Inoculation Of Seeds Research Articles

Synergistic Effects of Seed Inoculation with Piriformospora indica and Foliar Hormonal Application on Early Flowering in Rice Bean (Vigna umbellata) Variety Surabhi

This study aimed to evaluate the effectiveness of seed inoculation with Piriformospora indica and various foliar hormonal treatments in promoting early flowering in fodder rice bean (Vigna umbellata Thunb.), variety Surabhi, conducted at the College of Agriculture, Vellayani. The experiment was laid out in randomized block design with ten treatments and three replications. The plot size of 3 m2 was followed in the field experiment. The experiment assessed the impact of different treatments on flowering and other biometric traits in the leguminous crop. The treatments included untreated control, seed inoculation with Piriformospora indica before sowing and foliar applications of salicylic acid (100 ppm,150 ppm), GA₃ (200 ppm,300 ppm), Paclobutrazol (10 ppm,20 ppm) and KNO₃ (1%,1.5%) at 30 days after sowing (DAS). The results revealed that significant differences were observed among treatments for all thirteen biometric traits measured. Early flowering was recorded in plants treated with salicylic acid @ 100 ppm(65.35 days), followed by GA₃ @ 300 ppm (67.72 days), salicylic acid @ 150 ppm (67.81 days), and Paclobutrazol @ 10 ppm (69.87 days), whereas the control flowered last (80.96 days. The findings suggest that the application of specific concentrations of growth regulators and seed inoculation with P.indica can effectively reduce the time to flowering, enhancing the potential for improved seed production in fodder rice bean.

The Effects of Seed Inoculation with Bacterial Biofilm on the Growth and Elemental Composition of Tomato (Solanum lycopersicum L.) Cultivated on a Zinc-Contaminated Substrate

Biofilm obtained from Bacillus subtilis subsp. spizizenii inoculated on vegetable seeds has been shown to have plant growth-promoting capacity. Seed inoculation with biofilm produced by this strain could also reduce the adverse effects on plant growth caused by soil or substrate heavy metal overabundance. Therefore, the objective of this work was to evaluate the impact of biofilm inoculated on tomato (Solanum lycopersicum L.) seeds, which were planted on a substrate with artificially added zinc. First, seeds of the Río Grande tomato variety were exposed to increasing zinc concentrations, namely: 50, 100, 200, and 400 ppm, with and without bacterial biofilm inoculation. Zinc addition and seed inoculation affected germination parameters. For example, an extra 200 and 400 ppm of zinc led to high toxicity. Biofilm inoculation, however, reduced the noxious effects of excess zinc, bringing acute toxicity down to moderate. Then, tomato plants growing from inoculated and non-inoculated seeds were cropped for 4 months in both substrates with 400 ppm zinc and without added zinc. Extra zinc addition significantly (p < 0.05) reduced tomato root and shoot biomass, plant height, and fruit number at harvest time. However, seed biofilm inoculation avoided the harmful effect of zinc on plant growth parameters, fruit yield, and fruit quality. The roots and shoots of plants growing on contaminated substrates showed very noticeable increases in zinc levels compared to the control, while fruits only showed a much weaker zinc gain, even if this was significant (p < 0.05). Moreover, root shoot and fruit concentrations of elements other than zinc, (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, copper, lead, and cadmium) were not or only weakly affected by the addition of this metal to the substrate. In summary, the biofilm of B. subtilis proved to be effective as a bioinoculant to alleviate negative effects on tomatoes cropped in a substrate with excess zinc.

