Seed Priming Methods Research Articles

Mechanism and Methodologies of Seed Priming: Enhancing Germination and Crop Resilience

Due to its potential to improve seed germination and early seedling development, "seed priming" has garnered attention recently. This review article covers seed priming systems, their processes, and their many crop production purposes. Seed priming and its importance in seed performance are discussed. Seed priming methods include osmotic, hydro-, hormonal, and microbiological. Each technique is thoroughly detailed, including its procedures, requirements, and pros and cons. The molecular, physiological, and biochemical changes and priming substance-seed interactions of seed priming are examined. The article also discusses seed priming's benefits for stress tolerance, seed germination, seedling vigour, and sustainable agriculture. Most seed treatments use seed imbibition, which allows seeds to germinate but prevents radicals from reaching the seed coat. Dry, desiccation-resistant seeds can be stored until planting. Priming accelerates and synchronises future germination, and early seedlings from primed seeds are often more robust and resistant to abiotic stressors. Progressive farmers that want to boost agricultural productivity would benefit from this technology. This article discusses seed priming methods, mechanisms, and usage in various agricultural situations to boost crop productivity and seed performance.

Extracts from the leaves of knotweeds (Reynoutria spp.) have a stimulating effect on the germination and initial growth of wheat grains.

Knotweed (Reynoutria sp.) plants are known in the world mainly as invasive plants. However, it is known that their rhizomes or leaves contain secondary metabolites with biological activity. Our goal was to determine which of the three knotweed plants (Reynoutria japonica, Reynoutria × bohemica, and Reynoutria sachalinensis) is most suitable for seed growth stimulation. We tested alcoholic extracts of all three knotweed species by seed priming method on wheat germination and seedling characteristics, when 12 measured characteristics were monitored. Extracts from all three species of Reynoutria sp. generally showed an improvement in wheat germination and growth compared to the control. R. × bohemica appears to be the best source for stimulating wheat growth, as seedling vigor indexes I and II, R/S dry weight, shoot and seedling lengths, root, shoot, and seedling dry weights were significantly different (ANOVA, Duncan's test, α < 0.05). The plants Reynoutria spp. seem to be possible sources for the protection and stimulation of agriculture crops.

Application of magnesium-containing fertilizers by priming method for regulation of physiological processes in winter wheat

The studing the efficiency of new magnesium-containing fertilizer “AktiMax” use for priming soft winter wheat seeds of the “Skipetr” variety. The effect of the fertilizer is compared with the negative (no fertilizer) and positive (“Novosil”) controls. During the study, the optimal concentration 2.6 ml/l of the solution for processing by the selected method is found, which is equivalent to 20% of the recommended by the manufacturer (13 ml/l). At treating with a solution of this concentration, a slight decrease in seed germination is observed, and growth parameter records taken after 7 days showed an increase in leaf length by 15–20%. A slight decrease in the number of roots (by 10%) and branching of the root system is observed, which is presumably due to the availability of the fertilizer components. The effect fertilizer on the photosynthetic apparatus, carbon dioxide assimilation and transpiration rate when use in a range of concentrations is studied. On average, the transpiration activity increased by 2 times in the variant with the working concentration and by 1.8 times in the variant with one fifth of the working concentration. A slight increase in the efficiency of non-photochemical fluorescence quenching is revealed in plants at the “AktiMax” application. The efficiency of seed priming method use to stimulate the rate of winter wheat development is demonstrated that leads to reduction of unfavorable outcomes risks.

Efficacy of Different Priming Methods on Germination and Growth of French Bean (Phaseolus vulgaris L.) Under Field Conditions in Mugu, Nepal

