IAC Imperador Research Articles

What are the impacts of water deficit, cultivars, and agricultural years on the dynamics of nutrient uptake by common bean? Part I: n, P, and K

Knowing the effect of water deficit intensity on the nutrient uptake dynamics by common bean cultivars with contrasting growth habits in different years is necessary to appraise and recommend more specific fertilization management practices. A field study was carried out in the Southeast of Brazil for two years aiming to explain and compare the accumulation and extraction of the macronutrients nitrogen (N), phosphorus (P), and potassium (K) from two common bean cultivars with contrasting growth habits as a function of water deficit severity. The common bean cultivars IAC Imperador and IPR Campos Gerais, with determinate and indeterminate growth habits, respectively, were evaluated. Both cultivars were submitted to three irrigation management practices: severe water deficit (54% of the crop evapotranspiration – ETc), moderate water deficit (77% of ETc), and no water deficit (100% of ETc). Overall, the severe water deficit reduced N, P, and K accumulation in the common bean cultivars by 26, 37, and 23%, respectively. Under no water deficit, IPR Campos Gerais showed higher accumulation of biomass and nutrients N (27%) and P (42%) compared to IAC Imperador, in addition to higher interannual variability in the accumulation of nutrients. The maximum daily demand for nutrients N, P, and K of IAC Imperador was anticipated in 9, 13 and 11 days, respectively, compared to IPR Campos Gerais. Irrigation management, cultivar, and climate of the agricultural year are important factors in decision-making for the most adequate establishment of fertilization with N, P, and K in common bean.

Increased hormetic dose of glyphosate causes oxidative stress and reduces yield in common bean

Glyphosate can alter several physiological and biochemical processes and even plant nutrient absorption. This study aimed to verify whether biochemical and non-biochemical variables of the antioxidant complex are affected by low doses, considered hormetic, of glyphosate herbicide. Two experiments were conducted in the field, one in the winter and the other in the wet season, with the early cycle common bean cultivar IAC Imperador. The experimental design was in a randomized block, consisting of applying low doses of glyphosate (0.0, 1.8, 7.2, 12, 36, 54, and 108 g a.e. ha–1) in the phenological stage V4, with four replicates. Environmental conditions, such as air temperature, interfered in the early cycle common bean response to low doses of glyphosate. Lower doses of glyphosate did not alter the gas exchange of bean plants. However, the increase in the glyphosate doses reduced the net CO2 assimilation rate, stomatal conductance, and transpiration rate while increasing the SOD and CAT activity, and MDA and proline content. In the winter season, the dose 7.2 g a.e. ha–1 increased bean productivity, while the dose 36 g a.e. ha–1 induced oxidative stress in bean plants and reduced productivity. In the wet season, doses 36 and 54 g a.e. ha–1 increased bean productivity, and the dose 108 g a.e. ha–1 decreased grain yield. Thus, the more favorable climatic conditions in the wet season enhance plant metabolism, subsequently increasing plant tolerance to higher glyphosate doses.

Irrigation management of common bean cultivars with contrasting growth habits

A study was undertaken comparing the water requirements of two common bean ( Phaseolus vulgaris L.) cultivars to generate specific recommendations aimed at optimizing water use. To accomplish this work, the agronomic performance, responsiveness to water and water productivity of these two common bean cultivars of determinate and indeterminate growth habits were identified. The 2-year experiment was carried out during the winter growing season in the southeast of Brazil. Cultivars IAC Imperador, with an early season of determinate growth habit, and IPR Campos Gerais, having a mid-season of indeterminate growth habit, were subjected to five irrigation levels (54, 70, 77, 100, and 132 % of the crop evapotranspiration). Water deficit affected agronomic performance, reducing plant height (by up to 29 %), leaf area index (by up to 40 %), soil cover fraction (by up to 28 %), and grain yield (GY - by up to 31 %), in both cultivars. In contrast, excess water was more detrimental to cultivar IAC Imperador. Cultivar IPR Campos Gerais produced 18 % more than GY, showing superior water productivity and response to irrigation depth than IAC Imperador. Out of all the variables evaluated, the soil cover fraction correlated the most with grain yield in both common bean cultivars during the 2-year study. In other words, cover fraction evaluation in common bean allows for estimating crop production potential, which helps producers and technicians in their decision making regarding management practices. Thus, a cultivar directly affects water use in common bean production, thereby suggesting the need for a or water conservation strategy and sustainability of irrigated common bean production.

