Dry Weight Of Seedlings Research Articles

Effects of nanoparticle applications on seedling survival and morphological characteristics in Scots pine afforestation

This study was conducted in the afforestation area, using bare-root 2+0-year-old Scots pine seedlings from Kastamonu. The study aimed to determine the impact of nanoparticle (NP) applications on seedling morphological characteristics and seedling survival success. Three different concentrations (low, medium, high) and four different nanoparticle types [Fe₃O₄, CuO, ZnO, TiO2] were applied to the plant root-dipping method in the study. The effects of NP treatments on seedling height (SH), root collar diameter (RCD), stem fresh weight (SFW), root new weight (RFW), seedling fresh weight (SEFW), root dry weight (RDW), stem dry weight (SDW), seedling dry weight (SEDW), sturdiness quotient (SI), root: shoot ratio (R/S), and seedling survival in the field were evaluated. The study results revealed that NP types significantly affected all seedling variables except RFW, SDW, RDW, and SEDW, and NP doses significantly affected all seedling variables except RFW. The binary interaction effects of NP types and doses had a significant effect on all seedling variables, and higher values were obtained compared to the control treatment. Medium and high NP doses were more effective in seedling growth than low doses; the percentage of seedling survival was 61.4% in the control treatment and 95% in the TiO2-Medium NP treatment combination.

Chitosan modifies the substrate and influences growth of chili seedlings

ABSTRACT The addition of chitosan to soil has been shown to promote plant development, although its actions on the soil and the plants remain unclear. Chili (Capsicum annum L.) seedlings were grown in a greenhouse (20–33°C, 65%–70% RH) on a substrate (topsoil, rice husk charcoal, and coconut coir) at a ratio of 2:1:1 (v/v) amended with 0%, 1%, or 10% (w/w) chitosan powder. Shoot and root dry weights of chili seedlings grown in a substrate containing 1% chitosan exhibited a 2.5-fold and 1.6-fold increase compared to those in 0% and 10% chitosan treatments, respectively. Leaf chlorophyll content was 2.7-fold higher at 20 days after transplanting. Chitosan at 1% improved the cation exchange capacity (CEC), substrate organic matter, and plant essential nutrient absorption (P, K, Ca, Mg, Mn, Cu, and Zn). In contrast, the substrate added with 10% chitosan had a negative effect on chili seedlings, possibly due to an excess of total available nitrogen (1.54% or 1.6 times higher) and organic matter (30% or 1.6 times higher). Seedlings exhibited leaf chlorosis, poor root development, and fewer essential nutrients in tissues than the control and 1% chitosan treatments. Use of 1% chitosan appears to promote chili growth by improving substrate characteristics.

Modulation of metal transporters, oxidative stress and cell abnormalities by synergistic application of silicon and titanium oxide nanoparticles: A strategy for cadmium tolerance in rice

Heavy metals, especially cadmium (Cd), cause severe toxicity symptoms in crop plants. Applying nanoparticles (NPs) as nano-fertilizers is a novel approach to mitigating plants' Cd stress. However, knowledge about the combinational use of silicon (Si) and titanium dioxide (TiO2) NPs to mitigate Cd stress, especially in rice, must be highlighted. TiO2-NPs (15 mg L−1) and Si-NPs (2.5 mM) were applied alone and in combination to rice plants grown without (control; no Cd stress) and with (100 μM) Cd concentration. Results revealed that compared to the control plants, root length, shoot length, shoot fresh weight, and root dry weight of rice seedlings were significantly decreased by 25.43%, 26.64%, 34.13%, and 29.87% under Cd exposure. However, the synergistic effect of TiO2- and Si-NPs increased rice plants' shoot length, root length, root dry weight, and shoot fresh weight by 24.62%, 29.81%, 36.16%, and 33.07%, respectively, under the Cd-toxicity. The concentration of malondialdehyde (MDA) and H2O2 were amplified due to Cd stress, which leads to damage to the subcellular structures. Si and TiO2-NPs co-application improved the anti-oxidative enzymatic activities (catalase, peroxidase, superoxide dismutase) and an elevated concentration of non-enzymatic glutathione in Cd-exposed rice. The Cd accumulation was condensed by 21.37% and 19.7% in the shoot, while 48.31% and 45.65% in root tissues under Si-NPs + Cd and TiO2-NPs + Cd treatments compared to Cd-alone treated seedlings, respectively. The expression patterns of metal transporters, such as OsNramp1 and OsHMA3, were the highest when rice plants were cultivated under Cd stress and significantly reduced when treated with sole and combined Si- and TiO2-NPs treatments. In conclusion, combining Si- and TiO2-NPs significantly improved the antioxidant enzymatic activities, chlorophyll contents, biomass production, and reduced cellular damage. Despite limitations, our findings guide future research, addressing risks, optimizing concentrations, and assessing long-term effects that can balance agricultural progress with environmental sustainability.