Low seed germination and poor growth have been major problems in French bean production in the hilly region of Nepal. An effective solution may lie in seed priming, which enhances rapid and uniform seed emergence, thereby improving yield. A field experiment was conducted to find out the effect of different seed priming methods on various varieties of French beans under field conditions in Chhaayanath Rara-4, Mugu, Nepal. The experiment was conducted in two factorial RCBD with three replications. Factor A was three French bean varieties; black, ghoratte, and red beans, and Factor B included two methods of priming; hydro and halo along with control. The results revealed that the germination parameter was significantly influenced by the method of priming and it was found non-significant in the case of varieties. Maximum germination percentage and higher speed of germination were found in seeds treated with hydro-priming. Similarly, the growth parameter was found significant for both varieties as well as priming methods. Vegetative growth parameters such as plant height, number of leaves, and number of primary and secondary branches were found significantly higher in hydro-primed seeds and ghoratte variety. Likewise, the yield parameters such as days to first flowering, days to 50% flowering, and yield per hectare were found significantly higher in hydro-primed ghoratte beans. Hence, hydro-priming can be used as a simple and cost-effective technique to improve germination and growth of French beans along with suitable variety under field conditions in Mugu district, Karnali province, Nepal. Int. J. Appl. Sci. Biotechnol. Vol 12(3): 137-144.

Impact of conservation tillage practices in rice-blackgram cropping system

Field experiments were conducted with two tillage practices in rice (Puddled and Non- puddled) during rainy season and three seed priming methods (Bio- seed priming with Rhizobium, hydropriming and no seed priming) and two foliar spray (2% DAP and 2% urea) during post rainy seasons in blackgram. The results indicated that the soil penetration resistance was found to be lesser in the soils of non-puddled tillage. The rice yield reduction due to NPTR was non-significant (less than 3 per cent). However, the soil penetration resistance was higher with the soils of blackgram sown as succeeding crop in the PTR. The blackgram yield obtained under NPTR was 10.6 per cent higher than PTR system. Bio seed priming with Rhizobium increased the yield by 26.0 per cent over no seed priming. The study indicated that NPTR showed a positive impact on the yield in the rice-blackgram relay cropping system. Bangladesh J. Bot. 53(3): 519-525, 2024 (September)

ENHANCING GERMINATION AND SEEDLING VIGOR IN NIGELLA SATIVA: THE IMPACT OF NANO IRON OXIDE AND PHOSPHORUS PRIMING

Nigella sativa, commonly known as black cumin, is known for its health benefits due to its rich content of compounds like thymoquinone. This study explored the effects of various seed priming methods on Nigella sativa seeds, including control (unprimed), distilled water, nano iron oxide (Fe₂O₃), phosphorus (P), and a combination of Fe₂O₃ and P. We assessed how these treatments influenced several key aspects of seed germination: germination rate (GR), mean germination time (MGT), germination index (GI), coefficient of velocity of germination (CVG), and vigor index (VI).Our results showed that seeds treated with Fe₂O₃ nanoparticles had the highest germination rate at 93.5% and germinated faster than seeds from other treatments. This suggests that Fe₂O₃ nanoparticles effectively speed up the germination process. However, despite the improved germination rate, the seeds treated with Fe₂O₃ did not exhibit the highest seedling vigor; the control seeds had the highest vigor index, indicating that while Fe₂O₃ accelerates germination, it does not enhance seedling health as much as the untreated seeds. Additionally, there were no significant differences in the germination index and coefficient of velocity of germination between the treatments, suggesting these parameters were less influenced by the priming methods.In summary, nano-priming with Fe₂O₃ is effective for speeding up seed germination but does not necessarily improve seedling vigor. These findings provide valuable insights into how different priming techniques can be optimized to enhance seed performance and plant growth under various conditions.

Seed priming as a promising technique for sustainable restoration of dryland

The success of plant growth and development in dryland restoration relies on seed germination, seedling development, and establishment. The lack of rainfall and extreme temperature variations in arid regions impede germination and seedling establishment, necessitating new approaches and techniques. The present review summarizes the vital role of seed priming techniques for the sustainable restoration of drylands through their effects on enhancing seed germination, seedling growth and development, plants' nutrient use efficiency, soil fertility, essential enzymes, microbial community, and stress adaptation ability, helping to alleviate the effects of abiotic stresses on plants. The importance of seed priming is discussed in both agricultural and ecological restoration contexts. Priming maximizes crop yields, reduces crop failure, and promotes eco‐friendly farming practices. In ecological restoration, seed priming enhances plant establishment and survival, contributing significantly to the restoration of native vegetation and wildlife habitats. The review categorizes seed priming techniques into six subcategories, highlighting their unique advantages for optimizing restoration efforts. The review highlights the underlying mechanisms of seed priming techniques to improve seed germination and plant development in dryland regions, particularly under salinity and drought constraints. While seed priming has proven effective, it also faces several limitations, such as cost, seed longevity, and environmental concerns. Investigating environmentally friendly priming methods and understanding the prolonged effects of priming on seed viability and the environment is crucial. Further research is needed to find cost‐effective, eco‐friendly seed priming methods, and to explore the genetic and molecular bases of stress tolerance in various plant species across diverse environments.

