ABSTRACT 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. purposes production gains programs scenario hybridization perspective Ceará five replications grains variance means traits nonadditive non CE CE000 CE100 CE095 selection CE00 CE10 CE09 CE0 CE1

RESUMO Feijão-caupi é uma espécie nutritiva, cultivada em várias partes do mundo, com ampla variabilidade genética que pode ser explorada no melhoramento. Este trabalho teve como objetivo identificar genótipos fenotipicamente divergentes de Vigna unguiculata (L.) Walp., sob esta perspectiva quanto as variáveis agronômicas e fisiológicas visando produção de grãos verdes. Em um experimento conduzido em Fortaleza - CE, 13 variáveis foram avaliadas em 44 genótipos provenientes do Banco Ativo de Germoplasma da Universidade Federal do Ceará. O experimento foi instalado em delineamentos de blocos aumentados, com quatro testemunhas adicionais (cultivares comerciais). Os componentes de variância genético e ambiental foram estimados por máxima verossimilhança restrita e, a partir destes, foi calculado o coeficiente de correlação intraclasse (ICC). Foi realizada análise de componentes principais, agrupamento de Tocher e análise de correlação. As variáveis mais influenciadas pela variação genética foram: produção por planta, comprimento da vagem verde, comprimento do grão verde, massa de grãos por vagem e produtividade total, com ICC > 0.5. A análise de componentes principais permitiu identificar as características fisiológicas: gs, ci, ci.ca, e agronômicas: comprimento da vagem verde, massa de grãos verdes, número de grãos por vagem e precocidade da produção, como sendo importantes na diferenciação de genótipos de feijão-caupi. Os genótipos CE: 02, 151, 165, 172, 189, 244, 986 e 1002 possuem variabilidade genética e são recomendados para uso em um programa de melhoramento genético de feijão-caupi para produção de grãos verdes.

ABSTRACT Cowpea is a nutritious species cultivated worldwide whose high genetic variability can be exploited in breeding programs. The present study aimed to identify phenotypically divergent genotypes of Vigna unguiculata (L.) Walp., from this pe rspective concerning agronomic and physiological variables aiming at green grain production. An experiment was conducted in Fortaleza – CE, to analyse 13 variables in 44 genotypes from the Active Germplasm Bank of the Federal University of Ceará. The experiment was set up in an augmented block design with four additional controls (commercial cultivars). The genetic and environmental variance components were estimated by restricted maximum likelihood, after which the intraclass correlation coefficient (ICC) was calculated. Principal components analysis, Tocher’s clustering and correlation analysis were used in the study. The variables most influenced by genetic variance were production per plant, green pod length, green grain length, grain mass per pod, and total yield, with ICC > 0.5. Principal components analysis signalled the physiological variables gs, ci, and ci.ca and the agronomic variables of green pod length, green grain mass, number of grains per pod, and earliness of production as important for differentiating between cowpea genotypes. CE genotypes 02, 151, 165, 172, 189, 244, 986, and 1002 show genetic variability, and their use is recommended in cowpea breeding programs aimed at green-grain production.