Use of microbiological preparations in the cultivation of promising soybean varieties in the Oryol region

We studied the effect of microbiological preparations on increasing the yield of soybeans of different varieties. The work was carried out in the conditions of the Oryol region in 2019–2023. Objects of research: soybean varieties Leader 1, Mezenka, Orleya, Osmon, Zusha, as well as Biostim Start preparations, Rizoform Soya, Organit Р, Organit N, Pseudobacterin 3, Biodux, used in pre-sowing seed treatment and foliar feeding of soybean plants in phases 1…3 of trifoliate leaves and budding. The highest increase in soybean yield (6.0 %) compared to the control is provided by inoculation of seeds of the Zusha variety with Rizoform Soya in combination with Biostim Start. Pre-sowing seed treatment in combination with foliar fertilizing with preparations Organit Р, Organit N, Pseudobacterin 3, Biodux in the presence of native races of rhizobacteria in the soil contributed to the introduction of microorganisms included in their composition into the rhizosphere community of plants with subsequent participation in the activation of nitrogen nutrition processes of the latter. On average, for varieties, the number and weight of nodules in the variant with pre-sowing treatment and 2 foliar applications increased by 57.6 and 65 %, respectively, compared to the control, nitrogenase activity – by 67.3 %. The use of a combination of the preparations Organit Р, Organit N, Pseudobacterin 3 and Biodux by pre-sowing seed treatment and one foliar feeding in the phase 1…3 of trifoliate leaves provided the greatest increase in the yield of the Leader 1 variety 0.29 t/ha, Zusha – 0.35, Mezenka – 0 .40 t/ha. The maximum increase in protein content in grain was observed in the Mezenka variety in the variant with pre-sowing seed treatment and 1 or 2 foliar fertilizers – by 1.1 and 1.0 %, respectively.

Nitrogen Application and Seed Inoculation with Bradyrhizobium japonicum Bacteria Improved Yield and Quality Traits of Soybean [Glycine max (L.) Merrill] Grown as Second Crop

Nitrogen Application and Seed Inoculation with Bradyrhizobium japonicum Bacteria Improved Yield and Quality Traits of Soybean [Glycine max (L.) Merrill] Grown as Second Crop

Специфика фототрофных наземных микробных комплексов в посевах пшеницы

The article presents the results of determining the species and quantitative composition of algae and cyanobacteria in terrestrial growths under wheat crops. The wheat seeds were inoculated with various microorganisms in mono-, binary and triple combinations before sowing. Algocyanoflora of the “blooming” soil was represented by 24 species: Cyanobacteria – 7; Chlorophyta + Streptophyta – 12; Bacillariophyta – 5. The inoculants were representatives of prokaryotic and eukaryotic microorganisms – antagonists of Fischerella muscicola, Trichoderma sp. and the phytopathogen Fusarium culmorum. In one of the experimental variants, pre-sowing treatment with the fungicide “Maksim”® was used. It has been shown that during the formation of soil “blooming” the dominant microbiomes are green algae (Chlorococcum infusionum, Klebsormidium flaccidum) and cyanobacteria (species of the genera Leptolyngbya, Phormidium). When determining the number of phototrophic populations, it was found that their density ranges from 1.8 to 8.1 million cells/cm2. At the same time, the maximum development of phototrophs was found in the control variant, and the minimum number was found in the variant with a chemical disinfectant. In variants with microbial inoculation, the peak development of microphototrophs is typical for treatment with a triple mixture and a binary mixture of Fischerella + Trichoderma. Determination of the structure of microbial populations showed that the strongest dominance of cyanobacteria (80,2%) was detected on an artificial infectious background caused by pre-sowing inoculation of wheat seeds with the phytopathogen F. culmorum. A relatively high content of cyanobacteria (up to 60%) is observed in 4 experimental variants (Fischerella, Fischerella + Trichoderma, Trichoderma + Fusarium, Fischerella +Fusarium) and in the remaining 4 variants there is some dominance of microscopic algae ranging from 52 to 58%. Therefore, according to the results obtained, microbial inoculation does not lead to radical changes in the state of terrestrial phototrophic microbial communities, while chemical fungicide significantly suppresses the development of algae and cyanobacteria.