Seed priming methods tested on Salvia officinalis L. germination according to BBCH scale

Seed dormancy is a major impediment for the production of Salvia officinalis L. (sage) seedlings. This study aims to test seed priming methods to break the dormancy of sage seeds in controlled conditions. Seeds were subjected to four treatments respectively hydropriming, magneto-priming, electro-priming and control with no seed priming techniques. During germination development stage all parameters were registered according to BBCH (Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie) standardized scale. Daily assessments were made, germination indices were calculated, new germination secondary stages were observed and described, and daily range for each secondary stage were obtained. All priming methods had different effect on sage seeds. The hydropriming treatment was the most effective with 70% seeds germinated in 10 days. Sage seeds from magneto-priming determine more than 50% seeds to germinate in only 8 days. Control and electropriming treatment showed a similar value of seed germination, set around 64-65%. In control, electro- and hydropriming treatments are necessary 6 days for the achievement of more than 50% seed germination, while for magneto-priming are necessary 8 days. Hydropriming has the highest germination index, significantly higher than control and magneto-priming. During the germination, hydropriming shows a gradual transition of seeds from one BBCH sub-stage to another, while electro- and magneto-priming induce a heterogenous variation through the entire process. Overall, the hydropriming treatment registered better results of sage germination compared to the control treatment.

Bio-Priming of Seed with Trichoderma sp. and Bacillus sp. Leads to Improved Morpho-Physiological Parameters Related to Drought Tolerance in Maize

Maize (Zea mays L.) holds an important position as a major grain crop in Pakistan flourishing across a diverse range of environmental conditions. The maize crop encounters various severe abiotic challenges with drought being the most concerning factor leading to diminished plant growth and yield. Seed priming a well-established and widely adopted technique serves as an effective mechanism to alleviate drought stress ultimately boosting both growth and grain yield. The primary objective of this study was to evaluate the impact of diverse seed priming methods on the growth and development of maize plants. Additionally, the study sought to assess the potential of various seed priming techniques in mitigating drought stress in maize. A pot experiment was conducted using a completely randomized design under natural conditions. The aim was to scrutinize the influence of different priming agents on morpho-physiological traits associated with water deficit conditions in maize. The gathered data underwent ANOVA analysis revealing variations in all parameters for both maize varieties at a 5% probability level. Specifically, the Pak-Afgoi variety displayed notable responsiveness to the seed priming approach in alleviating drought stress in maize. Furthermore, the findings underscored the evident and substantial impact of seed priming on both maize varieties across a range of studied characteristics under drought stress conditions. In conclusion, the present study suggests that seed priming holds the potential to enhance drought tolerance in maize.

BamFx Induced Resistance by Seed Priming Method against Fusarium sp. in Cajanus cajan (L.) Mill sp.

Background: Pigeon pea [Cajanus cajan (L.) Mill sp.] enriches the soil through symbiotic nitrogen fixation. The pigeon pea plants are susceptible to a number of pathogenic fungi including Aspergillus sp. and Fusarium sp. Bam-FX® is a micromineral formulation that directly affects the physiological mechanisms and innate immune system of plants to help them overcome both abiotic and biotic stresses without the need for any form of genetic modification. Methods: In this study, we have tested different dilutions to soak the pigeon pea seeds. On 21th day, optimum germination (94%) was found in seeds treated with BamFX (1:1000) compared to 75% germination in untreated seeds. Result: The fungi were isolated from the soil and identified using 18s rRNA gene sequencing. The seedlings in BamFx treated groups were found resistant to pathogenic fungi, whereas, more than 97% in the untreated groups were found infected or diseased. The increased germination efficiency and resistance to fungal infections in BamFx treated seedlings proved a priming effect due to BamFx in pigeon pea seeds.

