Cândida Hermínia Campos de Magalhães Bertini

Cowpea is a crop of great economic and nutritional importance, used for human and animal consumption, particularly in semi-arid regions. Its growth and development depend on adequate conditions for the expansion of the root system and the establishment. Therefore, the objective of this study was to determine the effect of pot size on the shoot and root development of cowpea. The experiment was conducted in a greenhouse at the Department of Plant Science, Federal University of Ceará, in Fortaleza, Ceará, Brazil. Seeds of the Setentão variety were used in a completely randomized experimental design with five replications. The plants were grown in pots with volumes of 5, 11, 18, and 25 dm³, and shoot and root system traits were evaluated, including stem, leaves, pods, dry seeds, and roots. The data were subjected to analysis of variance and mean comparison tests, as well as correlation and principal component analyses. Pot size significantly influenced plant development and the most of the evaluated traits showed strong positive correlations, indicating a close interdependence between shoot and root system variables. Principal component analysis explained 65.7% of the total observed variation. Among the evaluated pot volumes, the 18 dm³ pot showed the best overall performance, considering vegetative, productive, and root traits, and is therefore recommended for cowpea studies and production under pot conditions.

Morphoagronomic and nutritional characterization of landraces is necessary in order to select genotypes with traits of interest. The objective of this work was to evaluate the potential of creole varieties in terms of production and nutritional composition. Seventeen landraces and three control cultivars were evaluated. The experiment was divided into two parts. In the first, carried out in the field, morphoagronomic characterization was carried out and in the second, nutritional characterization was carried out. In the field experiment, the varieties were sown in the experimental area and conducted in randomized blocks. The nutritional characterization experiment was carried out in the meat and fish laboratory of the food engineering course. Qualitative and multicategorical data were evaluated by hierarchical grouping analysis using the dendrogram and the Toucher method, while quantitative data were submitted to analysis of variance, and means were compared using Tukey's test (p<0.05). Landraces of cowpea present variability for the evaluated traits. For traits related to production and nutritional quality, landraces perform better than controls. This variability can be explored in genetic improvement programs, aiming to obtain more productive cultivars with grains of better nutritional value.

Studies employing molecular markers require DNA extraction. For cowpea, DNA extraction is typically performed on young leaf tissue; however, this procedure requires significant time, space and resources. This study aimed to establish a protocol for extracting DNA from scarified cowpea seeds while preserving the embryo viability. Three DNA extraction protocols were evaluated to determine the most suitable non-destructive method: the CTAB method, the NaOH-Tris method and a commercial kit. The commercial kit produced DNA of higher purity, when compared to the other protocols. Nevertheless, the amplified products from the commercial kit and the CTAB protocol were highly similar. Five genetic similarity groups were identified. No significant differences were observed for the germination rate or the emergence speed of scarified seeds. The genetic variability assessment validated the efficiency of the proposed methodology. This protocol effectively preserved the embryo viability, enabling the subsequent use of the seeds in genetic breeding programs.

The objective of this study was to understand the physiological and biochemical mechanisms of drought tolerance in contrasting cowpea genotypes. The experiment was carried out in a greenhouse at the Federal University of Ceará, State of Ceará, Brazil. A stress-tolerant (Pingo de Ouro 1.2) and sensitive (Santo Inácio) cowpea genotype was grown under total irrigation (control), moderate water deficit, severe water deficit and re-irrigation after severe water deficit to study its mechanisms of water drought tolerance. The experimental design was completely randomized in a 4x2 factorial scheme, with five replications. The factors corresponded to irrigation regimes and genotypes. The results indicated that the main mechanisms of drought tolerance in cowpea include greater leaf water potential and electron transport rate under conditions of severe water deficit. In addition, maintaining the chlorophyll content, increasing the content of carbohydrates and amino acids in the leaves for osmotic adjustment, less damage to the cell membrane and greater recovery capacity after rehydration were observed as the main mechanisms. Therefore, Pingo de Ouro 1.2 was more tolerant of water stress.

