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Drought stress consists of a significant productivity constraint in tomatoes. Two contrasting crosses were performed to estimate physiological and morphological traits in response to drought stress during the vegetative stage, aiming to identify superior genotypes for drought tolerance. Two genotypes (GBT_2037 – sensitive drought-sensitive and GBT_2016 – intermediate drought-tolerant) were used as female parentals, and a commercial hybrid (drought tolerant) was used as a pollen source in both crosses: C1 (GBT_2037 × Commercial hybrid) and C2 (GBT_2016 × Commercial hybrid). The populations of parentals (P), the first generation of descendants (F1), backcrosses (BC), and the second generation of self-pollination (F2) were exposed to drought stress for 20 days when they were analyzed: physiological traits (relative water content of leaves, proline, and relative chlorophyll content) and morphological (plant height, stem diameter, number of leaves, fresh and dry matter of roots and shoot and classification by wilt scale). The means of chlorophyll, root/shoot ratio, and water content in leaves for the F2 generation of C2 were higher than C1, indicating that C2 resulted in plants with greater capacity to maintain turgor under conditions of water stress and presented minor damage to the photosynthetic structures, consequently showing greater tolerance to drought stress.

The rhizosphere priming effect (RPE) is the change in decomposition of soil organic matter caused by root activity, and it can be affected by plant species, nutrient availability, and by many other factors. Although plant and soil nitrogen (N) are likely to greatly influence RPE and vice-versa, not much is known about these relationships. There is a need for more research, particularly in N-fertilized cropping systems. We examined the RPE on soil N mineralization in a 42-day greenhouse experiment. The experiment included three vegetable crops (broccoli, lettuce, and spinach) and two grain crops (sunflower and maize) and an unplanted control. These plantings were crossed with two fertilization treatments: fertilized (100 kg ha−1 of N) and unfertilized. We evaluated NO3−, NH4+, microbial N, and mobilized N, plant biomass, plant tissue N, and %RPE by planting treatment. We found that vegetables almost completely depleted NO3− in both fertilized and unfertilized soils, whereas grain crops did not. Further, vegetables took up more than twice as much N in their aboveground tissue compared to grain crops under N fertilization. Both vegetables and crops produced RPEs on N mineralization. Nitrogen fertilization significantly enhanced the RPE for vegetable crops but not for grain crops. This result corroborates the assertion that plants with higher N concentration in their tissues tend to produce a higher RPE than plants with lower N concentration. The RPE of vegetable crops were significantly enhanced with N fertilization. Our data strongly rejects the “N-mining” hypothesis which would predict a much reduced RPE with N fertilization, and suggest that this hypothesis is not a universal explanation for the observed priming phenomena.

Grain size is an essential trait in common bean breeding as it determines the acceptance of a new cultivar by producers, consumers, and the industry. The objectives of this study were to identify the ideal traits for selecting common bean lines in the F3 generation to obtain an adequate sieve yield and to identify the best lines for sieve yield by applying early generation selection. Two trials were conducted in two locations during the 2016/2017 crop season. These trials were composed of 300 F3 populations and two parents (used as checks). The experimental design used was an augmented block design without repetition for the treatments (lineages). After harvest, the grain yield, yield components, and sieve yield (SY) were evaluated. In conclusion, selection in the F3 generation can be performed for sieve yield, considering the traits SY12+13, SY14, and relative grain yield, as they present the highest values of heritability and greatest correlation between genotype and performance in the evaluated environments. Additionally, the lines selected to continue in the breeding program are composed of the 15 best lineages for traits SY12+13, SY14, and relative grain yield. Preference should be given to lines that excel in more than one of these traits. Grain size is an essential trait in common bean breeding as it determines the acceptance of a new cultivar by producers, consumers, and the industry. The objectives of this study were to identify the ideal traits for selecting common bean lines in the F3 generation to obtain an adequate sieve yield and to identify the best lines for sieve yield by applying early generation selection. Two trials were conducted in two locations during the 2016/2017 crop season. These trials were composed of 300 F3 populations and two parents (used as checks). The experimental design used was an augmented block design without repetition for the treatments (lineages). After harvest, the grain yield, yield components, and sieve yield (SY) were evaluated. In conclusion, selection in the F3 generation can be performed for sieve yield, considering the traits SY12+13, SY14, and relative grain yield, as they present the highest values of heritability and greatest correlation between genotype and performance in the evaluated environments. Additionally, the lines selected to continue in the breeding program are composed of the 15 best lineages for traits SY12+13, SY14, and relative grain yield. Preference should be given to lines that excel in more than one of these traits.

