TITLE:
Correlation and Path Coefficient Analyses of Cowpea (Vigna unguiculata L.) Landraces in Ethiopia
AUTHORS:
Tesfaye Walle, Firew Mekbib, Berhanu Amsalu, Melaku Gedil
KEYWORDS:
Direct Effect, Genotypic Association, Indirect Effect, Phenotypic Association, Seed Yield
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.13,
December
29,
2018
ABSTRACT: Understanding
the nature and extent of association between yield and yield related traits is the prerequisite study for any underutilized crop
improvements of sustainable genetic enhancement. However, there
is a lack of sufficient information on seed yield and related trait correlation
and path coefficient analysis of cowpea in Ethiopia. To fill the existing
knowledge gap, the present study was conducted to determine the nature and
extent of phenotypic and genotypic correlation and path coefficient analysis
among 18 quantitative traits. A total of 324 cowpea landraces were tested in 18 × 18
simple lattice design at Melkassa Agricultural Research Center and Miesso sub
center during 2016 cropping season. The magnitude of genotypic correlations was
higher than phenotypic correlations in most traits at both locations; this
implies that the traits under consideration were genetically controlled. Seed
yield was positively and highly significantly correlated with most of the
traits at phenotypic and genotypic levels, indicating the presence of strong
inherited association between seed yield and the other 17 traits. Almost all
traits genotypic direct and indirect effects were higher than the phenotypic
direct and indirect effects; this indicated that the other traits had a strong
genetically inherited relationship with seed yield. Genotypic path coefficient
analysis revealed that days to flowering, biomass and harvest index at Miesso,
and seed thickness, plant height, days to maturity and biomass at Melkassa had
relatively high positive direct effect on seed yield. However, seed width and
hundred seed weight had exerted negative direct effect on seed yield at each
location. Phenotypic path coefficient analysis showed that biomass and harvest
index had exerted high positive direct effect on seed yield at both locations.
From these results it can be concluded from this study that seed yield in
cowpea can be improved by focusing on traits pod length, seed length, seed
thickness, seed width, biomass and harvest index at both locations. The information
obtained from this study can be used for genetic enhancement of cowpea thereby
developing high yielding varieties.