Increased Root Weight Research Articles

Study on the Biological Characteristics of Dark Septate Endophytes under Drought and Cadmium Stress and Their Effects on Regulating the Stress Resistance of Astragalus membranaceus.

Astragalus membranaceus is a famous traditional medicinal plant. However, drought and cadmium (Cd) pollution are the main abiotic stress factors that affect plant growth and yield and the ability to improve the host's stress resistance through the use of beneficial endophytic fungi. To evaluate the tolerance of dark septate endophytes (DSE) to various abiotic stresses, 10 DSE strains [Microsphaeropsis cytisi (Mc), Alternaria alstroemeriae (Aa), Stagonosporopsis lupini (Sl), Neocamarosporium phragmitis (Np), Paraphoma chlamydocopiosa (Pc), Macrophomina phaseolina (Mp'), Papulaspora equi (Pe), Alternaria tellustris (At), Macrophomina pseudophaseolina (Mp), and Paraphoma radicina (Pr)] were investigated under different drought and Cd stressors in vitro by using solid-plate cultures and liquid-shaker cultures in the current study. The experiments involved using varying concentrations of PEG (0, 9, 18, and 27%) and Cd2+ (0, 25, 50, and 100 mg/L) to simulate different stress conditions on DSE. Additionally, the effect of DSE (Np and At) on the growth of A. membranaceus at different field water capacities (70% and 40%) and at different CdCl2 concentrations (0, 5, 10, and 15 mg Cd/kg) in soil was studied. The results demonstrated that the colony growth rates of Aa, Np, Pc, Mp', and Mp were the first to reach the maximum diameter at a PEG concentration of 18%. Aa, Np, and At remained growth-active at 100 mg Cd/L. In addition, Aa, Np, and At were selected for drought and Cd stress tests. The results of the drought-combined-with-Cd-stress solid culture indicated that the growth rate of Np was significantly superior to that of the other strains. In the liquid culture condition, the biomasses of Np and Aa were the highest, with biomasses of 1.39 g and 1.23 g under the concentration of 18% + 25 mg Cd/L, and At had the highest biomass of 1.71 g at 18% + 50 mg Cd/L concentration, respectively. The CAT and POD activities of Np reached their peak levels at concentrations of 27% + 50 mg Cd/L and 27% + 25 mg Cd/L, respectively. Compared to the control, these levels indicated increases of 416.97% and 573.12%, respectively. Aa, Np, and At positively influenced SOD activity. The glutathione (GSH) contents of Aa, Np, and At were increased under different combined stressors of drought and Cd. The structural-equation-modeling (SEM) analysis revealed that Aa positively influenced biomass and negatively affected Cd content, while Np and At positively influenced Cd content. Under the stress of 40% field-water capacity and the synergistic stress of 40% field-water capacity and 5 mg Cd/kg soil, Np and At significantly increased root weight of A. membranaceus. This study provides guidance for the establishment of agricultural planting systems and has good development and utilization value.

Post-heading accumulation of nonstructural carbohydrates and nitrogen in rice (Oryza sativa L.) roots

ContextRoots are plant organs that absorb nutrients and water. While roots serve as sink organs for nutrients in perennial and woody plant species, the dynamics of nutrient accumulation in roots for annual plant species, particularly in crop species like Oryza sativa L. (rice), are not well understood. Japanese rice cultivars bred for whole-crop silage exhibit large aboveground biomass and a notably small number of spikelets. This sink-source imbalance leads to the accumulation of non-structural carbohydrates (NSC) in stems after heading. Research questionIt is hypothesized that rice cultivars with substantial aboveground biomass might also develop significant belowground biomass. Consequently, the sink-source imbalance may result in NSC accumulation in roots. This study aims to test two hypotheses: firstly, that newly developed small-panicle rice cultivars accumulate NSC in roots post-heading, and secondly, that this post-heading NSC accumulation in roots can be influenced by cultural practices affecting spikelet number per panicle. MethodsTwo small-panicle cultivars, Tachisuzuka and Tachiayaka, and two large-panicle cultivars, Kusanohoshi and Hoshiaoba, were grown using different methods of three cultural practices: nitrogen application, transplanting season, and planting density. Measurements of dry matter, NSC (starch and sugars), and nitrogen in each plant part (panicle, leaf, stem, and roots) were taken over time after heading. The spikelet number per panicle was also counted. ResultsPost-heading, the small-panicle cultivars exhibited NSC accumulation in roots, a phenomenon not observed in the large-panicle cultivars. Although the three cultural practices altered the spikelet number per panicle and thus the sink capacity of the small-panicle cultivars, root NSC accumulation remained unaffected. Additionally, nitrogen weight per unit field area increased with increases in root weight in the small-panicle cultivars. ConclusionsThe imbalance in the sink-source relationship is likely responsible for the post-heading NSC accumulation in roots observed in small-panicle cultivars. However, the lack of root response in NSC accumulation to changes in panicle sink capacity suggests other mechanisms might be involved in root NSC accumulation. Notably, significant amounts of NSC and nitrogen remain in the roots of small-panicle cultivars after harvest. ImplicationsThe accumulation of NSC and nitrogen in roots post-heading could potentially enhance crop growth in subsequent years.

