Search

Beneficial microbes colonizing plant tissues are recognized as a value-added soil amendment for enhancing soil fertility. The present study aimed to evaluate the effects of co-inoculation with plant growth-promoting endophytic actinobacteria and nitrogen-fixing rhizobacteria for improved growth attributes, soil properties, microbial activity, yield, and nutrient uptake of wheat under field conditions for two consecutive years. Three endophytic actinobacterial isolates, Streptomyces sp. strain WR27, Streptomyces sp. strain WR15, and Streptomyces sp. strain WS6 were evaluated alone and in combination with nitrogen-fixing bacteria, Azotobacter in field experiment with recommended fertilization rate in north-western Indian plains. Results of the study indicated that all the growth attributes were higher in treatments receiving microbial inoculants than un-inoculated control. It was also observed that inoculation with actinobacterial isolates significantly increased total number of tillers m−2, spike length, number of grains spike−1, and 1000 grain weight as compared to control. Streptomyces sp. strain WR27 + Azotobacter and Streptomyces sp. strain WR15 + Azotobacter exhibited maximum grain yield (5.7 t ha−1, respectively) as compared to control (5.0 t ha−1). The treatment involving inoculation with Streptomyces sp. strain WR27 + Azotobacter recorded higher nutrient contents. Soil properties were significantly increased by application of actinobacterial inoculants in both years over the un-inoculated control. Furthermore, among different inocula, Streptomyces sp. strain WR27 + Azotobacter dual inoculation exhibited highest response efficiency for all the traits studied. Therefore, the results revealed multiple benefits of plant growth-promoting actinobacteria and Azotobacter inoculation for wheat crop in terms of improved soil properties and macronutrient content without hampering the soil fertility and productivity. Thus, it could be recommended as a plant growth-promoting bacteria for wheat at the recommended level of fertilizer application rates for field use in north-western India. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Nodule bacteria (rhizobia) represent the highly developed model for the evolutionary genetics of symbiotic microorganisms. We propose to divide these polyphyletically originated bacteria into two groups that have arisen through: a) genomic rearrangements in free-living N2-fixers (primary rhizobia originated via the phyletic evolution strategy); b) transfer of symbiotically specialized (sym) genes from rhizobia to various soil and plant-associated bacteria (secondary rhizobia originated via the reticular evolution strategy). Primary rhizobia are represented by genus Bradyrhizobium close to Rhodopsedomonas. Transformation of these phototrophic N2-fixers into plant symbionts is evidenced by transitional (ancestral) Bradyrhizobium genotypes that combine the legume nodulation with photosynthesis. A crucial stage in rhizobia evolution was represented by acquisition of the ability to produce lipochitooligosaccharide Nod factors (NFs) eliciting the nodule development. Acquisition of NF synthesis allowed the ancestral Bradyrhizobium strains to switch from autotrophy to assimilation of the plant photosynthesis products resulted in heterotrophic bradyrhizobia (e.g., B. japonicum, B. elkanii) harboring sym genes in chromosomes. The best studied secondary rhizobia are represented by the Rhizobiaceae (Rhizobium, Sinorhizobium, Neorhizobium) species in which sym genes are located in mobile plasmids or chromids. Interactions of these species with legumes may be addressed as altruistic symbiosis based on development of non-reproducible bacteroids which supply hosts with N compounds. Since the rhizobia evolution involves the "gain-and-loss" genetic strategy, constructing highly active strains for legume crop inoculation should be based on activation of positive regulators of symbiotic N2 fixation and on inactivation of its negative regulators. [ABSTRACT FROM AUTHOR]

The growing human population has a greater demand for food; however, the care and preservation of nature as well as its resources must be considered when fulfilling this demand. An alternative employed in recent decades is the use and application of microbial inoculants, either individually or in consortium. The transplantation of rhizospheric microbiomes (rhizobiome) recently emerged as an additional proposal to protect crops from pathogens. In this review, rhizobiome transplantation was analyzed as an ecological alternative for increasing plant protection and crop production. The differences between single-strain/species inoculation and dual or consortium application were compared. Furthermore, the feasibility of the transplantation of other associated micro-communities, including phyllosphere and endosphere microbiomes, were evaluated. The current and future challenges surrounding rhizobiome transplantation were additionally discussed. In conclusion, rhizobiome transplantation emerges as an attractive alternative that goes beyond single/group inoculation of microbial agents; however, there is still a long way ahead before it can be applied in large-scale agriculture. [ABSTRACT FROM AUTHOR]

Copyright of Agroindustrial Science is the property of Agroindustrial Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Micronutrient deficiency is a serious health issue in resource-poor human populations worldwide, which is responsible for the death of millions of women and underage children in most developing countries. Zinc (Zn) malnutrition in middle- and lower-class families is rampant when daily calorie intake of staple cereals contains extremely low concentrations of micronutrients, especially Zn and Fe. Looking at the importance of the problem, the present investigation aimed to enhance the growth, yield, nutrient status, and biofortification of wheat crop by inoculation of native zinc-solubilizing Bacillus spp. in conjunction with soil-applied fertilizers (NPK) and zinc phosphate in saline soil. In this study, 175 bacterial isolates were recovered from the rhizosphere of wheat grown in the eastern parts of the Indo-Gangetic Plain of India. These isolates were further screened for Zn solubilization potential using sparingly insoluble zinc carbonate (ZnCO3), zinc oxide (ZnO), and zinc phosphate {Zn3(PO4)2} as a source of Zn under in vitro conditions. Of 175 bacterial isolates, 42 were found to solubilize either one or two or all the three insoluble Zn compounds, and subsequently, these isolates were identified based on 16S rRNA gene sequences. Based on zone halo diameter, solubilization efficiency, and amount of solubilized zinc, six potential bacterial strains, i.e., Bacillus altitudinis AJW-3, B. subtilis ABW-30, B. megaterium CHW-22, B. licheniformis MJW-38, Brevibacillus borstelensis CHW-2, and B. xiamenensis BLW-7, were further shortlisted for pot- and field-level evaluation in wheat crop. The results of the present investigation clearly indicated that these inoculants not only increase plant growth but also enhance the yield and yield attributes. Furthermore, bacterial inoculation also enhanced available nutrients andmicrobial activity in the wheat rhizosphere under pot experiments. It was observed that the application of B. megaterium CHW-22 significantly increased the Zn content in wheat strawand grains along with other nutrients (N, P, K, Fe, Cu, andMn) followed by B. licheniformis MJW-38 as compared to other inoculants. By and large, similar observations were recorded under field conditions. Interestingly, when comparing the nutrient use efficiency (NUE) of wheat, bacterial inoculants showed their potential in enhancing the NUE in a greater way, which was further confirmedby correlation and principal component analyses. This study apparently provides evidence of Zn biofortification in wheat upon bacterial inoculation in conjunction with chemical fertilizers and zinc phosphate in degraded soil under both nethouse and field conditions. [ABSTRACT FROM AUTHOR]

The global threat of food security and food production for ever-increasing population are the key challenges nowadays. Enhanced agriculture production and a rise in the quality of crops are needed. Sustainable and eco-friendly agriculture approaches are required to improve crop yield and nutritional value which is decreased because of an increase in population rate, changing climate and inflation in a hidden hunger. Crop biofortification could overcome these challenges. Biofortification will indirectly target low-income households who cannot afford a more diverse diet by capitalizing on the consistent daily intake of food staples. Biofortified crops can be developed by conventional plant breeding, agronomic strategies and genetic engineering but these have not always been successful. In recent years, use of naturally occurring microorganisms in the soil, i.e. plant growth promoting microbes (PGPM) most especially bacteria and mycorrhizal fungi has been recommended as a promising approach for the biofortification of important crops. Micronutrient contents in different plant tissues such as roots, leaves and fruits can be enhanced by inoculation of soil and crops with rhizospheric and endophytic microbes. PGPM fortifies crops by a different mechanism such as siderophore production, zinc solubilization, nitrogen fixation, and phosphate solubilization. Microbial biofortification is a novel strategy because it not only the increases concentration of micronutrients in edible food crops but also improves yield on less fertile soil. In this review we are emphasizing the biofortification of crops by microbes as a sustainable and cost-effective alternation for improving Fe, Zn and Se content of crops. [ABSTRACT FROM AUTHOR]