The objective of this work was to assess the breeding influences in different agronomic and physiological traits in Brazilian soybean cultivars, released between 1965 and 2011, to identify traits associated with modern cultivars. A total of 29 cultivars were evaluated in two locations in the 2016/17 crop season. Genotype selection based on agronomic and physiological traits was determined using GYT (Grain Yield*Trait) methodology, which uses the Superiority Index to rank genotypes by mean of all traits. Grain Yield is combined with other target traits and shows the strengths and weaknesses of each genotype. Soybean breeding improved desirable traits during the 46 years of evaluation. Superiority index can be a powerful tool for breeders to obtain high genetic gains in the future. The cultivars DMario 58i, TMG 7161RR and TMG 7262 RR stand out as the best cultivars but present different sets of desirable traits. The traits grain yield, harvest index, number of pods per plant, reproductive-vegetative ratio, photosynthetic rate and transpiration rate are core traits which can be evaluated in soybean breeding programs.

Molecular markers are largely used to assist in crop improvement with the aim to achieve more favorable results in reduced time. In this study, we applied scientometric approaches to investigate and describe the application of molecular markers in genetic studies of common bean (Phaseolus vulgaris L.). A total of 671 articles, available on Thomson Reuters Web of Science database, published between 1991 and 2020, were analyzed, and it was determined that the USA and Brazil have the highest number of publications related to this subject. The main topics where molecular markers were used in common beans were fingerprinting, genetic diversity assessment, mapping, molecular marker development, marker-assisted selection, comparative genomics or evolution, and marker-trait association. They were also used to solve problems related to anthracnose (Colletotrichum lindemuthianum) and agronomic traits. As the genome sequence of common bean has been publicly available since 2014, SNP markers are frequently employed and their use is increasing, whereas other molecular markers are being bypassed.

In this study, we aim to develop and validate KASP molecular markers in soybean populations for Asian soybean rust (ASR) resistance gene Rpp1 (PI 200492, PI 594538A, PI 587880A), identify the gene hypothetically present in PI 594723, and validate KASP markers for Rpp2 (PI 230970), Rpp3 (PI 506764), Rpp4 (PI 459025A), and Rpp5 (PI 506764, PI 200487). Ten F2 soybean (Glycine max (L.) Merrill) populations derived from crosses between rust-susceptible (55I57RSF IPRO, 63I64RSF IPRO) x rust-resistant sources (PI 200492, PI 594738A, PI 587880A, PI 594723, PI 230970, PI 506764, PI 459025A and PI 200487) were evaluated. All F2 plants were individually evaluated in field conditions for ASR phenotypic reactions, classified according to sporulation level. SNP markers were developed according to markers associated with Rpp genes available at the SoyBase, using KASP methodology. Based on a slight difference in map position and different phenotypic disease reactions of PI 200492, the authors suggest that PI 594723 carries a resistance gene Rpp1-b. The Rpp1-b gene from PI 594723 was mapped in Chr 18 in a 12.4 cM region. The PIs carrying Rpp1-b (PI 594723, PI 587880A, and 594538A) showed strong resistance to ASR compared to the lines carrying Rpp1 (PI 200492). A total of 26 KASP markers were significantly associated (P Rpp1), M13 and M14 (Rpp2), M16, M17 and M20 (Rpp3), M25 and M26 (Rpp4), and M27 and M28 (Rpp5) have the potential to be used in marker-assisted selection strategies.

The objective of this work was to evaluate the grain yield and stability of common bean genotypes, as well as the representativeness and discrimination ability of locations in multi-environment trials (METs), using the GGE biplot analysis. The grain yield of 27 genotypes was evaluated in 16 trials carried out in nine locations, in the state of Santa Catarina, Brazil, during the first and second crop seasons of 2014/2015 and 2015/2016. A randomized complete block design with three replicates was used. As the trials were neither conducted in all locations, nor in all growing seasons of both years, a highly unbalanced dataset was used. Genotype 5 (CHC 01-175-1) was the most productive and stable, common bean genotype and can be considered the closest one to the ideal for the target region. Furthermore, this genotype performs well in both crop seasons, outperforming all the evaluated checks; therefore, it has the potential to be released as a new cultivar. Chapecó can be considered the ideal location for the selection of common bean genotypes, in the state of Santa Catarina, since it shows high representativeness and discrimination ability in the rainy and dry crop seasons. Resumo: O objetivo deste trabalho foi avaliar o rendimento de grãos e a estabilidade de genótipos de feijão, além da representatividade e da discriminância de locais em ensaios multiambientes, por meio de análises GGE biplot. O rendimento de grãos de 27 genótipos foi avaliado em 16 ensaios, realizados em nove locais do estado de Santa Catarina, Brasil, na primeira e na segunda safras de 2014/2015 e 2015/2016. Utilizou-se um delineamento experimental de blocos ao acaso, com três repetições. Como os testes não foram realizados em todos os locais nem em todas as estações de cultivo de ambos os anos, um conjunto de dados altamente desbalanceado foi usado. O genótipo 5 (CHC 01-175-1) foi o mais produtivo e estável, e pode ser considerado o mais próximo ao ideal para a região-alvo. Além disso, esse genótipo apresentou desempenho satisfatório tanto para a primeira quanto para a segunda safras, tendo superado o desempenho de todas as testemunhas utilizadas nos ensaios; portanto, esse genótipo tem potencial para ser lançado como uma nova cultivar. Chapecó pode ser considerado o local ideal de seleção de genótipos de feijão, no estado de Santa Catarina, pois apresenta elevada discriminância e representavidade, tanto para primeira quanto para a segunda safra.

