Integrated use of plant growth-promoting bacteria and nano-zinc foliar spray is a sustainable approach for wheat biofortification, yield, and zinc use efficiency.

Introduction and aims: The intensive cropping system and imbalance use of chemical fertilizers to pursue high grain production and feed the fast-growing global population has disturbed agricultural sustainability and nutritional security. Understanding micronutrient fertilizer management especially zinc (Zn) through foliar application is a crucial agronomic approach that could improve agronomic biofortification of staple grain crops. The use of plant growth-promoting bacteria (PGPBs) is considered as one of the sustainable and safe strategies that could improve nutrient acquisition and uptake in edible tissues of wheat to combat Zn malnutrition and hidden hunger in humans. Therefore, the objective of this study was to evaluate the best-performing PGPB inoculants in combination with nano-Zn foliar application on the growth, grain yield, and concentration of Zn in shoots and grains, Zn use efficiencies, and estimated Zn intake under wheat cultivation in the tropical savannah of Brazil. Methods: The treatments consisted of four PGPB inoculations (without inoculation, Azospirillum brasilense, Bacillus subtilis, and Pseudomonas fluorescens, applied by seeds) and five Zn doses (0, 0.75, 1.5, 3, and 6 kg ha-1, applied from nano ZnO in two splits by leaf). Results: Inoculation of B. subtilis and P. fluorescens in combination with 1.5 kg ha-1 foliar nano-Zn fertilization increased the concentration of Zn, nitrogen, and phosphorus in the shoot and grain of wheat in the 2019 and 2020 cropping seasons. Shoot dry matter was increased by 5.3% and 5.4% with the inoculation of P. fluorescens, which was statistically not different from the treatments with inoculation of B. subtilis as compared to control. The grain yield of wheat was increased with increasing nano-Zn foliar application up to 5 kg Zn ha-1 with the inoculation of A. brasilense in 2019, and foliar nano-Zn up to a dose of 1.5 kg ha-1 along with the inoculation of P. fluorescens in the 2020 cropping season. The zinc partitioning index was increased with increasing nano Zn application up to 3 kg ha-1 along with the inoculation of P. fluorescens. Zinc use efficiency and applied Zn recovery were improved at low doses of nano-Zn application in combination with the inoculation of A. brasilense, B. subtilis, and P. fluorescens, respectively, as compared to control. Discussion: Therefore, inoculation with B. subtilis and P. fluorescens along with foliar nano-Zn application is considered a sustainable and environmentally safe strategy to increase nutrition, growth, productivity, and Zn biofortification of wheat in tropical savannah.

Inoculation with Plant Growth-Promoting Bacteria and Nitrogen Doses Improves Wheat Productivity and Nitrogen Use Efficiency.

Wheat is one of the staple foods of the global population due to its adaptability to a wide range of environments. Nitrogen is one of the crucial limiting factors in wheat production and is considered a challenge to food security. Therefore, sustainable agricultural technologies such as seed inoculation with plant growth-promoting bacteria (PGPBs) can be adopted to promote biological nitrogen fixation (BNF) for higher crop productivity. In this context, the objective of the current study was to evaluate the effects of nitrogen fertilization and seed inoculations with Azospirillum brasilense, Bacillus subtilis and A. brasilense + B. subtilis on agronomic and yield attributes, grain yield, grain N accumulation, N use efficiency and applied N recovery in Brazilian Cerrado, which consists of gramineous woody savanna. The experiment was carried out in two cropping seasons in Rhodic Haplustox soil under a no-tillage system. The experiment was designed in a randomized complete block in a 4 × 5 factorial scheme, with four replications. The treatments consisted of four seed inoculations (control-without inoculation, inoculation with A. brasilense, B. subtilis and A. brasilense + B. subtilis) under five N doses (0, 40, 80, 120 and 160 kg ha-1, applied from urea) at the wheat tillering stage. Seed co-inoculation with A. brasilense + B. subtilis increased grain N accumulation, number of spikes m-1, grains spike-1 and grain yield of wheat in an irrigated no-tillage system of tropical savannah, regardless of the applied N doses. Nitrogen fertilization at a dose of 80 kg ha-1 significantly increased grain N accumulation and number of grains spikes-1 and nitrogen use efficiency. Recovery of applied N was increased with inoculation of B. subtilis and co-inoculation of A. brasilense + B. subtilis at increasing N doses. Therefore, N fertilization can be reduced by the inclusion of co-inoculation with A. brasilense + B. subtilis in the cultivation of winter wheat under a no-tillage system of Brazilian Cerrado.

Meta-analysis of the experimental coefficient of variation in wheat using the Bayesian and Frequentist approaches

A large set of variables is assessed for progeny selection in a plant-breeding program and other agronomic fields. The meta-analysis of the coefficient of variation (CVe) produces information for researchers and breeders on the experimental quality of trials. This analysis can also be applied in the decision-making process of the experimental plan regarding the experimental design, the number of repetitions, and the treatments and plants/progenies to be measured. In this study, we evaluated the dataset distribution and the descriptive statistics of CVe through the Frequentist and Bayesian approaches, aiming to establish the credibility and confidence intervals. We submitted CVe data of ten wheat (Triticum aestivum L.) traits reported in 1,068 articles published to the Bayesian and Frequentist analyses. Sample data were analyzed via Gamma and normal models. We selected the model with the lowest Akaike Information Criterion (AIC) value, and then we tested three link functions. In the Bayesian analysis, uniform distributions were used as non-informative priors for the Gamma distribution parameters with three ranges of q~U (a,b,). Thus, the prior probability density function was given by: [formula] The Bayesian and Frequentist approaches with the Gamma model presented similar results for CVe; however, the range Bayesian credible intervals was narrower than the Frequentist confidence intervals. Gamma distribution fitted the CVe data better than the normal distribution. The credible and confidence intervals of CVe were successfully applied to wheat traits and could be used as experimental accuracy measurements in other experiments.(AU)

