Growth and yield variability of groundnut (Arachis hypogaea L.) cultivars infected with cowpea aphid-borne mosaic virus disease

Abstract

Groundnut (Arachis hypogaea) is a major legume crop with diverse uses in Nigeria. Its productivity is however threatened by Cowpea aphid-borne mosaic virus (CABMV) in most groundnut producing areas, resulting in huge losses. This study was conducted to determine the resistance of some commercial groundnut cultivars under CABMV disease. The experiment was conducted in Minna, Southern Guinea Savanna agro-ecological zone of Nigeria. Twenty groundnut cultivars were evaluated separately as healthy and CABMV infected trials. The experiment was laid out in randomised complete block design with three replications. Seedlings were infected with the virus by mechanical inoculation at 10 days after sowing. The plants were observed for disease incidence, growth and yield attributes. The data collected were subjected to analysis of variance, principal component and cluster analyses at p≤0.05. One hundred percent infection was found regardless of the cultivar. The healthy plants exhibited significantly (p<0.05) higher morphological and yield parameters than infected plants. Principal component analysis revealed that 100-seed weight accounted for the greatest variability in healthy (eigen vector = 0.6239) and CABMV infected (eigen vector = 0.6005) plants. Cluster analysis showed that 18 (90 %) cultivars formed cluster 1, whereas one cultivar each was found in cluster 2 and 3. The top three cultivars for 100-seed weight: “SAMNUT 23” (56.0 g), “SAMNUT 25” (50.5 g) and “SAMNUT 26” (50.9 g) were the most tolerant to CABMV, whereas “ICG-92267” was identified as the best cultivar for dry matter production (24.0 g/plant). Planting of these tolerant cultivars is recommended in order to mitigate the stresses imposed by CABMV.

Keywords: disease incidence, principal components, clusters, groundnut