Wheat (Triticum aestivum L.) is one of the most important crops in the world. Brazil is one of the largest importers of this cereal, and wheat breeding programs are attempting to increase productivity and reduce external dependence. The objectives of this study were to quantify the spring wheat genetic gain in Brazil between 1984 and 2014 using data from multienvironment trials, and to verify if the genetic gain stagnated after the 2000s. This study used a highly unbalanced dataset containing grain yield (GY) data from 187 spring wheat trials that were performed at 25 locations between 2002 and 2015. In total, 126 cultivars, released between 1985 and 2014, were evaluated over 14 crop seasons. The cultivar evaluation indicated that there was a genetic gain in GY of 33.9 kg ha⁻¹ yr⁻¹ (r² = 0.53, P < 0.01), which represents an increase of 1.28% yr⁻¹. The dataset showed a linear regression for the genetic gain and indicates that wheat genetic gain has not stagnated in Brazil after the 2000s.

In this study, we summarized the evolution of scientific research about fungus Phakopsora pachyrhizi Sydow & Sydow affecting soybean [Glycine max (L.) Merrill]. We retrieved research articles from the Thomson Reuters Web of Science database that reported studies of the Asian soybean rust (ASR) from 1945 to 2018. We applied the scientometric analysis of the temporal trends of authors, journals, research partnerships, and resistance genes to ASR. Several studies aiming to understand fungal etiology, testing, or improve strategies to control the pathogen were developed. The temporal trends in publications showed an increase in the number of publications between 2005 and 2013. This is directly related to the dissemination of ASR in South and later North America, which facilitates field research and an increase in grant opportunities. The USA had the highest number of published articles (42%), followed by Brazil, Germany, Japan, and Argentina. The leading organizations associated with these publications are from Brazil and the USA. 19% of articles pertaining to ASR were published in the journal Plant Disease. Our results also showed that among the seven dominant genes identified for resistance to ASR, Rpp1, and Rpp2 are the most studied. Several countries, institutions, and plant scientists are deeply involved in ASR research and have been making efforts to control this disease and ensure food security worldwide.

The wheat cultivar UTF 25 is recommended for wheat-growing regions 1 and 2 of Paraná and Santa Catarina states. It has a good disease resistance, early cycle, and high grain yield potential, with an average yield of 3.511 kg ha-1. It is classified as bread wheat with white flour.

The objective of this work was to evaluate the association between estimates of adaptability, stability, and productivity in soybean (Glycine max), and to estimate the repeatability coefficient of these associations between years. A total of 22 genotypes were evaluated in 27 environments in the 2012/2013 crop season and in 19 environments in 2013/2014. In the next crop seasons, 28 genotypes were evaluated in 26 environments, in 2014/2015, and in 25 environments in 2015/2016, totalizing 97 trials. Fourteen methods were evaluated; Spearman correlation coefficients were obtained for the parameters of stability, adaptability, and productivity; and the repeatability coefficients, as well as the minimum number of required environments for a coefficient of determination of 80 and 90%, were calculated. The minimum number of environments required to estimate the degree of association between the parameters was low (seven sites). The methods of Eberhart & Russell and GGE biplot are essential in the evaluation of productivity, adaptability, and stability in soybean because they are able to encompass these aspects using a minimum set of methods. The methods of Annicchiarico (AN), Silva & Barreto (SB), Cruz (CR), and Storck & Vencovsky (SV) can be used to generate complementary information, such as: stability for general, favorable, and unfavorable environments (AN); adaptability in favorable and unfavorable environments (SB, CR, and SV); and average productivity in all environments and in favorable or unfavorable environments (SV). Resumo: O objetivo deste trabalho foi avaliar as associações entre estimativas de adaptabilidade, estabilidade e produtividade em soja (Glycine max), e estimar o coeficiente de repetibilidade dessas associações entre anos. Foram avaliados 22 genótipos em 27 ambientes, na safra 2012/2013, e em 19 ambientes na 2013/2014. Nas safras seguintes, foram avaliados 28 genótipos em 26 ambientes, em 2014/2015, e em 25 ambientes em 2015/2016, no total de 97 ensaios. Quatorze métodos foram avaliados; os coeficientes de correlação de Spearman foram obtidos para os parâmetros adaptabilidade, estabilidade e produtividade; e os coeficientes de repetibilidade, bem como o número mínimo de ambientes necessário para se obter um coeficiente de determinação de 80 e 90%, foram calculados. O número mínimo de ambientes necessários para estimar o grau de associação entre as estimativas dos parâmetros foi baixo (sete locais). Os métodos de Eberhart & Russell e GGE biplot são essenciais na avaliação da produtividade, da adaptabilidade e da estabilidade em soja, pois conseguem englobar estes aspectos com o uso de um conjunto mínimo de métodos. Já os métodos de Annicchiarico (AN), Silva & Barreto (SB), Cruz (CR) e Storck & Vencovsky (SV) podem ser utilizados para gerar informações complementares, tais como: verificação da estabilidade para ambientes em geral e para ambientes favoráveis e desfavoráveis (AN); adaptabilidade em ambientes favoráveis e desfavoráveis (SB, CR e SV); e produtividade média em todos os ambientes, e em ambientes favoráveis ou desfavoráveis (SV).