Effectiveness of potassium humate and endophytic bacteria from Serratia marcescens strain NPKC3_2_21 in increasing root weight of paddy cultivation in acidic soil

Abstract. Sutio G, Iskandar, Indriyati LT, Djajakirana G. 2023. Effectiveness of potassium humate and endophytic bacteria from Serratia marcescens strain NPKC3_2_21 in increasing root weight of paddy cultivation in acidic soil. Biodiversitas 24: 6316-6322. Phosphorus (P) deficiency is a significant factor limiting rice agricultural production in acidic soil. The availability of P in acidic soil is generally insufficient because a substantial portion of P is absorbed by Al³? and Fe²?, rendering it inaccessible to plants. This P deficiency in acidic soil hampers proper root growth. However, this limitation can be overcome by the application of potassium humate and endophytic bacteria. The objective of this study was to investigate the effects of phosphate fertilizer with and without potassium humate and/or endophytic bacteria on root growth in acidic fields. The research involved two treatment factors. The first factor comprised four levels of ex-madura phosphate rock fertilizer: 100% (1), 75% (2), 50% (3), 25% (4), and no application of phosphate rock fertilizer (5) and the second factor included potassium humate (A), endophytic bacteria from Serratia marcescens strain NPKC3_2_21 (B), a combination of potassium humate and S. marcescens endophytic bacteria (C), and the absence of both potassium humate and S. marcescens endophytic bacteria (D). The results revealed a positive interaction between phosphate fertilizer, the combination of potassium humate, and S. marcescens endophytic bacteria. Therefore, utilizing endophytic bacteria from S. marcescens and potassium humate could be an effective strategy for increasing root biomass in rice plants grown in acidic soil with a deficiency in available P.

Enhancing Vegetative Growth by Adding Phosphorus, Silicon, and Citric Acid to Pepper Plants Cultivated in Plastic Greenhouses

The research was conducted in a plastic greenhouse at the College of Agricultural Engineering Sciences, University of Baghdad - Jadiriyah Campus, during the 2021-2022 season, to study the effect of phosphorus, silicon, and citric acid on pepper plants using a factorial experiment design with three replicates. The first factor had three levels of phosphorus (0, 160, and 320 kg P2O5 per hectare), the second factor had three levels of potassium silicate (0, 75, and 100 kg per hectare), and the third factor had four levels of citric acid (0, 2, 4, and 6 kg per hectare). The statistical analysis showed that treatment P2S2C1 resulted in an increase in the main stem diameter (25.10 mm), treatment P3S3C1 led to an increase in the main branch diameter (16.10 mm), and treatment P3S3C2 showed an increase in the diameter of secondary and tertiary branches (13.50 mm and 8.90 mm, respectively). Treatment P2S3C1 resulted in an increased number of leaves and the dry weight of the total vegetative mass (1286.7 leaves and 415.0 g plant-1 respectively). Treatment P3S2C4 led to an increase in the dry weight of roots (25.47 g plant-1), treatment P2S3C4 showed an increased number of fruits (48.34 fruits plant-1), and treatment P3S3C4 resulted in an increased total yield (4.87 tons greenhouse-1).