Remote sensing can offer stakeholders opportunities to make precise and accurate decisions on agricultural activities. For instance, farmers can exploit aircraft systems to acquire survey-level, high-resolution imagery data for crop and soil management. Therefore, the objective of this study was to analyze whether an unmanned aerial vehicle (UAV) allows for the assessment and monitoring of biofertilization of the common bean upon vegetation indices (VIs). The biological treatment of the legume crop included its inoculation with phosphate-solubilizing bacteria (PSB), namely Bacillus subtilis and B. megaterium. Indicators of photosynthetic performance, such as chlorophylls (a and b) and carotenoids, were measured from actively growing leaves to determine effectiveness. In addition, images were acquired in the field, both spatially and temporally, to establish functional relationships between biometric and computational features. Microorganisms manifested as growth-promoting agents to the crop as they significantly increased its quantities of light-harvesting pigments. VIs allowed for predicting their impact on photosynthetic performance, making them on-site markers of PSB. Therefore, this research can provide insights into the remote, non-destructive mapping of spectral changes in the common bean upon the application of PSB. Imagery data from UAV would enable producers to generate information on the crop to intervene in the field at the right time and place for improved utilization of biofertilizers. [ABSTRACT FROM AUTHOR]

Cucurbit leaf crumple virus (CuLCrV) is among the prominent viruses infecting cucurbits in the USA. Attainable procedures of virus inoculation to crops are prerequisite for screening of resistance against the virus. Because mechanical (non-vector-mediated) infection by cucurbit leaf crumple virus (CuLCrV) is inefficient in economically important crops, screening for CuLCrV resistance is currently laborious and time-consuming using transmission by viruliferous whiteflies. We constructed an infectious partial tandem repeat construct of an isolate of CuLCrV from Georgia, USA, in the plant expression binary vector pCambia2300 and transformed it into Agrobacterium tumifaciens strain EHA105. Agroinfiltration of this construct into the abaxial surface of the leaves of common bean (Phaseolus vulgaris L.) produced a systemic infection characteristic of CuLCrV, although this approach was not successful for yellow squash. However, we report a very efficient and reproducible inoculation procedure established in squash when the leaves were injured with a microneedle and rubbed it with cell suspension harbouring the infectious viral construct. [ABSTRACT FROM AUTHOR]

Plant growth-promoting bacteria (PGPB) are endowed with several attributes that can be beneficial for host plants. They opened myriad doors toward green technology approach to reduce the use of chemical inputs, improve soil fertility, and promote plants' health. However, many of these PGPB harbor antibiotic resistance genes (ARGs). Less attention has been given to multi-resistant bacterial bioinoculants which may transfer their ARGs to native soil microbial communities and other environmental reservoirs including animals, waters, and humans. Therefore, large-scale inoculation of crops by ARGs-harboring bacteria could worsen the evolution and dissemination of antibiotic resistance and aggravate the negative impacts on such ecosystem and ultimately public health. Their introduction into the soil could serve as ARGs invasion which may inter into the food chain. In this review, we underscore the antibiotic resistance of plant-associated bacteria, criticize the lack of consideration for this phenomenon in the screening and application processes, and provide some recommendations as well as a regulation framework relating to the development of bacteriabased biofertilizers to aid maximizing their value and applications in crop improvement while reducing the risks of ARGs invasion. [ABSTRACT FROM AUTHOR]

Due to the observed climate warming, water deficiency in soil is currently one of the most important stressors limiting the size and quality of plant crops. Drought stress causes a number of morphological, physiological, and biochemical changes in plants, limiting their growth, development, and yield. Innovative methods of inducing resistance and protecting plants against stressors include the inoculation of crops with beneficial microorganisms isolated from the rhizosphere of the plant species to which they are to be applied. The aim of the present study was to evaluate 12 different strains of rhizosphere bacteria of the genera Pantoea, Bacillus, Azotobacter, and Pseudomonas by using them to inoculate strawberry plants and assessing their impact on mitigating the negative effects of drought stress. Bacterial populations were assessed by estimates of their size based on bacterial counts in the growth substrate and with bioassays for plant growth-promoting traits. The physiological condition of strawberry plants was determined based on the parameters of chlorophyll fluorescence. The usefulness of the test methods used to assess the influence of plant inoculation with rhizosphere bacteria on the response of plants growing under water deficit was also evaluated. A two-factor experiment was performed in a complete randomization design. The first experimental factor was the inoculation of plant roots with rhizosphere bacteria. The second experimental factor was the different moisture content of the growth substrate. The water potential was maintained at −10 to −15 kPa under control conditions, and at −40 to −45 kPa under the conditions of water deficit in the substrate. The tests on strawberry plants showed that the highest sensitivity to water deficiency, and thus the greatest usefulness for characterizing water stress, was demonstrated by the following indices of chlorophyll "a" fluorescence: FM, FV, FV/FM, PI, and Area. Based on the assessment of the condition of the photosynthetic apparatus and the analysis of chlorophyll "a" fluorescence indices, including hierarchical cluster analysis, the following strains of rhizosphere bacteria were found to have favorable effects on strawberry plants under water deficit: the Bacillus sp. strains DLGB2 and DKB26 and the Pantoea sp. strains DKB63, DKB70, DKB68, DKB64, and DKB65. In the tests, these strains of Bacillus sp. exhibited a common trait—the ability to produce siderophores, while those of Pantoea sp. were notable for phosphate mobilization and ACCD activity. [ABSTRACT FROM AUTHOR]

Due to the costly energy demands of nitrogen (N) fixation, diazotrophic bacteria have evolved complex regulatory networks that permit expression of the catalyst nitrogenase only under conditions of N starvation, whereas the same condition stimulates upregulation of high-affinity ammonia (NH3) assimilation by glutamine synthetase (GS), preventing excess release of excess NH3 for plants. Diazotrophic bacteria can be engineered to excrete NH3 by interference with GS, however control is required to minimise growth penalties and prevent unintended provision of NH3 to non-target plants. Here, we tested two strategies to control GS regulation and NH3 excretion in our model cereal symbiont Azorhizobium caulinodans AcLP, a derivative of ORS571. We first attempted to recapitulate previous work where mutation of both PII homologues glnB and glnK stimulated GS shutdown but found that one of these genes was essential for growth. Secondly, we expressed unidirectional adenylyltransferases (uATs) in a ΔglnE mutant of AcLP which permitted strong GS shutdown and excretion of NH3 derived from N2 fixation and completely alleviated negative feedback regulation on nitrogenase expression. We placed a uAT allele under control of the NifA-dependent promoter PnifH, permitting GS shutdown and NH3 excretion specifically under microaerobic conditions, the same cue that initiates N2 fixation, then deleted nifA and transferred a rhizopine nifAL94Q/D95Q-rpoN controller plasmid into this strain, permitting coupled rhizopine-dependent activation of N2 fixation and NH3 excretion. This highly sophisticated and multi-layered control circuitry brings us a step closer to the development of a "synthetic symbioses" where N2 fixation and NH3 excretion could be specifically activated in diazotrophic bacteria colonising transgenic rhizopine producing cereals, targeting delivery of fixed N to the crop while preventing interaction with non-target plants. Author summary: Inoculation of cereal crops with associative diazotrophic bacteria that convert atmospheric nitrogen (N2) into ammonia (NH3) could be used to sustainably improve delivery of nitrogen to crops. However, due to the costly energy demands of N2 fixation, bacteria restrict excess production of NH3 and release to the plants. Diazotrophs can be engineered for excess NH3 production and release, however genetic control is required to minimise growth penalties and prevent unintended provision of NH3 to non-target weed species. Here, we engineer coupled control of N2 fixation and NH3 release in response to the signalling molecule rhizopine supplemented in vitro. This control circuitry represents a prototype for the future development of a "synthetic symbiosis" where bacterial N2 fixation and NH3 excretion could be specifically activated following colonisation of transgenic rhizopine producing cereals in the field, minimising bacterial energy requirements and preventing provision of NH3 to non-target plants. [ABSTRACT FROM AUTHOR]