The objective of this work was to evaluate the productive performance, and the adaptability and stability parameters of modern soybean (Glycine max) cultivars in multi-environment trials, as well as to identify the ideal genotypes for eight growing environments in Brazil. A randomized complete block experimental design was carried out, with three replicates, for the evaluation of 46 soybean cultivars in eight environments, in the microregions of adaptation 102, 201, and 202, in the 2014/2015 crop season. A complex genotype x environment interaction occurred, with changes in the ranking of genotypes among locations. The NA 5909 RG, M6410IPRO, NS 5959 IPRO, NS6823RR, M5917IPRO, NS 6767 RR, and 6563RSF IPRO cultivars showed the highest mean yields. The NA 5909 RG, NS6823RR, M6410IPRO, and NS 5959 IPRO cultivars showed high adaptability and stability and high grain yield, in the evaluated environments, and were ranked next to the ideal genotype for the analyzed environments. There are modern soybean cultivars, which are adapted, stable, and highly productive, for cultivation in the microregions 102, 201, and 202 for soybean crop adaptation in Brazil.

An optimal number of test locations and replications in yield trials allows improvements in the efficiency of a breeding program and selection reliability. The objectives of this study were to verify the optimal number of test locations and replications per test location in edaphoclimatic regions (ECR) and macroregions (MRs) of soybean adaptation in Brazil. Grain yield data from 184 soybean trials in 57 locations was evaluated in crop seasons 2012–2013 to 2015–2016. The number of replications currently used (3) is sufficient to achieve selection reliability and reduce costs in all MRs. However, the optimal number of replications needs to be determined for each location. Locations that require a high number of replicates to achieve H = 0.75 must be removed and/or replaced to improve selective accuracy. The optimal mean number of test locations in macroregions MR1 and MR2 is seven locations per ECR, and in MR3 and MR4, it is five locations per ECR. Thus, analyses of the optimal number of locations and replications may be applied to other regions to improve the yield trial efficiency of soybean cultivars.

Experimental design without replication, such as Federer's augmented block design, allows us to determine productivity, adaptability and stability in multi-environment trials. This work aimed to select productive wheat lines with high adaptability and stability in preliminary trials. The grain yield of 140 homozygous wheat lines was measured in 2015 at three locations. The cultivar TBIO Mestre was used as a check. Genetic parameters were evaluated by mixed models, and selection was based on the harmonic mean of the relative performance of the genetic values (HMRPGV) using models 74 (individual analysis) and 75 (joint analysis) of Selegen software. In the joint analysis, 33 wheat lines stood out in terms of productivity, adaptability and stability. These lines have the potential to be evaluated in Value for Cultivation and Use (VCU) trials for future release of new wheat cultivars.

Breeding companies release new high-yielding soybean genotypes every year. The main trait is grain yield (GY), and the performance need to be evaluated by statistical methods to identify superior genotypes. Biplot analysis are good tools for selecting superior genotypes and to increase efficiency in selection. This study aimed to: (a) identify genotypes with high GY and stability in edaphoclimatic regions (ECR) in southern of Brazil; (b) compare the year-by-year and across-years analyses to identify ideal genotype (IG) for each ECR; and (c) identify the association between genotypes and locations using the across-year approach. GY data from yield trials performed in the crop seasons of 2013, 2014, and 2015 were used. The analysis of IG was performed for each year independently and across the years. Moreover, environment-genotype relationship analysis was used to identify the association between genotypes and ECR. Genotypes with high GY and widely adapted for each ECR were identify. The across-year analysis was superior to the year-by-year analysis. However, only genotypes evaluated in more than 1 year and in sufficient locations provide accurate information about GY and stability; otherwise, the results should be adopted with caution.