Aplikasi pupuk organik vermikompos sebagai komposisi media tanam pada pertumbuhan bibit kelapa sawit di pre-nursery

The research was conducted with the aim of identifying the response of organic fertilizer vermicompost as a composition of planting media in pre-nursery on the growth of oil palm seedlings. This research was conducted in Teaching Farm Wedomartani, Ngemplak, Sleman Regency, Yogyakarta from April to June 2022. This study implemented a randomized block design with a single factor. The composition of the planting media as a factor that consisted of five treatments, namely: subsoil (100%), subsoil (80%) + vermicompost (20%), subsoil (70%) + vermicompost (30%), subsoil (60%) + vermicompost (40%), and subsoil (50%) + vermicompost (50%). Each treatment was repeated three times. The results showed that the application of vermicompost as planting media composition in the pre-nursery with subsoil gave the oil palm seedlings higher growth than the control (without vermicompost). The application of subsoil with vermicompost gave the plant height, number of leaves, stem diameter, and wet and dry plant weight higher than the control. Application of subsoil (80%) + vermicompost (20%) produced the best plant height, number of leaves, stem diameter, and wet and dry weight of oil palm seedlings.

Keadaan bahan kering bibit kelapa sawit dengan aplikasi kompos tankos dan Bacillus sp.

Organic fertilizer in the form of compost is possible to be continuesly applied in oil palm plantations, including in nurseries. This is one of the efforts to support the realization of sustainable oil palm plantations. This experiment aims to examine the effect of adding compost made out of empty oil palm bunches (EOPB) and bacteria Bacillus sp. applied either singly or in combination between the two to the state of the dry matter of oil palm seedlings. The experiment was carried out at the Ciparanje Experimental Garden, Faculty of Agriculture, Padjadjaran University from February to May 2022. The experiment was a field test using a randomized block design consisting of nine treatments, repeated three times. The treatments included NPK inorganic fertilizer, Bacillus sp. (25 mL and 35 mL), EOPB compost (100 g, 150 g and 200 g) given to each oil palm seedlings. The experimental results showed that the administration of Bacillus sp. 25 mL/seedling alone had good effect on the dry weight of the roots and dry weight of the oil palm seedlings, while the addition of 150 g/seedling EOPB compost alone had a good effect on the dry weight of the oil palm seedling shoots. The condition of the dry matter of the seedlings with the provision of Bacillus sp. and EOPB compost is as good as oil palm seedlings which are only given NPK fertilizer so that in this case the EOPB compost and Bacillus sp. can be used as an alternative fertilizer to be applied in oil palm nurseries.

Integrated Transcriptomic and Metabolomics Analyses Reveal Molecular Responses to Cold Stress in Coconut (Cocos nucifera L.) Seedlings.