Фосфатмобилизующие микроорганизмы сельскохозяйственных растений аридных экосистем Астраханской области

Crop productivity and yield are negatively affected by the deficiency of phosphorus in agricultural soil. Phosphate fertilizers are widely used to improve crop yields globally. Therefore, there is an urgent need to increase plant-available phosphorus in soil using feasible environmentally friendly technologies. Isolation and screening of strains with increased phosphate-solubilzing activity are necessary stages of research to intensify the phosphorus nutrition of plants by presowing inoculation of seeds with effective microorganisms. 50 isolates of microorganisms (49 bacterial and 1 yeast) were isolated from the rhizosphere and rhizoplane of agricultural plants in arid ecosystems of the Astrakhan region. Bacterial isolates are morphologically represented by Gram-positive spore-forming (3 pcs.) and non-spore-forming (43 pcs.) rod-like bacteria and cocci (3 pcs.). Preliminary screening of phosphate solubilization by isolates on solid nutrient media revealed a group of 6 isolates with maximum specific phosphate mobilization (the specific phosphate mobilization coefficient – Kr –value was 2.0–6.9 units) and the ability to reduce the pH of the medium. Determination of the dynamics of mobile phosphate content allowed us to identify an isolate capable of maintaining the mobile phosphorus amount at up to 6 μmol/ml and lowering in pH up to 4.73 in the medium. The studied isolate should be recommended as the basis of a biological preparation for optimizing the mineral nutrition of plants.

Nitrogen sources and defoliation levels in cowpea bean

This study was aimed at evaluating the effect of artificial defoliation and different nitrogen sources on production traits of cowpea using mixed generalized linear models. The experiment was developed in a 3x5x2 factorial arrangement, being: three Nitrogen sources; five levels of artificial defoliation; and two defoliation seasons, with four repetitions. The plots were distributed in the Randomized Block Design, developed in a greenhouse and in the field. The following characteristics were evaluated: number of pods produced per plant; number of grains produced per pod; number of grains produced per plant; average length of pods; average weight of 100 grains; and estimated production. The GLIMMIX procedure was used because it allows the probability distribution of the response variable to take the appropriate distribution model. Production per Hectare (PHA) of plants subjected to leaf loss area can be increased up to 50% defoliation level, the variety Tumucumaque overcompensates in productivity, with maximum yields at 27.03% of defoliation and significant decrease above 75%, regardless of phenological stage. Even with losses above these levels, this cultivar had high indexes of productivity, revealing its high resistance to leaf loss injury. The use of chemical nitrogen fertilization and inoculation of cowpea seeds, variety Tumucumaque with Bradyrhizobium is unnecessary in the edaphoclimatic conditions of Bom Jesus – PI; The use of nitrogen fertilization with ammonium sulfate and inoculation of cowpea seeds with Bradyrhizobium does not influence the resistance of the Tumucumaque variety to defoliation levels; Defoliation levels above 75% impair the performance of production traits of cowpea, Tumucumaque.

Genetic Diversity and Virulence of Phytopathogenic Burkholderia glumae Strains Isolated from Rice Cultivars in Valleys of the High Jungle of Perú.

Burkholderia glumae causes bacterial leaf blight in rice, and its global spread has been exacerbated by climate change. To understand the genetic diversity and virulence of B. glumae strains isolated from rice cultivars in Perú, 47 isolates were obtained from infected rice fields, all belonging to B. glumae, and confirmed by recA and toxB sequences. The BOX-PCR typing group has 38 genomic profiles, and these turn into seven variable number tandem repeats (VNTR) haplotypes. There was no correlation between clustering and geographical origin. Nineteen strains were selected for phenotypic characterization and virulence, using both the maceration level of the onion bulb proxy and inoculation of seeds of two rice cultivars. Several strains produced pigments other than toxoflavin, which correlated with onion bulb maceration. In terms of virulence at the seed level, all strains produced inhibition at the root and coleoptile level, but the severity of symptoms varied significantly between strains, revealing significant differences in pathogenicity. There is no correlation between maceration and virulence scores, probably reflecting different virulence mechanisms depending on the host infection stage. This is the first study to evaluate the VNTR diversity and virulence of Peruvian strains of B. glumae in two commercial cultivars.