Effect of Auger Size and Depth of Operation on Bulk Density, Cone Index, Germination, Root Length, Root Weight and Cob Weight for Maize Crop

Minimum tillage methods offer numerous benefits compared to conventional tillage, including reduced farm operations to establish a good seedbed. Spot tillage, in particular, has advantages such as preserving soil structure, preventing erosion, saving time and energy, and reducing input costs. For this study, the effect of different auger size (40, 50 & 70mm) which was operated by 12V DC motor at different depth of operations (80, 120 & 160mm) were determined. The different parameters were measured such as bulk density, cone index, germination percentage, root length, root weight and cob weight for maize crop (GAYMH-3) and same for traditional sowing method. The results showed that auger size (40, 50 & 70mm) and depth of operation (80, 120 & 160mm) significantly influenced bulk density as bulk density of the soil increased with depth and decrease with increase in auger size. The larger auger (70mm) resulting in lower values in bulk density due to more soil removal. However, cone index was not significantly affected by auger size (40, 50 & 70mm) and depth of operation (80, 120 & 160mm). Seed germination for maize was consistently around 90%, with no significant effects of auger size and depth of operation were observed. An auger size (70mm) was associated with shorter root lengths. Increasing depth resulted in greater root development, leading to longer roots was observed in small size augers. Larger auger size and deeper depths generally resulted in higher root weights. Cob weight increased with auger size (70mm) and deeper depths. Auger size and depth significantly impacted cob weight. Overall, results showed that auger having the size of 70mm and depth of operation at 160mm was desirable compared to other auger size in terms of lower bulk density and cone index but increased root weight and cob weight of maize crop.

ICT4Agroecology part I: outcomes for cassava production system

ABSTRACT This study discusses the results of a 5-year Agroecology Research and Advocacy project at three Tanzanian field sites in different agroecological zones. We investigated four common agroecological practices: compost application, mulching, intercropping, and biological pest control either alone or in combination. Two custom-built ICT tools – AgroEco Research (AER) and AgroEco Analysis (AEA) application – supported the field research. AER and AEA integration allowed secure data storage and real-time automated visualization and statistical analyses without programming. At no field station did legume intercropping or biological pest control increase cassava yields. The Chambezi field station had the highest yields even under untreated control conditions and only here, soil fertility amendments further increased root weights. Intercropping with cowpea legumes, alone or in combination with other practices, had no significant effect on cassava plant size or survival at the Mumbaka and Vianzi field sites and even negatively affected one or both parameters. Organic pest control had no effect on any target variable, except for plant size at Chambezi. Therefore, labor-intensive and expensive pest control practices may not be worth the investment at least when virus-resistant cassava varieties like Kiroba are used.

Temporal-spatial variations of root and soil nutrient under continuous intercropping of alfalfa and oat

We investigated root and soil nutrient characteristics in the monoculture and continuous alfalfa/oat intercropping in the high-yield years by using soil filling and frame planting method in the field, and analyzed the relationship between root systems and soil nutrients. The results showed that intercropping reduced root weight and total root length proportion of oat in the 0-10 cm soil layer compared with the monoculture. However, intercropping significantly increased root weight and root surface area of oat in the 20-30 cm soil layer, root length and root density of alfalfa in the 10-20 cm soil layer, and the contents of available phosphorus and organic matter of the alfalfa/oat intercropping system in the 0-40 cm soil layer. As the planting years increased, total root length, root weight, root surface area, and proportion of root weight and root length of alfalfa in the 0-20 cm soil layer gradually increased in the intercropping system, and the root weight, total root length, root surface area, and root average diameter of oat increased, especially the root weight and root surface area of oat in the 20-30 cm soil layer. Moreover, the content of available nutrients in all soil layers decreased subsequently. In the alfalfa/oat intercropping system, continuous intercropping could significantly increase total root length of alfalfa in the 10-20 cm soil layer, improve root weight and root surface area of oat in the 20-40 cm soil layer (especially in the 20-30 cm soil layer). With the increases of planting years, intercropping intensified the absorption and competition of available nutrients by the roots of alfalfa and oat in the 0-40 cm soil layer, thereby reduced the accumulation of available nutrients in the soil.