Soil acidity is a serious problem constraining faba bean (Vicia faba L.) production in southern Ethiopia. Therefore, we conducted experiments in 2016 and 2017 to investigate the response of the crop to seed inoculation with Rhizobium bacteria and phosphorus application. The treatments consisted of inoculating seed of faba bean with three rhizobium isolates (FB-1018, FB-1035 and FB-Murdoch) plus one uninoculated and five rates of phosphorus fertilizer (0, 10, 20, 30, and 40 kg P ha−1). The experiments were laid out as a randomized complete block design in a factorial arrangement with three replications. We first tested the soil for selected physical and chemical properties. We then collected plant data on nodulation, yield components, and yield. The soil is strongly acidic (pH 5.1) and very low in contents of available phosphorus. The results revealed that the main effects of inoculation and phosphorus application significantly (P ≤ 0.01) influenced nodulation and yield. Inoculating faba bean seed with FB-1035 rhizobium isolate resulted in the highest grain yield of 3137 kg ha−1. Similarly, applying 30 kg P ha−1 resulted in the optimum grain yield of 3105 kg ha−1. We concluded that both seed inoculation and application of phosphorus fertilizer equally increased the yield of the crop, exceeding the yields of the respective control treatments by about 39% and 68%. The results imply that inoculating faba bean seed with Rhizobium bacteria is a valuable approach to enhance the yield of the crop for enhancing food and nutrition security with environmental sustainability. [ABSTRACT FROM AUTHOR]

Drought is one of the most detrimental environmental stressors to plants with the potential to decrease crop yields and affect agricultural sustainability. Native bacteria with beneficial traits enhance plant growth and help avoid and reverse the effects of drought in plants to a greater extent. In the present study, we aimed to (i) isolate drought tolerant Bacillus isolates from the rhizosphere soil of wheat crop grown at different locations in Jaisalmer district, Rajasthan state and (ii) further evaluate their ability to enhance plant growth and induce drought tolerance in wheat ( Var. HD-2967) grown under drought stress conditions. Of more than 100 isolates, two putative Bacillus isolates capable of tolerating 30 % polyethylene glycol-6000 (PEG-6000) [equivalent to -9.80 MPa (Megapascal)] were identified as Bacillus altitudinis DT-89 and Bacillus paramycoides DT-113. These isolates exhibited different plant growth promoting (PGP) attributes such as phosphate solubilization, and production of siderophore, exopolysaccharide, ammonia, indole acetic acid and cytokinin at low osmotic stress of 10% PEG-6000 but shown variable response at higher osmotic stress particularly at 30% PEG-6000. However, they did not show any antifungal activity and one isolate was negative for phosphate solubilization. Of two strains, B. altitudinis DT-89 function more prominently with respect to plant growth promotion and drought tolerance to plant in the early stage but protective traits of B. paramycoides DT-113 was more prominent after 75 days as evident by increased EPS (164%), root dry weight (144.44%), chlorophyll content (90.26%), SOD (389%) and proline (99.3%). The results support both the strains as a potential candidate to alleviate drought stress and enhance plant growth in the drought regions. [ABSTRACT FROM AUTHOR]

Zinc is an important micronutrient needed for the optimum growth and development of plants. Contrary to chemical zinc fertilizers, the use of zinc-solubilizing bacteria is an environmentally friendly option for zinc enrichment in edible parts of crops. This study was conducted with the objective of selecting potential zinc-solubilizing rhizobacteria from the rhizosphere of chickpea grown in soils of eastern Uttar Pradesh and further assessing their impact on the magnitude of zinc assimilation in wheat crops. Among 15 isolates, CRS-9, CRS-17, CRS-30, and CRS-38 produced net soluble zinc in broth to the tune of 6.1, 5.9, 5.63, and 5.6 μg ml–1, respectively, in zinc phosphate with the corresponding pH of 4.48, 5.31, 5.2, and 4.76. However, the bacterial strains CRS-17, CRS-30, CRS-38, and CRS-9 showed maximum zinc phosphate solubilization efficiency of 427.79, 317.39, 253.57, and 237.04%, respectively. The four bacterial isolates were identified as Bacillus glycinifermentans CRS-9, Microbacterium oxydans CRS-17, Paenarthrobacter nicotinovorans CRS-30, and Bacillus tequilensis CRS-38 on the basis of morphological and biochemical studies and 16S rRNA gene sequencing. Bacterial inoculants significantly colonized the roots of wheat plants and formed a biofilm in the root matrix. These strains significantly increased seed germination (%) and vigor indices in wheat grown under glasshouse conditions. After 30 days of sowing of wheat under microcosm conditions, eight zinc transporter (TaZIP) genes were expressed maximally in roots, with concomitant accumulation of higher zinc content in the bacterially treated plant compared to the absolute control. Out of the four strains tested, two bacteria, B. tequilensis CRS-38 and P. nicotinovorans CRS-30, improved seed germination (%), vigor indices (2–2.5 folds), plant biomass, grain yield (2.39 g plant–1), and biofortificated grains (54.25 μg g–1Zn) of wheat. To the best of our knowledge, this may be the first report on the presence of zinc solubilization trait in B. glycinifermentans CRS-9, M. oxydans CRS-17, and P. nicotinovorans CRS-30. [ABSTRACT FROM AUTHOR]

Soil salinity has a serious impact on plant growth and agricultural yield. Inoculation of crop plants with fungal endophytes is a cost-effective way to improve salt tolerance. We used metabolomics to study how Trichoderma harzianum T-22 alleviates NaCl-induced stress in two barley (Hordeum vulgare L.) cultivars, Gairdner and Vlamingh, with contrasting salinity tolerance. GC-MS was used to analyse polar metabolites and LC-MS to analyse lipids in roots during the early stages of interaction with Trichoderma. Inoculation reversed the severe effects of salt on root length in sensitive cv. Gairdner and, to a lesser extent, improved root growth in more tolerance cv. Vlamingh. Biochemical changes showed a similar pattern in inoculated roots after salt treatment. Sugars increased in both cultivars, with ribulose, ribose, and rhamnose specifically increased by inoculation. Salt stress caused large changes in lipids in roots but inoculation with fungus greatly reduced the extent of these changes. Many of the metabolic changes in inoculated cv. Gairdner after salt treatment mirror the response of uninoculated cv. Vlamingh, but there are some metabolites that changed in both cultivars only after fungal inoculation. Further study is required to determine how these metabolic changes are induced by fungal inoculation. [ABSTRACT FROM AUTHOR]

Cultivation of Agaricus bisporus is a large horticultural industry for many countries worldwide, where a single variety is almost grown exclusively. Mushroom virus X (MVX), a complex of multiple positive-sense single stranded RNA (ss(+)RNA) viruses, is a major pathogen of typical A. bisporus crops. MVX can manifest a variety of symptoms in crops and is highly infective and difficult to eradicate once established in host mycelium. Currently our knowledge regarding the molecular response of A. bisporus fruit bodies to MVX infection is limited. In order to study the response of different A. bisporus strains with different susceptibilities to MVX, we designed a model system to evaluate the in-vitro transmission of viruses in A. bisporus hyphae over a time-course, at two crucial phases in the crop cycle. The symptom expression of MVX in these varieties and the transcriptomic and proteomic response of fruit bodies to MVX-infection were examined. Transmission studies revealed the high potential of MVX to spread to uninfected mycelium yet not into the fruit bodies of certain strains in a crop. MVX affected colour and quality of multiple fruit bodies. Gene expression is significantly altered in all strains and between times of inoculation in the crop. Genes related to stress responses displayed differential expression. Proteomic responses revealed restriction of cellular signalling and vesicle transport in infected fruit bodies. This in-depth analysis examining many factors relevant to MVX infection in different A. bisporus strains, will provide key insights into host responses for this commercially important food crop. • MVX affected colour and quality of multiple fruit bodies. • MVX significantly alters gene expression in all strains. • Transcription factors and stress response genes expression were altered. • Proteomic revealed restriction of cellular signalling and vesicle transport. [ABSTRACT FROM AUTHOR]