Canonical correlations between high and low heritability wheat traits via mixed models / Correlações canônicas entre caracteres de trigo de alta e baixa herdabilidade via modelos mistos

ABSTRACT: Canonical correlation analysis based on genotypic correlations allows determining the associations between groups of traits and carrying out the direct or indirect selection of superior genotypes. This study investigated the existence of linear and multivariate relationships between high and low heritability traits via canonical correlation analysis based on genotypic correlations. The experiment was conducted at the Professor Diogo Alves de Melo Experimental Field at the Universidade Federal de Viçosa, in Viçosa, MG. 90 wheat cultivars were evaluated under a 9 × 10 alpha-lattice design, with three replications and plots consisting of four rows of three meters spaced at 0.20 meters. Canonical groups were established between spike height and plant height, days for heading, number of spikelets per spike, and number of grains per spike (Group I) and, spike weight, spike grain mass, 100-grain mass, hectoliter weight, and grain yield (Group II). There was dependence between the established groups, which allowed the investigation of the relationships between traits based on their genotypic values. The traits cycle and plant height can be used for indirect selection of genotypes superior in hectoliter weight and grain yield, which are important factors for industries and farmers.

RESUMO: As análises de correlações canônicas baseadas nas correlações genotípicas, permitem determinar associações entre grupos de caracteres e realizar a seleção direta ou indireta de genótipos superiores. Objetivou-se com este trabalho investigar a existência de relações lineares e multivariadas entre caracteres de alta e baixa herdabilidade via análise de correlações canônicas com base nas correlações genotípicas. O experimento foi conduzido no Campo Experimental Professor Diogo Alves de Melo da Universidade Federal de Viçosa, em Viçosa, Minas Gerais. 90 cultivares de trigo foram avaliadas sob o delineamento alpha-lattice 9 × 10, com três repetições e parcelas constituídas por quatro linhas de três metros espaçadas a 0.20 metros. Os grupos canônicos foram estabelecidos entre altura de espiga e planta, dias para o espigamento, número de espiguetas por espiga e número de grãos por espiga (Grupo I) e, peso de espiga, massa de grãos da espiga, massa de 100 grãos, peso hectolitro e produtividade de grãos (Grupo II). Houve dependência entre os grupos estabelecidos, o que permitiu a investigação das relações entre os caracteres com base em seus valores genotípicos. Os caracteres ciclo e altura de plantas podem ser utilizados para a seleção indireta de genótipos superiores em peso hectolitro e produtividade, fatores estes importantes para indústrias e produtores.

Genetic parameters and selection gain in tropical wheat populations via Bayesian inference / Parâmetros genéticos e ganho de seleção em populações tropicais de trigo via inferência bayesiana

ABSTRACT: The development process of a new wheat cultivar requires time between obtaining the base population and selecting the most promising line. Estimating genetic parameters more accurately in early generations with a view to anticipating selection means important advances for wheat breeding programs. Thus, the present study estimated the genetic parameters of F2 populations of tropical wheat and the genetic gain from selection via the Bayesian approach. To this end, the authors assessed the grain yield per plot of 34 F2 populations of tropical wheat. The Bayesian approach provided an adequate fit to the model, estimating genetic parameters within the parametric space. Heritability (h2) was 0.51. Among those selected, 11 F2 populations performed better than the control cultivars, with genetic gain of 7.80%. The following populations were the most promising: TbioSossego/CD 1303, CD 1303/TbioPonteiro, BRS 254/CD 1303, Tbio Duque/Tbio Aton, and Tbio Aton/CD 1303. Bayesian inference can be used to significantly improve tropical wheat breeding programs.

RESUMO: O processo de desenvolvimento de uma nova cultivar de trigo requer tempo entre a obtenção da população base e a seleção da linhagem mais promissora. Estimar parâmetros genéticos com mais precisão nas primeiras gerações com vistas a antecipar a seleção significa avanços importantes para os programas de melhoramento de trigo. Assim, o presente estudo estima os parâmetros genéticos de populações F2 de trigo tropical e o ganho genético da seleção via abordagem Bayesiana. Para tanto, os autores avaliaram a produtividade de grãos por parcela de 34 populações F2 de trigo tropical. A abordagem Bayesiana proporcionou um ajuste adequado ao modelo, estimando parâmetros genéticos dentro do espaço paramétrico. A herdabilidade (h2) foi de 0,51. Dentre as selecionadas, 11 populações F2 obtiveram desempenho superior às cultivares controle, com ganho genético de seleção de 7,80%. As seguintes populações foram as mais promissoras: Tbio Sossego/CD 1303, CD 1303/Tbio Ponteiro, BRS 254/CD 1303, Tbio Duque/Tbio Aton e Tbio Aton/CD 1303. A inferência Bayesiana pode ser usada para melhorar significativamente programas de melhoramento de trigo tropical.

Canonical correlations between high and low heritability wheat traits via mixed models / Correlações canônicas entre caracteres de trigo de alta e baixa herdabilidade via modelos mistos

Canonical correlation analysis based on genotypic correlations allows determining the associations between groups of traits and carrying out the direct or indirect selection of superior genotypes. This study investigated the existence of linear and multivariate relationships between high and low heritability traits via canonical correlation analysis based on genotypic correlations. The experiment was conducted at the Professor Diogo Alves de Melo Experimental Field at the Universidade Federal de Viçosa, in Viçosa, MG. 90 wheat cultivars were evaluated under a 9 × 10 alpha-lattice design, with three replications and plots consisting of four rows of three meters spaced at 0.20 meters. Canonical groups were established between spike height and plant height, days for heading, number of spikelets per spike, and number of grains per spike (Group I) and, spike weight, spike grain mass, 100-grain mass, hectoliter weight, and grain yield (Group II). There was dependence between the established groups, which allowed the investigation of the relationships between traits based on their genotypic values. The traits cycle and plant height can be used for indirect selection of genotypes superior in hectoliter weight and grain yield, which are important factors for industries and farmers.