Effect of organic seed priming on germination and growth of bhendi (Abelmoschus esculentus L. Moench) in coastal saline soil

An experiment was conducted in the Vegetable Unit, Department of Horticulture, Annamalai University, Chidambaram, Tamil Nadu during 2022 to find out the effective seed priming method in bhendi. The experiment was carried out in Complete Randomized Design (CRD) which includes different organics in different concentrations viz., Panchagavya @ 2% and @ 4%, Cow urine @ 2% and 4%, Vermiwash @ 0.1% and 0.25%, Beejamrutham @ 2% and 4%, Coconut water @ 25% and 50% and Control. The results of the experiment demonstrated that among the organic seed priming evaluated, Coconut water @ 50% has resulted in a higher germination percentage, speed of germination,shoot length,root length,seedling length,seedling fresh weight,dry weight and seedling vigour index.

Impact of Priming with UV Radiation on Seed Germination and Seedling Growth of Chakhao Rice Cultivar

The development of eco-friendly technology with innovative ideas is always essential to enhance plant growth and improve yield in a sustainable manner. Seed priming methods such as conventional and physical priming are well-known pre-sowing techniques that are considered to be effective in improving the growth and yield of a crop. In view of this, an experiment was conducted to study the impact of physical priming with non-ionizing radiation like UV-C on seed germination and early seedling growth of Chakhao cultivars of rice (Oryza sativa). Three Chakhao rice cultivars namely Black (Amubi) - V1, Red (Angangbi) - V2, and White (Angoubi) - V3 were used, and seeds were initially exposed to UV-C (8.32 KJm-2) radiation for 3 hours. Then seeds were soaked in water at 28 ± 2 ºC for 2 days and the emerging seedlings were again treated with UV-C (8.32 KJm-2) for different durations i.e. 30 mins (T3), 45 mins (T4) and 60 mins (T5). Seeds without any UV-C treatment (T1) and only seed treatment for three hours (T2) were taken as control. The data on germination rate, speed of germination, root length, shoot length, and seedling vigor index were recorded as per standard procedures. The study found that all three types of rice, V1, V2, and V3, had the highest germination percentage (71.07%, 73.63%, and 69.71%), speed of germination (9.53 days, 9.40 days, and 9.320 days), shoot length (9.83 cm, 8.43 cm, and 10.70 cm), root length (9.03 cm, 6.40 cm, and 8.97 cm), and seedling vigor index (1688.50, 1570.23, and 1729.13) when treated with UV-C for 60 minutes followed by 45 minutes of seedling treatment. This indicates that UV-C seed priming is an effective method for enhancing the growth of rice seedlings.

Enhancing growth and yield parameters of Sinapis alba through optimized seed priming techniques

AbstractEarly seed germination significantly influences crop growth and production, prompting the exploration of seed priming as a pivotal technique. Despite the acknowledged importance of faster germination and emergence for successful seedling establishment, oilseed crops like Sinapis alba have received limited attention concerning seed priming methods, unlike cereal and grain crops. This study aimed to bridge this gap by subjecting S. alba seeds to six priming treatments: T1 = control, T2 = distilled water, T3 = NaCl (0.5%), T4 = KNO3 (0.5%), T5 = CaCl2 (0.5%), and T6 = Moringa leaf extract at a 1:30 ratio (30 times diluted), to assess their impact on various growth and yield parameters. The data analysis revealed significant effects of seed priming on various parameters, with exceptions in plant height unaffected by seed soaking. Seed priming notably enhanced germination percentage, germination rate index, and seedling vigor index, while reducing mean germination time to emergence significantly. Furthermore, primed seeds exhibited significant increases in seedling fresh and dry weights, crop growth rate, net assimilation rate, root and shoot lengths, leaf area, chlorophyll content, early flowering, branch numbers, pod counts, and 1000‐seed weight compared to non‐primed seeds. The biological yield was relatively higher in treated seeds. Additionally, seed yield and oil content were found to be higher in primed seeds compared to the control. Among the treatments, KNO3 along with Moringa, displayed the most desirable outcomes across overall seedling parameters, suggesting their recommendation for effective priming treatments to improve the growth and yield of S. alba.

