Seedling Vigor Research Articles

DROUGHT STRESS ALLEVIATION: THE CONTRIBUTION OF A SOIL BACTERIUM AND AN ARBUSCULAR MYCORRHIZAL FUNGUS IN SCALLION

Recent climate change and global warming have caused extreme heat and low rainfall which negatively affected soil nutrient, fertility status, decreased water content, and changed physiochemical properties of agricultural soils in many parts of the globe. As a result of drought, crop production is seriously reduced. The beneficial effects of soil microorganisms including arbuscular mycorrhizal fungi and rhizospheric bacteria on crop production and soil health are vital for the sustainable management of stressed agricultural practices. The present study evaluated the effects of an arbuscular mycorrhizal fungus, Rhizophagus irregularis, and a rhizospheric bacterium, Pseudomonas flourescens, alone and in dual inoculation on the survival, growth, mycorrhizal colonization, nutrient uptake, glomalin production, and soil aggregation of Allium fistulosum plants. In water-stressed soil, seedling survival, growth, total biomass, nutrient uptake, glomalin production, and soil aggregation were significantly increased when inoculated with R. irregularis and P. flourescens. Dual inoculation with R. irregularis and P. flourescens produced vigorous seedlings which contained higher amount of nitrogen, phosphorus, potassium contents, glomalin production, and soil aggregation compared to single inoculation. The present results indicate that arbuscular mycorrhizal fungi and beneficial rhizospheric bacteria offer potential for biofertilizers and mitigating drought in A. fistulosum plants.

Ecofriendly Management of Dry Root Rot in Black Gram Caused by Macrophomina phaseolina

In the present study Trichoderma asperellum (ECK), Trichoderma asperellum (TNAU), Streptomyces sp (native) and Pseudomonas fluorescens (TNAU) were tested in vitro by dual culture technique. Among the six treatments Trichoderma asperellum (ECK) and Streptomyces sp (native) was found to be more effective as compared to other bio-control agents and inhibited maximum fungal growth (100 %) of Macrophomina phaseolina followed by Trichoderma asperellum (TNAU) (81.6 %). The disease incidence controlled by all other isolates was ranged from 67.72 to 81.66%. The growth promoting activity of various bio-control agents and chemical was assessed based on seedling vigour index by standard Roll Towel Method (ISTA,1993). The treated seeds and controls are placed on the pre-soaked germination paper. After one-week various growth parameters like root length, shoot length, vigour index are determined by using the formulae. The seeds treated with Trichoderma asperellum (ECK) and Streptomyces sp (native) exhibited increased yield parameters like increased germination percentage, root length, shoot length, and Seedling vigour index 2562.0. Under field conditions the seeds are treated with different biocontrol agents and carbendazim. The various growth parameters like root length, shoot length and seedling vigour index observed under field conditions. Streptomyces sp (native) was found to be most effective in reducing pre and post emergence mortality and also it enhances the yield than other treatments. In field trail among the six treatments, treatment containing seed treatment of Streptomyces sp (native) was found to be most effective in reducing pre and post emergence mortality with germination of 87.0 %. Streptomyces sp (native) was found to be more effective as compared to other bio-control agents in increasing the yield parameters like root length, shoot length, and seedling vigour and also it enhances the yield (322.8 Kg/ha) compared to other treatments. Streptomyces sp (native) needs further species level characterization and other biotrophic and tritrophic interaction studies for developing commercial formulation.

Seed priming and GA3 field application enhanced growth, yield and postharvest quality of okra