Physiological mechanisms of exogenous organic acids to alleviate aluminum toxicity in seedlings of mungbean, buckwheat, and rice

One of the major constraints for crop yield in acidic soils is the phytotoxicity of aluminum ions (Al3+), which primarily affects the roots. To mitigate the harmful effects of Al toxicity, plants use organic acids to chelate Al internally and externally. In this study, the effects of exogenous organic acids on Al toxicity in rice, mung bean, and buckwheat were investigated. Specifically, the study examined the ameliorative effect of three organic acids (oxalic acid, malic acid, and citric acid, each at a concentration of (100 μmol/L) on root elongation, fresh weight, Al content, organic acid key enzymes, and rhizosphere pH in hydroponic media containing (100 μmol/L) Al. The experimental results revealed species-specific responses to aluminum tolerance and the alleviating effects of different organic acids. Buckwheat was found to be the most aluminum-tolerant, followed by mung bean, while rice was the least tolerant. Exogenous application of oxalic acid promoted root elongation, increased root fresh weight, and enhanced the activity of the PEPC enzyme in mung bean. Malic acid, on the other hand, alleviated Al toxicity in rice by promoting root elongation, increasing root fresh weight, enhancing the activity of the PEPC enzyme, and decreasing the activity of the MDH enzyme. In buckwheat, citric acid application reduced Al toxicity by promoting root elongation, increasing root weight, and decreasing the activities of CS and GO enzymes. These findings indicate that different organic acids can reduce Al toxicity in different plant species by employing different physiological mechanisms.

Trichoderma strains application in promoting rooting of Schlumbergera cactus

The aim of this work is to evaluate and deepen knowledge on the use of Trichoderma to stimulate the vegetative growth and rooting of plants. In this case, a trial was carried out on cuttings of Schlumbergera, a genus of cactus that is very important from an ornamental point of view but that presents numerous difficulties in the process of rooting in substrate, where cuttings often rot due to excess humidity or die due to the attack of pathogenic fungi. The trial started in March 2021 and lasted for ten months in the CREA greenhouses in Pescia, Italy. The experimental trial showed a significant effect on the rooting of Schlumbergera cuttings and on all agronomic parameters assessed on the plants in cultivation, following treatment in the growing medium with Trichoderma spp. The cuttings treated with the fungi in fact showed an increase in root weight and length, vegetative weight, number of new shoots and flowers, floral life, and a significant reduction in mortality of the treated cuttings. These results show how Trichoderma, in addition to its activity as an antagonist of pathogenic fungi, can increase the rooting and growth of plants and the production and duration of flowers, particularly on plant species where there is often little information. This experimentation may be of particular interest for cactus and succulent growers, since there is no research in the literature on biological propagation methods for these plants.

The impact of arbuscular mycorrhizal symbiosis, Funneliformis mosseae, on rosemary phytoremediation ability under urban traffic

The aim of this study was to investigate the symbiotic relationship between arbuscular mycorrhizae (Funneliformis mosseae) and the ability of rosemary (Rosmarinus officinalis) to mitigate urban traffic pollution. A factorial experiment with three replications and three factors (inoculated/non-inoculated with G. mosseae, traffic volume, and pot type) was conducted in Shiraz, a metropolis in south-central Iran. Inoculation with F. mosseae led to a 33% increase in root weight and a 20% increase in root length under a traffic volume of 4,200 Vehicles/H. Additionally, as traffic volume increased, stem length and dry weight of the entire plant inoculated with the fungus increased by 8.33% and 29.53%, respectively. The presence of fungus in the rosemary plant decreased the accumulation of Cd and increased the accumulation of Pb by 12.82% and 55.82%, respectively under traffic conditions of 4,200 Vehicles/H. The transfer factor (TF) of Cd and Pb in rosemary plant inoculated under these traffic conditions decreased by 25.74% and 25.24%, respectively. These findings indicate that mycorrhiza-inoculated rosemary plants can thrive in Cd- and Pb-contaminated soils, effectively remediating heavy metals, particularly Pb, with a TF >1.