The objective of this work was to identify core locations in two soybean macroregions in Brazil for the evaluation and selection of soybean (Glycine max) lineages. Twenty-two cultivars were tested in 23 locations in these two macroregions (MR1 and MR2), during four years, from 2012 to 2015. Trials were conducted in a randomized complete block design with three replicates. All analyses were performed using the GGEbiplot software. The genotype main effects plus genotype × location interaction + genotype main effects plus genotype × environment interaction and genotypic effect vs. genotype x environment effect analyses were used to identify core locations, i.e., locations with high representativeness and consistency of results. Chapada, in the state of Rio Grande do Sul, and Maracaju, in the state of Mato Grosso do Sul, were the core locations in MR1 and MR2, respectively. These locations were the most representative and consistent over the years, and the genotypic effect explained a high proportion of phenotypic variance. Resumo: O objetivo deste trabalho foi identificar locais-chave de teste em duas macrorregiões sojícolas no Brasil, para avaliação e seleção de linhagens de soja (Glycine max). Foram testadas 22 cultivares em 23 locais, nessas duas macrorregiões (MR1 e MR2), durante quatro anos, de 2012 a 2015. Os ensaios foram conduzidos em delineamento de blocos ao acaso, com três repetições. Todas as análises foram realizadas com uso do programa GGEbiplot. As análises efeito principal de genótipo mais interação genótipo × local + efeito principal de genótipo mais interação genótipo × ambiente e efeito genotípico vs. efeito do genótipo x ambiente foram utilizadas para identificar locais de teste, isto é, locais com alta representatividade e consistência de resultados. Chapada, no Rio Grande do Sul, e Maracaju, no Mato Grosso do Sul, foram os principais locais em MR1 e MR2, respectivamente. Estes locais foram os mais representativos e consistentes ao longo dos anos, e o efeito genotípico explicou uma alta proporção da variância fenotípica.

A better understanding of genotype x environment interactions (GEIs) can improve the selection and recommendation of wheat genotypes that are widely adapted and stable in different environments. The objective of this study was to evaluate a strategy to perform a joint analysis in wheat yield trials with genotypes classified according to their interactions with the environment. Measurements of the adaptability and stability estimates were used in the proposed strategy. We analyzed grain yield data from 367 wheat genotypes in 348 yield trials classified into 58 groups. In each group, 25 genotypes at different numbers of locations were evaluated using data from 2010, 2011 and 2012. Joint analysis of variance was performed for each group to determine the genotype contribution to the GEI. The genotypes were grouped into two classes: genotypes that interacted with the environment and genotypes with no interaction with the environment. An additional joint analysis of variance was performed for each class. Grouping genotypes into different classes provided valuable information concerning the dynamics of the GEI, which could enable plant breeders to maximize the efficiency of selection and offer recommendations for stable and widely adapted genotypes. The highest selective accuracy for the genotype effects was obtained for the joint analysis when the GEI was insignificant. The joint analysis of trials for wheat genotypes that interacted with the environment presented the highest selective accuracy for the GEI effect and a reduced selective accuracy for the genotype effect.

Genomic selection (GS) can potentially accelerate genetic improvement of soybean [Glycine max L. (Merrill)] by reducing the time to complete breeding cycles. The objectives of this study were to (1) explore the accuracy of GS in soybean, (2) evaluate the contribution of intrapopulational structure to the accuracy of GS, and (3) compare the efficiencies of phenotypic selection and GS in soybean. For this, phenotypic and genotypic data were collected from 324 soybean genotypes (243 recombinant inbred lines and 81 cultivars) and GS was performed for five yield related traits. BayesB methodology with a 10-fold cross-validation was used to compute accuracies. The GS accuracies were evaluated for grain yield, plant height, insertion of first pod, days to maturity, and 1000-grain weight at eight locations. We found that GS can reduce the time required to complete a selection cycle in soybean, which can lead to increased production of this commercially important crop. Furthermore, genotypic accuracy was similar regardless of population structure correction.

The search for productive and stable genotypes is the main goal of breeding programs. The Genotype × Environment interaction strongly influences genotype performance, and makes the selection of new cultivars difficult. One way to take advantage of this interaction is to identify genotypes with high grain yield (GY) and stability in different environments. The objective of this study was to evaluate the consistency of correlation between GY and stability evaluation methods in multi-environment trials and identify which methods are more suitable for selecting genotypes. GY data from 11 soybean (Glycine max [L.] Merr.) cultivars conducted in Value for Cultivation and Use trials in 10 locations in Paraná and Mato Grosso do Sul states, Brazil, in the 2013-2014, 2014-2015, and 2015-2016 crop seasons. A randomized complete block design with three replicates was used. Seven methods were applied to evaluate stability, and Spearman's correlation coefficient was used to compare methods. Positive associations were observed between GY and the harmonic mean of genotypic values (HMGV) across environments and genotype main effect + Genotype × Environment interaction effect by ideal genotype (GGE IG) methodologies, and between GY and the Lin and Binns method modified by Carneiro for general and unfavorable environments. The Eberhart and Russell, additive main effects and multiplicative interaction (AMMI1), and GGE for stability (GGE STA) methods presented no positive associations with GY in any year. Positive associations were found between the Wricke, AMMI1, and Eberhart and Russell methods because they were related to the static stability concept. The HMGV and GGE IG methods can be used together because they are consistently associated with GY and based on the dynamic stability concept.