Highly nutritive and antioxidants-enriched okra (Abelmoschus esculentus) gets sub-optimal field yield due to the irregular germination coupled with non-synchronized harvests. Hence, the research aimed at assessing the combined impact of seed priming and field-level gibberellic acid (GA3) foliar spray on the yield and post-harvest quality of okra. The lab studies were conducted using a complete randomized design (CRD), while the field trials were performed following a factorial randomized complete block design (RCBD) with three replications. Okra seeds were subjected to ten different priming methods to assess their impact on seed germination and seeding vigor. In the premier step, okra seeds were subjected to ten different priming methods, like hydro priming for 6, 12, and 18 h, halo priming with 3% NaCl at 35 ℃, 45 ℃, and 60 ℃, acid priming with 80% H2SO4 for 2.5, 5, and 10 min. Based on the observation, hydro priming for 12 h exhibited the best germination rate (90%), followed by halo seed priming at 60 ℃ and acid priming for 5 min. Furthermore, the halo priming at 60 ℃ demonstrated the greatest seedling vigor index (1965), whereas acid priming for 5 min resulted in favorable outcomes in terms of early emergence in 2.66 days. In addition, varying concentrations of GA3 (0, 100, 200, and 300 ppm) were also administered to the best three primed seedlings for evaluating their field performance. The findings indicated that applying GA3 at a concentration of 300 ppm to seedlings raised through acid priming (80% H2SO4 for 5 min) resulted in improved leaf length, reduced time to flowering (first and 50%) and harvest, increased pod diameter, individual pod weight, and yield per plant (735.16 g). Additionally, the treatment involving GA3 at 300 ppm with halo priming (3% NaCl) at 60 ℃ exhibited the longest shelf life (21 days) of okra with the lowest levels of rotting (6.73%) and color change (1.12) in the polyethylene storage condition.

Impact of Seed Priming on germination and Seedling Vigor in Coreopsis tinctoria and Callistephus chinensis

Impact of Seed Priming on germination and Seedling Vigor in Coreopsis tinctoria and Callistephus chinensis

Germination and Seedling Properties of Lotus corniculatus L. Under Simulated Drought Stress

Drought is an important abiotic stress factor that reduces agricultural production and yield in many crops, including forage crops, in agricultural areas around the world. Lotus corniculatus L. is the agriculturally crucial perennial legume forage crop that can tolerate moderate drought. However, studies to determine the responses of L. corniculatus to drought are limited. Therefore, this study was carried out to determine the seed germination and early seedling growth properties of L. corniculatus at different PEG6000 induced-drought treatments under in vitro conditions. In order to do this, L. corniculatus (cv. ‘AC Langille’) seeds were planted in MS (Murashige and Skoog/Gamborg) medium containing 0%, 4%, and 8% (w/v) PEG6000 for 14 days. In this study, germination percentage, mean germination time, germination rate index (speed of germination), shoot and root length, root to shoot length ratio, shoot and root fresh weight, shoot and root dry weight, shoot and root dry matter ratio, root shoot dry matter ratio, shoot and root water content and seedling vigor index parameters were measured. Our results showed that increasing drought levels resulted in an overall significant reduction in germination and seedling growth parameters except shortened mean germination time (especially, 4% PEG6000 treatment) and increased shoot and root dry matter ratio at higher (especially, 8% PEG6000 treatment) drought levels. When important growth parameters such as length, fresh and dry weight, dry matter ratio and water content, which show the development of root and shoot organs, are evaluated together, it has been determined that the root is negatively affected by drought stress at a higher rate. Based on these data, it can be concluded that the L. corniculatus will suffer a high yield loss under the drought stress at the osmotic potential (-1.03 bar) created by 8% PEG6000 treatment.

Response of nine triticale genotypes to different salt concentrations at the germination and early seedling stages.

Salinity stress poses a major challenge to agricultural productivity worldwide, and understanding their responses at the early growth stage is vital for devising strategies to cope with this stress. Therefore, to improve triticale productivity, this study investigated the salinity stress tolerance of different salt-tolerant triticale genotypes aiming to cultivate them on saline soils. To this end, salinity stress impacts on nine triticale genotypes, i.e., Zhongsi 1084, Gannong No. 2, Gannong No. 4, Shida No. 1, C6, C16, C23, C25 and C36 at germination and early seedling stages was evaluated. Each genotype was subjected to six treatments inducing control, 40, 80, 120, 160, and 200 mM NaCl treatments to study their effect on seedling and termination traits of the nine genotypes. Compared to the overall mean seedling vigor index, the seedling vigor index was higher in the genotypes Zhongsi 1084 and C6 (39% and 18.1%, respectively) and lower in Gannong No.2 (41%). Increasing NaCl concentrations negatively affected germination and seedling traits. Compared to other genotypes, Zhongsi 1084 had the highest mean germination rate, germination vigor index, germination percentage, mean daily germination and germination energy. It also showed the lowest relative salt injury. The relative salt injury was higher in the genotype Shida No. 1 than those in Gannong No. 2, Gannong No. 4, Shida No. 1, C16, and C36 genotypes. All genotypes exhibited desirable mean germination time except for line C6. High significant positive correlations were observed among germination rate, germination vigor index, germination percentage, mean daily germination, seedling vigor index, and root length. Principal component analysis (PCA) grouped the most desirable genotypes into two clusters. Our study determined salt stress tolerance of nine triticale genotypes at germination and early seedling stages. to select salt-tolerant genotypes that can be cultivated on saline soil or after salt irrigation.