Peculiarities of Bacillus Subtilis strains influence on the development of Triticum Aestivum L. in inoculative cultures

The research relevance is predetermined by the need to study strains of Bacillus subtilis bacteria that have a positive effect on plant growth and development and exhibit a stimulating effect at optimal bacterial loads. The research is of great importance for agriculture, ecology, and sustainable development. The research aims to determine the effect of new strains of B. subtilis (H3, H10, H13, H36, H38, H40, H43, H45) on the development of winter wheat (Triticum aestivum L.) seedlings when inoculated with inoculated crops. Laboratory, vegetation, and mathematical and statistical methods were used in the study: deep cultivation of strains, roll method of germination of test plant seeds, and data processing using Statistica 8.0 and MS Excel. The results of the model experiment on the effect of culture liquids of B. subtilis strains under different technological forms and dilutions on the growth and development of wheat test plants are summarised. It has been established that at dilutions of 1:10, 1:50, 1:100, and 1:500, the stimulating effect of bioagents is observed, and the maximum effect is achieved at a dilution of 1:100. It has been shown that the greatest positive effect on wheat seed germination was observed for B. subtilis inoculants applied to seeds in mature technological forms (spore culture, 2.0 x 107 cells per seed). The germination energy of Triticum aestivum L. seeds increased by 96.5% when interacting with B. subtilis inoculants, and the raw weight of seedlings increased by 84.0-109.6% depending on the experiment variant compared to the control, which indicates the growth-stimulating properties of the new strains. It was proved that the use of mature cultures of B. subtilis H38, H40 and H45 resulted in an increase in root weight by 4.8-11.3% compared to the control without bacterisation. When treated with culture fluids of B. subtilis H3, H10, H13, H36, and H43 in the form of vegetative cells, the root mass decreased by 11.8-44.0% compared to the control. The use of the studied strains of B. subtilis effectively affects the development of winter wheat and is a promising inoculant with a growth-stimulating effect. The practical significance of the study is to understand and determine the potential benefits of using Bacillus subtilis bacterial strains to enhance the growth and development of plants, in particular winter wheat (Triticum aestivum L.)

Biomass Allocation and Nutrients Utilization in Wheat as Affected by Phosphorus Placement and Salt Stress

Phosphorus (P) management in wheat grown under saline soil conditions requires a better understanding of how P placement and salt stress affect spatial root distribution, plant agronomic performance, and nutrient utilization. A column culture experiment was conducted with two wheat genotypes, Alice and LX99, five P placements (‘Top Dressed High P’, TopHP; ‘Top Dressed Reduced P’, TopRP; ‘Deep Banded High P’, DeepHP; ‘Deep Banded Reduced P’, DeepRP; and ‘No P added’, −P), and two salt stress levels (‘salt stress’, +S; ‘non-salt stress’, −S) to investigate differences in biomass accumulation, nutrient utilization, and root distribution (0–20 cm, 20–40 cm, and 40–100 cm) among treatments. Deep P placement under non-salt stress increased root distribution at 20–40 cm soil depth for both genotypes compared to top P placement. P application under salt stress increased root weight at all three soil depths in both genotypes and P accumulation in aboveground plant parts (except for LX99 under TopRP). The highest P utilization efficiency occurred in Alice with TopRP and in LX99 with DeepRP under non-salt and salt stresses. Overall, a coordinated adaptation in allocating biomass between belowground and aboveground plant parts, along with altered nutrient utilization, was necessary to reach a growth compromise in response to P supply changes and salinity. Therefore, genotype, P placement depth, and soil salinity should be considered to improve wheat P utilization efficiency under saline conditions.

A meta-analysis on rootstock-induced effects in grafted watermelon (Citrullus lanatus var. lanatus)