Screening of Bacillus sp. (OQ654027) Mediated Seed Bio-priming Enhance Plant-Growth-Promotion for Sustainable Crop Production of Groundnut and Chickpea

Plant growth-promoting bacteria are valuable microbes that enhance the plant growth, development, and yield. Several seed priming methods are able to improvise seed germination, seedling potency, to overwhelmed abiotic stress and biotic stress management which gets prime attention. Generally, plant-growth promoting bacteria are utilized for biopriming technique that is able to survive under stress environmental conditions. The aims of the present investigation were to screening ofKC9bacterial isolate as PGPB in groundnut and chickpea and study the effects ofKC9 bacterial isolation seed, seedling germination and growth during the development of both seeds. In this study KC9 has been isolated from the soil sample of chickpea crop field at Saurashtra region. Preliminary screening was conducted based on their identification via morphological, biochemical i.e., catalase, starch hydrolysis, sugar utilization, motility, IMViC test, gram’s nature and by 16S rRNA gene nucleotide sequences and identified as Bacillus sp. that has been submitted to the NCBI for Accession number. Further examine the production of indole acetic acid (IAA), Ammonia (NH3), HCN, Siderophore and Phosphate solubilization. KC9 (Bacillus sp.) was recognized as most efficient plant-growth promoting bacteria. For the pot experiment seed biopriming method is employing to coat the seeds of chickpea and groundnut with Bacillus inoculant consider as treated and seeds sown with double distilled water as control. Bacillus coated seed biopriming also minimize the seed germination time period that takes only 3-4 days to proper seed radicle development. By the statistical approach of paired t-test of pot experiment on chickpea and groundnut seeds and seedlings were treated with Bacillus strain exhibited significantly higher levels at of seed germination, seedling growth via root length, shoot length and number of leaves in compared to non-treated control plants. In this present investigation , impact of seedling germination on the inoculated condition with KC9 of groundnut and chickpea, determining remarkable changes in total chlorophyll content (11.81 µg/g and 10.40 µg/g), relative water content(RWC) obtained 86% and 83%., total free amino acids (92.14±0.03µg/ml whereas 37.5±0.02µg/ml), total phenolic acid content (76.28±0.03mg GAE/100g and chickpea is 52.83±0.08 mg GAE/100g) and total flavonoid content increases with the treatment of KC9 (Bacillus sp.) 626±0.05QE/100g is recorded in groundnut seedlings and chickpea is 0.085±0.01QE/100g respectively.

Impact of bio-priming (Rhizobium leguminosarum ) to improve seedling vigour and germination potential to overcome abiotic stress in green gram

Diverse seed priming methods are used to ameliorate seed germination, seedling vigour, and to overcome abiotic stress. Insertion to these, only the bio-priming system provides the fresh benefit of biotic stress operation, earning it special attention. Bio-priming is applicable in nearly all crops around the world and is an environmentally friendly volition to chemical pesticides. Seed bio-priming generally refers to use of salutary microorganisms to influence germination potential. In this study, Rhizobium leguminosarum were used in different concentration following Complete Randomized Design with three replications. Green gram (TMB-37) was collected from AICRP pulses in BCKV, Mohanpur, Nadia, West Bengal for this investigation. The experiment comprised of seven bio-priming treatments along with control. The seeds were subjected to in-vitro studies and data were analysed statistically. Seed bio-primed with Rhizobium leguminosarum @ 20 percent recorded higher seed germination percentage (82.71 %), shoot length (25.49 cm), seedling fresh weight (2.77 g), seedling dry weight (0.24 g), seedling vigour index I (3467.91) and seedling vigour index II (19.85). The results of this study demonstrated that Rhizobium leguminosarum @ 20 percent was the best.

A novelmicronutrients and methyl jasmonate cocktail of elicitors via seed priming improves drought tolerance by mitigating oxidative stress in rice (Oryza sativaL.).