Physiological impact of heat stress and their alleviation measures in agriculture: A review

Abiotic stresses are becoming more prevalent in modern agriculture as a result of shifting climate scenarios. Elevated temperature stress is one of the most important abiotic stresses to address since it has detrimental consequences for plant physiology, molecular structure, and phenology. The morphological impact occurs in the form of reduced germination, poor emergence, poor seedling vigor, abnormal seedling. Heat stress also results in the closure of stomata, reduced leaf size and consequent increase in stomatal density. One of the major physiological impacts of heat stress is on the fluidity of the membrane structure of the plant cell. Heat stress leads to increased fluidity of the thylakoid membrane and disruption of metabolic functions, which either deliver or accept electrons from PSII and, thus, cause dislodging of PSII from thylakoid membrane. The respiration generally increases in the temperature range of 0-35/ 40⁰C, reaches plateau at 40-50⁰C and decreases beyond 50⁰C due to damage to the respiratory mechanism. Elevated temperature directly impacts the cellular water content and indirectly through the increased water depletion rate from the soil. In order to design the appropriate corrective actions, it is crucial to research all the factors leading to heat stress thoroughly. The traditional agronomic and breeding interventions are crucial, but the rising food demand and the intensifying heat stress call for some cutting-edge biotechnological interventions, such as transgenics, genome editing, and CRISPR/cas9, to induce genome-level heat tolerance. The present review deals in detail with each of the previously listed aspects.

OsJMJ718, a histone demethylase gene, positively regulates seed germination in rice.

Seed vigor has major impact on the rate and uniformity of seedling growth, crop yield, and quality. However, the epigenetic regulatory mechanism of crop seed vigor remains unclear. In this study, a (jumonji C) JmjC gene of the histone lysine demethylase OsJMJ718 was cloned in rice, and its roles in seed germination and its epigenetic regulation mechanism were investigated. OsJMJ718 was located in the nucleus and was engaged in H3K9 methylation. Histochemical GUS staining analysis revealed OsJMJ718 was highly expressed in seed embryos. Abiotic stress strongly induced the OsJMJ718 transcriptional accumulation level. Germination percentage and seedling vigor index of OsJMJ718 knockout lines (OsJMJ718-CR) were lower than those of the wild type (WT). Chromatin immunoprecipitation followed by sequencing (ChIP-seq) of seeds imbibed for 24 h showed an increase in H3K9me3 deposition of thousands of genes in OsJMJ718-CR. ChIP-seq results and transcriptome analysis showed that differentially expressed genes were enriched in ABA and ethylene signal transduction pathways. The content of ABA in OsJMJ718-CR was higher than that in WT seeds. OsJMJ718 overexpression enhanced sensitivity to ABA during germination and early seedling growth. In the seed imbibition stage, ABA and ethylene content diminished and augmented, separately, suggesting that OsJMJ718 may adjust rice seed germination through the ABA and ethylene signal transduction pathways. This study displayed the important function of OsJMJ718 in adjusting rice seed germination and vigor, which will provide an essential reference for practical issues, such as improving rice vigor and promoting direct rice sowing production.

Thermotolerance of sunflower inbreds using temperature induction response technique

A lab experiment was conducted with 47 sunflower inbreds to evaluate the thermal tolerance at seedling stage using TIR technique. The seedlings are subjected to high temperature stress (HT) with three different temperature treatments control, induction treatment (IT) and lethal treatment (LT). Survival percentage, total seedling length, plumule length, radicle length, seedling weight and seedling vigor index were effected both in IT and LT but the effect was more pronounced in lethal. Based on seed vigor index and percent reduction of total seedling length, inbreds were classified into tolerant, moderately tolerant and susceptible.