Sweet watermelon (Citrullus lanatus var. lanatus) grafting with complementary rootstocks is necessary for new variety design and to enhance product profiles, including fruit yield and quality and tolerance to biotic and abiotic stresses.. Integrated selection of successful watermelon grafts using multiple traits ensures breeding and economic gains. Therefore, the objective of this study was to undertake a meta-analysis on the responses of watermelon when grafted with contrasting rootstocks involving cucurbit species or interspecific hybrids using agronomic, physiological and quality traits, and insect pest and disease reactions for rootstock selection, variety development and deployment. A meta-analysis was conducted involving 65 studies, and data were analysed using various statistical methods. Results indicated significant (p < 0.05) variations among watermelon varieties for economic traits when grafted onto different cucurbit rootstock species. Interspecific hybrid [Cucurbita maxima × C. moschata] and Lagenaria siceraria (Molina) Standl rootstocks induced high and variable effects on fruit yield and related traits of grafted watermelon.. Watermelon/L. siceraria graft combinations showed high phenotypic variation on sugar profiles. Lycopene content of grafted watermelon was highly variable when grafted onto C. lanatus var. citroides and C. maxima × C. moschata rootstocks. Graft combinations involving L. siceraria and C. maxima × C. moschata were significantly (p < 0.05) differentiated for fruit flesh firmness and color. C. lanatus var. citroides rootstock enhanced low and variable infections for root-knot nematodes, whereas C. maxima × C. moschata rootstock induced high and variable resistance to Fusarium and Verticillium wilt in grafted watermelon. Fruit yield and quality traits of grafted watermelon positively and significantly (p <0.05; p <0.001) correlated with root and photosynthetic parameters useful in selection programs. Overall, the meta-analysis revealed the need to integrate root traits (e.g., increased root weight and total root length, higher root surface area and average root diameter), high photosynthetic efficiency, fruit yield and quality in selecting desirable rootstock in the development of market preferred watermelon varieties.

Assessment of wastewater toxicity from the pharmaceutical industry of salicylic acid and paracetamol on the roots of a plant species: Phaseolus vulgaris

Pharmaceutical compounds are currently a group of emerging environmental contaminantswhere their presence is reported in all ecosystems (water, soil, etc.). Their effects often resultin strong metabolic disturbances which affect all vital functions of organisms, including plantswhich are non-target species. During their development, plants can absorb and accumulatemany xenobiotics, including pharmaceutical compounds that are able to cross the root walls.In order to evaluate the toxic effects of salicylic Acid (SA) and Paracetamol (PAR) on bean(Phaseolus vulgaris) were investigated. The root length showed significant reduction with anincrease in the concentration of PAR in parallel, with an increase in the length of the rootsobtained at the highest concentration of SA. On increasing the concentration from PAR andSA, the gradual increase in fresh weight of roots was observed compared to the control. Afterexposure to the different concentrations, PAR and SA treatments caused damage to theprotein synthesis. In addition, a significant stimulation of proline synthesis is recorded aftertreatment with PAR compared with the value obtained in the presence of SA at the highestconcentration. Lipid peroxidation supported by a significant increase in MDA and H 2 O 2levels, particularly for PAR treatments, are also observed. The evaluation of the respiratoryactivity of the isolated bean roots shows an oxygen consumption related to the PARconcentrations. This consumption is much higher in the presence of SA. Finally, our resultsshow that pharmaceutical products and their residues (such as PAR and SA), released into theenvironment in large quantities and without treatment, can produce morphological,biochemical and metabolic changes in the roots of non-target plant species such as bean thatcan seriously disrupt root functioning.

Alleviation of metal stress in rape seedlings (Brassica napus L.) using the antimony-resistant plant growth-promoting rhizobacteria Cupriavidus sp. S-8-2

This study investigated an effective strategy for remediating antimony (Sb)-contaminated soil using the bacterial strain screened from Sb-contaminated fern rhizospheres due to its superior growth-promoting, heavy-metal(loid) resistant, and antibiotic-tolerant characteristics. The strain that belongs to Cupriavidus sp. was determined by 16S rRNA sequencing and showed no morphological changes when grown with high concentrations of Sb (608.8 mg/L). The strain showed prominent indole acetic acid (IAA), phosphate-solubilizing abilities, and ACC deaminase activity under Sb stress. Moreover, IAA and soluble phosphate levels increased in the presence of 608.8 mg/L Sb. Inoculation of rape seedlings with Cupriavidus sp. S-8-2 enhanced several morphological and biochemical growth features compared to untreated seedlings grown under Sb stress. Inoculation of Cupriavidus sp. S-8-2 increased root weight by more than four-fold for fresh weight and over two-fold for dry weight, despite high environmental Sb. The strain also reduced Sb-mediated oxidative stress and malondialdehyde contents by reducing Sb absorption, thus alleviating Sb-induced toxicity. Environmental Scanning Electron Microscope (ESEM) imaging and dilution plating technique revealed Cupriavidus sp. S-8-2 is localized on the surface of roots. Identifying the Sb-resistant plant growth-promoting bacterium suggested its usefulness in the remediation of contaminated agricultural soil and for the promotion of crop growth. We highly recommend the strain for further implementation in field experiments.