First report of Colletotrichum chlorophyti causing soybean anthracnose in Brazil.

Soybean [Glycine max (L.) Merr.] is one of the world's five major food crops, and Brazil produces the highest share at around 42%. Anthracnose caused by Colletotrichum is an important limiting factor to soybean production. In November 2013, anthracnose symptoms, characterized by brown irregular-shaped lesions on petioles, stems, and pods were observed in soybean fields (1% of incidence) in Vera, Mato Grosso State, Brazil. From the five plants gathered in the field, three leaves along with their corresponding petioles were meticulously chosen for the removal of symptomatic tissues. Sampling of these tissues involved carefully cutting a 0.5 × 0.5 cm fragment in the lesion area. The fragments were disinfected with 70% ethanol for 1 min, followed by 1% sodium hypochlorite for 2 min. Then the fragments were rinsed three times in sterile distilled water, placed on water-agar, and incubated at 25 °C for four days, in a 12/12 h photoperiod. Hyphal tips were transferred to potato dextrose agar (PDA) plates and incubated as previously described for seven days. A Colletotrichum sp. single-spore isolate (LFN0461) was selected, grown, preserved in filter paper, and stored at -80 °C. In 2023, it was reactivated for molecular characterization. On PDA, colony showed a rough-like mycelial growth, violaceous-black (front/reverse), with curved-shaped conidia 14.7 - 28.2 × 2.1 - 8.96 µm (average 18.4 × 4.7 µm). The DNA was extracted from 10-day-old mycelium using the cetyltrimethylammonium bromide (CTAB) method. The rDNA internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), histone (HIS3), and β-tubulin 2 (TUB2) regions were amplified by polymerase chain reaction (PCR), using the primer pairs ITS-1F + ITS-4 (Gardes and Bruns 1993; White et al. 1990), GDF1 + GDR1 (Guerber et al. 2003), CYLH3F + CYLH3R (Crous et al. 2006), and Bt2A + Bt2B (Glass and Donaldson 1995), respectively. The sequences were deposited in the GenBank database (accession numbers: PP209207 - ITS; PP213392 - GAPDH; PP213393 - HIS3; MN688797 - TUB2). The reconstruction of the multilocus phylogenetic tree revealed that the LFN0461 isolate clustered with C. cholorophyti reference strain (IMI 103806) with 99.9% of Bayesian probability. Given the seed-borne nature of soybean anthracnose (Boufleur et al. 2021; Yang et al. 2013), pathogenicity tests were carried out by soybean seeds inoculation. Fifty seeds of NS6220 IPRO (Nidera) cultivar were inoculated by water restriction method, with LFN0461 colonies grown on PDA amended with mannitol (Machado et al. 2004), while 50 seeds were placed on PDA amended with mannitol as negative control. Soybean seeds remained in contact with the inoculum for 48 hours. Subsequently, seeds were sown in 2 L pots (n = 10) containing sterilized substrate, which were placed in a greenhouse at 25 ± 5 ºC. After 10 days, inoculated soybean seedlings exhibited characteristic necrotic lesions on cotyledons and hypocotyls, while negative control plants remained asymptomatic. Colletotrichum chlorophyti was successfully reisolated from the symptomatic tissues. Currently, C. chlorophyti has been reported to cause soybean anthracnose and infect seeds in the United States (Yang et al. 2013, 2012). Although this pathogen has not been reported since our first observation in 2013 in Brazil, many Colletotrichum isolates are misidentified due to reliance on morphology (Boufleur et al. 2021). To our knowledge, this study is the first report of C. chlorophyti causing soybean anthracnose in Brazil, joining a new group of emergent Colletotrichum spp. associated with this disease.