Brazil is one of the largest soybean (Glycine max L. Merrill) producers in the world, as well as main exporter. Little information is available about both the composition of Brazilian genotypes in respect to soluble sugars contents such as sucrose, glucose, raffinose and stachyose, and the effect of genotype × environment interaction (GEI). This study evaluated the soluble sugar contents, the GEI and the genetic variability of highly cultivated cultivars and new soybean lines. A sample of 46 commercial Brazilian cultivars and 35 pre-commercial lines were evaluated at six locations during the 2014/15 crop season, in a randomized complete block design with three replications. Soluble sugars were evaluated using an infrared spectroscopy (NIR) method. The average contents of sucrose, glucose, raffinose and stachyose were 3.3, 1.62, 0.39 and 3.07% which were lower than the levels found in other countries. All field traits were highly influenced by the environment. The cultivar NS 6121 RR presented a reduced (and stable across the environments) raffinose and stachyose content and can be used as a source of novel genes in breeding programs. Brazilian soybean presents genotypic differences which can be exploited to reduce or increase soluble sugar contents in breeding programs. There is a strong GEI for sucrose, glucose, raffinose and stachyose contents for Brazilian environments. The evaluated genotypes presented reduced contents of raffinose and stachyose, which are considered antinutritional factors. The new soybean lines presented similar soluble sugar contents to the tested cultivars.

WRKY transcription factors (TFs) are responsible for the regulation of genes responsive to many plant growth and developmental cues, as well as to biotic and abiotic stresses. The modulation of gene expression by WRKY proteins primarily occurs by DNA binding at specific cis-regulatory elements, the W-box elements, which are short sequences located in the promoter region of certain genes. In addition, their action can occur through interaction with other TFs and the cellular transcription machinery. The current genome sequences available reveal a relatively large number of WRKY genes, reaching hundreds of copies. Recently, functional genomics studies in model plants have enabled the identification of function and mechanism of action of several WRKY TFs in plants. This review addresses the more recent studies in plants regarding the function of WRKY TFs in both model and crop plants for coping with environmental challenges, including a wide variety of abiotic and biotic stresses.

Drought stress on reproductive stages constitute a major problem for common bean (Phaseolus vulgaris L.) production because it affects flowering and pod-filling processes which are highly drought-sensitive. In this study, we used a greenhouse experiment to evaluate the response to drought stress in ten highly cultivated Brazilian genotypes in response to moderate intermittent drought during flowering and pod-filling periods (R7 and R8 stages). Morphological, biochemical, physiological and agronomic traits were used to identify tolerant cultivars and elucidate their strategies to cope this stress. The drought intensity index for the experiment reached 0.63. The cultivar IAC Imperador can be defined as a tolerant cultivar, presenting the lowest grain yield reduction (43%) and a reduced drought susceptibility index (0.65). This cultivar elevated their level of proline in roots under stress, which allowed the osmotic adjustment and the maintenance of an intermediate stomata closure during the day, which maintained the intrinsic WUE stable in NS and DS conditions. In addition, this cultivar was able to mobilize the assimilated carbon for the production of pods and grains, evidenced by the high harvest index and the high grain filling index. In this way, IAC Imperador can be used as a check in breeding programs to identify and select lineages with drought tolerance in common bean.

Selection of disease resistant genotypes is the main goal of wheat (Triticum aestivum L.) breeding programs. However, because of the lack of genotypes resistant to all diseases and the strong influence of the environment on the level of resistance of the genotypes, the use of fungicides is necessary in the cultivation of wheat. The objective of this study was to compare the gain in yield and the selection efficiency of wheat genotypes due to the fungicide application in trials carried out in different sites and years. This study used grain yield data from 816 wheat genotypes evaluated in 248 advanced trials at eight sites during the years from 2004 to 2012. The gain resulting from fungicide application for a given genotype was estimated by the difference between yield of plots on which fungicide was applied and control treatment. The greatest gains with fungicide application were observed in sites with lower average temperatures and higher rainfall indices, such as Campo Mourão, Castro, Não-Me-Toque and Guarapuava. On the other hand, the lowest gains with fungicide application occurred in Dourados and Palotina, environments where crops in general suffer water stress and present higher average temperatures. The year effect resulted in yield increases due to fungicide application ranging from 16.9 to 60.7%. The selection and evaluation of the response to the application of fungicide in wheat should be environment-specific to maximize the use of genotype x environment interaction. RESUMO A seleção de genótipos resistentes a doenças é uma meta prioritária dos programas de melhoramento genético de trigo (Triticum aestivum L.). Mas, devido não existir genótipos resistentes à todas as doenças e a forte influência do ambiente no nível de resistência dos genótipos, o uso de fungicidas é necessário no cultivo do trigo. O objetivo deste estudo foi comparar o ganho em produtividade e a eficiência da seleção de genótipos de trigo devido à aplicação de fungicida em ensaios realizados em diferentes locais e anos de cultivo. Foram utilizados dados de produtividade de grãos de 816 genótipos de trigo avaliados em 248 ensaios de competição, em oito locais, nas safras agrícolas de 2004 a 2012. O ganho com a aplicação de fungicida para um dado genótipo foi estimado pela diferença entre a produtividade das parcelas que receberam fungicida e o tratamento controle. Os maiores ganhos com a aplicação de fungicida foram observados em locais que apresentam menores temperaturas médias e maiores indíces pluviométricos, tais como Campo Mourão, Castro, Não-Me-Toque e Guarapuava. Já os menores ganhos com a aplicação de fungicidas ocorreram em Dourados e Palotina, ambientes que geralmente impõem estresses hídricos a cultura e que possuem temperaturas médias mais elevadas. O efeito de anos de cultivo resultou em incrementos de produtividade devido a aplicação de fungicida que variaram de 16,9 a 60,7%. A seleção e a avaliação da resposta à aplicação de fungicida em trigo deve ser ambiente-específica, buscando maximizar o aproveitamento da interação genótipo x ambiente.