DIVERGÊNCIA GENÉTICA E SELEÇÃO DE CULTIVARES DE FEIJÃO BASEADA EM ARQUITETURA DE PLANTA E PRODUTIVIDADE

ABSTRACT The characterization of genetic divergence in common bean cultivars for various traits related to plant architecture and grain yield is unprecedented. This study proposes to determine whether common bean cultivars of different grain types differ for 12 traits of plant architecture and grain yield; examine the correlations between these traits; analyze the genetic divergence of these cultivars; and select superior cultivars for these traits. A total of 22 common bean cultivars with the grains types most produced in Brazil were evaluated in two growing seasons. Plant architecture was analyzed based on 12 traits, and grain yield was determined at maturity. Significant genotype and genotype × environment interaction effects were obtained, indicating the existence of genetic variability for all evaluated traits. Several plant architecture traits were correlated, but none was highly correlated with grain yield. Firstand second-internode lengths are more important in differentiating common bean cultivars. Principal component and Tocher’s analyses resulted in the formation of four and seven groups of cultivars, respectively. Both methods are efficient in analyzing genetic divergence; however, Tocher's method is more informative. Cultivars BRS Campeiro, SCS 205 - Riqueza, BRS Esteio, IAC Imperador and Guapo Brilhante have a high grain yield potential, but only BRS Campeiro, BRS Esteio and Guapo Brilhante have upright plant architecture.

Competitive ability of bean cultivars with Urochloa plantaginea

The objective of this work was to evaluate the competitive ability of carioca bean cultivars BRS FC104, BRS FC402, IAC Imperador, IAC Milênio, IPR Tangará, and SCS Riqueza in the presence of Alexandergrass (Urochloa plantaginea) in different proportions of plants in association. The experiments were carried out in a greenhouse in a completely randomized design with four replications. The treatments were arranged according to the proportions of beans and Alexandergrass plants: 100:0, 75:25, 50:50, 25:75, and 0:100 or 40:00, 30:10, 20:20, 10:30, and 0:40 plants per pot. The competitiveness of the species was analyzed using diagrams applied to replacement experiments and also through relative competitiveness indices. At 30 days after crop emergence, leaf area (LA), height (HP), diameter (DP), and shoot dry mass (SM) of the plant shoots were measured, as well as variables related to the physiology of the species. There was competition among carioca bean cultivars in the presence of Alexandergrass regardless of the proportion of plants, causing decreases in DP, LA and SM. Basically, there is competition for the same environmental resources between beans and Alexandergrass. Highlights: There is competition between bean and Alexandergrass, for the same environmental resources; There is varietal difference - IAC Imperador and SCS 205 Riqueza are the most competitive ones; The escape to competition is the best approach to guarantee yield in Alexandergrass-infested fields.

Yield predict and physiological state evaluation of irrigated common bean cultivars with contrasting growth habits by learning algorithms using spectral indices

This study aimed to analyze and compare the accuracy of models to predict the grain yield (GY) of common bean cultivars with contrasting growth habits using spectral indices. The common bean cultivars used were IAC Imperador and IPR Campos Gerais, which have determinate and indeterminate growth habits, respectively. The plants were grown under five irrigation levels (54, 70, 77, 100, and 132% of the crop evapotranspiration) to generate variability. The normalized difference vegetation (NDVI) and leaf chlorophyll (LCI) indexes were measured at the following phenological stages: V4 (third trifoliate leaf), R5 (pre-flowering), R6 (full flowering), and R8 (grain filling). The spectral indices were used individually for each phenological stage and associated with simple and multiple regressions (SLR and MLR) and artificial neural networks (ANN) to predict GY. Then, stratified models by cultivar and general models were established using data from both cultivars. The accuracy of NDVI-based GY predictions for both models at R6 phenological stage (ANN and SLR average) was acceptable (R2 = 0.64; RMSE = 0.37 Mg ha−1; MBE = −0.14 Mg ha−1) but poor for LCI predictions. The highest accuracies were observed at reproductive phenological stages, mainly R6. The ANNs algorithm did not show superior GY prediction accuracy compared to SLR. NDVI-based remote sensing is feasible to predict and monitor common bean yield potential using cultivar-specific and general models.