Sustainable Methods of Soybean Cultivation in Poland

Many countries in Europe are struggling with a shortage of feed protein; moreover, efforts are being made to limit the import of post-extraction soybean meal, most often from GMO crops. To achieve the above assumptions, varietal progress is necessary and, above all, breeding work should aim at greater adaptation to regional conditions. This study was designed to evaluate the potential for growing Ukrainian soybean ‘Annushka’ in the southeastern Baltic Sea area, in accordance with the application of mineral nitrogen fertilizer and the inoculation of seeds with Bradyrhizobium japonicum. Soybean ‘Annushka’ yielded 0.98–1.68 t ha−1 in the conditions of central Poland. Our experiments have shown significant variations in seed, protein, and fat yields over the years. The maximum amounts of these characteristics were recorded in 2017. Nitrogen fertilization combined with seed inoculation with B. japonicum has proven to be an important factor in improving soybean yields; however, it slightly modified the content of organic compounds in seeds. Improvement in seed and protein yields relative to the control amounted, respectively, to Nitragina + 30 kg N ha−1 (58.8%; 72.6%), HiStick® Soy + 30 kg N ha−1 (57.6%; 68.3%), and Nitroflora + 60 kg N ha−1 (57.6%; 71.9%).

Soybean Response to Seed Inoculation with Bradyrhizobium japonicum and/or Nitrogen Fertilization

Seed inoculation with symbiotic bacteria is a commonly employed practice in soybean cultivation. As a result, nodulation proceeds properly and plants self-supply atmospheric nitrogen, requiring either minimal or no additional nitrogen fertilization. The aim of the study was to investigate the response of soybeans to the application of the recommended or double dose of commercial inoculants (HiStick® Soy or TURBOSOY®) and/or mineral nitrogen fertilization compared to the untreated control. It was demonstrated that a double dose of the tested preparations had the most favorable effect on nodulation. However, the impact of weather conditions modified their effectiveness during the study years, which was especially visible in 2022. Sowing seeds without inoculation (control) resulted in the formation of sparse root nodules and consequently the lowest leaf area index (LAI) and soil plant analysis development (SPAD) measurements. In addition, the values of SPAD and LAI indices varied across the years of the study, indicating that weather conditions modified nitrogen uptake by plants. Overall, seed inoculation and/or nitrogen fertilization positively influenced the chemical composition of seeds compared to the control. The only decrease observed was in the oil content, while the double dose of HiStick® Soy preparation reduced the polyphenol content. The double dose of the tested inoculants had the most favorable impact on yield components and seed yield. However, applying inoculation at the recommended dose or in combination with nitrogen fertilization yielded similar or slightly worse results, depending on the year. Therefore, soybean seed inoculation should be recommended, although the effectiveness of the procedure will depend on various factors, including the type of inoculant, dosage, nitrogen fertilization, and weather conditions.

Azospirillum brasilense Inoculation in a Maize–Urochloa–Rice Cropping System Promotes Soil Chemical and Biological Changes and Increases Productivity

Large quantities of cover crop residues in the soil, combined, or not, with the inoculation of seeds with diazotrophic bacteria, can increase organic matter (OM) and protect soil microorganisms, such as arbuscular mycorrhizal fungi (AMF) and dark septate endophytic (DSE) fungi. Thus, the use of these sustainable biotechnologies can benefit microbial interactions, soil fertility and rice production in the Brazilian Cerrado region. In this study, we evaluated the effects of maize and Urochloa ruziziensis, intercropped or individually, as cover crops and an inoculation of Azospirillum brasilense on the chemical (fertility) and biological (C–microbial biomass and C–CO2 released) attributes of soil and the effects of root colonization by AMF and DSE on the yield of rice grown in succession in highlands. The experiment was conducted under field conditions, in a typical dystrophic Red Oxisol. The experimental design consisted of randomized blocks arranged in strips, incorporating a combination of eight residual cover crops: ((1) maize, (2) maize–I (I = inoculation of seeds with A. brasilense), (3) Urochloa (U. ruziziensis), (4) Urochloa–I, (5) maize + Urochloa–I, (6) maize + Urochloa–I, (7) maize–I + Urochloa and (8) maize–I + Urochloa–I). This was accompanied by two treatments of rice as a successor crop (inoculated or not with A. brasilense), with four replicates, totaling 64 experimental units. A cover crop and rice seed inoculation prompted increases in OM and AMF relative to DSE, while the inoculation of rice, regardless of the cover crop treatment, increased the soil’s P content. The combination of maize + Urochloa–I and inoculated rice as the next crop generated increases in its sum of bases (SBs) and cation exchange capacity (CEC). There was a 19% increase in rice grain yields when the seed was inoculated.