Coconut is an important tropical and subtropical fruit and oil crop severely affected by cold temperature, limiting its distribution and application. Thus, studying its low-temperature reaction mechanism is required to expand its cultivation range. We used growth morphology and physiological analyses to characterize the response of coconuts to 10, 20, and 30 d of low temperatures, combined with transcriptome and metabolome analysis. Low-temperature treatment significantly reduced the plant height and dry weight of coconut seedlings. The contents of soil and plant analyzer development (SPAD), soluble sugar (SS), soluble protein (SP), proline (Pro), and malondialdehyde (MDA) in leaves were significantly increased, along with the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and the endogenous hormones abscisic acid (ABA), auxin (IAA), zeatin (ZR), and gibberellin (GA) contents. A large number of differentially expressed genes (DEGs) (9968) were detected under low-temperature conditions. Most DEGs were involved in mitogen-activated protein kinase (MAPK) signaling pathway-plant, plant hormone signal transduction, plant-pathogen interaction, biosynthesis of amino acids, amino sugar and nucleotide sugar metabolism, carbon metabolism, starch and sucrose metabolism, purine metabolism, and phenylpropanoid biosynthesis pathways. Transcription factors (TFs), including WRKY, AP2/ERF, HSF, bZIP, MYB, and bHLH families, were induced to significantly differentially express under cold stress. In addition, most genes associated with major cold-tolerance pathways, such as the ICE-CBF-COR, MAPK signaling, and endogenous hormones and their signaling pathways, were significantly up-regulated. Under low temperatures, a total of 205 differentially accumulated metabolites (DAMs) were enriched; 206 DAMs were in positive-ion mode and 97 in negative-ion mode, mainly including phenylpropanoids and polyketides, lipids and lipid-like molecules, benzenoids, organoheterocyclic compounds, organic oxygen compounds, organic acids and derivatives, nucleosides, nucleotides, and analogues. Comprehensive metabolome and transcriptome analysis revealed that the related genes and metabolites were mainly enriched in amino acid, flavonoid, carbohydrate, lipid, and nucleotide metabolism pathways under cold stress. Together, the results of this study provide important insights into the response of coconuts to cold stress, which will reveal the underlying molecular mechanisms and help in coconut screening and breeding.

Morphological, Biochemical and Quality Control Analysis of Peas Genotypes under Cadmium Toxicity at the Seedling Stage

Cadmium toxicity is an emerging problem as it is the most abundant heavy metal in Pakistani soils. Peas are being grown near cities where an elevated level of cadmium persists. So, this study was conducted for the evaluation of 10 peas genotypes (TRIPLET, MID No. 2, Oskar, LM (OSE), METEOR, P-1, Rohina, PEA-09, LM-POIS, and LAMPO) under cadmium stress at the seedling stage in the greenhouse of Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad. There were 3 treatments of cadmium (0, 4, and 8 mg/kg soil) and each treatment was replicated five times in a completely randomized design. Different morphological traits i.e., fresh root weight, fresh seedling weight, root length, seedling length, dry root weight, dry seedling weight and biochemical traits i.e., Cd in the root, shoot, and soil were recorded by atomic absorption spectrometry. Generally, T1 reduced root and shoot parameters while 8 ppm Cd application comparatively enhanced the growth of peas genotypes. LM-POIS and LM (OSE) genotypes performed well under Cd stress and LM-POIS had also an elevated level of Cd in the shoot on the other hand TRIPLET and LAMPO were the least performing genotypes. It is suggested that Cd contamination significantly reduces pea growth; therefore, Cd-tolerant-peas genotypes should be developed or introduced. Further, Cd exposure in the soil should be minimized and already Cd-polluted soils should be remediated.

Effects of Different Boron Doses on Germination, Seedling Growth and Relative Water Content of Linseed (Linum usitatissimum L.)