Ultra-dry storage extends the viability of groundnut (Arachis hypogaea L.) seeds

In general, the groundnut seed possess short viability. Therefore, an experiment was conducted to extend the storability of seeds by ultra-dry moisture content. The results showed that the groundnut kernels dried to 5% moisture content, vacuum packed in aluminium foil pouch and stored at-200C, -5 0C and 50C maintained the germination above Indian Minimum Seed Certification Standards (>70%) with maximum seedling vigour for the period upto 20 months.

Germination and Seedling Development Performances of Some Soybean (Glycine max (L.) Merrill) Cultivars Under Salinity Stress

The aim of the study was to determine the effects of different salt concentrations on the germination and seedling development parameters of some grain and forage soybean (Glycine max (L.) Merrill) cultivars. The study was conducted under controlled conditions in the Field Crops Laboratory of Faculty of Agriculture in Siirt University. The subject of the research consists of different salt concentrations (S0= 0, S1= 50, S2= 100, S3= 150, and S4= 200 mM NaCl) applied to four different soybean cultivars (Adasoy, Nazlıcan, Yeşilsoy, and Anp-2018). The laboratory experiment was set up in Petri dishes according to the randomized complete parcels design with 4 replications. In the study, germination parameters such as germination percentage (%), mean germination time (days), germination index, germination uniformity coefficient, and germination energy, and some seedling parameters such as radicle and stem length (cm), seedling fresh and dry weight (mg) and seedling vigor index were examined. Significant differences have been found among the examined cultivars in terms of all the parameters considered in the evaluations. Adasoy cultivar came to the fore in germination parameters and Adasoy, Anp-2018, and Yeşilsoy cultivars came to the fore in seedling development characteristics. In the study, the effect of salt concentrations on germination and seedling development parameters (except seedling dry weight) was statistically significant (p

Plant growth promoting rhizobacteria incorporated soilless substrates – A potential arena for high quality nursery production of ornamentals

Nursery raising of ornamental flowering annuals using soilless substrates is becoming a lucrative industry worldwide. Pakistan, being an agricultural country, still doesn't have its own cheaper and sustainable soilless substrates for high quality nursery production. Therefore, a study was conducted at University of Agriculture, Faisalabad, Pakistan and Purdue University, West Lafayette, IN, USA, for development and evaluation of a cheaper, sustainable, and easily available soilless substrate using agricultural by-products along with its value addition by inoculating it with plant growth promoting rhizobacteria. For this purpose, coco-coir, rice hulls ash and composted sugarcane pressmud were combined in ratio of 1:1:1; v/v/v and were inoculated with Bacillus (MN-54), Enterobacter (MN-17) and Trichoderma species in 108 CFU mL−1 and 107 CFU mL−1 solutions. These inoculated treatments along with uninoculated treatment, a negative control (sand: silt; 1:1, v/v) were evaluated for their physico-chemical and nursery raising aspects for ‘Inca’ marigold and ‘Giant Dahlia Flowered’ zinnia. The study revealed that Enterobacter MN-17 (107 CFU mL−1) inoculated substrate had highest water holding capacity (72.9 %), total porosity (81.04 %) and organic matter contents (92.9 %). Whereas, Trichoderma spp. (108 CFU mL−1) inoculated substrate had better electrical conductivity (1.59 dS m−1) and pH (5.64) and resulted in highest final germination percentage (93.6 %), with greatest seedling vigor index (2195), seedling shoot length (10.2 cm), root length (12.5 cm) and leaf total chlorophyll contents (57.4 SPAD) in marigold. However, in zinnia, Enterobacter MN-17 (107 CFU mL−1) inoculated substrate resulted in highest germination percentage (98.3 %), greatest seedling vigor index (3302), seedling root length (15.8 cm) and leaf total chlorophyll contents (55.8 SPAD), whereas same strain with 108 CFU mL−1 took shortest time for mean germination (3.8 days). In conclusion, substrate enriched with Enterobacter MN-17 (107 CFU mL−1) or Trichoderma spp. (108 CFU mL−1) may be used to produce high quality ornamental flowering annuals nursery.

Photosynthetically active radiation is required for seedling growth promotion by volcanic dacitic tuff breccia (Azomite).