Summary: Methylotrophs, which can utilize methanol as a sole carbon source, are promising microorganisms to be exploited in a methanol‐based bioeconomy, in which a variety of useful compounds are biotechnologically produced from natural gas‐derived methanol. Pink‐pigmented facultative methylotrophs (PPFMs) are common plant phyllospheric bacteria and are known to enhance seedling growth and total biomass of various plants. However, improvement of crop yield by inoculation of PPFMs at the field level has not been well investigated. We herein describe improvement of crop yield of several rice cultivars by foliar spraying of PPFMs. After selection of PPFM strains and rice cultivars by the in vitro seedling growth test, we further conducted paddy field experiments. The crop yield of the sake‐brewing rice Oryza sativa cultivar Hakutsurunishiki was reproducibly improved in a commercial paddy field for over a 5‐year period. A one‐time foliar spray of PPFM cells (living or killed) or a cell wall polysaccharide fraction, after the heading date, acted in the phyllosphere and effectively improved crop yield. Our results show that the established process with PPFMs is feasible for improvement of food production in the methanol bioeconomy. [ABSTRACT FROM AUTHOR]

In this work, U. maydis-Arabidopsis pathosystem was used to evaluate the PLP2A Arabidopsis gene roll in response to U. maydis infection. For this, both wild-type and pla2a mutant plants were inoculated with a haploid strain of U. maydis, and the progress of the infection was followed, results show that transcript plays an important role in the establishment of the infection being evident in the mutant plant compared to wild-type plants. On the other hand, the orthologous gene was found in corn, the natural host of U. maydis, with 69% identity to the AtPLA2A gene. The PLP2A gene expression was analyzed by RT-PCR assays and the results showed that this gene is induced from the first day after inoculation, the transcript increases as the infection progresses; this supports the theory that the transcript AtPLA2A is involved in the mechanisms of resistance and susceptibility to the pathogen. The use of Arabidopsis has made it possible to understand the defense responses in the plant and the pathogenic process of U. maydis, therefore, the results obtained can clarify the role of PLA2A in a comparative and integrative way in host and non-host plants of U. maydis. [ABSTRACT FROM AUTHOR]

A vast majority of terrestrial plants are dependent on arbuscular mycorrhizal fungi (AMF) for their nutrient acquisition. AMF act as an extension of the root system helping phosphate uptake. In agriculture, harnessing the symbiosis can potentially increase plant growth. Application of the AMF Rhizophagus irregularis has been demonstrated to increase the yields of various crops. However, there is a paradigm that AMF colonization of roots, as well as the plant benefits afforded by inoculation with AMF, decreases with increasing phosphorus (P) supply in the soil. The paradigm suggests that when fertilized with sufficient P, inoculation of crops would not be beneficial. However, the majority of experiments demonstrating the paradigm were conducted in sterile conditions without a background AMF or soil microbial community. Interestingly, intraspecific variation in R. irregularis can greatly alter the yield of cassava even at a full application of the recommended P dose. Cassava is a globally important crop, feeding 800 million people worldwide, and a crop that is highly dependent on AMF for P uptake. In this study, field trials were conducted at three locations in Kenya and Tanzania using different AMF and cassava varieties under different P fertilization levels to test if the paradigm occurs in tropical field conditions. We found that AMF colonization and inoculation responsiveness of cassava does not always decrease with an increased P supply as expected by the paradigm. The obtained results demonstrate that maximizing the inoculation responsiveness of cassava is not necessarily only in conditions of low P availability, but that this is dependent on cassava and fungal genotypes. Thus, the modeling of plant symbiosis with AMF under different P levels in nature should be considered with caution. [ABSTRACT FROM AUTHOR]

To support the adaption of soybean [ Glycine max (L) Merrill] cultivation across Central Europe, the availability of compatible soybean nodulating Bradyrhizobia (SNB) is essential. Little is known about the symbiotic potential of indigenous SNB in Central Europe and the interaction with an SNB inoculum from commercial products. The objective of this study was to quantify the capacity of indigenous and inoculated SNB strains on the symbiotic performance of soybean in a pot experiment, using soils with and without soybean history. Under controlled conditions in a growth chamber, the study focused on two main factors: a soybean cropping interval (time since the last soybean cultivation; SCI) and inoculation with commercial Bradyrhizobia strains. Comparing the two types of soil, without soybean history and with 1–4 years SCI, we found out that plants grown in soil with soybean history and without inoculation had significantly more root nodules and higher nitrogen content in the plant tissue. These parameters, along with the leghemoglobin content, were found to be a variable among soils with 1–4 years SCI and did not show a trend over the years. Inoculation in soil without soybean history showed a significant increase in a nodulation rate, leghemoglobin content, and soybean tissue nitrogen concentration. The study found that response to inoculation varied significantly as per locations in soil with previous soybean cultivation history. An inoculated soybean grown on loamy sandy soils from the location Müncheberg had significantly more nodules as well as higher green tissue nitrogen concentration compared with non-inoculated plants. No significant improvement in a nodulation rate and tissue nitrogen concentration was observed for an inoculated soybean grown on loamy sandy soils from the location Fehrow. These results suggest that introduced SNB strains remained viable in the soil and were still symbiotically competent for up to 4 years after soybean cultivation. However, the symbiotic performance of the SNB remaining in the soils was not sufficient in all cases and makes inoculation with commercial products necessary. The SNB strains found in the soil of Central Europe could also be promising candidates for the development of inoculants and already represent a contribution to the successful cultivation of soybeans in Central Europe. [ABSTRACT FROM AUTHOR]

The adoption of bioinputs in agriculture has aroused great interest in recent years and, in this scenario, the inoculation of crops with synthetic microbial communities (SynComs) has shown to be promising. In sugarcane crop, inoculation with nitrogen-fixing bacteria (NFB) in consortium with arbuscular mycorrhizal fungi (AMF) has shown positive results on plant development and nutrition. However, considering that the microbiota plays a fundamental role in the growth and health of the host plant, especially the endophytes, which are closely associated, few studies have explored the effects of SynCom inoculation on the endophytic microbiota of sugarcane. This study aimed to evaluate the impact of SynCom inoculation on the structure of the endophytic microbiota of sugarcane. The results of the analyses revealed that the microbiota diversity remained unchanged due to the inoculation treatment, while differences in microbial communities were found between the two evaluated commercial cultivars, RB867515 and RB92579, and between the two plant organs, roots and culms, under field conditions at the end of the first crop growth cycle (~360 days). Furthermore, microbes specifically detected in roots or culms present potential valuable applications in sugarcane cultivation in the future. Altogether, our data support that the inoculated microorganisms exerted their beneficial effects during the initial stages of plant development, which opens up space for new research with SynComs in these primordial stages of cane cropping. • Inoculation of a SynCom onto sugarcane does not alter its microbiota after 360 days. • There are differences in alpha diversity of bacteria between two commercial cultivars. • There are differences in beta diversity of bacteria and fungi between roots and stems. [ABSTRACT FROM AUTHOR]

The Bradyrhizobium vignae strain ORS3257 is an elite strain recommended for cowpea inoculation in Senegal. This strain was recently shown to establish symbioses on some Aeschynomene species using a cocktail of Type III effectors (T3Es) secreted by the T3SS machinery. In this study, using a collection of mutants in different T3Es genes, we sought to identify the effectors that modulate the symbiotic properties of ORS3257 in three Vigna species (V. unguiculata, V. radiata and V. mungo). While the T3SS had a positive impact on the symbiotic efficiency of the strain in V. unguiculata and V. mungo, it blocked symbiosis with V. radiata. The combination of effectors promoting nodulation in V. unguiculata and V. mungo differed, in both cases, NopT and NopAB were involved, suggesting they are key determinants for nodulation, and to a lesser extent, NopM1 and NopP1, which are additionally required for optimal symbiosis with V. mungo. In contrast, only one effector, NopP2, was identified as the cause of the incompatibility between ORS3257 and V. radiata. The identification of key effectors which promote symbiotic efficiency or render the interaction incompatible is important for the development of inoculation strategies to improve the growth of Vigna species cultivated in Africa and Asia. [ABSTRACT FROM AUTHOR]