Drought is a major limiting factor for rice (Oryza sativa L.) production globally, and a cost-effective seed priming technique using bio-elicitors has been found to have stress mitigating effects. Till date, mostly phytohormones have been preferred as bio-elicitors, but the present study is a novel attempt to demonstrate the favorable role of micronutrients-phytohormone cocktail, i.e., iron (Fe), zinc (Zn), and methyl jasmonate (MJ) via seed priming method in mitigating the deleterious impacts of drought stress through physio-biochemical and molecular manifestations. The effect of cocktail/priming was studied on the relative water content, chlorophyll a/b and carotenoid contents, proline content, abscisic acid (ABA) content, and on the activities of ascorbate peroxidase (APX), superoxide dismutase (SOD), NADPH oxidase (Nox), and catalase (CAT). The expressions of drought-responsive genes OsZn-SOD, OsFe-SOD, and Nox1 were found to be modulated under drought stress in contrasting rice genotypes -N-22 (Nagina-22, drought-tolerant) and PS-5 (Pusa Sugandh-5, drought-sensitive). A progressive rise in carotenoids (10-19%), ABA (18-50%), proline (60-80%), activities of SOD (27-62%), APX (46-61%), CAT (50-80%), Nox (16-30%), and upregulated (0.9-1.6-fold) expressions of OsZn-SOD, OsFe-SOD, and Nox1 genes were found in the primed plants under drought condition. This cocktail would serve as a potential supplement in modern agricultural practices utilizing seed priming technique to mitigate drought stress-induced oxidative burst in food crops.

Effect of Seed Priming and Moisture Conservation Measures on Growth and Yield of Baby Corn (Zea mays L.) under Rainfed Upland Situation

A field experiment was conducted during rabi, 2019-20 and 2020-21 at the PG experimental plot of the Department of Agronomy, BNCA to assess seed priming and moisture conservation measures on productivity and profitability of baby corn under the rainfed situation. The soil of the experimental site was acidic (pH 4.64), sandy loam in texture, medium in organic carbon (0.64%), low in available N (232.06 kg ha-1), P2O5 (13.84 kg ha-1) and K2O (115.27 kg ha-1). The experiment was laid out in factorial randomized block design with 4 levels of seed priming methods. S0: No priming; S1: Seed priming with 1% urea solution; S2: priming with 1% potash solution (MOP); S3: priming with 3 times diluted cow urine and 3 levels of soil moisture conservation measures viz. M0: No mulching; M1: use of bio mulch; M2: use of black polythene mulch. Results revealed that the highest and quickest seedling emergence (11.96 numbers m-2) was recorded under the treatment of seed priming with three times diluted cow urine which was at par with the treatment of seed priming with 1% urea and 1% KCl (MOP) solution. The total number of leaves m-2, total leaf area plant-1 and leaf area index (LAI) of baby corn were also changed significantly due to different moisture conservation measures but those parameters remain static due to different seed priming methods. The CGR (g m-2 day-1), RGR, (g g-1 day-1) and NAR (mg cm-1 day-1) of baby corn were also changed significantly due to different soil moisture conservation measures. The highest and most significant baby corn yield without husk(22.59 q ha-1) with 305.61 q ha-1 of green fodder yield along with harvest index (6.00), production efficiency (25.67 kg‑1 day-1 ha-1) and nutrient use productivity (9.41 kg‑1 ha-1 kg-1) were recorded under the treatment where black polythene mulching was used as soil moisture conservation measure.

Priming methods affected deterioration speed of primed rice seeds by regulating reactive oxygen species accumulation, seed respiration and starch degradation.

Seed priming is a pre-sowing seed treatment that is beneficial for rice seed germination and seedling growth, but the reduced seed longevity after seed priming greatly limited its adoption. The deterioration of primed seeds showed large differences among different studies, and the priming method might play an important role in regulating the deterioration speed of primed seeds. However, whether and how the priming method affected the deterioration of primed rice seeds during storage remains unknown. In this study, two typical seed priming methods, namely hydropriming (HP) and osmopriming (PEG) were compared under artificially accelerated aging conditions, the changes in germination performance, starch metabolism, seed respiration and reactive oxygen species accumulation before and after accelerated aging were determined. Hydroprimed rice seeds exhibited significantly faster deterioration speed than that of PEG-primed seeds in terms of germination speed and percentage. Meanwhile, α-amylase activity and total soluble sugar content in hydroprimed seeds were reduced by 19.3% and 10.0% respectively after aging, as compared with PEG-primed seeds. Such effects were strongly associated with the increased reactive oxygen generation and lipid peroxidation, as the content of superoxide anion, hydrogen peroxide and malondialdehyde in hydroprimed seeds were 4.4%, 12.3% and 13.7% higher than those in PEG-primed seeds after aging, such effect could be attributed to the increased respiratory metabolism in hydroprimed seeds. In addition, the simultaneous use of N-acetylcysteine with HP and PEG priming greatly inhibited the deterioration of primed rice seeds, suggesting that the ability to scavenge reactive oxygen species may be the key factor affecting the speed of deterioration in primed rice seeds during storage.