PARAMETERS AND GENETIC VARIABILITY IN BLACK BEANS F5 FAMILIES

The objective of this work was to contrast expectations of the segregating generations F2, F3, F4, and F5 with homozygous genetic constitutions, to determine the genetic parameters, dissimilarities through multivariate models, and the associations between characters of agronomic importance for the breeding of black beans. The experiment was conducted in the 2017/2018 crop season in the county of Tenente Portela – RS, Rio Grande do Sul, Brazil. The experimental design used was that of augmented blocks, with the cultivars IAC Imperador, IPR Tangará, BRS Estilo composing the common treatments, considered as pure lines, and 131 lineages of the F5 segregating generation, composing the unusual treatments, arranged in three blocks. After the characterization of the 134 genotypes, it was possible to verify that through Singh's relative contribution, the character of number of seeds per plant was the most decisive for the genetic variability of this study. The use of biometric methods allows it to be possible to evidence patterns in relation to the genotype clusters, through the use of standardized average Euclidean distance patterns, Tocher's optimization method, UPGMA clustering method, and Artificial Neural Networks with unsupervised learning. With the results obtained, it was possible to verify the existence of genetic variability among the studied populations, allowing the cluster analysis to delimit

What are the impacts of water deficit, cultivars, and years on the dynamics of nutrient uptake by common bean? Part II: Ca, Mg, and S

We aimed to explain and compare Ca, Mg, and S uptake dynamics by two common bean cultivars with contrasting growth habits as a function of water deficit severity in two years to generate more specific information for their fertilization management. A field study was set up using the cultivars IAC Imperador, with a determinate growth habit and early cycle, and IPR Campos Gerais, with an indeterminate growth habit and intermediate cycle. These cultivars were maintained under three irrigation levels, that is, severe (54% ETc), moderate (77% ETc), and no water deficit (100% ETc). The absorption order was Ca > Mg > S, regardless of the treatment. For the IAC Imperador, the Ca uptake ranged from 72 to 127 kg ha−1, Mg from 17.2 to 39.1 kg ha−1 and S from 7.9 to 16.5 kg ha−1, while for the IPR Campos Gerais it ranged from 92 to 156 kg ha−1, 21.0 to 36.5 kg ha−1 and 14.6 to 33.7 kg ha−1, respectively. Overall, severe water deficit reduced Ca, Mg, and S absorption by more than 25%. The IPR Campos Gerais presents, on average, 64% higher S accumulation, while the highest Ca and Mg accumulation order depends on the year. Compared to the IAC Imperador, this cultivar showed a later S absorption peak (up to +23 days), and higher interannual variability in the growth and nutrient absorption due to its indeterminate growth habit. These differences evidence the importance of specific fertilizer management practices for Ca, Mg and S in common bean, assisting in optimizing nutrient use.

Low doses of glyphosate can affect the nutrient composition of common beans depending on the sowing season

Glyphosate application, even in low doses, changes the nutrient composition of crops. The objective of this research was to evaluate the effects of low doses of glyphosate and the sowing season on the macronutrient and micronutrient contents of early cycle common beans. Two experiments were conducted in the field, namely one in the winter season and one in the wet season, using the early cycle common bean cultivar IAC Imperador. The experimental design was a randomized complete block design consisting of the application of low doses of glyphosate [0.0, 1.8, 7.2, 12.0, 36.0, 54.0, and 108.0 g acid equivalent (a.e.) ha−1] in the phenological stage V4 with four replications. Environmental conditions, such as air temperature, interfered with the response of early cycle common beans to low doses of glyphosate. In the winter season, doses of 7.2 g a.e. ha−1 and 36.0 g a.e. ha−1 increased the nutrient composition in the bean leaves, whereas only the Cu content increased in the grains by the dose of 1.8 g a.e. ha−1. In the wet season, there was no increase in the nutrient composition in the bean leaves. The Cu, Zn, Mn, and Fe contents in the grains increased with from the dose of 12 g a.e. ha−1 to above the amount normally observed in common beans, thereby improving the nutritional quality of the food. Our study indicated that low doses of glyphosate alter the nutrient composition of common beans, whereas environmental conditions interfere with the response of common beans to low doses of glyphosate.