Due to the importance of phosphorus (P) in agriculture, crop inoculation with phosphate-solubilizing bacteria is a relevant subject of study. Paenibacillus sonchi genomovar Riograndensis SBR5 is a promising candidate for crop inoculation, as it can fix nitrogen and excrete ammonium at a remarkably high rate. However, its trait of phosphate solubilization (PS) has not yet been studied in detail. Here, differential gene expression and functional analyses were performed to characterize PS in this bacterium. SBR5 was cultivated with two distinct P sources: NaH2PO4 as soluble phosphate source (SPi) and hydroxyapatite as insoluble phosphate source (IPi). Total RNA of SBR5 cultivated in those two conditions was isolated and sequenced, and bacterial growth and product formation were monitored. In the IPi medium, the expression of 68 genes was upregulated, whereas 100 genes were downregulated. Among those, genes involved in carbon metabolism, including those coding for subunits of 2-oxoglutarate dehydrogenase, were identified. Quantitation of organic acids showed that the production of tricarboxylic acid cycle-derived organic acids was reduced in IPi condition, whereas acetate and gluconate were overproduced. Increased concentrations of proline, trehalose, and glycine betaine revealed active osmoprotection during growth in IPi. The cultivation with hydroxyapatite also caused the reduction in the motility of SBR5 cells as a response to Pi depletion at the beginning of its growth. SBR5 was able to solubilize hydroxyapatite, which suggests that this organism is a promising phosphate-solubilizing bacterium. Our findings are the initial step in the elucidation of the PS process in P. sonchi SBR5 and will be a valuable groundwork for further studies of this organism as a plant growth-promoting rhizobacterium. [ABSTRACT FROM AUTHOR]

The experiment was carried out in the green houses research station (B) in the College of Agriculture, University of Baghdad, Al-Jadrya campus during the spring season of 2016 to study the response of nitrogen fixing bacterial biofertilizers which including Rhizobium phaseoli, Azotobacter chroococcum and Azospirillum brasilense and molybdenum on growth and yield of green beans in The plastic house. The experiment was conducted according to the randomized complete block design (RCBD) with three replications each included 11 treatments represent the interactions between nitrogen fixing bacteria isolates, molybdenum solo application, molybdenum and bacteria isolates interactions, in addition to the recommended nitrogen application and control treatment. Results were analyzed using the least significant differences (LSD) test at 5% level of significance. Results showed significantly increase N% in the pods (2.73 %) in T7, Treatment included all bacteria isolates and Mo (T11) gave the most significant percentage of p in the pods (0.21%) and root nodular fresh weight of 2920.00 mg.plant-1, treatment (T5) gave the highest K % in the pods (1.46%), As for the T10, results showed significant concentration of Mo in the pods (0.63 mg.kg-1), Moreover, T3 significantly increased percentage of carbohydrate (3.74%), As for the T9, results showed significant percentage of Dry matter 21.38%, T6 gave the most significant T.S.S. (8.17 %). Solo treatment (T2) gave the highest concentration of Fe in the pods (55.58 mg.kg-1), root branches (11.56 branch. plant-1), root dry weight (9.11 g. plant-1), shoot branches per plant, leaf area and leaf chlorophyll concentration that reached 4.00 branch. plant-1, 63.15 dm2. plant-1 and 210.97 mg.100g-1 fresh weight respectively, weight of pods (9.76 g.pod-1) and total production (633.74 Kg. house-1) with an area of 418.5 m². [ABSTRACT FROM AUTHOR]

Copyright of Bioscience Journal is the property of Bioscience Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Seed inoculation with Azospirillum brasilense might be an interesting alternative to reduce the nitrogen demand applied to plants and to enhance the effect of these fertilizers. This study aimed to evaluate the components of maize crops and its response to inoculation with A. brasilense associated with sowing and top cover nitrogen fertilization. A completely randomized block experimental design was used, and the tests were carried out in two crop years. The treatments in the first crop year were: BF + CF: {nitrogen base fertilization (BF) + cover fertilization (CF)}; BF + BI: {BF + A. brasilense bacterium inoculation (BI)}; BF + BI + CF; BI; BI + CF and NFI: {no fertilization or inoculation}. The same treatments were tested in the second crop year, and the CF was added. The tests were carried out in the field, in the municipality of Abelardo Luz - SC - Brazil. The climate is humid mesothermal with hot summers and cold winters (Cfa). The following parameters were evaluated: plant height, leaf and grain nitrogen, yield, thousand-grains weight, and grain moisture. The inoculation of A. brasilense associated with cover fertilization could be an alternative to reduce the demand for N, including an increase in productivity. The use of A. brasilense without N fertilization provided an increase in crop yield. [ABSTRACT FROM AUTHOR]

Background: Replacing synthetic fertilizers by biological nitrogen fixation (BNF) is regarded as an environmentally sound practice, but some diazotrophic bacteria are capable of emitting N2O by denitrification. The ability to use nitrate represents an ecological advantage for the survival of some microorganisms under O2-limiting conditions, but may contribute to increased N2O emissions. Scope: The importance of denitrification performed by N2-fixing bacteria used as inoculants in South America is discussed, especially the possibility of these bacteria act as N2O source or sink. Conclusions: There is no doubt of the importance of BNF as a sustainable N source for plants. Through genome investigation, we demonstrated that some strains widely used as inoculants for BNF harbor the entire denitrification pathway to reduce nitrate to N2. Others contain none, or only some of the denitrification genes, resulting in complete absence of denitrification or production of intermediates such as NO2−, NO or N2O. Evidence of differential effects of bacterial strains on soil N2O were reported, but more studies are still needed to affirm crop inoculation can be a driver for source or sink of this gas. Finally, considerations were made about BNF as an indispensable resource to indirectly mitigate greenhouse gas emissions in agroecosystems. [ABSTRACT FROM AUTHOR]

Legumes interact with diverse soil bacteria of the genus Rhizobium to form dinitrogen (N2)-fixing symbiotic root nodules. This symbiotic interaction occurs under plant nitrogen (N)-deficit and only between compatible partners. When young nodules are formed, bacteroids begin to fix atmospheric N2 and provide ammonium to the plant which in return provides phytosynthates to the bacteria. Ability and Competitiveness to Form root Nodules (AFN and CFN) within natural populations have a strong impact on early partner choice. In soil, there are frequently multiple compatible partners and legume roots are often colonized by multiple rhizobia displaying different Symbiotic N2 Fixation (SNF) efficiencies. In mature nodules, Post-Infection Partner Preference (PIPP) shape partner choice by favoring effective symbiotic N2fixing structures to the expense of inefficient ones. Little is known about mechanisms involved in legume-rhizobium partner choices despite the relevance of this trait to design new strategies to improve inoculation of legume crops. [ABSTRACT FROM AUTHOR]

Green gram (Vigna radiata L. Wildzek) is a neglected crop with great potential to boost food security among small scale farmers. Inoculation of this crop with beneficial soil microbiota can sustainably improve its production especially under water stress conditions. Here, we aimed at determining the effect of bradyrhizobia and arbuscular mycorrhizal fungi (AMF) co-inoculation on growth and nitrogen fixation of green grams under water stress conditions. Potted green grams variety KS20 were planted in sterilized soil and inoculated with Bradyrhizobium, Funneliformis mosseae, Rhizophagus irregularis, a commercial consortium of four AMF isolates (Rhizophagus irregularis, Funneliformis mosseae, Glomus etunicatum and Glomus aggregatum) and a consortium of the four aforementioned AMF isolates and Bradyrhizobium. The plants were subjected to three water stress levels, irrigation after interval of 4 days, 8 days and 12 days and maintained for 50 days. After harvesting, the plants were measured for nodulation, percentage root mycorrhizal colonization, growth parameters and shoot nitrogen (N), phosphorous (P) and potassium (K). Remarkably, all AMF inoculations significantly P ≤ 0.05 increased shoot dry weight (SDW), root dry weight (RDW) and P compared to Bradyrhizobium and control plants under all the watering regimes. Inoculation with Rhizophagus irregularis resulted to highest shoot dry weight, root dry weight and P under water regime 3, which provided the most intense water stress condition. Moreover, strong positive correlation (R2 = 0.8765, P = 0.006) was observed between shoot dry weight, P and AMF root colonization under all watering regimes. [ABSTRACT FROM AUTHOR]