As análises de correlações canônicas baseadas nas correlações genotípicas, permitem determinar associações entre grupos de caracteres e realizar a seleção direta ou indireta de genótipos superiores. Objetivou-se com este trabalho investigar a existência de relações lineares e multivariadas entre caracteres de alta e baixa herdabilidade via análise de correlações canônicas com base nas correlações genotípicas. O experimento foi conduzido no Campo Experimental Professor Diogo Alves de Melo da Universidade Federal de Viçosa, em Viçosa, Minas Gerais. 90 cultivares de trigo foram avaliadas sob o delineamento alpha-lattice 9 × 10, com três repetições e parcelas constituídas por quatro linhas de três metros espaçadas a 0.20 metros. Os grupos canônicos foram estabelecidos entre altura de espiga e planta, dias para o espigamento, número de espiguetas por espiga e número de grãos por espiga (Grupo I) e, peso de espiga, massa de grãos da espiga, massa de 100 grãos, peso hectolitro e produtividade de grãos (Grupo II). Houve dependência entre os grupos estabelecidos, o que permitiu a investigação das relações entre os caracteres com base em seus valores genotípicos. Os caracteres ciclo e altura de plantas podem ser utilizados para a seleção indireta de genótipos superiores em peso hectolitro e produtividade, fatores estes importantes para indústrias e produtores.

Poultry litter and cover crops influence the agronomic performance and grain yield of wheat

The use of poultry litter as a source of nitrogen (N) and the decomposition of ground cover plants can be an alternative and N management strategy in the wheat crop, in succession. Therefore, the objective of this study was to evaluate the effect of isolated and/or intercropped cultivation of ground cover plants in autumn/winter and the use of poultry litter on some plant parameters and on the final yield of wheat grains. The experimental design was randomized blocks, in split plots, with three replications. The treatments in the plots were composed of isolated coverings Avena strigosa Schreb., Raphanus sativus L. and intercropping of A. strigosa + R. sativus and fallow as a control. In the subplots, the N managements in the wheat crop with 100% of the N recommendation via poultry litter, 100% of the N via mineral (urea), 50% via poultry litter + 50% mineral and the control, without N application. The management of nitrogen fertilization and the cover crops altered the yield components of the wheat crop. The use of poultry litter increased the final grain yield, being an alternative as a partial replacement, when associated with urea, or total N. Isolated crops R. sativus and A. strigosa + R. sativus intercropping significantly influenced agronomic performance and final grain yield.

Agronomic feasibility of wheat and triticale cultivars in the semiarid of Minas Gerais state, Brazil / Viabilidade agronômica de cultivares de trigo e triticale na região semiárida do estado de Minas Gerais, Brasil

The production of winter cereals is becoming increasingly important in Brazil, largely due to advanced techniques that enable considerable qualitative and quantitative gains. This is due to plant breeding under different soil and climate conditions combined with proper management. The present study aims to assess the agronomic feasibility of growing wheat and triticale cultivars with two sowing times in the semiarid region of northern Minas Gerais State, Brazil. The experiment was conducted in 2018 at the Instituto de Ciências Agrárias (Institute of Agricultural Sciences) of Universidade Federal de Minas Gerais, Montes Claros campus. A randomized block design was used, with four replications and an 8 × 2 factorial arrangement consisting of eight genotypes (six wheat and two triticale cultivars) and two sowing times (April 21 and May 12, 2018). The irrigated production of wheat and triticale was agronomically feasible in the semi-arid region of Minas Gerais state and sowing time affected the main agronomic traits of interest of winter cereals. However, it is essential to study the economic feasibility of the crop. Sowing in April was the most indicated for wheat and triticale, with IPR Potyporã, IPR 144 and IPR 111 as the recommended cultivars.Key words: Agronomic traits. Triticum. aestivum L. X Triticosecale wittimack. Winter cereals.

A produção brasileira de cereais de inverno está ganhando cada vez mais importância, principalmente pelo uso de técnicas avançadas, o que permite um ganho qualitativo e quantitativo considerável. Isso ocorre em função do melhoramento genético nas diferentes condições edafoclimáticas associado ao manejo adequado dessas plantas. Assim, esse trabalho objetivou avaliar a viabilidade agronômica de cultivares de trigo e triticale em duas épocas de semeadura na região semiárida do estado de Minas Gerais, Brasil. O experimento foi conduzido no delineamento de blocos casualizados com quatro repetições, em arranjo fatorial 8 × 2, composto por oito genótipos (6 cultivares de trigo e 2 cultivares de triticale) e duas épocas de semeadura (21 de abril e 12 de maio de 2018). A produção irrigada de trigo e triticale no semiárido mineiro foi agronomicamente viável, e a época de semeadura afetou as principais características de interesse agronômico dos cereais de inverno. Porém, é fundamental estudar a viabilidade econômica para a indicação da cultura. A semeadura em abril foi a mais indicada para trigo e triticale, nesse caso, recomenda-se o uso das cultivares IPR Potyporã, IPR 144 e IPR 111.

Azospirillum brasilense and Zinc Rates Effect on Fungal Root Colonization and Yield of Wheat-Maize in Tropical Savannah Conditions.