Physiological seed quality in cultivars of the carioca bean produced in the North of São Paulo and kept under storage

New bean cultivars, in addition to having high productivity, should meet requirements regarding the physiological attributes of the seeds, maintaining them during storage, minimising their deterioration and guaranteeing the producer a crop that is quickly and uniformly established. The aim of this study was to evaluate the physiological attributes of the seeds of thirteen bean cultivars (Phaseolus vulgaris L.) from the carioca commercial group, produced during the winterspring harvest in the North of the state of São Paulo, at two different times: after harvest and during the eighth month of storage. The experimental design was completely randomised, in a 13 x 2 factorial scheme with four replications. The factors corresponded to the 13 carioca bean cultivars (Pérola, BRSMG Majestoso, BRS Estilo, BRSMG Madrepérola, IPR Campos Gerais, IPR Tangará, IPR Andorinha, IPR 139, IAC Imperador, IAC Formoso, IAC Alvorada, IAC Milênio and Bola Cheia) and two periods of evaluation (0: after harvest and 8: eight months after harvest). Each of the cultivars under study displayed physiological qualities that were within the required standards after harvest. The BRS Estilo, BRSMG Madrepérola, BRSMG Majestoso, IAC Imperador
 and IPR Andorinha cultivars maintain germination within these standards after eight months of storage. The seeds of the IAC Imperador cultivar show greater vigour than those of the other cultivars when produced during the winter-spring harvest in the North of the state of São Paulo.

Can low doses of glyphosate stimulate common bean growth?

Plant growth can be stimulated by low doses of glyphosate. The objective of this work was to evaluate the effect of low doses of glyphosate and sowing season on the growth of the early cycle common bean. Two experiments were conducted in the field, the first in the winter and the second in the wet season, with the early cycle common bean cultivar IAC Imperador. The experimental design was a randomized complete block design, consisting of low doses of glyphosate applied on phenological stage V4, with four replications. Environmental conditions, such as air temperature, interfered in the early cycle common bean response to low doses of glyphosate. In the winter season, a dose of 36 g a.e. ha−1 promoted growth in the common bean, and a dose of 7.2 g a.e. ha−1 improved the harvest index. In the wet season, there was no growth stimulus, and the harvest index increased with a dose of 36 g a.e. ha−1. The harvest index was the only characteristic improved in both seasons, but with different doses. Our study indicates that growth characteristics of early cycle common bean are stimulated by low doses of glyphosate, but this response is dependent on the growing environment.

Agronomic performance, quality and nitrogen use efficiency by common bean cultivars

Nitrogen (N) is the nutrient most required by common bean (Phaseolus vulgaris L.) and the rational management of this element in the crop is very important for increasing the sustainability of agricultural systems. The objective of this study was to evaluate the agronomic performance, qualitative performance and the response and efficiency of N use by 16 common bean cultivars with the commercial grain type “Carioca” in the autumn-winter season under irrigation. The experiment was conducted in a Latossolo Vermelho eutroférrico (Oxisol) under conventional tillage. A randomized block design was used in split plots with four replicates. The plots were consisted of the common bean cultivars: ANFc 9, BRS Ametista, BRS Estilo, BRSMG Madrepérola, Pérola, IAC Alvorada, IAC Imperador, IAC Milênio, IAC Sintonia, IPR Andorinha, IPR Campos Gerais, IPR Tangará, IPR 139 (Juriti Claro), TAA Bola Cheia, TAA Dama and TAA Gol. The subplots comprised the absence and presence of nitrogen (0 and 100 kg ha−1 of N). The agronomic performance of common bean is affected by top-dressing N application, and the cultivars IPR Campos Gerais and IPR Tangará stood out under N application. The common bean cultivars BRS Estilo, IAC Imperador and IPR Campos Gerais are responsive and efficient in the use of N. The qualitative performance of common bean grains is influenced by the top-dressing N application, and the cultivar IAC Alvorada showed the best results. Top-dressing N application increases the protein content and decreases the cooking time of common bean grains.