Improvement of millet cultivation technology in the Kabardino-Balkarian Republic

The article studies the effectiveness of using mineral fertilizers, growth stimulants and bacterial preparations in the cultivating millet technology. The research was carried out in 2021–2023 on the experimental field of the Kabardino-Balkarian Scientific Research Institute of Agriculture, which located in the steppe zone of the Kabardino-Balkarian Republic. The object of study is the mid-late millet variety Kavkazskie Zori, bred by Kabardino-Balkarian Research Institute of Agriculture. Inoculation of seeds with Rizoagrin (Agrobacterium radiobacter) and Azophyte (Azotobacter vinelandii) was carried out on the day of sowing, exogenous spraying of plants with growth stimulants Mival Agro (10 g/ha), MS-extra (0.5 kg/ha) – in the three-leaf phase. Treatment of seeds with biological preparations Rizoagrin and Azofit increases field germination by 8.9 and 5.3%, respectively, relative to the control. They also have a positive effecton the preservation of plants for harvesting. The usage of biological products provides an increase in the yield of millet by 0.38–0.54 t/hacompared to the control, fertilizers – 0.64 t/ha, growth stimulants – 0.27–0.46 t/ha. Maximum productivity was achieved with the biological product Rizoagrin and the growth stimulator MS-extra against the background of N10P26K26 – 2.48 t/ha.

Production of Seedlings of Corymbia citriodora Inoculated with Endophytic Bacteria

This study aimed to evaluate the effect of inoculants of endophytic bacteria producing indoleacetic acid (IAA) on the physiological quality of seeds and the production of seedlings of Corymbia citriodora (Hook.) KD Hill & LAS Johnson. In the physiological quality test of the seeds, the treatments used were individual inoculation with Priestia megaterium, Exiguobacterium sibiricum, Pantoea vagans strain 45URP4-1, and Bacillus sp.; joint effect of the four strains (mix); inoculation only with the carrier (cassava starch and activated charcoal); carrier with 1.0 μg mL−1 of IAA; and non-inoculated control without IAA and without a carrier. In the production of seedlings in a greenhouse, the treatments were the same, except for the mix, which was replaced by P. vagans strain 7URP1-6 (Pvs7), as inoculation with the mix increased the number of abnormal seedlings. In the physiological quality test of seeds, seeds inoculated with the bacteria individually did not have the physiological quality impaired and the carrier created a microenvironment around the seeds, benefiting germination percentage, germination speed index, average germination time, and average germination speed. In the greenhouse, seedlings inoculated with Pvs7, P. megaterium and E. sibiricum were taller, with a larger stem diameter and dry mass of shoot, roots, and total. Seeds inoculated with E. sibiricum had higher averages for height, chlorophyll b content, and shoot and total dry mass, as well as a greater ability to colonize the rhizosphere and roots of C. citriodora, resulting in the production of higher-quality seedlings. Inoculation of seeds of C. citriodora with endophytic bacteria proved to be a promising alternative for plant development.

Effect of Mineral Fertilization and Seed Inoculation with Microbial Preparation on Seed and Protein Yield of Pea (Pisum sativum L.)