The cowpea is a legume that is widely grown in the north-east of Brazil, and which has been gaining ground in other regions of the country. The main producer is the state of Ceará, with a large planted-area, albeit low productivity due to a lack of producer technology and adapted cultivars. The aim of this study was to identify and recommend superior genotypes in terms of adaptability and stability under rainfed and irrigated conditions, in addition to genotypes with reduced grain darkening. To this end, six experiments were conducted in different districts of Ceará (Crato, Pentecoste, Crateús, Madalena, Bela Cruz and Limoeiro do Norte) and one laboratory experiment, to evaluate grain darkening. The experimental design of the field trials was of randomised blocks, with 14 genotypes and 4 replications. The analysis of variance showed a significant effect from the genotypes and environments and their interaction, so GGE Biplot analysis was carried out to evaluate adaptability and stability. To evaluate grain darkening, a completely randomised design was used in a simple factorial scheme with six previously selected genotypes and five different storage times (0, 2, 4, 6 and 8 months). There was a significant effect from the genotypes and storage time. Genotype 1 showed the least darkening, and can be recommended for environments to which it is best adapted (Crato and Crateús). Genotype 9 was considered the most stable for grain yield, and can be more broadly recommended for the semi-arid region of the state of Ceará. O feijão-caupi é uma leguminosa amplamente cultivada no Nordeste brasileiro e que tem ganhado espaço em outras regiões do país. O principal estado produtor é o Ceará, com grandes áreas plantadas, mas com baixas produtividades, carecendo de tecnificação dos produtores e cultivares adaptadas. Objetivou-se com esse trabalho identificar e recomendar genótipos superiores quanto à adaptabilidade e estabilidade em condições de sequeiro e irrigadas, além de genótipos com reduzido escurecimento de grãos. Para isso foram conduzidos seis experimentos em diferentes municípios do Ceará (Crato, Pentecoste, Crateús, Madalena, Bela Cruz e Limoeiro do Norte) e um experimento em laboratório a fim de avaliar o escurecimento dos grãos. O delineamento experimental dos ensaios em campo foi o de blocos ao acaso, com 14 genótipos e 4 repetições. Na análise de variância verificou-se efeito significativo de genótipos, ambientes e sua interação, então procedeu-se à análise GGE Biplot para avaliar a adaptabilidade e estabilidade. Na avaliação do escurecimento, utilizou-se o delineamento inteiramente casualizado em esquema fatorial simples com seis genótipos previamente selecionados em cinco tempos de armazenamento (0, 2, 4, 6 e 8 meses). Verificou-se efeito significativo de genótipos e tempo de armazenamento. O genótipo 1 apresentou menor escurecimento e pode ser recomendado aos ambientes onde melhor se adaptou (Crato e Crateús). O genótipo 9 foi o considerado mais estável para rendimento de grãos e pode ser recomendado de forma mais ampla para o semiárido do estado do Ceará.

Cowpea is a species used for various purposes, including green grain production. New cowpea cultivars should be developed to answer the growing market demands for green gains, which can be achieved via breeding programs. In this scenario, diallel cross is a breeding method that allows researchers to select the most suitable parents for hybridization. From this perspective, this study aimed to identify cowpea parents and hybrids with good combining abilities to initiate a breeding program aimed at green grain production. The experiment was developed at the Plant Science Department of the Federal University of Ceará. Fifteen treatments (five parents and ten hybrids) were set up in a randomized block design with ten replications. The variables of green pod length, green pod mass, number of grains, grain mass per green pod, and green grain length were studied in this experiment. The data were subjected to analysis of variance, test of means, and diallel analysis. The parents and hybrids showed variations for the evaluated traits. Both additive and non-additive effects influence the behavior of inherited traits. The parent CE0002 and hybrid combinations BRS Juruá x CE1002 and CE0957 x CE0002 are recommended for selection, showing desirable aspects for green grain production.