A successful microbial inoculant can increase root colonization and establish a positive interaction with native microorganisms to promote growth and productivity of cereal crops. Zinc (Zn) is an intensively reported deficient nutrient for maize and wheat production in Brazilian Cerrado. It can be sustainably managed by inoculation with plant growth-promoting bacteria and their symbiotic association with other microorganisms such as arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE). The objective of this study was to evaluate the effect of Azospirillum brasilense inoculation and residual Zn rates on root colonization and grain yield of maize and wheat in succession under the tropical conditions of Brazil. These experiments were conducted in a randomized block design with four replications and arranged in a 5 × 2 factorial scheme. The treatments consisted of five Zn rates (0, 2, 4, 6 and 8 kg ha-1) applied from zinc sulfate in maize and residual on wheat and without and with seed inoculation of A. brasilense. The results indicated that root colonization by AMF and DSE in maize-wheat cropping system were significantly increased with interaction of Zn rates and inoculation treatments. Inoculation with A. brasilense at residual Zn rates of 4 kg ha-1 increased root colonization by AMF under maize cultivation. Similarly, inoculation with A. brasilense at residual Zn rates of 2 and 4 kg ha-1 reduced root colonization by DSE under wheat in succession. The leaf chlorophyll index and leaf Zn concentration were increased with inoculation of the A. brasilense and residual Zn rates. The inoculation did not influence AMF spore production and CO2-C in both crops. The grain yield and yield components of maize-wheat were increased with the inoculation of A. brasilense under residual Zn rates of 3 to 4 kg ha-1 in tropical savannah conditions. Inoculation with A. brasilense under residual Zn rates up to 4 kg ha-1 promoted root colonization by AMF and DSE in the maize cropping season. While the inoculation with A. brasilense under 2 and 4 kg ha-1 residual Zn rates reduced root colonization by AMF and DSE in the wheat cropping season. Therefore, inoculation with A. brasilense in combination with Zn fertilization could consider a sustainable approach to increase the yield and performance of the maize-wheat cropping system in the tropical savannah conditions of Brazil.

Worldwide Selection Footprints for Drought and Heat in Bread Wheat (Triticum aestivum L.).

Genome-environment Associations (GEA) or Environmental Genome-Wide Association scans (EnvGWAS) have been poorly applied for studying the genomics of adaptive traits in bread wheat landraces (Triticum aestivum L.). We analyzed 990 landraces and seven climatic variables (mean temperature, maximum temperature, precipitation, precipitation seasonality, heat index of mean temperature, heat index of maximum temperature, and drought index) in GEA using the FarmCPU approach with GAPIT. Historical temperature and precipitation values were obtained as monthly averages from 1970 to 2000. Based on 26,064 high-quality SNP loci, landraces were classified into ten subpopulations exhibiting high genetic differentiation. The GEA identified 59 SNPs and nearly 89 protein-encoding genes involved in the response processes to abiotic stress. Genes related to biosynthesis and signaling are mainly mediated by auxins, abscisic acid (ABA), ethylene (ET), salicylic acid (SA), and jasmonates (JA), which are known to operate together in modulation responses to heat stress and drought in plants. In addition, we identified some proteins associated with the response and tolerance to stress by high temperatures, water deficit, and cell wall functions. The results provide candidate regions for selection aimed to improve drought and heat tolerance in bread wheat and provide insights into the genetic mechanisms involved in adaptation to extreme environments.

Integrative Soil Application of Humic Acid and Foliar Plant Growth Stimulants Improves Soil Properties and Wheat Yield and Quality in Nutrient-Poor Sandy Soil of a Semiarid Region.

Sandy soils (containing > 50% sand) are widely distributed worldwide and are characterized by their poor structure, low organic matter, weak hydraulic and nutritional properties, and low crop productivity. Using a 2-year pot experiment, in this study, we investigated the effects of humic acid (HA) as a soil amendment and study two plant growth stimulants (PGSs), zinc oxide nanoparticles (ZnONPs), and L-tryptophan (L-TRP), as a foliar application on wheat grown in nutrient-poor sandy soil. Three HA rates (0 (HA0), 0.2 (HA0.2), and 0.4 (HA0.4) g kg-1 soil) and five PGS levels [control, 50 mg l-1 (ZnONPs50), 100 mg l-1 (ZnONPs100), 0.25 mmol l-1 (L-TRP0.25), and 0.5 mmol l-1 (L-TRP0.5)] were used. The soil hydro-physico-chemical properties, morpho-physiological responses, yield, and quality were measured. HA addition amended the soil structure by allowing rapid macroaggregate formation, decreasing bulk density and pH, and increasing porosity and electrical conductivity, thereby improving soil hydraulic properties. HA0.2 and HA0.4 additions improved growth, yield components, and grain minerals, resulting in higher grain yield by 28.3-54.4%, grain protein by 10.2-13.4%, wet gluten by 18.2-23.3%, and dry gluten by 23.5-29.5%, respectively, than HA0. Foliar application of ZnONPs or L-TRP, especially at higher concentrations compared to the control, noticeably recorded the same positive results as HA treatments. The best results were achieved through the integration of HA0.4 + ZnONPs100 or L-TRP0.5 to the tested nutrient-poor sandy soil. The interactive application of HA0.4 + ZnONPs100 or L-TRP0.5 and the use of mineral fertilizer, which is considered a surplus point in permaculture, can be recommended for sustainable wheat production in nutrient-poor sandy soil.

Lipopolysaccharide and flagellin of Azospirillum brasilense Sp7 influence callus morphogenesis and plant regeneration in wheat.

In vitro somatic callus culturing is used widely in plant biotechnology, but its effectiveness depends largely on the donor plant genotype. Bacteria or components of their cells are rarely used to activate morphogenesis. In this work, inoculation of explants from immature wheat (Triticum aestivum L.) embryos with a suspension of living cells of the bacterium Azospirillum brasilense Sp7 resulted in callus death after 7 days of growth, in contrast to explant treatment with a suspension of heat-killed whole cells of Sp7. The experiments used two wheat lines, LRht-B1a and LRht-B1c, which differ in morphogenic activity. Growing calluses with the lipopolysaccharide of A. brasilense Sp7 increased the yield of regenerated plants 2- to 3.5-fold in both lines. This increase was through the activation of regenerant formation from morphogenic calluses. We have demonstrated for the first time the effects of bacterial flagellin on plant tissue culture. The polar-flagellum flagellin of A. brasilense Sp7 leveled the genotypic differences in the morphogenic ability of callus tissue. Specifically, it increased the yield of morphogenic calluses in the weakly morphogenic line LRht-B1a to the yield value in the highly morphogenic line LRht-B1c but lowered the yield of regenerants in the highly morphogenic line LRht-B1c to the yield value in the weakly morphogenic line LRht-B1a. Thus, bacterial lipopolysaccharides and flagellins can be used to regulate the formation of morphogenic calluses and regenerants in plant tissue culturing in vitro.