The aim of this study was to determine the effects of different NPK rates and N application methods and seed inoculation with a microbial preparation on selected elements of plant growth and the productivity parameters seed yield, protein content in seeds and the yield of protein. The research hypothesis suggested that seed inoculation and a split rate of N application with an optimal supply of plants with PK could improve the nutritional status and increase the efficiency of nutrient use in peas. The studies included two factors: the application of NPK at doses of N0P0K0 (control), N15P15K15 (pre-sowing), N15P30K30 + N15 (pre-sowing + N15 at BBCH 22–23), N30P30K30 (pre-sowing), N30P45K45 + N15 (pre-sowing + N15 at BBCH 22–23) and N45P45K45 (pre-sowing), and seed inoculation with the microbial preparation Rhizogumin. The results of the study showed significant effects of seed inoculation and mineral fertilization on pea plant growth and the productivity parameters seed yield, protein content and protein yield. It was concluded that among the studied combinations, seed inoculation and the application of mineral fertilizers with fractional nitrogen fertilization with N30P45K45 + N15 were the most effective. This combination significantly increased seed yield, protein content and protein yield compared to the control treatment (by 26.2%, 11.1% and 43,5%, respectively).

Bacillus aryabhattai dose recommendation for corn seed inoculation

The use of plant growth-promoting bacteria (PGPB) can be a sustainable alternative to improve the uniformity and speed of emergence and initial growth of plants. However, the effects of Bacillus aryabhattai inoculation are still incipient and inconclusive, and there is no recommendation for the use of inoculant doses containing B. aryabhattai. This study was conducted to investigate the effectiveness of B. aryabhattai inoculation in improving the germination and initial growth of corn plants (Zea mays L.), and to determine the optimal inoculant dose to be recommended for inoculation of corn seeds. Corn seeds were inoculated with 0, 10, 20, 30 and 40-mL kg–1 of the inoculant containing the strain CMAA 1363 of Bacillus aryabhattai. Four replicates of 50 seeds were sown in plastic boxes containing washed coarse sand. At 18 days after sowing, the emergence rate (E), shoot length (SL), root length (RL), shoot dry matter (SDM) and root dry matter (RDM) was recorded. The results showed that the use of inoculant containing B. aryabhattai improved the initial growth and dry matter production of corn plants. This suggests that B. aryabhattai could be an excellent option for producing microbiological inoculants with enormous potential for use in Brazilian and global agriculture. The optimal dose of inoculant containing B. aryabhattai to be applied to corn seeds can range between 20 and 22-mL kg–1 of inoculant.

Mass Production of Arbuscular Mycorrhizal Fungi on the Sorghum Plants Inoculated with Burkholderia arboris Using Soybean Mill Waste and Vermicompost-Amended Soil-Sand Substrate.

Arbuscular mycorrhizal (AM) fungi are being used as a new generation of biofertilizers to increase plant growth by improving plant nutrition and bio-protection. However, because of the obligatory nature of the plant host, large-scale multiplication of AM propagules is challenging, which limits its applicability. This study evaluates the ability of Burkholderia arboris to increase AM production in soybean mill waste and vermicompost amended by soil-sand mixture planted with sorghum as a host plant. The experiment was conducted in a nursery using a completely randomized design with four inoculation treatments (B. arboris, AM fungi, B. arboris + AM fungi, and control) under sterilized and unsterilized conditions. AM production was investigated microscopically (spore density and root colonization), and biochemically (AM-specific lipid biomarker, 16:1ω5cis derived from neutral lipid fatty acid (NLFA), and phospholipid fatty acid (PLFA) fractions from both soil and roots). Integrating B. arboris with AM fungi in organically amended pots was found to increase AM fungal production by 62.16 spores g-1 soil and root colonization by 80.85%. Biochemical parameters also increased with B. arboris inoculation: 5.49nmol PLFA g-1 soil and 692.68nmol PLFA g-1 root and 36.72nmol NLFA g-1 soil and 3147.57nmol NLFA g-1 root. Co-inoculation also increased glomalin-related soil protein and root biomass. Principal component analysis (PCA) further supported the higher contribution of B. arboris to AM fungi production under unsterilized conditions. In conclusion, inoculation of AM plant host seeds with B. arboris prior to sowing into organic potting mix could be a promising and cost-effective approach for increasing AM inoculum density for commercial production. Furthermore, efforts need to be made for up-scaling the AM production with different plant hosts and soil-substrate types.