The sensitivity of wheat crop to environmental variations frequently results in significant genotype (G) x environment (E) interaction (GEI). We compared statistical methods to analyze adaptability and stability of wheat genotypes in value for cultivation and use (VCU) trials. We used yield performance data of 22 wheat genotypes evaluated in three locations (Guarapuava, Cascavel, and Abelardo Luz) in 2012 and 2013. Each trial consisted of a complete randomized block design with three replications. The GEI was evaluated using methodologies based on mixed models, analysis of variance, linear regression, multivariate, and nonparametric analysis. The Spearman’s rank correlation coefficient was used to verify similarities in the genotype selection process by different methodologies. The Annicchiarico, Lin and Binns modified methodologies, as well as the Harmonic Mean of the Genetic Values (HMGV) allowed to identify simultaneously highly stable and productive genotypes. The grain yield is not associated with Wricke, Eberhart and Russell stability parameters, scores of the first principal component of the AMMI1 method, and GGE biplot stability, indicating that stable genotypes are not always more productive. The data analyzed in this study showed that the AMMI1 and GGE biplot methods are equivalent to rank genotypes for stability and adaptability. RESUMO A sensibilidade às variações ambientais observada na cultura do trigo implica na interação genótipo (G) × ambiente (A) (IGA) significativa. Objetivamos com o presente estudo comparar metodologias estatísticas para a análise da adaptabilidade e estabilidade de genótipos de trigo em ensaios de valor de cultivo e uso (VCU). Foram utilizados dados de desempenho produtivo de 22 genótipos de trigo avaliados em 3 locais (Guarapuava, Cascavel e Abelardo Luz), nas safras agrícolas de 2012 e 2013. Em cada ensaio, foi empregado o delineamento de blocos completos casualizados, com 3 repetições. Na avaliação da IGA, foram utilizadas metodologias baseadas em modelos mistos, análise de variância, regressão linear, análises multivariadas e não paramétricas. Para verificar semelhanças na seleção dos genótipos pelas diferentes metodologias, utilizou-se o coeficiente de correlação de postos de Spearman. As metodologias Annicchiarico, Lin e Binns modificada, bem como a média harmônica dos valores genéticos (MHVG) permitem identificar genótipos estáveis e, ao mesmo tempo, mais produtivos. A magnitude do rendimento de grãos não é associada às estimativas de estabilidade de Wricke, de Eberhart e Russell, escores do primeiro componente principal do método AMMI1 e a estabilidade pela análise GGE biplot, indicando que genótipos estáveis não necessariamente são mais produtivos. Para os dados analisados neste estudo, os métodos AMMI1 e GGE biplot mostraram-se equivalentes em relação ao ordenamento dos genótipos pela estabilidade e adaptabilidade.

Soybean (Glycine max (L.) Merrill) is an important source of oil for biodiesel production in Brazil. However, the traits related to oil content and fatty acid profile are not targeted by soybean breeding programs. Developing methods to increase oleic and reduce linolenic fatty acid content within soybean genotypes will increase the use of soybeans for food and feed, as well as biodiesel production. Biodiesel produced with high polyunsaturated fatty acids (PUFAs) content has a high tendency to undergo oxidation, making storage difficult and overall quality reduced. On the other hand, oils with high levels of monounsaturated fatty acids (MUFAs) are preferred for biodiesel production because oxidation is not increased, improve cold flow properties significantly and nitrogen oxide emissions are decreased. In addition, soybean oil with high concentration of PUFAs causes low oxidative stability, resulting in rancidity, a rapid decline of optimal flavor and reducing storage time of manufactured food products. 242 recombinant inbred lines (RILs) were evaluated in six locations in Brazil for grain yield, oil content, oil production, and fatty acid composition. A multi-trait index based on factor analysis and ideotype-design (FAI-BLUP index) was applied to identify genotypes best related with the ideotype for biodiesel production. This method is based on mixed models, with genotype and environment effects being considered as random and fixed, respectively. In addition, the best linear unbiased prediction (BLUP) method was used to predict the genetic values. Six RILs outperformed both parents and can be selected as genotypes more suitable for biodiesel production. Genetic selection reduced linolenic fatty acid content by 14%. Results indicated the presence of genetic variability for fatty acid composition. The significant increases in oleic and reductions in linolenic contents may be easily achieved with the introduction of mutant FAD2-1A and FAD2-1B genes through breeding programs or biotechnological strategies.