Sustainable production of common beans: inoculation, co-inoculation and mineral fertilization in early-cycle cultivars

Using sustainable management to maximize crop yield without increasing production costs is one of the great challenges of modern agriculture. This study aimed to evaluate the effect of nitrogen (N) supply management, associating inoculation with Rhizobium tropici, co-inoculation schemes with Azospirillum brasilense and mineral top-dressing fertilization, on the agronomic and qualitative performance of early-cycle common bean cultivars. The experiment was installed in a randomized block design, in a 2 x 12 factorial scheme (2 cultivars and 12 N supply management), with four repetitions. The N supply management consisted of the association of mineral fertilization with N (45 and 90 kg ha−1 of N in top-dressing), inoculation of seeds with Rhizobium tropici and co-inoculation of seeds and leaves with Azospirillum brasilense. The agronomic and qualitative performance of common bean was affected by the nitrogen supply management and by the cultivars, and the response was independent of the interaction between cultivars and N supply management. Except for plant dry mass, all variables analyzed showed maximum response in the treatment of seed inoculation with Rhizobium tropici, leaf-spray of Azospirillum brasilense and mineral top-dressing fertilization with 90 kg ha−1 of N, which led to a 27% increase in yield compared to the control. The cultivar IAC Imperador has a superior agronomic performance (grain yield = 2,840 kg ha−1) compared to IPR Curió (2,484 kg ha−1). The results demonstrated the feasibility of using co-inoculation with Azospirillum brasilense as a tool to increase yield, grain quality and sustainability in common bean production systems.

UV-B and Drought Stress Influenced Growth and Cellular Compounds of Two Cultivars of Phaseolus vulgaris L. (Fabaceae).

Combined enhanced UV-B radiation and drought may induce different morphological and physiological alterations in plants than either abiotic stress alone. We evaluated morphology, biomass, and primary and secondary metabolism changes in seedlings of two common bean cultivars, IAC Imperador (drought-resistant) and IAC Milênio. To test the hypothesis that cultivars responded differently to combined stresses in a controlled environment, seedlings of the examined been cultivars were exposed to UV-B and/or drought treatments for three weeks. The cultivars behaved differently, especially to the drought treatment, suggesting that they use different mechanisms to cope with unfavorable environmental conditions. IAC Imperador showed a stronger protective response, modifying wax composition and primary metabolism, and improving its resistance to UV-B radiation. For IAC Imperador, the accumulation of cuticular wax and alkane was higher under combined stress but production of primary alcohols was reduced, suggesting a possible fatty acyl switch. Root/shoot length and biomass ratios increased in both cultivars, particularly for the combined stress, indicating a common plant response. We show that these two bean cultivars responded more strongly to UV-B and combined stress than drought alone as evident in changes to their chemistry and biology. This shows the importance of investigating plant morphological and physiological responses to combined stress.

Influence of high temperature on the reproductive biology of dry edible bean (Phaseolus vulgaris L.)

ABSTRACT: The aim of this study was to investigate the effect of heat stress on 12 bean genotypes through the analysis of their reproductive biology in terms of flowering, pollen viability, meiotic behavior, and production. Plants were grown in a climate chamber at 25-20 °C (day and night) and at a high temperature treatment 37-26 °C (day and night) from the vegetative (V4) development stage to physiological maturity. The experimental design was 2 × 12 factorial arrangement with six replications and the factors consisted of heat treatments and genotypes. In three replications, the number of newly opened flowers was checked daily. At physiological maturity, the following traits were evaluated: percentage of pod set, number of pods, number of viable seeds, number of aborted seeds, 100 seed weight, and seed yield (g per plant). The other three replications were used to collect flowers to create slides to study viability of the pollen grain and analyze the meiotic behavior. The heat treatment factor significantly affected the following traits: total number of pollen grains, number of flowers, number of pods, pod set, number of viable seeds, 100 seed weight, and seed yield. The raised temperature reduced these variables, except for percentage of pod set, and increased meiotic irregularities. The mean values regarding seed yield were 16.39 g per plant for the control treatment and 7.46 g per plant under high temperature. IAC Imperador, FT Nobre, Perola, BRS Estilo, and IAC Diplomata stood out for higher bean seed yield under increased temperature.