Boron is one of the most important nutrients required for the growth and development of plants. However, boron deficiency or excess also affects the physiological development of plants such as germination and seedling development. In this study, the effects of boron applications of 0-8 ml L-1 (4 concentrations) in 2 linseed cultivars [Beyaz Gelin (C1) and Sarı Dane (C2)] were investigated under laboratory conditions. In the study; germination percentage (GP), mean germination time (MGT), seeding length (SL), root length (RL), seedling fresh weight (SFW), seedling dry weight (SDW), root fresh weight (RFW), root dry weight (RDW) and relative water content (RWC) parameters were examined. As a result of the study, it has been determined that there are decreases in the properties of the cultivars in terms of the parameters examined with boron applications. It has been determined that especially 8 mg L-1 application has a toxic effect and prevents seedling and root development.

Analyzing the impacts of cadmium alone and in co-existence with polypropylene microplastics on wheat growth.

Heavy metals typically coexist with microplastics (MPs) in terrestrial ecosystems. Yet, little is known about how the co-existence of heavy metals and MPs affect crops. Therefore, this study aimed to evaluate the impact of cadmium (Cd; 40 mg/L) alone and its co-existence with polypropylene (PP)-MPs (50 and 100 µm) on seed germination, root and shoot growth, seedling dry weight (DW), and antioxidant enzyme activities of wheat. The study demonstrated that the germination rate of wheat did not vary significantly across treatment groups. Yet, the inhibitory impact on wheat seed germination was strengthened under the co-existence of Cd and PP-MPs, as the effect of a single treatment on seed germination was non-significant. The germination index and mean germination time of wheat seeds were not affected by single or combined toxicity of Cd and PP-MPs. In contrast, Cd and PP-MPs showed synergistic effects on germination energy. Wheat root and shoot length were impeded by Cd alone and in combination with PP-MPs treatments. The DW of wheat seedlings showed significant change across treatment groups until the third day, but on the seventh day, marginal differences were observed. For example, on third day, the DW of the Cd treatment group increased by 6.9% compared to CK, whereas the DW of the 100 µm PP-MPs+Cd treatment group decreased by 8.4% compared to CK. The co-occurrence of Cd and PP-MPs indicated that 50 μm PP-MPs+Cd had an antagonistic impact on wheat seedling growth, whereas 100 μm PP-MPs+Cd had a synergistic impact due to the larger size of PP-MPs. The antioxidant enzyme system of wheat seeds and seedlings increased under single Cd pollution, while the activities of superoxide dismutase, catalase, and peroxidase were decreased under combined pollution. Our study found that Cd adversely affects wheat germination and growth, while the co-existence of Cd and PP-MPs have antagonistic and synergistic effects depending on the size of the PP-MPs.

Evaluation of Trichoderma spp. on Fusarium oxysporum f. sp. asparagi and Fusarium wilt Control in Asparagus Crop.

Among the key diseases affecting the asparagus crop (Asparagus officinalis L.), vascular wilting of asparagus caused by Fusarium oxysporum f. sp. asparagi stands out worldwide. This disease significantly shortens the longevity of the crop and limits economic production. Traditional control measures have been largely ineffective, and chemical control methods are difficult to apply, making biological control approaches, specifically the use of Trichoderma, an economical, effective, and risk-free alternative. This study aimed to identify the main factors that affect the efficacy of biopesticides studied as Biological Control Agents (BCAs) against Fusarium wilt in asparagus and to assess the efficacy of Trichoderma-based biopesticides under greenhouse and semi-field conditions. We evaluated the response of three Trichoderma spp. (T. atroviride, T. asperellum, and T. saturnisporum) to environmental variables, such as temperature and water activity, and their antagonistic capacity against Fusarium oxysporum f. sp. asparagi. All three Trichoderma species inhibited the growth of the pathogen in vitro. A decrease in water activity led to a greater reduction in the growth rate. The efficacy of the three biological control agents decreased with higher temperatures, resulting in minimal inhibition, particularly under conditions of restricted available water in the environment. The effect of the fungal inoculum density was also analyzed at two different temperatures. A direct correlation between the amount of inoculum and the score on the Disease Severity Index (DSI) was observed. A notable reduction in DSI was evident in treatments with high inoculum density (106 conidium/mL) for all three species of Trichoderma tested at both temperatures. In greenhouse and semi-field tests, we observed less disease control than expected, although T. asperellum and T. atroviride showed lower disease severity indices and increased the dry weight of seedlings and crowns, whereas T. saturnisporum resulted in the highest disease rate and lowest dry weight. This work highlights that the efficacy of Trichoderma as BCAs is influenced by various factors, including the quantity of soil inocula, and environmental conditions. The study findings have strong implications for selecting appropriate Trichoderma species for controlling specific pathogens under specific environmental conditions.