A Laminarin-Based Formulation Protects Wheat Against Zymoseptoria tritici via Direct Antifungal Activity and Elicitation of Host Defense-Related Genes.

The present study aimed to evaluate the potential of the laminarin-based formulation Vacciplant to protect and induce resistance in wheat against Zymoseptoria tritici, a major pathogen on this crop. Under greenhouse conditions, a single foliar spraying of the product 2 days before inoculation with Z. tritici reduced disease severity and pycnidium density by 42 and 45%, respectively. Vacciplant exhibited a direct antifungal activity on Z. tritici conidial germination both in vitro and in planta. Moreover, it reduced in planta substomatal colonization as well as pycnidium formation on treated leaves. Molecular investigations revealed that Vacciplant elicits but did not prime the expression of several wheat genes related to defense pathways, including phenylpropanoids (phenylalanine ammonia-lyase and chalcone synthase), octadecanoids (lipoxygenase and allene oxide synthase), and pathogenesis-related proteins (ß-1,3-endoglucanase and chitinase). By contrast, it did not modulate the expression of oxalate oxidase gene involved in the reactive oxygen species metabolism. Ultrahigh-performance liquid chromatography-mass spectrometry analysis indicated limited changes in leaf metabolome after product application in both noninoculated and inoculated conditions, suggesting a low metabolic cost associated with induction of plant resistance. This study provides evidence that the laminarin-based formulation confers protection to wheat against Z. tritici through direct antifungal activity and elicitation of plant defense-associated genes.

Production and nutritional value of wheat and triticale cultivars in different harvest times in the Minas Gerais semiarid / Produção e valor nutricional de cultivares de trigo e triticale em diferentes épocas de colheita no semiárido mineiro

The objective of the present study was to evaluate the productive performance and nutritional value of forage of wheat and triticale cultivars at different harvest times in the semiarid region of Minas Gerais. Eight wheat cultivars and two triticale cultivars harvested at three stages of plant development were evaluated: Rubberization, grain at the stage of soft mass and harvest maturation. The experimental design adopted was a randomized block in a factorial scheme 10 × 3, with three replicates, 10 cultivars and 3 developmental stages for plant collection. The main agronomic characteristics and nutritional value were evaluated of forage of the cultivars under study. The study demonstrated the potential of wheat and triticale cultivation for forage in the semiarid region of Minas Gerais. The mean dry matter yield of wheat cultivars was 5.90 t ha-1, 7.85 t ha-1 and 7.98 t ha-1 and triticale 6.47 t ha-1, 9.97 t ha-1 and 10.5 t ha-1 for the rubber harvesting stages, grain at the stage of soft mass and harvest maturation, respectively. For the average crude protein content, the wheat cultivars showed 15.07%, 9.13%, 10.60% and the triticale cultivars showed 14.4%, 9.31% and 10.05% for the harvest stages of rubber formation, grain at the stage of soft mass and harvest maturation, respectively. When evaluating the average levels of total digestible nutrients, the wheat and triticale cultivars showed an average of 48.90% and 48.67% in the rubber harvesting stage and 42.68% and 49.60% in the grain in the mass stage suave and 44.43% and 42.90% at harvest maturation. The highest yield of digestible dry matter was observed with the cultivars harvested at the grain stage at the soft mass stage. Triticale IPR 111 and Wheat IPR PANATY had greater productive potential and better nutritional quality for use as forage.(AU)

Objetivou-se com o presente estudo avaliar o desempenho produtivo e valor nutricional da forragem de cultivares de trigo e triticale em diferentes épocas de colheita no semiárido Mineiro. Foram avaliados oito cultivares de trigo e duas cultivares de triticale colhidas em três estádios de desenvolvimento das plantas: no Emborrachamento, grão no estádio de massa macia e maturação de colheita. O delineamento experimental adotado foi em blocos ao acaso em esquema fatorial 10×3, com três repetições sendo 10 cultivares e 3 estádios de desenvolvimento para colheita das plantas. Foram avaliadas as principais características agronômicas e o valor nutricional da forragem das cultivares em estudo. A pesquisa demonstrou o potencial do cultivo do trigo e triticale para forragem no semiárido de Minas Gerais. A produtividade média de matéria seca das cultivares de trigo foi de 5,90 t ha-1, 7,85 t ha-1 e 7,98 t ha-1 e triticale 6,47 t ha-1, 9,97 t ha-1 e 10,5 t ha-1 para os estádios de colheita de emborrachamento, grão no estádio de massa macia e maturação de colheita respectivamente. Para os teores médios de proteína bruta as cultivares de trigo apresentaram 15,07%, 9,13%, 10,60% e as cultivares de triticale 14,4%, 9,31% e 10,05% para os estádios de colheita de emborrachamento, grão no estádio de massa macia e maturação de colheita respectivamente. Ao se avaliar os teores médios de nutrientes digestíveis totais as cultivares de trigo e triticale apresentaram média de 48,90% e 48,67% no estádio de colheita de emborrachamento, 42,68% e 49,60% no grão no estádio de massa macia e 44,43% e 42,90% na maturação de colheita. A maior produtividade de matéria seca digestível foi observada com as cultivares colhidas no estádio de grão no estádio de massa macia. O Triticale IPR 111 e o Trigo IPR PANATY tiveram maior potencial produtivo e melhor qualidade nutricional para uso como forragem.(AU)