Impact of Seed Inoculation with Trichoderma afroharzianum Strains on Plant Growth, Root Morphology, and Leaf Phenolic Content in Hemp (Cannabis sativa L.) at Early Growth Stages

Industrial hemp (Cannabis sativa L.) is receiving increasing attention for its multiple end-uses; therefore, an improvement in its production is needed to meet the increased demand. In the present study, the effect of seed inoculation with two Trichoderma afroharzianum strains, T-AA and T-22, on plant growth and root morphology of hemp plants at sixth-leaf (S6) and tenth-leaf (S10) stages was assessed for two consecutive years (2020 and 2021). In addition, the ability of the two strains to enhance the accumulation of phenolic compounds in hemp leaves was also evaluated. The results obtained revealed the ability of T-22 to improve the growth and root morphology of hemp plants both in 2020 and 2021, although with different impact, probably ascribable to the different weather conditions in the two years. In 2020, the positive effects of T-22 were detected at S10 stage with significant increases in the shoot and root length (38% and 17%, respectively) and dried biomass (35% and 30%, respectively) compared to untreated plants. The total root surface area and the number of tips, forks, and crossings also increased significantly (24–36%) at this stage. In 2021, significant increases in the shoot length and dried biomass (40% and 30%, respectively) were observed at S6 stage, whereas root length and dried biomass increased significantly at S6 (55% and 47%, respectively) and S10 stage (121% and 40%, respectively). Significant increases in the total surface area and volume, as well as in the number of tips, forks, and crossings were also observed at both S6 and S10 stage (50–63% and 105–187%, respectively). Interestingly, in both years and at both stages, the two strains induced significant increases in the leaf accumulation of phenolic compounds and the antioxidant activity, which were greater in T-22- compared to T-AA-treated plants (18–102% and 13–34%, respectively). The results are discussed in light of the potential practical applications of T-22 as a biostimulant of hemp plant growth under favorable and unfavorable environmental conditions, and of both strains as promising tools for the improvement of the leaves’ economic value as a source of health-promoting compounds.

Influence of nitrogen fertilization, seed inoculation and the synergistic effect of these treatments on soybean yields under conditions in south-western Poland

Soybean, belonging to legumes, has a specific ability to biological nitrogen fixation, which can be reinforced by seeds inoculation. However, support with a starter dose of mineral nitrogen fertilizer may be necessary to achieve high seed yields. A four-year field experiment was conducted to determine the effect of mineral N fertilization (0, 30, 60 kg ha−1), seed inoculation with two commercial inoculants and combinations of these treatments on yield components and yielding of soybean in conditions of south-western part of Poland. The synergistic effect of mineral fertilization at dose 30 kg ha−1 and inoculation on soybean productivity was the most beneficial. Similar effects were observed when 60 kg N ha−1 was applied both separately and with inoculation. However, due to the environmental impact of mineral fertilizers and to promote plants to biological nitrogen fixation (BNF), it is advisable to use lower doses of N fertilizer (at 30 kg ha−1) and inoculate soybean seeds in agro- climatic conditions of south-western Poland. Therefore, based on this study we recommend to apply starter dose of N and inoculation.

Effect of endophytic strains of Bacillus subtilis on mycorrhization of wheat roots under salt stress

The effect of inoculation of wheat plant seeds by cells of 2 endophytic strains of Bacillus subtilis on the formation of endomycorrhiza in the roots under salt stress was studied. It was found that the indicators of mycorrhization of plant roots decreased both during salt stress in the soil and during seed treatment with endophytic bacteria. At the same time, under conditions of salt stress, an increase in mycorrhization rates was found in plants inoculated with B. subtilis. It was revealed that B. subtilis bacteria reduced stress in plants resulting from soil salinization. The obtained results showed the possible nature of the simultaneous relationship of plants with representatives of two kingdoms – bacteria and fungi. Probably, under conditions of stress action on the host plants, it is more profitable for all 3 participants of the symbiotic system to survive together, preserving the reproductive potential for the next generations.