Inoculation of agronomic crops with arbuscular mycorrhizal fungi is a promising agronomic practice, which has been solidified by recommendation of recently-registered inoculants in Brazil. The need to understand effects of different inoculant formulations is, therefore, a fundamental aspect for basic and applied research. The aim of this study was to evaluate inoculum potential of the arbuscular fungus R. clarus cultivated in a pot culture system compared to the in vitro system and test the effect of both on growth and yield of soybean. Inoculum potential was tested in greenhouse conditions using maize as host plant. Values of root colonization showed that inoculum potential was 7% higher in the in vitro system. In order to evaluate the effects of both inoculants, an experiment was carried out in greenhouse conditions following a completely randomized design with three treatments and six replicates. The inoculant produced in vitro increased all nodulation parameters, but did not affect shoot mass or nitrogen of soybean plants. Grain yield, however, was 20% higher with the use of pot-produced inoculum. Pot culure system is the most promising technique to produce soybean inoculum, considering possible yield gains. [ABSTRACT FROM AUTHOR]

Abstract Seeds contaminated with bacterial pathogens were found to be the primary cause of sprout-associated outbreaks of human gastrointestinal infections. This study was undertaken to determine if cells of selected Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC) strains, artificially inoculated onto the flowers of vegetable plants, will result in contamination of sprouts/seedlings that develop from seeds produced by the inoculated flowers. Pistils of alfalfa, fenugreek, lettuce, and tomato flowers were inoculated with cells of selected S. enterica or EHEC strains. A total of 906, 715, 1236, and 1276 mature seeds, produced by lettuce, tomato, alfalfa or fenugreek flowers inoculated with Salmonella were collected as 48, 94, 109, and 116 composite samples (367 in total), respectively. Correspondingly, 934, 640, 1827 and 1027 seeds, produced by the four respective types of flowers after inoculation with E. coli were divided into 42, 81, 162, and 107 composite samples (392 in total), respectively. Seeds in each composite sample were surface-decontaminated with NaOCl solution and germinated at 25 °C in the dark for 5 days. Subsequently, pathogen populations on the sprouts/seedlings developed from each composite seed sample were determined by the plate count assay. The overall Salmonella recovery rate from vegetable sprouts/seedlings developed from the 367 composite seed samples was 2.7%, while none of the sprouts/seedlings grown from the 392 composite seed samples with prior E. coli inoculation tested positive for the pathogen. One of the 94 tomato seedling samples contained 4 CFU of Salmonella and five additional samples tested positive by enrichment (6.4%). Two out of 109 (1.8%) alfalfa and 116 (1.7%) fenugreek composite samples tested positive for Salmonella by enrichment. However, none of the lettuce seedlings tested positive for Salmonella or E. coli even after enrichment. This study suggests that under controlled environmental conditions, human pathogens inoculated onto flowers of vegetable plants can result in the contamination of sprouts/seedlings via seeds produced by the inoculated flowers. However, the frequency of sprout/seedling contamination was low and could be affected by characteristics of the pathogens and plant species tested. Highlights • Salmonella cells inoculated to flowers transmitted to sprouts/seedlings via seeds. • Incidence of Salmonella transmission through the floral pathway was low. • Salmonella transmission frequency was pathogen type- and vegetable type-dependent. • Contamination of vegetable seeds through floral pathway was not observed with EHEC. [ABSTRACT FROM AUTHOR]

Fresh produce are vulnerable to pathogens during pre‐ and postharvest stages. Most fresh vegetable and fruits are consumed directly or merely washed with chlorine. We investigated two emerging decontamination technologies, pulse light (PL) and ultraviolet (UV), in combination with washing (referred as water‐assisted PL [WPL] and water‐assisted UV [WUV]). Blueberries, grape tomatoes, and iceberg lettuce shreds were tested in this study to represent fresh vegetables and fruits with smooth and rough surfaces. Salmonella spp. were used as a model microorganism due to its prevalence in outbreaks. Spot‐inoculation and dip‐inoculation were used to simulate potential contaminations during irrigation, harvest, transportation, and processing. Two intensity levels of PL (∼0.15 and 0.3 J/cm2 per pulse; 3 pulses/s) and UV (∼13 and 28 mW/cm2) were tested for 1 and 2 min. For all three types of fresh produce, blueberries, grape tomatoes, and iceberg lettuce shreds, WPL and WUV showed similar Salmonella inactivation effects on fresh produce. For spot‐inoculated fresh produce, WPL and WUV treatments reduced 4.5 to 5.7, 4.4 to 5.4, and 1.9 to 3.1 logs of Salmonella on blueberries, tomatoes, and lettuce shreds, respectively. For dip‐inoculated fresh produce, WPL and WUV treatments reduced 1.8 to 2.3, 1.9 to 2.5, and 1.9 to 2.6 logs of Salmonella on blueberries, tomatoes, and lettuce shreds, respectively. The majority of the WUV and WPL treatments could eliminate Salmonella in the wash water for blueberries and tomatoes, but not for lettuce. Practical Application: Two light systems, pulsed light and UV, for decontamination of fresh produce were evaluated and compared. Results demonstrated that the two systems showed similar decontamination effect on fresh produce, demonstrating that the UV system could be used to replace the pulsed light system to reduce equipment cost. [ABSTRACT FROM AUTHOR]

Reducing chemical fertilizer while remaining high crop yield has become a trend of agricultural practice. The purpose of this study was to investigate the effects of nitrogen (N) input on the structure of the fungal community and mycorrhizal inoculum potential in rhizosphere of Curcuma longa, aiming to minimize the use of chemicals and optimize the effect of biofertilizer for sustainable turmeric farming. For this, a field study was conducted in two successive years 2015 and 2016 with applications of varrying N fertilizer rates N0 (0 kgN ha−1 y−1), N150 (150 kgN ha−1 y−1), N350 (350 kgN ha−1 y−1), and N500 (500 kgN ha−1 y−1) in combination with mycorrhizal biofertilizer on turmeric plants in Hung-Yen. Rhizosphere soils were then analyzed for the abundance of predominant fungal taxon based on amplicon sequencing of rDNA internal transcribed spacer regions. Metagenomic results indicated significant effects of N inputs on rhizosphere fungal communities composition, with dominance of ascomyceteous fungi under optimized N levels, whereas basidiomycetous fungi were more abundant under higher N input. Operational taxonomic units relating to the predominantly abundant genus Glomus were found apparently in higher proportion under optimized N inputs (N150). The results demonstrate an enhanced productivity and icreased mycorrhizal inoculating potential by appropriated N fertilizer application in turmeric rhizosphere. [ABSTRACT FROM AUTHOR]

Aims: The function of strigolactone isomers in sorghum phosphorus acquisition efficiency (PAE) is still a matter of speculation. Therefore, the objective of this study was to investigate the effects of cultivar-specific strigolactone composition on sorghum growth indices, responsiveness of arbuscular mycorrhizal fungi (AMF), and PAE. Methods: Two Striga-resistant (orobanchol-producing) and two Striga-susceptible (5-deoxystrigol-producing) sorghum (Sorghum bicolor (L.) Moench) cultivars were planted with and without AMF inoculation as well as with and without P fertilization. Growth indices and AMF colonization were measured 30 days after sowing from pot trial plants in a growth chamber. Results: AMF colonization was highest in Tetron and lowest in IS9830, both Striga-resistant cultivars. Conversely, PAE was lowest in Tetron and highest in IS9830 and revealed strong positive relationships with root length, leaf area and shoot DW. Conclusions: Although the strigolactone composition had no clear general effects on the growth indices of the four different sorghum cultivars, breeders should consider it for combining efficient AM symbiosis and high PAE values. [ABSTRACT FROM AUTHOR]