Deoxynivalenol biosynthesis and accumulation in wheat under application of carrageenan / Biossíntese e acúmulo de desoxinivalenol em trigo submetido à aplicação de carragena

Mycotoxins pose a large threat to human and livestock besides reducing the quality of food/feed. It is believed that these toxins are biosynthesized as a mechanism of defense (stress-response) of fungi. The most important mycotoxin for winter-cereal crops is known by deoxynivalenol (DON), a trichothecene biosynthesized mainly by Fusarium graminearum. This manuscript brings data of three years (2018, 2019 and 2020) of field research (24 field experiments) in Western Santa Catarina and North-Western Rio Grande do Sul, Brazil using a sulphated polysaccharide exclusive from red seaweed, carrageenan, associated with fungicides to help suppressing deoxynivalenol (DON) biosynthesis and accumulation in wheat kernels. A reduction of 36.4% in DON contamination was observed. Weather conditions have influenced the accumulation of DON in wheat kernels. Carrageenan has shown to be a biological compound capable of helping on the suppression of DON biosynthesis and accumulation in wheat kernels regardless of weather conditions.

As micotoxinas representam uma grande ameaça para humanos e animais, além de reduzirem a qualidade de alimentos/rações. Acredita-se que essas toxinas sejam biossintetizadas como mecanismo de defesa (resposta ao estresse) de fungos. A micotoxina de maior interesse para cereais de inverno é conhecida por desoxinivalenol (DON), um tricoteceno biossintetizado principalmente por Fusarium graminearum. Esse estudo traz dados de três anos (2018, 2019 e 2020) de pesquisa de campo (24 experimentos) conduzidos no Oeste de Santa Catarina e no Nordeste do Rio Grande do Sul, Brasil, utilizando um polissacarídeo sulfatado exclusivo de algas vermelhas, carragena, associado a fungicidas para ajudar na supressão da biossíntese e acúmulo de desoxinivalenol (DON) em grãos de trigo. Foi observada uma redução de 36,4% na contaminação por DON. As condições climáticas influenciaram no acúmulo de DON nos grãos de trigo. A carragena se demostrou como um composto biológico capaz de atenuar a biossíntese e acúmulo de DON em grãos de trigo independente das condições climáticas.

Variation in the hectolitre weight of wheat grain for equipment and sample size / Variação da massa de hectolitro em função do equipamento e tamanho da amostra

Hectolitre weight (HW) is the principal quantitative parameter used by receiving units as an indicator of the quality of wheat grain (Triticum aestivum L.). The moisture content and the equipment used can be considered important sources of variation to assess a batch, requiring correct sizing of the sample used to measure the HW. This research identified the variability between the equipment used to evaluate HW with or without correcting the grain moisture content, and to estimate the ideal number of samples for the commercial classification of wheat batches. The experiment was carried out in a randomised block design with four replications. Seven batches of wheat grain from different cultivars and/or production sites were used to measure the HW using three types of equipment (Equipment 'A', Equipment 'B' and Equipment 'C'), with and without correcting the grain moisture content to 13%. Higher values for HW were determined with Equipment 'A' (77.15) compared to Equipment 'B' (75.08) and Equipment 'C' (74.69), classifying the wheat according to type. The moisture content affected the HW, but did not change the final classification of the wheat in terms of type. The ideal number of samples for HW ranged from 1 to 18 at the lowest level of precision (HW=mean±1 kg hl-¹) and from 67 to 1820 samples for the highest precision (HW=mean±0.1 kg hl-¹). Equipment 'B' requires a smaller number of samples (possibly as few as one) for the same level of precision (HW=mean±1 kg hl-¹), whereas Equipment 'A' requires a greater number of samples for the majority of batches. Correctly classifying wheat by HW therefore depends on a larger number of samples.

A massa de hectolitro (MH) é o principal parâmetro quantitativo usado nas unidades de recebimento como indicador de qualidade dos grãos de trigo (Triticum aestivum L.). O teor de umidade e o equipamento utilizado podem ser considerados fontes de variação importantes na classificação de um lote, necessitando correto dimensionamento amostral para mensuração da MH. O objetivo dessa pesquisa foi identificar a variabilidade entre equipamentos para avaliação da MH com correção ou não do teor de umidade da massa de grãos e estimar o número ideal de amostras para classificação comercial de lotes de trigo. O experimento foi realizado em delineamento experimental de blocos ao acaso com quatro repetições. Sete lotes de grãos de trigo, oriundos de diferentes cultivares e/ou locais de produção, foram usados para mensuração da MH em três equipamentos (Equipamento "A", Equipamento "B" e Equipamento "C"), com e sem correção da umidade dos grãos para 13%. Maiores valores da MH foram determinados no Equipamento "A" (77,15) comparado ao Equipamento "B" (75,08) e Equipamento "C" (74,69), com classificação distinta do trigo quanto ao tipo. O teor de umidade afetou a MH, mas não alterou a classificação final do trigo quanto ao tipo. O número ideal de amostras para MH variou de uma a 18 amostras para o menor nível de precisão (MH = média ± 1 kg hl-¹) e, de 67 a 1820 amostras para a maior precisão (MH = média ± 0,1 kg hl-¹). O Equipamento "B" requer menor número de amostras (podendo chegar a uma) para um mesmo nível de precisão (MH = média ± 1 kg hl-¹), enquanto o Equipamento "A" necessita maior número de amostras para a maioria dos lotes. Assim, a correta classificação do trigo pela MH depende de maior número de amostras.

Stress-induced expression of IPT gene in transgenic wheat reduces grain yield penalty under drought.