Effect of Trichoderma viride on insoluble phosphorus absorption ability and growth of Melilotus officinalis

Phosphorus (Pi) deficiency is a major factor of limiting plant growth. Using Phosphate-solubilizing microorganism (PSM) in synergy with plant root system which supply soluble Pi to plants is an environmentally friendly and efficient way to utilize Pi. Trichoderma viride (T. viride) is a biocontrol agent which able to solubilize soil nutrients, but little is known about its Pi solubilizing properties. The study used T. viride to inoculate Melilotus officinalis (M. officinalis) under different Pi levels and in order to investigate the effect on Pi absorption and growth of seedlings. The results found that T. viride could not only solubilizate insoluble inorganic Pi but also mineralize insoluble organic Pi. In addition, the ability of mineralization to insoluble organic Pi is more stronger. Under different Pi levels, inoculation of T. viride showed that promoted the growth of aboveground parts of seedlings and regulated the morphology of roots, thus increasing the dry weight of seedlings. The effect of T. viride on seedling growth was also reflected the increasing of chlorophyll fluorescence parameters and photosynthetic pigment content. Moreover, compared to the uninoculated treatments, inoculation of T. viride also enhanced Pi content in seedlings. Thus, the T. viride was a beneficial fungus for synergistic the plant Pi uptake and growth.

Optimal Substrate Moisture Content for Kiwifruit (Actinidia valvata Dunn) Seedling Growth Based on Analyses of Biomass, Antioxidant Defense, and Photosynthetic Response

The fruits of kiwifruit are well known for their abundant nutritional value and health benefits, but kiwifruit vines are susceptible to environmental factors such as drought or waterlogging. Optimum substrate moisture content (SMC) can decrease cultivation costs and improve the quality of seedlings in soilless cultivation. To quantify the water requirements of kiwifruit seedlings, a greenhouse study was conducted to investigate the growth, antioxidant defense, and photosynthetic parameters of seedlings of Actinidia valvata Dunn at six levels of SMC (20%, 40%, 60%, 80%, 100%, and 120%). Results showed that shoot and root dry matter accumulation increased gradually with the increase in SMC from 20% to 100% and was lower at 120% SMC than at 100% SMC. Electrolyte leakage and malondialdehyde content were the lowest at 80% and 100% SMC. Antioxidant enzyme activities, including superoxide dismutase, peroxidase, and catalase, chlorophyll content, net photosynthetic rate, maximal quantum yield of PSII photochemistry, photosynthetic electron transfer rate, and actual quantum yield were the highest at 80% and 100% SMC, but there was no significant difference in these parameters between the two treatments (80% and 100% SMC). However, the shoot and root dry weights of seedlings at 100% SMC were 13.20% and 33.02% higher than those at 80% SMC, respectively. In summary, 100% SMC provided optimal water supply for the photosynthetic efficiency and dry matter accumulation of shoots and roots. The results are expected to be useful for the mass production of high-quality kiwifruit seedlings in greenhouse or nursery containers, with the potential to save water.