Copyright of Avances is the property of Instituto de Informacion Cientifica y Tecnologica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Cassava brown streak disease (CBSD) caused by Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) is the main constraint to cassava (Manihot esculenta Crantz) production in Mozambique. Using RT-PCR to amplify partial coat protein nucleotide sequences, we detected for the first time the occurrence of CBSV in two non-cassava perennial wild plant species: Zanha africana (Radlk.) Exell. and Trichodesma zeylanicum (Burm.f.) R.Br., that occur widely within and near cassava fields in Nampula, Zambezia, Niassa and Cabo Delgado provinces. In addition, we also detected CBSV and UCBSV in Manihot carthaginensis subsp. glaziovii (Müell-Arg.) Allem., a wild cassava relative. These findings were verified in biological assays through mechanical inoculation of CBSV to T. zeylanicum , albeit at low rates of infection. Phylogenetic analysis clustered the CBSV isolates from the non-cassava plant species with those from cultivated cassava, with high sequence homology among CBSV (91.0–99.6%) and with UCBSV (84–92%) isolates. These results provide definitive evidence of a wider host range for CBSV and UCBSV in Mozambique, indicating that these viruses are not restricted to cultivated cassava. Our findings are key to understanding the epidemiology of CBSD and will aid in the development of sustainable management strategies for the disease. Highlights • Alternative host plants of Cassava brown streak viruses were determined. • There was evidence of natural infection of CBSV in non-cassava relative plants. • CBSV was successfully transmitted in T. zeylanicum by mechanical inoculation. • CBSV and UCBSV, associated with CBSD in cassava, naturally infect M. glaziovii. [ABSTRACT FROM AUTHOR]

Two field experiments were conducted during the summer seasons of 2016 and 2017 at the Experimental Station Farm; South El- Tahrir; Horticultural Research Station, El- Behiera Governorate. This investigation aimed to study the effect of bio- fertilizer potassien(Bacillus circulance)in combination with different rates of mineral potassium fertilizer (0,32,64 and 96kgK2O/fed) on the growth, yield and quality characters of potato CV. Spunta . Potassium fertilizer at 64 or 96 kgK2O/fed with application of bio-K fertilizer promoted growth of potato and the highest mean value of plant height, number of leaves plant- 1, foliage fresh weight, leaves fresh weight, foliage dry weight, leaves dry weight , total chlorophyll and enhanced N, P and K uptake, as well as increased tuber weight ton/fed, average tuber weight and improved tubers quality characters expressed as dry matter, protein, starch, and total carbohydrates contents and specific gravity in the two seasons. It could be concluded that the interaction effect of inoculation potato tuber seeds with bio fertilizer at application of 67% (64 kg K2O/fed) of the recommended K level (96 kg K2 fed-1) increased the productivity of potato tuber and improved tuber quality characteristics, as the same as (96 kg K2fed-1). In addition to saving about 33% of potato requirement of K fertilizers and avoid environmental pollution hazards caused by excessive application of chemical fertilizers. [ABSTRACT FROM AUTHOR]

In this study, the susceptibility of different sweet (19) and sour cherry (3) cultivars (cvs.) to the bacterial pathogens Pseudomonas syringae pv. syringae and P. s. pv. morsprunorum race 1 causing bacterial canker (sensu stricto) and leaf spot was evaluated. Susceptibility to bacterial canker was examined by artificial inoculations of 1‐year‐old rooted trees, which revealed susceptibility of all cvs. to both P. syringae pathovars. Susceptibility level differed among cvs.; sweet cherry cvs. Katalin, Linda, Summit, New Star and Bigarreau Burlat were highly susceptible, sour cherry cvs. Érdi bôtermô and sweet cherry Drogan's Yellow, Carmen, Germersdorfer and Noir de Meched were susceptible. Sour cherry cvs. Španska and Újfehértói fürtös, as well as sweet cherry cv. Rita were found to be less susceptible to bacterial canker. Susceptibility to bacterial leaf spot disease was evaluated on naturally infected (field conditions) and artificially inoculated leaves (laboratory conditions). Severe symptoms of bacterial spot with shot hole appearance were observed in cherry leaves at the beginning of May under field conditions. In all collected leaf samples, presence of P. s. pv. morsprunorum race 1 was determined. Sweet cherries Valery Chkalov, Summit, Bigarreau Burlat and New Star were highly susceptible to this bacterium. No symptoms of bacterial spot were found on sweet cherries Solomary gomboly, Linda, Germersdorfer, Hedelfinger, Katalin, Margit, Carmen, Aida, Sunburst, Alex, Peter, Rita and Kavics and sour cherry Érdi bôtermô. In laboratory conditions, susceptibility of the tested cvs. varied and mostly depended on the inoculation method. Nonetheless, sweet cherry cvs. Carmen and Margit and sour cherry Érdi bôtermô exhibited a certain level of resistance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Soil Sciences & Agricultural Engineering is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highlights • N and P had comparable effects on common bean productivity. • Main common bean varieties used in Zimbabwe do not respond to inoculation. • Investments in N and P on acutely degraded soils does not result in common bean yield gains. Abstract Common bean is an important crop with potential to curb malnutrition in poor Sub-Saharan African populations. Yields of common bean ( Phaseolus vulgaris L.) are, however poor, limited by low soil phosphorus (P), nitrogen (N) and poor biological N 2 -fixation. On-farm experiments were carried out to study the effect of N, P and rhizobia inoculation on common bean yield and yield components during the 2014/2015 and 2015/2016 cropping seasons in Eastern Zimbabwe. Experiments were conducted on five farmers’ fields located in two agroecologies; three fields were considered to be degraded with soil organic carbon (SOC) < 4 g kg−1 and available P < 6 mg kg−1, while the two non–degraded sites had SOC > 7 g kg−1 and available P > 15 mg kg−1. Two common bean varieties (Gloria and NUA45) were tested in a split-plot arranged in randomized complete block design. The main plot factor was the combination of N (0 and 40 kg ha−1) and P (0 and 20 kg ha−1), and the sub-plot factors were variety (Gloria and NUA 45) and inoculation with Rhizobium tropici strain CIAT899 (+/− inoculum). At planting, both N and P were applied at 20 kg ha−1, with an additional 20 kg ha−1 N top dressing applied at flowering. Analysis of variance indicated common bean did not respond to rhizobia inoculation (P > 0.05) whilst P significantly increased the number of nodules and active nodules per plant (P < 0.001), and grain yield. Application of 40 kg ha−1 N significantly increased the number of pods per plant, number of seeds per pod, and grain yields. A significant NP interaction was only observed on grain yield for non-degraded soils. Co-application of N and P in non-degraded sites increased grain yields from 0.27 to 1.48 Mg ha−1during the first season and from 0.37 to 2.09 Mg ha−1during the second season. On degraded sites, NP application resulted in uninspiring grain yield gains of 0.09 to 0.19 Mg ha−1 during the first season, and from 0.16 to 0.28 Mg ha−1 in the second season. In general, effects of N or P were not significantly different, suggesting that farmers could invest in either of these nutrients for increased common bean grain yields. Strategically, P investments would be more logical as residual P effects to rotational cereals improve overall cropping system performance. The response of common bean to inoculation in Zimbabwe still needs to be widely investigated for these and other varieties. [ABSTRACT FROM AUTHOR]

A greenhouse experiment was conducted to investigate the effect of different levels of NaCl salt on tomato upon B. cinerea infection the causal agent of gray mold disease. The disease assessment was recorded after inoculation by using the scale based on percentage leaf area affected, and the growth of the plants was recorded for each treatment. Three weeks after inoculation by conidial suspension, the estimated disease severity on plants of tomato was 35.18% compared to the control. The highest incidence disease increase of gray mold (39.21%) was obtained with using 300 mM of NaCl after inoculation with B. cinerea compared with the other concentrations and as well as distilled water. Under severe salt stress (150 and 300mM) increased susceptibility of gray mold disease severity were observed in plants inoculated with B. cinerea, while under mild salt stress (50mM of NaCl) this effect was reversed. The treatment of plant by B.cinerea has reduced the growth of the aerial part of tomato plants (39.06%) after three weeks inoculation compared to the control. Three levels of NaCl (50, 100 and 150mM) increased respectively the plant height from 12.73 to 29.84%, 0.28 to 27.16% for the fresh eight and 5.75 to 33.35% for dry weight compared to the plants inoculated and irrigated by distilled water. NaCl addition at 300mM on plants inoculated with B. cinerea decreased the height, fresh weight and dry weight at 0.99, 4.45 and 11.01% respectively. [ABSTRACT FROM AUTHOR]