BACKGROUND: The heterologous expression of isopentenyl transferase (IPT) under the transcriptional control of the senescence-associated receptor-like kinase (SARK) promoter delayed cellular senescence and, through it, increased drought tolerance in plants. To evaluate the effect of pSARK::IPT expression in bread wheat, six independent transgenic events were obtained through the biolistic method and evaluated transgene expression, phenology, grain yield and physiological biomass components in plants grown under both drought and well-irrigating conditions. Experiments were performed at different levels: (i) pots and (ii) microplots inside a biosafety greenhouse, as well as under (iii) field conditions. RESULTS: Two transgenic events, called TR1 and TR4, outperformed the wild-type control under drought conditions. Transgenic plants showed higher yield under both greenhouse and field conditions, which was positively correlated to grain number (given by more spikes and grains per spike) than wild type. Interestingly, this yield advantage of the transgenic events was observed under both drought and well-watered conditions. CONCLUSIONS: The results obtained allow us to conclude that the SARK promoter-regulated expression of the IPT gene in bread wheat not only reduced the yield penalty produced by water stress but also led to improved productivity under well-watered conditions.

Wheat yield and seed physiological quality affected by initial seed vigor, sowing density, and environmental conditions / Rendimento de grãos e qualidade fisiológica de sementes de trigo influenciados pelo vigor inicial da semente, densidade de semeadura e condições ambientais

Optimization of seed density range, combined with the use of quality seeds may help generate more profit from wheat production, as these factors affect grain yield and the quality of seeds. The aim of this study was to evaluate the effects of initial vigor level and sowing densities on the productive performance of the plants and the physiological performance of the seeds of two wheat cultivars in two cultivation environments. The experiment was carried out in the cities of Londrina and Ponta Grossa, Paraná, Brazil, in a randomized block design with four replications, following a 2 × 2 × 4 factorial scheme with two levels of seed vigor (high and low), two cultivars (BRS Gralha-Azul and BRS Sabiá), and four sowing densities (150, 250, 350, and 450 seeds m-²). The following characteristics were evaluated: emerged seedlings, shoot dry matter, spike density, vegetation index, and grain yield. Additionally, the physiological potential of the seeds produced in Londrina was evaluated by first germination count, germination, accelerated aging, seedling emergence, and emergence speed index tests. The increase in density up to 450 seeds m-2 favored the productive performance of the crop in both cultivation environments; however, it reduced the physiological performance of the seeds produced in Londrina. The cultivars BRS Gralha-Azul and BRS Sabiá had better performance and grain yield in Londrina and Ponta Grossa, respectively. High-vigor seeds favored the establishment of the stand, especially under unfavorable environmental conditions.

O ajuste da densidade de semeadura ótima para a cultura trigo aliado à utilização de sementes de qualidade pode contribuir para gerar maior lucratividade na produção de trigo, pois esses fatores afetam o rendimento de grãos e a qualidade das sementes. O objetivo do trabalho foi avaliar os efeitos do nível de vigor inicial e das densidades de semeadura sobre o desempenho produtivo das plantas e o desempenho fisiológico das sementes de duas cultivares de trigo em dois ambientes de cultivo. O experimento foi conduzido nas cidades de Londrina e em Ponta Grossa, Paraná, Brasil, em delineamento experimental de blocos casualizados com quatro repetições, em esquema fatorial 2 × 2 × 4, sendo avaliados dois níveis de vigor de sementes (alto e baixo), duas cultivares (BRS Gralha-Azul e BRS Sabiá) e quatro densidades de semeadura (150, 250, 350 e 450 sementes m-²). As seguintes características foram avaliadas: número de plântulas emergidas, matéria seca da parte aérea de plantas, densidade de espigas, índice de vegetação e rendimento de grãos. Adicionalmente, foi avaliado o potencial fisiológico das sementes produzidas em Londrina pelos testes de primeira contagem, germinação, envelhecimento acelerado, emergência de plântulas e índice de velocidade de emergência. O aumento da densidade até 450 sementes m-2 favoreceu o desempenho produtivo da cultura nos dois locais de cultivo, porém, reduziu o desempenho fisiológico das sementes produzidas em Londrina. As cultivares BRS Gralha-Azul e BRS Sabiá apresentaram desempenho e rendimento de grãos superiores em Londrina e Ponta Grossa, respectivamente. Sementes de alto vigor favorecem o estabelecimento do estande, principalmente em condições ambientais desfavoráveis.

Yield and physiological quality of wheat seeds produced under different irrigation depths and leaf Silicon / Produtividade e qualidade fisiológica de sementes de trigo produzidas sob diferentes lâminas de irrigação e Silício foliar

Water availability is one of the main factors responsible for wheat productivity, as well as the quality of the produced seeds. Silicon (Si) has an important role in mitigating the effects of various biotic and abiotic stresses. Thus, Si application can be used to mitigate the effects of different irrigation depths on the production and quality of wheat seeds. The work aimed to evaluate the yield and physiological quality of wheat seeds produced from plants fertilized with leaf Si and grown under different irrigation depths. The experiment was laid out in a split-plot randomized block design, with four replications. The plots consisted of three irrigation depths (0, 50, and 100% of the total irrigation requirement [TIR]). Si treatments were allocated (without application [0 mM] and 5 mM SiO2, applied at the tillering stage) in the subplots. The following parameters were evaluated: water balance of the system; soil moisture; yield; thousand seed weight; germination; electrical conductivity; accelerated aging; seedling length and emergence. The water balance of the system was negative for the 0% TIN irrigation depth after anthesis and there was less soil moisture in this irrigation depth. There was no effect of irrigation depths and Si application on plant yield. The smaller irrigation depths imposed reduced the thousand seed weight and increased the electrical conductivity of the seeds produced. Plants fertilized with Si did not differ in germination, but they produced more vigorous seedlings with greater growth and uniformity.(AU)