Magnetic Field Exposure Effect on Water Properties and its Effect on Pumpkin(Cucurbita moschata Duchesne) and Okra (Abelmoschus esculentus Moench) Seedling Growth Performance

This study aims to understand the effect of magnetic field on water properties and plants growth performance. Magnetic water is produced when water is passed through a magnetic field which alters the state of water macromolecules. The changes to physico-chemical properties of magnetized water affect the biological properties of organisms. This experiment was conducted at a greenhouse in the Institute Sustainable Agrotechnology (INSAT) experimental farm, Universiti Malaysia Perlis, Padang Besar, Perlis, Malaysia. It carried out according to Randomize Complete Block Design (RCBD) with four replications. The magnetic field was applied on water to evaluate through three different intensities; 0.10, 0.15, and 0.20 Tesla, in addition to control treatment (without magnetic) for seedling growth of pumpkin (CV. Labu Loceng) and okra (CV. Bendi Alabama). The morphological study of water and study of seedling height, stem diameter, leaf numbers, seedling weight and dry weight of seedling are researched. The magnetic water at 0.20 Tesla had significantly increases in the leaf number per seedling 6.000 leaf seedling-1 and dry seedling weight 0.5700 g of pumpkin. Meanwhile, the magnetic water at 0.20 Tesla increased significantly in seedling height, stem diameter, leaf number per seedling, seedling weight and dry seedling weight of okra reached to 13.750 cm, 2.677 mm, 5.500 leaf seedling-1, 1.7800 g and 0.3369 g, respectively compared to control.

Effect of seawater irrigation on germination and growth of Bauhinia variegate seedlings and seed treatment with gibberellins

The sea height level along Libyan coasts is considered one of the environmental pressures that lives in soil vegetation characteristics. Therefore, two experiments were conducted (laboratory - pots) to find out the effect of irrigation with seawater at the concentration (10%, 20%, 40%, 60%) on germination of seeds and seedlings of Bauhinia variegate trees with an age of 6 months, and treated using pre-soaking in gibberellin acid ( GA3) 500ppm for 24 hours. The results showed that the exposure of seeds and seedlings of B.variegate trees to salinity led in two experiments to a significant decrease in percentage germination, an increase in means germination time, moreover, a decreased seedlings lengths, number of leaves/plant, shoot and root lengths, fresh and dry weight of seedlings compared with a control. The results also showed that the seeds and seedlings of B.variegate trees were able to germinate in different concentrations of seawater, except for 60% concentration which caused in death of seeds and seedlings, while pre-soaking treatment of seeds with gibberellin acid was not successful to overcome the salt stress, although slightly improved some studied traits. The results concluded that the possible seeds and seedlings agriculture of B.variegate trees in coastal locations in which seawater concentration did not exceed 40%, existed to be used in reforestation of degraded lands. Key words: Bauhinia variegata, seawater, GA3, Libyan coasts.

Physiological analysis and transcriptome profiling reveals the impact of microplastic on melon (Cucumis melo L.) seed germination and seedling growth

The wide application of agricultural plastics leads to microplastic (MP) accumulation in the soil and inevitably result in MP pollution. Melon is an economically important horticultural crop that is widely cultivated with plastic film mulching. However, the impact of MP pollution on plant growth remains largely unclear. Here we reported the morphological, physiological, biochemical responses and transcriptome re-programing of melon responses to MP on seed germination and seedling growth. Polyvinyl chloride particles were added to potting mix to simulate MP exposure environment (MEE). The results showed that low and medium concentrations (1–4 g kg−1) of MEE had a significant adverse effect on seed germination and seedling growth. In both cases, the germination potential was decreased, young root forks increased, and tips decreased; and the dry weight of seedlings, the total length, surface area, forks and tips of root were also decreased. However, the root activity was increased. The concentration of MEE to give the best parameters was at 2 g kg−1. Catalase enzymatic activity and reactive oxygen species (ROS) in roots were decreased continuously with increased MEE concentrations. The peak values of peroxidase activity, O2.- content and generation rate, ROS enrichment and malondialdehyde content all reached the highest at 2 g kg−1. MEE also increased the proline content and decreased the contents of ascorbic acid, soluble sugar and soluble protein in these seedlings. Medium and high concentrations of MEE (4–8 g kg−1) also increased the chlorophyll b content. Low concentrations MEE (1–2 g kg−1) inhibited actual photochemical efficiency of photosystem II and photochemical quenching, two key chlorophyll fluorescence parameters. Transcriptome analysis showed that the differentially expressed genes caused by the MEE were mainly belonged to defense response, signal transduction, hormone metabolism, plant-pathogen interaction, and phenylpropanoid biosynthesis. The results of this study will help to understand the ecotoxicological effects of MEE on melons and provide data for ecological risk assessment of Cucurbitaceae vegetable cultivation.