Streptomyces spp. Biofilmed Solid Inoculant Improves Microbial Survival and Plant-Growth Efficiency of Triticum aestivum

Streptomyces species have been successfully used in diverse biotechnological processes; however, little is known about actinobacterial biofilm formation and its use as a biofilmed inoculant. The present study assessed and compared the ability of some plant growth-promoting actinobacterial strains to form biofilms on a carrier to improve microbial survival and colonize the rhizosphere and roots of Triticum aestivum, resulting in positive interactions and benefits to the plant. Forty-one actinobacterial isolates from Persea americana organic rhizosphere farms were tested on plant growth and biofilm-forming capacities, showing their potential use as bio-fertilizers in agriculture. Three Streptomyces strains were selected and tested for biofilm formation and plant growth-promoting (PGP) features. Biofilms were induced on the perlite carrier and used to inoculate seven treatments with T. aestivum in pot essays, resulting in a &gt;200% increase in root weight and a &gt;400% increase in total biomass. Endophytic colonization was achieved in all the treatments. Microbial survival ranged between 108 and 109 CFU/g after 12 weeks of treatment, indicating actinobacterial permanence on the carrier. Successful consortia formation was observed for mixed-strain treatments, suggesting long-term plant recolonization.

Turpta (Raphanus sativus L.) Farklı Yumru Ağırlığı ve Bor Gübrelemesinin Bitki Gelişimi, Bakla Özellikleri, Tohum Verimi, Çimlenme ve Çıkış Üzerine Etkileri

In this experiment the effects of different root weights (50-99, 100-149, 150-199, 200-250 g) and increasing doses of boron application to soil (0, 100, 200, 300 g/da) on plant, siliqua, characteristics, and seed yield, germination and emergence in radish were investigated. In this research ‘‘Ç.Ü. Seleksiyon No:2’ radish genotype was used as plant material which developed by selection breeding method at Cukurova University, Faculty of Agriculture, Department of Horticulture. The experiment was carried out in open field and greenhouse conditions in 2017-2018 and 2018-2019. Radish roots were grown in an open field. Roots harvested for seed production were classified according to their weight and transferred to pots in the greenhouse. In this study, plant length (cm) plant diameter (mm), number of leaves (number/plant), number of siliquas (number/plant), siliqua length and width (mm), number of seeds (number/siliqua), 1000 seed weight (g), seed yield (g/plant), seed germination (%) and seed emergency (%) were analysed. According to the results of the two-year research, positive effects of increasing root weight were observed on the parameters measured in the plants, while the application of boron at different doses was found to be significant only in terms of the number of leaves. In terms of siliqua and seed characteristics, it was revealed that the increase in the root weight and applied boron dose was not effective except the increase in seed yield. Although seed germination was not affected by the applications, the best results were obtained from the application of 200 g/da boron at seedling emergence.

The Multifarious Endophytic Actinobacterial Isolate, Streptomyces tubercidicus UAE1, Combined With the Seaweed Biostimulant Further Promotes Growth of Avicennia marina