A disponibilidade de água é um dos principais fatores responsáveis pela produtividade do trigo, bem como da qualidade das sementes produzidas. O silício (Si) possui importante papel na atenuação dos efeitos de diversos estresses bióticos e abióticos. Desta forma, a aplicação de Si pode ser uma ferramenta para mitigar os efeitos de diferentes lâminas de irrigação na produção e qualidade de sementes de trigo. O objetivo do trabalho foi avaliar a produtividade e a qualidade fisiológica de sementes de trigo produzidas a partir de plantas fertilizadas com Si foliar e cultivadas sob diferentes lâminas de irrigação. O delineamento experimental foi blocos casualizados, em esquema de parcelas subdividas, com quatro repetições. As parcelas foram constituídas por três lâminas de irrigação (0, 50 e 100% da irrigação total necessária [ITN]). Nas subparcelas foram alocados os tratamentos de silício (sem aplicação [0 mM] e 5 mM de SiO2, aplicado na fase de perfilhamento). Foram avaliados: balanço hídrico do sistema; umidade do solo; produtividade; massa de mil sementes; germinação; condutividade elétrica; envelhecimento acelerado; comprimento e emergência de plântulas. O balanço hídrico do sistema foi negativo para a lâmina de 0% da ITN após a antese e houve menor umidade do solo nesta lâmina. Não houve efeito das lâminas de irrigação e da aplicação de Si na produtividade das plantas. As menores lâminas de irrigação impostas reduziram a massa de mil sementes e aumentaram a condutividade elétrica das sementes produzidas. Sementes produzidas em plantas fertilizadas com Si não diferiram quanto a germinação, porém originam plântulas mais vigorosas com maior crescimento e uniformidade.(AU)

Wheat yield and seed physiological quality as influenced by seed vigor, nitrogen fertilization and edaphoclimatic conditions / Rendimento de trigo e qualidade fisiológica de sementes influenciados pelo vigor de sementes, adubação nitrogenada e condições edafoclimáticas

Wheat is one of the most important cereals grown in the world, and in Brazil, increasing national production is still a challenge. Nitrogen (N) supply can favor grain yield and the physiological quality of wheat seeds. However, the definition of adequate N rate and fertilization timing must consider genotype, cultivation environment, and initial seed vigor level. The aim of this work was to evaluate the effect of initial seed vigor and the combinations of rates and timings of N application on grain yield and seed physiological quality of wheat cultivars under different edaphoclimatic conditions. The experiment was carried out in Londrina and Ponta Grossa, state of Paraná, in a randomized block design in a 2 × 2 × 7 factorial scheme, with four replicates. Treatments consisted of two seed vigor levels (vigorous and non-vigorous seeds), two wheat cultivars (BRS Gralha-Azul and BRS Sabiá) and seven combinations of fertilization timings and N rates (kg ha-1) (control-0N; 20N at sowing and 60N at tillering; 40N at sowing; 80N at sowing; 40N at sowing and 40N at tillering; 40N at tillering; 80N at tillering). Number of emerged seedlings, vegetation index, shoot dry matter, number of fertile spikes m-2 and grain yield were evaluated. Additionally, the physiological potential of seeds produced in Londrina was evaluated by the testes of first count, germination, seedling emergence in sand and emergence speed index. The climatic conditions during the experiment, in both cultivation environments, were similar to average historical records, with some periods of water deficit. The highest grain yield was obtained with the BRS Gralha-Azul in Londrina, and with BRS Sabiá in Ponta Grossa. The use of vigorous seeds favored the stand establishment and the response of plants to N fertilization. The treatments 40N + 40N, and 40N + 0N favored the majority of evaluated variables. Both cultivars showed potential for the production of high physiological potential seeds in Londrina environment. Inadequate N supply impairs wheat grain yield and seed production.(AU)

O trigo é um dos cereais mais importantes cultivados no mundo, sendo que no Brasil o aumento da produção nacional ainda é um desafio. A aplicação de nitrogênio (N) pode favorecer o aumento do rendimento de grãos e da qualidade fisiológica de sementes de trigo. Porém, a definição da dose correta de N e do momento adequado da adubação deve considerar o genótipo, o ambiente de cultivo e o nível de vigor inicial das sementes. O objetivo deste trabalho foi avaliar o efeito do vigor inicial de sementes e de combinações de doses de N e épocas de adubação sobre o rendimento de grãos e a qualidade fisiológica de sementes de cultivares de trigo em diferentes condições ambientais. O experimento foi conduzido em Londrina e em Ponta Grossa, Paraná, em delineamento em blocos casualizados em esquema fatorial 2 × 2 × 7, com quatro repetições. Os tratamentos consistiram em dois níveis de vigor de sementes (sementes vigorosas e não vigorosas), duas cultivares de trigo (BRS Gralha-Azul e BRS Sabiá) e sete combinações de épocas de adubação e doses de N (kg ha-1) (testemunha-0N; 20N na semeadura e 60N no perfilhamento; 40N na semeadura; 80N na semeadura; 40N na semeadura e 40N no perfilhamento; 40N no perfilhamento; 80N no perfilhamento). Foram avaliados: número de plântulas emergidas, índice de vegetação, matéria seca da parte aérea, número de espigas m-2 e rendimento de grãos. Adicionalmente, foi avaliado o potencial fisiológico das sementes produzidas em Londrina pelos testes de primeira contagem, germinação, emergência de plântulas em areia e índice de velocidade de emergência. As condições climáticas durante a condução do experimento, em ambos locais de cultivo, foram semelhantes aos registros médios históricos, com alguns períodos de déficit hídrico. O maior rendimento de grãos foi obtido com a BRS Gralha-Azul em Londrina e BRS Sabiá em Ponta Grossa. O uso de sementes vigorosas favoreceu o estabelecimento do estande e a resposta das plantas à fertilização com N. Os tratamentos 40N + 40N e 40N + 0N favoreceram a maioria das variáveis avaliadas. Ambas cultivares demostraram potencial para a produção de sementes de elevado potencial fisiológico no ambiente de Londrina. O suprimento inadequado de N prejudica o rendimento de grãos e a produção de sementes de trigo.(AU)