Prospection of cowpea genotypes for green-grain production

Resumo

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 perspective
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 coeffi cient (ICC) was calculated.
Principal components analysis, Tocher’s clustering and correlation analysis were used in the study. The variables most infl uenced 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.