Mangrove (Avicennia marina) is a “green lung” tree growing along the Arabian Gulf coastline in the United Arab Emirates. Here, we aimed to determine the impact of the application of a commercial seaweed extract (SWE) biostimulant and endophytic actinobacterial isolates on growth performance and endogenous hormonal levels of mangroves. Therefore, we isolated endophytic plant growth-promoting (PGP) actinobacteria (PGPA) from mangrove roots and evaluated their potential as biological inoculants on mangrove seedlings under greenhouse and open-field nursery conditions. Seven salt-tolerant isolates had the ability to produce different levels ofin vitroplant growth regulators (PGRs) and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase (ACCD) and to solubilize phosphorus. Accordingly, only one isolate,Streptomyces tubercidicusUAE1 (St), was selected based on its relative superiority in displaying multiple modes of action and in successfully colonizing mangrove tissues for 15 weeks. In the greenhouse experiments, plants treated withStand SWE significantly (p&amp;lt; 0.05) improved dry biomass by 40.2% and 55.1% in roots and 42.2% and 55.4% in shoots, respectively, compared to seawater-irrigated non-treated mangrove plants (control). However,St+SWE caused a greater significant (p&amp;lt; 0.05) increase in dry weight of roots (67.6%) and shoots (65.7%) than did control plants. Following the combined treatment ofSt+SWE,in plantaPGR levels were found to be greatly enhanced over the non-treated control plants grown in non-SWE supplemented sediments, or plants inoculated with onlySt without the supplementation with SWE,or with non-inoculated plants grown in sediments supplied with SWE only. This was evident from the significant (p&amp;lt; 0.05) increases in the photosynthetic pigments and production of PGRs, as well as the reduction in the endogenous ACC levels of plant tissues compared to those in other treatments. Tissue nutrient contents of seedlings also increased by at least two-fold inSt+SWE treatment as compared to control. Similar effects were observed on all growth parameters under natural open-field nursery conditions. CombiningStwith SWE not only stimulates plant growth but also potentially has additive effects on mangrove ecosystem productivity in nutrient-impoverished soils in the Arabian coastal areas. This report is the first in the field of marine agriculture that uses SWE as a nutrient base for actinobacteria capable of producing PGRs and ACCD.

Pertumbuhan dan Hasil Tanaman Sawi Pagoda (Brassica narinosa L.) Akibat Pemberian Pupuk Organik Cair Kascing, Papua Nutrient dan MA-11

This research was conducted at the screen house of the Faculty of Agriculture, University of Papua. The objective was to determine the best type of liquid organic fertilizer for the growth and yield of Pagoda mustard plants. Using a non-factorial randomized block design (RAK), with 4 treatments repeated 4 times, in order to obtain 16 trials. The treatments in this study included 1) Control, 2) Liquid organic fertilizer Kascing (10 ml), 3) Papua Nutrient liquid organic fertilizer (10 ml), 4) MA-11 liquid organic fertilizer (10 ml + 10 g granulated sugar). The results showed that the fertilizer treatment in Papua Nutrient showed a significant effect. This treatment gave the best results when compared to the Kascing fertilizer treatment and the MA-11 fertilizer treatment. The Papua Nutrient fertilizer treatment had a significant effect on plant height, leaf width, growth rate, leaf width increase rate, wet weight and root weight with the highest average.

Trichoderma spp. promote root growth and high populations of Meloidogyne enterolobii on tomato crop

Summary Meloidogyne enterolobii is an emerging pathogen in Brazil, considered highly destructive to tomato. Due to the lack of cultivars resistant to this nematode, the objective of this work was to evaluate the effect of Trichoderma spp. strains on the promotion of tomato growth and biological control of M. enterolobii populations. The use of eight strains from the CENARGEN collection and three formulated products at a concentration of 1.43 × 106 conidia ml−1 significantly increased the fresh weight of roots compared to control plants inoculated only with nematodes. These Trichoderma strains, except CEN316, also promoted a significant increase in the number of nematodes and in the reproduction factor (RF). With the increase of spore concentration (1 × 108 conidia ml−1) in the second assay, the inoculation of nematode or fungi plus nematode promoted an increase in the fresh weight of roots, except in treatments CEN162, CEN287, UFT 201, and CEN287 + nematodes, which maintained the fresh weight of roots equal to the control without nematodes. None of the spore concentrations (1.43 × 106 and 1 × 108 ml−1) of different Trichoderma spp. strains influenced the plant height (45 and 90 days after nematode inoculation) or the dry plant weight 90 and 110 days after nematode inoculation, respectively. However, there was a positive and significant correlation between RF and fresh root weight, eggs (g root)−1 and total eggs, in the two doses. Furthermore, the Trichoderma spp. strains did not result in control of M. enterolobii under glasshouse conditions after a complete life cycle of the tomato plant: high nematode infection was observed in both doses of the fungi, including in treatments with the commercial formulations.