Improvement of quality-related traits of grains is a constant concern in white oat breeding programs, which challenges breeders to understand their dynamics. The performance of different genetic combinations must be thoroughly evaluated to make high nutritional quality cultivars available. This study aimed to estimate the heterosis on F1 and F2 generations, vigor loss, due to inbreeding, and correlation between the grain chemical components to understand the dynamics of these traits, considering two segregating oat progenies. The populations Albasul × UPF 15 (population 1) and IAC 7 × UFRGS 19 (population 2) were developed. Both populations showed transgressive segregant individuals. The combination Albasul × UPF 15 provided significant heterosis for traits β-glucan total and soluble fiber contents, while the population obtained by crossing IAC 7 × UFRGS 19 generated significant gain by heterosis for total fiber, insoluble fibers and non-structural carbohydrate contents. Considering the F2 average for each population, one can observe that population 1 presents higher β-glucan and lipid contents than population 2. On the other hand, population 2 has higher protein content than population 1. In both populations, the non-structural carbohydrate content is strongly and negatively correlated whith protein, total and insoluble fibers. Correlations between total fibers and lipids and between total fibers and insoluble fibers were both positive and high in both populations.

The present study aimed to evaluate the associations between agronomic and bread-making quality traits in wheat under different growing environments. Nineteen Brazilian wheat cultivars were evaluated at six locations (Cascavel-PR, Castro-PR, Guarapuava-PR, Palotina-PR, Abelardo Luz-SC, and Nao-Me-Toque-RS) during five years (2007 to 2011). The direction and magnitude of the associations between agronomic and bread-making quality traits were strongly dependent on the test location and year of evaluation. This study discusses the impli­cations of choosing test locations on bread-making quality traits and for breeding purposes, with emphasis on indirect selection.

O ganho genético obtido com a seleção em gerações segregantes é dependente do cruzamento, das condições experimentais e do caráter alvo de seleção. O objetivo deste trabalho foi determinar o ganho com a seleção em planta espaçada, na geraç��o F2 para número de afilhos, utilizando diferentes critérios de seleção, além de verificar a efetividade destas seleções na geração subseqüente, nos métodos de semeadura deplanta espaçada e linha cheia. As gerações segregantes foram desenvolvidos em 2006 (F2) e 2007 (F2 e F3), sendo a geração F3 avaliada em planta espaçada e linha cheia. Foram empregados três critérios de seleção: a) elevado número de afilhos e alta produção de grãos; b) reduzido número de afilhos com elevada produção de grãos e c) bulk da população. Foram testadas 15 combinações envolvendo genitores com diferente potencial de afilhamento. Os resultados indicam que mesmo em reduzida magnitude, as estimativas de herdabilidade para estimar a média da próxima geração, revelaram eficiência, porém, somente quando as gerações utilizadas foram desenvolvidas em iguais condições de ambiente e manejo. A seleção para elevado ou reduzido número de afilhos e em bulk, foram dependentes do sistema de manejo em que a população segregante tenha sido submetida. A seleção para elevado número de afilhos revelou o maior ganho genético para produção de grãos, porém, a efetividade da seleção em planta espaçada não proporcionou o mesmo comportamento em competição. O melhor desempenho em rendimento de grãos foi detectado na seleção para reduzido número de afilhos, com média elevada para massa de grãos em competição.The genetic gain obtained with the selection in segregating generations depends on the cross, experimental conditions and the target trait selected. The objective of this work was to determine the genetic gain with selection in spaced plants, in the F2 generation for the character number of tillers, using different selection criteria. In addition it aimed at to verify the effectiveness of these selections by looking at next generations of plants selected by the spaced plant and full row methods. The segregating generations were conducted in the years 2006 (F2) and 2007 (F2 and F3), being the F3 generation evaluated as spaced plant and full row. Three selection criteria were used: i) high tiller number and grain production; ii) low tiller number with high grain production and iii) a bulk of 15 parental genotypes with different tillering potential. The results pointed out that heritability estimates were efficient for the prediction of next generation means when the generations used were under the same environmental and management conditions. The efficiency of the selection for high or low tillering ability and the bulk selection were dependent of the crop management system used. The selection for high tiller number was associated to a higher genetic gain for grain production. However, the efficiency of the selection was different when spaced and competing plants are compared. The best performance for grain yield was achieved selecting for low tiller number in competing plants, resulted in higher total grain weight.