A plant's growth and development are shaped by its genome and the capacity to negotiate its environment for access to light, water, and nutrients. There is a vital need to understand the interactions between the plant, its physical environment, and the fertilizers used in agriculture. In this study, a commercially available volcanic ash fertilizer, Azomite®, characterized as dacitic (rhyolitic) tuff breccia, was tested for its effect on promoting early seedling vigor. Early growth and photomorphogenesis processes are well studied in Arabidopsis. Seedling assays under different light conditions were used to dissect the underlying mechanisms involved. These assays are well established and can be translated to agriculturally important crop plants. The volcanic ash fertilizer was tested at different concentrations on seedlings grown on basic media lacking sucrose either in continuous darkness (Dc), continuous Red (Rc), Far-Red (FRc), or White Light (WLc). Micronutrients in the volcanic ash significantly increased seedling growth under Rc and WLc, but not under Dc and FRc, indicating that photosynthetically active radiation was required for the observed growth increase. Furthermore, red-light photoreceptor mutant, phyB-9, lacked the growth response, and higher amount of fertilizer reduced growth in all conditions tested. These data suggest that light triggers the ability of the seedling to utilize micronutrients in volcanic ash in a dose-dependent manner. The methods described here can be used to establish mechanisms of activity of various nutrient inputs and, coupled with whole-genome expression profiling, can lead to better insights into optimizing nutrient field applications to improve crop production.

Determination of the Optimal and Lethal Dose for Mutagenicity of Rice Cultivars by Ethel Methane Sulphate

The experiment was carried out in the laboratories of the Department of Field Crops - College of Agriculture - Al-Qasim Green University to study optimal and lethal doses for mutagenicity of rice (Oryza sativa L.) cultivars by Ethel Methane Sulphate. The experiment design included two factors, the first factor being three cultivars : (V1= Amber 33, V2= Jasmine, and V3= Tigris) and the second factor nine concentrations (E0 = 0, E1 = 0.5, E2 = 1, E3=1.5, E4 = 2, E5 = 2.5, E6 =3, E7 =3.5 and E4 =4, respectively). The treatments were distributed in a factorial experiment according to the design of a complete randomized design (CRD) with three replications. The results obtained showed that the control treatment recorded the highest germination percentage but did not differ significantly from the E1 and E2 treatments, the E2 treatment gave the highest seedling vigor, dry matter production rate, and leaf growth rate, and there were no differences in the rice cultivars in the study in all the studied traits, the interactions were not significant in all the studied traits except the leaf growth rate, the treatment E3×V3, and E2×V2 excelled in the leaf growth rate and gave the highest value, while the E4×V2 treatment had the lowest leaf growth rate.

Effect of Spraying Mother Plant with the Seaweed Extract and Nano-magnesium on Seed Germination and Seedling Vigor of Maize

Effect of Spraying Mother Plant with the Seaweed Extract and Nano-magnesium on Seed Germination and Seedling Vigor of Maize

Effect of Seed Priming Duration with Bio-Stimulator (Appetizer) on Germination Characteristics and Seedling Emergence of Sorghum

Two factorial experiments were conducted. One of them was laboratory experiment which was carried out at the Laboratory of Agricultural Engineering Sciences College, University of Baghdad during 2023. The other was conducted at the lath house with used the pots during spring season of 2023. The aim was to investigate the effect of seed priming duration with bio-stimulator (Appetizer) on germination characteristics and seedling emergence of Sorghum. The design of Lab. experiment was (CRD) while for the other experiment was (RCBD) with four replications. Each experiment consisted of two factors. The first factor included seeds priming treatments with bio-stimulator (Appetizer) concentrations (1, 2 and 3) ml l-1 and seeds soaking in distilled water, in addition to unsoaked seeds treatment (dry seed). The second factor was included seeds priming periods that is (8,16 and 24) h in room temperature. The results of Laboratory experiment showed that sorghum seeds primed with appetizer concentrations 3 ml l-1 gave highest averages of germination percentage in the first count, germination percentage in the final count, radical length, plumule length, seedling dry weight and seedling vigour index. While the comparision treatment (dry seed) gave the lowest averages for these characteristics and the priming period (24h) gave highest averages of germination percentage in the first count, germination percentage in the final count, radical length, plumule length, seedling dry weight and seedling vigour index. The results showed that iteration between the factors (seeds priming treatments with Appetizer and seed priming duration ) has significant effect in most characterstics. The results of pots experiment showed that sorghum seeds primed with appetizer concentrations 3 ml l-1 gave highest averages of emergence percentage in the first count and emergence percentage in the final count. The priming period (24h) gave highest averages of emergence percentage in the first count and emergence percentage in the final count.