Biosolubilized zinc from ZnO in bacterial culture supernatant enhanced seed germination, early growth, and zinc accumulation in rice (Oryza sativa L.) under hydroponic system through seed priming method

Presently, zinc sulfate (ZnSO4) based fertilizers are reported inefficient in flooded paddy fields which necessitates to find a better alternative for sustainable rice cultivation. This study was conducted to find out the effectiveness of bacterially solubilized Zn (BSZn) on the early growth of rice plants and the concentration of Zn in the plant parts in comparison to conventional ZnSO4. BSZn preparations were obtained from culture supernatant following ZnO solubilization by bacterial isolates Burkholderia spp. and Achromobacter sp. The effectiveness of BSZn was assessed on rice seed germination on Petri plates and the growth of seedlings upon treatment in hydroponic culture under controlled conditions. In general, BSZn obtained from certain Burkholderia spp. increased seed germination percentage (SG%) (98–100%), mean germination rate (MGR), mean daily germination (MDG), decreased mean germination time (MGT) and impart stimulating effect on seed germination as indicated by increased vigor indices compared to ZnSO4 treatment regimes. The obtained data from the hydroponic culture of rice seedling growth indicated a positive influence of most of the BSZn preparation on dry and wet weight of roots and shoots, and seedling length compared to ZnSO4 at p < 0.05. Both chlorophyll and carotenoid content of the seedling increased in the presence of some BSZn preparations. In general, compared to shoot, the root of seedlings accumulated a higher amount of Zn (up to 888 µg Zn/g dry biomass). Zn concentration data indicated that BSZn16 obtained from Burkholderia sp. EIKU16 culture help to accumulate significantly higher amounts of Zn in rice seedlings under hydroponic culture than that while treated with ZnSO4.

Seed germination and vegetative propagation of Helichrysum odoratissimum

Helichrysum odoratissimum is a popular indigenous herb of South Africa, well known for its aromaticity. It offers potential as a source of extracts for the development of cosmeceutical products as it has been reported to be a natural antibiotic, and has antifungal, antimicrobial, antioxidant and antiviral properties. In order to be commercialized, a sustainable production system is required to ensure a consistent supply of good quality material. Therefore, the production of H. odoratissimum by seed and stem cutting was evaluated. The interactive effect of different seed priming methods and temperature levels were investigated on germination indices of H. odoratissimum seeds. A randomized complete block design with three replicates was used to evaluate the effect of season, cutting position, rooting hormone and growth media on survival percentage, number of buds, number of leaves, rooting percentage, number of roots per cutting and root length of H. odoratissimum stem cuttings. Data for both aspects was analysed using ANOVA and means with significant differences were separated with a t-test at 5% level of significance. Smoke treated seeds incubated at 20 °C had a significantly higher germination percentage (91,7%), mean germination rate (0.59) and coefficient velocity of germination (59.5) compared to most other treatments. Almost all factors tested in vegetative propagation significantly affected parameters measured. Apical cuttings taken during autumn resulted in significantly higher survival (78.5) and rooting percentages (71.1%) compared to other seasons. Cuttings planted in a perlite, vermiculite and sand mixture during autumn significantly outperformed all other season/media combinations with regards to rooting percentage (75%). PGR application improved the number of roots obtained significantly in autumn and winter, but not in summer and spring, compared to the control. It was therefore concluded that, for higher seed germination H. odoratissimum seeds must be primed with smoke water and incubated at 15–20 °C and cuttings may be taken autumn for higher rooting and survival rates as well as improved root length. A PGR application can be beneficial depending on the type of medium used.