Whole-genome assembly of A02 bacteria involved in nitrogen fixation within cassava leaves.

The endophytic nitrogen (N)-fixing bacterium A02 belongs to the genus Curtobacterium (Curtobacterium sp.) and is crucial for the N metabolism of cassava ( Manihot esculenta Crantz). We isolated the A02 strain from cassava cultivar SC205 and used the 15N isotope dilution method to study the impacts of A02 on growth and accumulation of N in cassava seedlings. Furthermore, the whole genome was sequenced to determine the N-fixation mechanism of A02. Compared with low N control (T1), inoculation with the A02 strain (T2) showed the highest increase in leaf and root dry weight of cassava seedlings, and 120.3 nmol/(mL·h) was the highest nitrogenase activity recorded in leaves, which were considered the main site for colonization and N-fixation. The genome of A02 was 3,555,568 bp in size and contained a circular chromosome and a plasmid. Comparison with the genomes of other short bacilli revealed that strain A02 showed evolutionary proximity to the endophytic bacterium NS330 (Curtobacterium citreum) isolated from rice (Oryza sativa) in India. The genome of A02 contained 13 nitrogen fixation (nif) genes, including 4 nifB, 1 nifR3, 2 nifH, 1 nifU, 1 nifD, 1 nifK, 1 nifE, 1 nifN, and 1 nifC, and formed a relatively complete N fixation gene cluster 8-kb long that accounted for 0.22% of the whole genome length. The nifHDK of strain A02 (Curtobacterium sp.) is identical to the Frankia alignment. Function prediction showed high copy number of the nifB gene was related to the oxygen protection mechanism. Our findings provide exciting information about the bacterial genome in relation to N support for transcriptomic and functional studies for increasing N use efficiency in cassava.

Effects of sand burial on seedling growth of the coastal dune plant Viola grayi: Tolerance and adaptive responses to sand accretion

AbstractThe responses of Viola grayi seedlings to complete sand burial were experimentally assessed in this study. Approximately 10‐month‐old seedlings were buried in sand to a depth of 0, 1, 5, or 15 cm. The re‐emerged seedlings were counted for 5 months, and the dry weights were compared. The results showed that shallow burial promoted the shoot development and total growth of seedlings. The dry weights of stems and leaves and the total dry weight of seedlings were higher in plants buried at depths of 1 and 5 cm than in unburied plants. The dry weight of roots did not differ among them. No seedlings buried at a 15‐cm depth re‐emerged. Most seedlings buried at 1‐ and 5‐cm depths produced adventitious roots from below‐ground stems. The tolerance and adaptive responses of V. grayi seedlings to sand accretion may contribute to their establishment in sand‐accumulating habitats.

VALORIZATION OF TOMATO PLANT WASTES AND OPTIMIZATION OF GROWTH CONDITIONS FOR INDOLE-3-ACETIC ACID PRODUCTION BY Streptomyces plicatus STRAIN PT2

