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Abstract

The study was carried out to investigate the effects of inoculating three cowpea cultivars: "OLO II", "OLOYIN" and IT86D-719 with three unrelated viruses: Cowpea aphid-borne mosaic virus (CABMV), genus Potyvirus, Cowpea mottle virus (CMeV), genus Carmovirus and Southern bean mosaic virus (SBMV), genus Sobemovirus singly and in mixture on growth and yield of cultivars at 10 and 30 days after planting (DAP). Generally, the growth and yield of the buffer inoculated control plants were significantly higher than those of the virus inoculated plants. Inoculation of plants at an early age of 10 DAP resulted in more severe effect than inoculations at a later stage of 30 DAP. The average values of plant height and number of leaves produced by plants inoculated 30 DAP were higher than those produced by plants inoculated 10 DAP. Most of the plants inoculated 10 DAP died and did not produce seeds. However, " OLOYIN" cultivar was most tolerant and produced reasonable yields when infected 30 DAP. The effect of single viruses on growth and yield of cultivars showed that CABMV caused more severe effects in IT86D-719, SBMV had the greatest effect on "OLO II" while CMeV induced the greatest effect on "OLOYIN". Yield was greatly reduced in double infections involving CABMV in combination with either CMeV or SBMV in "OLOYIN" and "OLO II", however, there was complete loss in yield of IT86D-719. Triple infection led to complete yield loss in all the three cultivars.

Serological Screening of Cowpea Genotypes for Resistance against Cowpea Aphid Borne Mosaic Virus Using DAS-ELISA

“…The CABMV resistant genotypes proclaimed in the present study could therefore be utilized to develop resistance against multiple viral infections. It is also accounted that early infection of virus severely impedes the crop productivity (Kareem and Taiwo, 2007). The near to 50% reduction in chlorophyll content of infected leaves vis-à-vis healthy plants in the present study could also attribute to severe reduction in yield of infected plants owing to reduced photosynthetic efficiency.…”

“…As a result, selection of cowpea cultivars with multiple resistances is fundamental to control mixed infections (Anderson et al, 1996). Alternatively, it has been reported that under mixed infections, when symptoms are severe, one of the infecting virus generally is a Potyvirus (Kareem and Taiwo, 2007). Therefore, breeders should use cowpea genotypes with high resistance to viruses from the genus Potyvirus in the production of cowpea cultivars resistant to mixed infection (Lima et al, 2011).…”

Genetic Diversity of Cowpea (Vigna unguiculata (L.) Walp.) Accession in Kenya Gene Bank Based on Simple Sequence Repeat Markers

“…(2 n = 22), is one of the most ancient human food sources [1]. It is one of the most important legume crops in the world and it is a major food crop in Africa, Latin America, and India because of its high protein content [2, 3]. As a result, cowpea is referred to as a poor man's meat [4].…”

Molecular Characterization of a Large Diversity of Bambara Groundnut Potyviruses (<i>Vigna subterranea</i> (L.) Verdc.) in Burkina Faso

“…The main viruses reported globally on the plant include Cowpea mild mottle virus (CPPMV, carlavirus), Voandzeia mosaic necrosis virus (VMNV, tymovirus), Cowpea mottle virus (CPMoV, carmovirus), Southern bean mosaic virus (SBMV, sobemovirus), Cucumber mosaic virus (CuMV, cucumovirus) as well as a number of potyviruses, namely Cowpea aphid aphid-borne mosaic virus (CABMV), Bean common mosaic virus blackeye strain (BCMV-BlCM), Voandzeia distortion mosaic virus (VDMV), Peanut mottle potyvirus (PnMV) [3] [4]. Viruses of genus Potyvirus are major factors of the reduction of Bambara groundnut production by causing yield losses ranging between 13% and 100% in cowpea [5] [6]. Potyviruses are mostly transmitted by aphid vectors and through virus contaminated seeds, which makes their control difficult.…”