Genetic variability, character association and yield potentials of twenty five accessions of cowpea (Vigna unguiculata L. Walp)

Abstract

Inadequate knowledge of the level of genetic
variability and genotype x environment interaction in
cowpea are major constraints to its improvement in
Nigeria. Therefore, study objectives were to determine
genetic variability, character association and yield potential
of twenty five accessions of cowpea in the field during
2014 and 2015 cropping seasons. A randomized complete
block design (RCBD) with three replications was adopted
in each season. Data were collected on 12 quantitative
traits from 10 randomly tagged plants per accession per
replicate. Analysis of variance revealed highly significant
differences among accessions for all traits. Seed yield per
plant fell between 0.00 g in AC19 and 134.97 g in AC18 in
2014, while the range fell between 0.00 g in AC19 and
54.09 g in AC20 in 2015. Accessions AC12, AC17, AC20 and AC18, consistently showed the highest yield, therefore
these can be considered the best candidates for selection.
Broad-sense heritability ranged from 48.75% (emergence) to
98.09% (pod length) in 2014 and ranged between 8.95%
(number of main branches) and 94.32% (pod length) in 2015.
Genetic advances as percent of mean ranged from 19.32%
(emergence) to 474.89% (plant height) in 2014 and ranged
from 3.43% (number of main branches) to 108.70% (days to
flowering) in 2015. High positive correlations between seed
yield and peduncle length (r = 0.85** and 0.84** in 2014; r =
0.55** in 2015), number of pods (r = 0.98** and 0.98** in
2014; r = 0.61** and 0.71** in 2015), seeds/pod (r = 0.57**
and 0.57** in 2014; r = 0.78** and 0.68** in 2015), and
seeds/plant (r = 0.97** and 0.97** in 2014; r = 0.67** and
0.75** in 2015) of these accessions will be useful in designing
an effective selection program for the crop. © 2020
Department of Agricultural Sciences, AIOU