Aims: A Pseudomonas fluorescens DUS1-27 isolate was screened for its effect on Brassica napus L. growth over 14 days in a soil-based system and a hydroponic system. Bacterial inoculation enhanced overall plant biomass in the soil-based system, however, plant biomass was reduced in the hydroponic system. Here, we investigate the probable cause for the contrasting plant growth observed for the two systems.Methods: Using 3,3′-Diaminobenzadine, total peroxidase activity was visualised in roots of B. napus, and quantified in soil and hydroponic growth media. Amperometry was used to quantify levels of H2O2 in the hydroponic growth media. Quantitative real-time PCR was used to determine catalase gene expression levels in both B. napus roots and P. fluorescens.Results: Total peroxidase activity and H2O2 levels in the hydroponic growth media were higher in plants inoculated with the P. fluorescens isolate. Catalase gene expression in B. napus and P. fluorescens was up-regulated in both organisms when co-cultured in a hydroponic system.Conclusions: Pseudomonas fluorescens is capable of enhancing the growth of B. napus in a soil-based system, whereas in a hydroponic system its addition leads to growth inhibition due to the increased levels of H2O2 in the system. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the influence of arbuscular mycorrhizal fungi on the initial development of pre-sprouted seedlings in three sugarcane varieties (CTC 9004 M, IACSP 955094 and IACSP 962042). The experiment was conducted in a greenhouse in the experimental field and in the agricultural microbiology laboratory of the Goianesia Evangelical Faculty located in the city of Goianésia, Goiás. The experimental design was a 3x2 factorial scheme with 5 replications in which the first factor was constituted by three varieties of sugarcane and the second factor by treatments: sterile soil with inoculation of arbuscular mycorrhizal fungi (AMF) and sterile soil without inoculation. AMF were inoculated directly into the roots of the seedlings. For the determination of growth and development were made count of number of tiller, stem diameter, dry mass of roots, shoot height, mycorrhizal colonization, spore density and identification of associated genera. The data received statistical treatment through the Assistat program. There was statistical difference only in the variety factor, in the variables plant height, spore density and mycorrhizal colonization rate. The genera Claroideglomus, Diversipora and Glomus were identified in all three varieties. [ABSTRACT FROM AUTHOR]

This study assessed both the physico-chemical properties of winery solid waste (WSW) composts with or without microbial inoculation and the phyto-toxicity of their extract. Four different composts with initial pile height of 1 or 1.5 m were prepared through aerobic thermophilic process by mixing the filter materials (FM) and waste plant materials at 40 : 60 ratio on dry volume basis. Cured composts were evaluated for selected physicochemical properties and germination attributes at varied extract concentrations (0, 10, 25, 50 and 100%) using cowpea, maize and tomato seeds. Microbial inoculation exerted significant effects on compost Bray-P2 content, while interaction between inoculation and compost pile size similarly had significant effect on ammonium-N content. The contents of bulk density, volatile solids, water holding capacity, pH, electrical conductivity, nitrate-N and exchangeable K among the various composts did not differ significantly. The composts possessed high electrical conductivity (range : 9.03-10.23 dS/m) suggesting high soluble salts concentrations. Compost type and extract concentration interaction exerted significant effect on the germination index (GI) of all three crops; with phyto-toxic effects on maize and tomato at 50% extract concentration and beyond. The compost extracts showed varying degree of phyto-toxicities to maize and tomato, while cowpea experienced no phyto-toxicity effect. Besides, the composts also showed phyto-nutrient and phyto-stimulant capabilities with greater than 100% root length and GI values. Nonetheless, the phyto-toxicity recorded in maize and tomato can be eliminated using lower application rates. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ceres is the property of Revista Ceres and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary: A study was undertaken to model growth of Salmonella on tomatoes for developing and validating a predictive model for use in risk assessment. Cylindrical portions (0.14 g) of Roma tomato pulp were inoculated with a low dose (0.89 log MPN) of Salmonella Newport. The inoculated tomato portions were incubated for 0–8 h at 16–40 °C in 2 °C increments to obtain most probable number (MPN) data for model development and validation. A multiple‐layer feedforward neural network model with two hidden layers of two nodes each was developed. The proportion of residuals in an acceptable prediction zone (pAPZ) from −1 (fail‐safe) to 0.5 log (fail‐dangerous) was 0.93 (194/209) for dependent data and 0.96 (86/90) for independent data for interpolation. A pAPZ ≥0.7 indicated that the model provided acceptable predictions. Thus, the model was successfully validated. It was also validated for extrapolation to seven other Salmonella serotypes. [ABSTRACT FROM AUTHOR]

Common bean and soybean yield poorly on smallholder farms in Rwanda. We evaluated the benefits of inoculation combined with P fertilizer and manure on yields of common bean and soybean in three agro-ecological zones (AEZs), and their residual effects on a subsequent maize crop. In the first season, the treatments included inoculum, three rates of manure, and two rates of P fertilizer, with nine replications (three per AEZ). Both legumes responded well to inoculation if applied together with manure and P fertilizer. Grain yields varied from 1.0 t ha −1 to 1.7 t ha −1 in unamended control plots to 4.8 t ha −1 for common bean and 3.8 t ha −1 for soybean in inoculated plots with both P and manure addition. The response of common bean and soybean to inputs varied greatly between AEZs. In the AEZ with low and erratic rainfall (Bugesera), yields of both legumes and maize were low and maize after soybean failed to yield any grain due to drought. In this regard, early maturing legume varieties are advised in regions of low rainfall. Responses of maize to an input applied to the legumes strongly increased when other inputs were applied together to the legume. This allowed greater maize yields which ranged from 0.8 t ha −1 in control plots to 6.5 t ha −1 in treatments previously inoculated with P and manure added for maize grown after common bean and from 1.9 t ha −1 in control plots to 5.3 t ha −1 for maize grown after soybean. The amount of N 2 -fixed measured using the 15 N-natural abundance method differed between the two legumes and varied between 15 and 198 kg N 2 ha −1 for common bean and between 15 and 186 kg N 2 ha −1 for soybean and differed enormously among treatments and AEZs. Application of inputs to the legumes also resulted in enhanced N and P uptake of the subsequent maize. The use of inoculum combined with manure and P fertilizer is a good option for smallholder farmers growing common bean and soybean in rotation with maize. We observed strong effects of environment and call for care when targeting crops and technologies for sustainable crop production. [ABSTRACT FROM AUTHOR]

The impacts of rhizobium inoculation on growth and yield of chickpea have mainly been tested in experiments conducted in greenhouses or on research stations. We report the response of the crop to inoculation (I) and phosphorus fertilizer (P) application across a large number of smallholder’s farms over four regions of Ethiopia, covering diverse soil fertility and agro-ecological conditions. Increased grain yields due to the soil fertility treatments was evident for 99% target farmers. On average, I and P increased grain yield by 21% and 25% respectively, while the combined application of I and P resulted in a 38% increase. However, observed grain yields on control plots and responses to the treatments on individual farms varied greatly, and relative yield responses (%; yield of P and/I minus control yield, divided by control yield) ranged from 3% to 138%. With the exception of a few extremely poorly yielding locations, average responses to P and I were high across a wide range of control yields, indicating the possibility of boosting chickpea productivity for smallholders with P fertilizer and inoculant technology. Variation in response to rhizobium inoculation was mostly independent of agro-ecology and soil type although it was found to be low on a number of farms with extremely high N contents (%). Assuming that a relative yield increase of 10% due to treatment effects is required to be visible, 71%, 73% and 92% of the farmers observed a yield benefit by applying P, I, and P + I, respectively. The results are discussed with respect to the additive benefits of P fertilizers and rhizobial inoculation and their implications for wide scale promotion of inoculant technology to smallholders. [ABSTRACT FROM AUTHOR]