This study focused on the production of the phytohormone indole-3-acetic acid (IAA) using tomato plant tissues as feedstock and on highlighting its growth promotion effect on tomato seedlings. Twelve actinobacterial strains were screened for IAA production under standard growth conditions and the strain Streptomyces plicatus PT2 was selected as a promising producer. The establishment of growth conditions to increase IAA production by S. plicatus PT2 was conducted using Plackett-Burman mathematical design with seven variables. The variables L-tryptophan quantity and tomato roots-extract rate were the two significant variables influencing IAA production. The most impacting variables were optimized using the surface methodology (RSM) formulated according to the Central Composite Design (CCD). The optimized broth supplemented with 4 mg L-1 of L-tryptophan and 25% of tomato roots-extract significantly improved the IAA production from 96.3 µg mL-1 within 120h to a maximum of 110.29 µg mL-1 within 96h. The in-planta application of the produced IAA and a chemical IAA showed a significant increase in the dry weight, the shoot and root lengths of tomato seedlings. This is the first study showing the production of IAA using Streptomyces plicatus strain PT2 by exploring tomato plant tissues and its plant-growth promotion efficacy compared to a chemical marketed one. These results support a reasonable approach for the valorization of abundant worldwide tomato plant wastes in the phytohormones production bioprocesses.

Response of Cocoa (Theobroma cacao L.) Seedling Growth on Various Growing Media and Organic Plant Supplements

Cocoa (Theobroma Cacao L.) as a plantation crop which success is determined by healthy and quality seedlings. The use of planting media with a mixture of manure and plant organic supplements may result in healthy soil because it contains soil microorganisms that are beneficial and may support the growth of cocoa seedlings. Purpose of this study was to determine the initial growth response of cocoa seedlings on various growing media and dosages of an organic plant supplement as liquid organic fertilizer. The research was conducted in February–September 2022 in a nursery located in Kradenan, Purwoharjo, Banyuwangi Regency and in Agricultural Laboratory of University of Jember, Bondowoso Campus, Bondowoso Regency. Study was carried out in a 4 x 4 factorial using a randomized block design with three replications. The first factor was planting media which consisted of four levels of treatment, namely soil + chicken manure, soil + goat manure, soil + cow manure, and soil + rabbit manure. The second factor was dose of organic plant supplement which consisted of 4 levels, namely the control treatment of 0, 50, 100, and 150 mL polybag-1. Data were analyzed using analysis of variance and follow-up tests using Duncan’s multiple range test at 5% level. Variables observed included seedling height, number of leaves, stem diameter, leaf length, leaf width, number of roots, root length, fresh weight, and dry weight of seedlings. The results showed that there was an interaction effect on all parameters except seedling height, number of leaves, and number of roots. The conclusion of the study showed that there was an effect of interaction treatment with the best treatment combination planting media using cow manure and organic plant supplement dose of 50 mL polybag-1.

Effects of Sodium Bicarbonate Stress on Seed Germination and Seedling Growth of Mustard (Brassica campestris L.)

Numerous stresses cause negative impacts on crops and salinity-alkalinity plays a significant role in these stresses that harm the crops and their production. Sodium bicarbonate is an alkaline salt that also affects crops. The present experiment was performed to study the impacts of seed germination and early seedling growth of mustard under various NaHCO3 salt treatments. This experiment was a completely randomized design, and seeds of mustard were sown in petridishes lined with Whatman No. 1 filter paper in triplicates. Different concentrations (0, 2.5, 5.0, 7.5, and 10.0 mM) of NaHCO3 salt solution were used to moisten the filter papers. The control (0 mM) treatment was applied using distilled water. The seedlings were measured on the fourteenth day of sowing. The outcomes demonstrated that the germination percentage declined significantly at sodium bicarbonate salt treatments (5.0, 7.5, and 10.0 mM), while the % DFC for germination was found to be increased with increasing salt levels. In various salt (2.5, 5.0, 7.5, and 10.0 mM) concentrations, there was a significant reduction got in seedling growth, as assessed by the seedling vigor index, length of seedlings, and fresh weight of seedlings. The percentage of phytotoxicity increased while the tolerance index dropped with salt treatments. The dry weight of shoot and whole seedlings was also inhibited significantly by salt treatments (2.5, 5.0, 7.5, and 10.0 mM), and root dry weight got a significant reduction at (5.0, 7.5, and 10.0 mM) levels of salt treatments.