doses of gamma irradiation and the nyawai seed's endurance. Low irradiation doses, 5 to 30 Gy, are deemed capable of promoting seedling development, leaf retention, and diversity in leaf structure. The higher irradiation doses than 30 Gy decreased seedling growth, leaf number, and seedling survival. In addition, these doses also affect some morphological changes, including seedling height and leaf length and width.

UJI BEBERAPA ISOLAT JAMUR ENDOFIT TERHADAP JAMUR TULAR BENIH DAN PERTUMBUHAN BIBIT CABAI MERAH

The aim of this study was to test several endophytic fungi isolates with high antagonistic power against seed borne fungi in vitro and their effect on the growth of chili (Capsicum annuum L.) seedlings in vivo. This research was conducted at the Plant Disease Laboratory and Greenhouse Faculty of Agriculture, Riau University from October 2018 to February 2019. This research was conducted experimentally using a completely randomized design (CRD) consisting of 5 treatments and 4 replications. The treatment of endophytic fungi was applied using the seed immersion method. The results showed that giving the endophytic fungi Rhizictonia sp., Cephaloporium sp., T. virens from oil palm roots and T. virens from oil palm stems were able to suppress the incidence of seed-borne pathogenic fungi Fusarium sp., Colletotrichum sp. and Aspergillus sp.. Provision of endophytic fungus T. virens from oil palm roots can increase seed germination capacity by 14%, number of live seeds by 17% and increase seedling height and leaf number.

Phytotoxic Effect of Treated Wastewater on Seed Germination and Percent Root Elongation Inhibition in Some Vegetable Crops

Aims: Summer irrigations for citrus fruits and fodder are considered as pre-irrigations for growing annual crops in Tunisia. However, given the quality of this treated wastewater, pre-irrigation effect on the seed germination capacity remains unclear. We propose to study the effect of different concentrations of treated wastewater on the germination of some vegetables.
 Methodology: This laboratory experiment investigates the effect of different concentration from 0 to 100% (0%, 20%,40%, 60%, 80% and 100%) of treated wastewater on seed germination (%), germination index (Ig), root elongation and root elongation inhibition index (REI%) for some vegetable crops, the most commonly used by farmers: Radish, Okra and Pea.
 Results: Pea germination rate (%G) dropped significantly from 60% to 30% with WW concentration. The germination index (Ig) decreased for Radish and Pea seeds with increasing WW concentration; it decreases from 1.03 to 0.72 and from 0.8 to 0.33 for radish and pea, respectively. While, the sprouting index for okra increased from 1.24 to 2.2 with increasing WW concentration. According to the REI% values, there is no effect of WW concentration on the root elongation of okra. On the other hand, the most pronounced REI% was noticed for Pea which has shown positive REI% values for all the concentrations with an inhibition effect of about 67% for the 100% WW treatment. For the radish, the root elongation inhibition started from the 40% WW concentration.
 Conclusion: The crops tested have been arranged in the following order: Okra>Radish>Pea depending on the tolerance to treated wastewater. We conclude that the effect of treated wastewater on seed germination is depending on crops species and we should take care before using the treated wastewater for pre-sowing irrigation purposes.

Phytotoxicity assessment study of gold nanocluster on broad bean (Vicia Faba L.) seedling

ABSTRACT In this study, we investigated the phytotoxicity of gold nanoclusters (AuNCs) on seed germination capacity, physiological response to stress and uptake, and the transport of gold nanomaterials in broad beans. Although similar findings were observed for AuNCs on broad bean root tip cells between micronucleus assays and traditional phytotoxicity experiments, the former was more sensitive and rapid. At experimental concentrations of 0–200 mg/L, the toxicity performance of broad bean seedlings showed an overall positive correlation with the concentration of AuNCs. AuNCs posed a potential risk to the environment at a concentration of 20 mg/L. Moreover, studies on the uptake and transport of gold nanomaterials showed that the smaller the particles entering the bean, the higher the transport coefficient, while materials not entering the bean were mainly adsorbed on the root surface of the bean seedlings by competition with potassium ions.

Microwave lupine seeds treatment modes on the germination ability

Electric, magnetic and electromagnetic fields can be successfully applied in various processes of agricultural production. To improve the sowing properties, seeds of various crops are subjected to special treatment. Research shows that treating seeds with the energy of electromagnetic fields also increases the germination capacity of seeds. However, the effect of treatment depends on the level of influencing factors. Therefore, it is very important to observe the correct treatment regimes (exposure parameters). The article presents the results of experimental studies to assess the influence of the microwave power intensity and exposure duration onto the sowing properties of lupine seeds. Based on the processing of experimental data, regression equations were obtained that take into account the effect of the magnitude of the specific microwave power of exposure and exposure on the ability of lupine seeds to germinate. The experiment showed that with the help of microwave treatment it is possible to obtain not only the effect of stimulation, but also the inhibition of plant growth. Regimes have been also identified in which seeds are insensitive to microwave treatment. At the same time, modes have been identified in which a stimulating effect manifested itself, as well as areas of insensitivity and negative impact. At the same time, it can be unambiguously asserted that an increase in exposure to microwave exposure is most pronounced at higher values of specific microwave power. Compared to the results of processing wheat seeds, to stimulate lupine seeds, it is necessary to provide higher values of the specific power of microwaves and exposure. The best processing result was obtained at a specific power level of 1.17 kW/kg and an exposure of 60 s. Therefore, this mode can be recommended for pre-sowing microwave treatment of lupine seeds.

Does the Age of Pinus sylvestris Mother Trees Influence Reproductive Capacity and Offspring Seedling Survival?

We assess how the age of Pinus sylvestris mother trees influences seed size, seed viability, germination capacity and later offspring seedling survival under greenhouse conditions. Thirty trees ranging from 30 to 219 years old were selected in the north facing slopes in the Sierra de Guadarrama, where we could find the oldest Pinus sylvestris trees in central Spain. Forty cones per tree were harvested to study cone and seed characteristics (size and weight), seed viability and germination capacity related to the mother tree age. In addition, 25 germinated seeds per tree were grown in a greenhouse to assess offspring seedling survival during a death trial, where watering was stopped. Significant differences between trees in cone and seed morphological traits were observed. The age of the mother tree had a significant effect on cone size, seed size, and seed weight, but there was no effect on seed germination capacity and seed viability. Seedling survival was mainly affected by the decrease in water availability. However, a significant effect of the tree age was found once soil moisture had reached 0%. Our results show the ability of overmature Pinus sylvestris trees to maintain a relatively high reproductive capacity that assures its persistence.