Phenotypic parameters of macromineral and phenolic compound concentrations and selection of Andean bean lines with nutritional and functional properties

ABSTRACT The development of Andean common bean lines that contain high macromineral concentration and a phenolic compound concentration that meets the consumer’s dietary requirements is unprecedented in the literature. The objectives of this study were to obtain estimates of phenotypic parameters for the macromineral and phenolic compound concentrations in a recombinant inbred line (RIL) population of Andean beans and to select lines with nutritional and functional properties. The RIL was obtained from a cross between cultivars Hooter and Cal 96. The lines in the F5:6 and F5:7 generations and the cultivars were evaluated in two consecutive experiments in the same experimental area. The concentrations of potassium (K), phosphorus (P), magnesium (Mg), and calcium (Ca) were determined by acid digestion, whereas the phenolic compound concentration was obtained by the Follin-Ciocalteu method. A significant genotype effect was observed for all traits evaluated in the F5:6 and F5:7 generations. Intermediate-to-high heritability estimates (h2: 43.15 to 98.85%) were obtained for the concentrations of K, P, Mg, Ca and phenolic compounds. These traits exhibited transgressive segregation and quantitative inheritance in the RIL population of Andean beans. Lines DFA 34-18 and DFA 46-18 have high K and P concentrations and low phenolic compound concentration and will be selected by the human nutrition. Lines DFA 04-18 and DFA 05-18 and cultivars Pérola, IPR Siriri, IAC Imperador, and IPR Tangará showed high concentrations of two or more macrominerals and phenolic compounds; therefore, they have nutritional and functional properties and will be selected by the breeding program.

Componentes de produção, produtividade e atributos tecnológicos de cultivares de feijoeiro do grupo comercial carioca

In the National Register of Cultivars of the Ministry of Agriculture, Livestock and Supply are registered about 350 cultivars of bean. Bean cultivars, in addition to adaptation to the growing site, should present productive potential and meet the consumers' demands regarding the qualitative attributes. The objective of this study was to evaluate the production, productivity and qualitative attributes of bean cultivars of Carioca commercial group during the autumn-winter period, in order to obtain information on productive capacity and grain quality, with characteristics that meet the producers and also the consumers. The experimental design was a randomized block design, with 13 treatments and 4 replicates. The treatments consisted of the bean cultivars: Perola, BRS Estilo, BRSMG Madreperola, BRS Notavel, IAC Alvorada, IAC Imperador, IAC Milenio, IPR 139 (Juriti Claro), IPR Andorinha, TAA Bola Cheia, TAA Dama, TAA Gol e ANfc 9. All common bean cultivars stood out for grain yield, but BRSMG Madreperola, IAC Milenio, IAC Alvorada, TAA Dama, ANfc 9 and BRS Estilo obtained values ​​above the general average of 3,460 kg ha-1. The bean cultivars TAA Dama and BRS Estilo presented interesting characteristics in terms of productivity and grain quality, being suitable for both the producer and the consumer. The cultivars BRSMG Madreperola, IAC Milenio, IAC Alvorada and ANfc 9 presented high productivity and technological quality of the grains, but with time for maximum hydration higher than that used in brazilian cuisine.