Seed priming with humic acid modifies seedling vigor and biochemical response of lentilunder heat stress conditions

Seed priming with humic acid modifies seedling vigor and biochemical response of lentilunder heat stress conditions

Improving ability to germinate and produce vigorous seedlings of tamarind (Tamarindus indica) trees

Improving ability to germinate and produce vigorous seedlings of tamarind (Tamarindus indica) trees

The root of influence: root-associated bacterial communities alter resource allocation in seagrass seedlings

IntroductionSeagrass roots harbour diverse assemblages of microorganisms that likely benefit the growth and survival of meadows. Yet, restoration efforts rarely consider their effect on developing seagrass seedlings. Sediment origin should determine the types of rhizosphere and root-colonising (rhizoplane) microorganisms and thus the performance of seedlings during restoration, particularly for slow growing climax species like Posidonia. Recent Posidonia restoration attempts in South Australia used commercially sourced 'play pit sand' for seedling propagation and planting, but have been impacted by high mortality. More natural substrates like seagrass meadow sediment have not been previously investigated for suitability over conventional substrates with regard to seedling growth and survival.MethodsTo assess the relevance of seagrass associated microorganisms in the growth of Posidonia angustifolia seedlings, we investigated the bacterial communities from tank-raised seedlings propagated in autoclave treated and untreated 'play pit sand' and meadow mix (comprising a 1:3 ratio of natural meadow sediment and beach sand) over a 12-week period. Autoclave treatment was adopted in order to diminish the bacterial load prior to planting and thus inform their contribution (if any) on early seedling growth. Samples for bacterial community analysis and seedling growth measurements (numbers and total length of roots/leaves, root diameter, seedling weight, starch reserves) were taken at 4 and 12 weeks. Bacterial assemblages were surveyed from DNA extracts from bulk and rhizosphere sediments and root tissues, as well as from swabs of P. angustifolia fruit, established meadow sediment and water samples prior to seedling propagation, by constructing Illumina 16S rRNA gene libraries.ResultsWhile most growth measurements did not vary significantly between sediment type or treatment, proportional growth of roots versus leaves (as expressed as a pseudo root:shoot ratio) was significantly related to treatment, sediment type and seed length. Seedlings from meadow mix invested more in leaves, regardless of treatment, when compared to play sand. Autoclave treatment increased investment in roots for play sand but increased the investment in leaves for meadow mix. Bacterial communities differed significantly between sediments and between sample types (bulk, rhizosphere and roots), with the roots from meadow mix seedlings containing an increased abundance of various potentially beneficial bacterial taxa.DiscussionWhile such changes appear to affect the early development of seedlings, bacterial community dynamics are also likely coupled to changes in nutrient availability. Further research is thus required to disentangle host seedling growth-nutrient-bacterial community dynamics with the view to identifying microbes that may support the growth and vigour of seedlings under different nutrient conditions as part of future restoration efforts.

Seed pelleting technique for mechanized sowing in green gram [Vigna radiata (L.) R. Wilczek

Background: Now-a-days, use of machines is becoming important due to shortage of labour for field operations. One such case is seed drill sowing which warranted enough seed size for easy sowing. Pelleting of seed is one of the techniques through which the size of the seed can be increased thereby it can be sown easily by seed drill. Green gram is one of the important pulses which needs pelleting technique for mechanized sowing. Methods: The experiments on standardization of seed pelleting technique and evaluating under field conditions were conducted in the Department of Seed Science and Technology, Seed Centre, Tamil Nadu Agricultural University, Coimbatore, India during 2019-2022. The green gram var. CO 8 seeds were primed and pelleted with TNAU pelleting mixture. Then, the pelleted seeds were sown by pneumatic seed drill and evaluated for its field performance. Result: The results showed that the green gram seeds primed with MnSO4 @ 0.5% and pelleted with 7 layers of TNAU pelleting mixture along with imidacloprid 70 WS @ 7 g/kg have recorded increased seedling vigour without affecting the seed germination. Also, the seeds sown by seed drill have recorded with better plant growth traits and higher yield. Also, single seed placement was achieved by seed drill sowing and about 25% seeds can be saved.