Cowpea has great socioeconomic importance for the Northeast region of Brazil. However, this region suffers from water scarcity, leading to reduced production. Therefore, it is important to identify varieties adapted to water stress conditions. With that aim, this work characterized cowpea creole varieties at the seedling stage using ISSR markers and the Screening Box method. DNA samples extracted from 50 creole varieties were evaluated using ISSR markers. Among them, two were used as controls, one tolerant (Pingo de Puro 1,2) and the other susceptible (Santo Inácio) to drought. Multivariate and cluster analyses were used to identify genetic variability for drought tolerance. Then, an experiment using the Screening Box method was carried out under a greenhouse, where water deficit was induced in 22 varieties, including the control ones. These plants were selected based on the genetic characterization performed with the ISSR. In the first experiment, 45 varieties were grouped with the control creole varieties. Some showed a small genetic distance from the tolerant, indicating genetic similarity. However, significant differences were observed among creole varieties in the greenhouse experiment. In conclusion, nine landraces can be considered tolerant to water stress according to the results of the experiments. Keywords: ISSR markers; genetic characterization; DNA. Tolerância ao estresse hídrico em diferentes variedades de feijão-caupi em fase de plântula RESUMO: O feijão-caupi tem grande importância socioeconômica para a região Nordeste do Brasil. No entanto, esta região sofre com a escassez de água, levando à redução da produção. Portanto, é importante identificar variedades adaptadas às condições de estresse hídrico. Objetivou-se caracterizar variedades crioulas de feijão-caupi na fase de muda, utilizando marcadores ISSR e o método Screening Box. Utilizando marcadores ISSR, foram avaliadas amostras de DNA extraídas de 50 variedades. Dentre elas, duas foram utilizadas como testemunhas, uma tolerante (Pingo de Puro 1,2) e outra suscetível (Santo Inácio) à seca. Para identificar a variabilidade genética para tolerância à seca, foram utilizadas análises multivariadas e de agrupamento. Em seguida, foi realizado um experimento utilizando o método Screening Box, onde foi induzido déficit hídrico em 22 variedades, incluindo as testemunhas. Essas plantas foram selecionadas com base na caracterização genética realizada com o ISSR. No primeiro experimento, 45 variedades foram agrupadas com as variedades crioulas de controle. Alguns deles apresentaram uma pequena distância genética dos tolerantes, o que indica similaridade genética. No entanto, no experimento em casa de vegetação, foram observadas diferenças significativas entre as variedades crioulas. Concluindo, nove variedades crioulas podem ser consideradas tolerantes ao estresse hídrico de acordo com os resultados dos experimentos. Palavras-chave: marcadores ISSR; caracterização genética; DNA.

Cowpea is a legume that is grown worldwide and used for different purposes, especially as green grains. However, considering the low availability of cowpea cultivars for green grain production, selecting genotypes that have better traits for this purpose is necessary. In this context, the objective of this study was to estimate genetic parameters and evaluate different selection indices for identifying superior cowpea genotypes and subsidizing cowpea breeding programs focused on green grain production. A field experiment was conducted at the Center of Agricultural Sciences of the Federal University of Ceará (UFC), Ceará, Brazil. The treatments consisted of 42 cowpea genotypes from the Active Germplasm Bank of the UFC. Fourteen traits were used for characterization. The experiment was conducted in an augmented block design with four controls. The data obtained were subjected to analysis of variance, and genetic parameters, correlations, and selection indices were determined. The traits days to flowering (DFL), days to fruiting (DFR), green pod weight (GPW), green pod width (GW), green pod length (GPL), green pod thickness (GPT), number of grains per pod (NGP), and green grain thickness (GGT) showed heritability higher than 70%, indicating that selection in an early generation is favorable. The genetic correlations between the trait pairs DFL×DFR, GPW×GPL, and GW×GGT were higher than the phenotypic and environmental correlations. Genotypes CE-228, CE-688, CE-994, CE-165, CE-796, and BRS-Paraguaçu showed simultaneous superiority for the evaluated traits and are the most appropriate for green grain production.

Cowpea is a worldwide consumed legume due to its high nutrient concentrations. Selecting genotypes with high nutrient concentrations can contribute to developing biofortified cultivars. This study aimed to evaluate the nutritional potential and indicate genotypes of Vigna unguiculata for genetic improvement based on nutritional traits. Forty-three cowpea genotypes belonging to the Active Germplasm Bank of the Federal University of Ceará were used in the study. The analyses of dry matter, ash, ether extract, proteins, and minerals (phosphorus, potassium, calcium, magnesium, sulfur, sodium, copper, iron, zinc, manganese, and boron) were performed in triplicate. The data were subjected to analysis of variance, means comparison test, genetic parameters, nutritional quality indexes, and the sum of ranks. Genetic variances predominated concerning environmental variation for the nutrient concentrations of cowpea can be transmitted to future generations. The CE-0151, CE-0189, CE-0207, CE-0228, CE-0248, CE-0542, CE-0685, CE-0686, CE-0796, CE-0997, and CE-1002 genotypes are indicated for selection for continuing the biofortified cowpea breeding program.