Quantile Regression Applied to Genome-Enabled Prediction of Traits Related to Flowering Time in the Common Bean

Genomic selection (GS) aims to incorporate molecular information directly into the prediction of individual genetic merit. Regularized quantile regression (RQR) can be used to fit models for all portions of a probability distribution of the trait, enabling the conditional quantile that “best” represents the functional relationship between dependent and independent variables to be chosen. The objective of this study was to predict the individual genetic merits of the traits associated with flowering time (DFF—days to first flower; DTF—days to flower) in the common bean using RQR and to compare the predictive abilities obtained from Random Regression Best Linear Unbiased Predictor (RR-BLUP), Bayesian LASSO (BLASSO), BayesB, and RQR for predicting the genetic merit. GS was performed using 80 genotypes of common beans genotyped for 380 single nucleotide polymorphism (SNP) markers. Considering the “best” RQR fit models (RQR0.3 for DFF, and RQR0.2 for DTF), the gains in predictive ability in relation to BLASSO, BayesB, and RR-BLUP were 18.75%, 22.58%, and 15.15% for DFF, respectively, and 15.20%, 24.65%, and 12.55% for DTF, respectively. The potential cultivars selected, considering the RQR “best” models, were among the 5% of cultivars with the lowest genomic estimated breeding value (GEBV) for the DFF and DTF traits—the IAC Imperador, IPR Colibri, Capixaba Precoce, and IPR Andorinha were included in the list of early cycle cultivars.

Biostimulants action in common bean crop submitted to water deficit

The water deficit (WD) is one of the severe problems in agriculture resulting in yield loss. The understating of crops behavior face to this condition becomes of great importance, and the use of biostimulants may act as a vegetal growth-promoting, considering its capacity of attenuate the impacts of WD on plants. This study aimed at evaluating the common bean changes in biometric parameters and its yield supplemented with biostimulants, as a response to the imposition of WD. The assay was conducted in a protected environment in Botucatu, Brazil, with common bean cv. IAC Imperador, disposed in split-plot in randomized blocks, with 4 repetitions. The treatments in the plots correspond to the irrigation depths (10 kPa and 40 kPa) and in the subplots the treatment B1 (control); B2 (Bacillus amyloliquefaciens BV 03) and B3 (Bacillus amyloliquefaciens BV 03 + brown algae extract – Ascophyllum nodosum). The irrigation was by drip and the management using a tensiometer. The biometric variables included stem diameter; leaf number and leaf area; leaf dry mass, stem, root and total; root length, diameter and volume; and yield parameters. Discussing the results, it was possible to conclude that the common bean is a very water dependable crop, with WD imposition interfering in all the studied variables, with growth decrease, biomass accumulation and yield. The applied biostimulants (B2 and B3) presented low capacity to attenuate the WD effects in common bean under the cultivation conditions adopted.

Analysis of the common bean (Phaseolus vulgaris L.) transcriptome regarding efficiency of phosphorus use.

Common bean is a highly important food in tropical regions, where most production occurs on small farms with limited use of technology and, consequently, greater vulnerability to abiotic stresses such as nutritional stress. Usually phosphorus (P) is the most limiting nutrient for crop growth in these regions. The aim of this study was to characterize the gene expression profiles of the genotypes of common bean IAC Imperador (P-responsive) and DOR 364 (P-unresponsive) under different P concentrations using RNA-seq transcriptome sequencing technology. Plants were grown hydroponically, with application of two P concentrations (4.00 mg L-1 restrictive level and 8.00 mg L-1 control level). Differential expression analyses, annotation, and functional classification were performed comparing genotypes within each P rate administered and comparing each genotype response to the different P levels. Considering differential expression analyses within genotypes, IAC Imperador exhibited 1538 up-regulated genes under P restriction and 1679 up-regulated genes in the control, while DOR 364 exhibited 13 up-regulated genes in the control and only 2 up-regulated genes under P restriction, strongly corroborating P-unresponsiveness of this genotype. Genes related to phosphorus restriction were identified among the differentially expressed genes, including transcription factors such as WRKY, ERF, and MYB families, phosphatase related genes such as pyrophosphatase, acid phosphatase, and purple acid phosphatase, and phosphate transporters. The enrichment test for the P restriction treatment showed 123 enriched gene ontologies (GO) for IAC Imperador, while DOR 364 enriched only 24. Also, the enriched GO correlated with P metabolism, compound metabolic processes containing phosphate, nucleoside phosphate binding, phosphorylation, and also response to stresses. Thus, this study proved to be informative to phosphorus limitation in common bean showing global changes at transcript level.