A field trial was carried out in 2017 cropping season to assess the response of twenty five cultivars of cowpea to single and mixed infections with Blackeye cowpea mosaic virus (BICMV) and Cowpea mottle virus (CMeV) on seed quality. The field trial was conducted at the Teaching and Research Farm, Ahmadu Bello University, Zaria, Mokwa Station (090211 N and 50135 E, 201 m above sea level). The trial was a randomized complete block design replicated three times. Three cowpea seeds of each cultivar were sown after dressing with Apron – star at the rate of 3.0 kg seed per 10 g of the chemical. Seeds were sown at an intra and inter–row spacing of 0.30 × 0.75 m along the ridges and later thinned to two per stand at 2 weeks after sowing. Four independent trials were conducted simultaneously, for single and mixed infections. For the single virus infection, seedlings of the twenty five cultivars were inoculated at 10 days after sowing while for the mixed virus infections, seedlings were inoculated at 10 and 17 DAS. Seed viability was determined at the Crop Production Laboratory, Department of Crop Production, Federal University of Technology, Minna, Nigeria. The results of the experiment revealed that all cultivars were susceptible to single and mixed infections of the two viruses but to different extents. The viability of seeds from single infection with CMeV was slight in some instances, also, test of accelerated ageing for f

Pepper (Capsicum annuum) is a major vegetable of global importance. Its production is however affected by varying biotic and abiotic stresses. Virus infections possess a genuine danger to pepper cultivation in Nigeria and all over the world resulting in over 50 % yield losses. Thus, the need to subject available pepper germplasm to screening against virus diseases for possible identification of resistant genes which may be used in breeding programmes to obtain improved lines that are high yielding. This study was undertaken to evaluate the growth and performances of ten pepper breeding lines under cucumber mosaic virus disease. The experiment was laid out in completely randomised design with five replications. Ten pepper breeding lines were evaluated as healthy and inoculated with cucumber mosaic virus and evaluated for their responses. Data were recorded for disease incidence, severity, growth and yield attributes. The data were subjected to analysis of variance. The results revealed that NHPK/D6-1-1 which showed mild disease incidence (36.7 % on average) with an average severity (score = 2.2), produced the highest number of leaves per plant (13) and branches (8) under diseased condition was the least vulnerable. The CMV-infected breeding lines were fruitless except for NHPK/D6-1-1 and NHPK/21-4-1-2 which produced an average of 2 fruits per plant. The selection of NHPK/D6-1-1 and NHPK/21-4-1-2 for further evaluation is therefore recommended for possible CMV-tolerant genes. The identification of virus-resistant breeding lines would provide more effective control of virus diseases in pepper production. Keywords: Capsicum annuum; Cucumber mosaic virus; Breeding lines; NHPK

Field surveys were conducted during the 2015 cropping season to identify and determine the distribution of legume viruses in Niger State, Nigeria. A total of 27 locations were visited during the surveys. Leaves were collected from weed plants showing virus and virus-like symptoms in fields of cowpeas, groundnuts and soyabean. Samples were also collected from asymptomatic plants within the vicinity of infected plants. The antigen coated plate - enzyme linked immunosorbent assay (ACP –ELISA) method was employed for virus detection in the collected leaf samples. Results showed that Blackeye cowpea mosaic virus (BICMV), Cowpea mild mottle virus (CPMMV) and Cowpea mottle virus (CPMoV) were the viruses detected. Thus Aeschynomene indica, Amaranthus caudatum and Centrosema pubescens were positive to BICMV; while Aspilia africana, Cleome viscera, Euphorbia hirta and Heterotis rotundifolia were hosts of CPMoV and CPMMV was detected in Chenopodium amaranticolor, Desmodium scorpiurus, and Vicia faba. The detection of these viruses in weed species in the surveyed areas indicates their importance in the ecology, survival and the significant role they play in the epiphytology of the various virus diseases. The occurrence of BICMV, CPMoV and CPMMV in these weed species is believed to be the first report in the study area.

Cowpea being a dependable source of protein for human growth and development is widely cultivated in sub-Saharan Africa including Nigeria. In spite of its numerous uses, infection by viruses constitutes serious problems to its productivity and once plants are infected, there is no remedy as is with other pathogens such as bacteria, fungi and nematodes. A field trial was conducted to investigate the reactions of twenty five cowpea cultivars to single and mixed infections with two unrelated viruses: Blackeye cowpea mosaic virus (BlCMV) and Cowpea mottle virus (CPMoV) on seed germination and longevity. The trial was conducted at the Teaching and Research Farm of the Ahmadu Bello University (ABU), Zaria, Mokwa Station and set up in a randomized complete block design (RCBD) with three replicates. For the single virus infection, seedlings of the twenty five cultivars were inoculated at 10 days after sowing (DAS), while for the mixed virus infections, seedlings were inoculated at 10 and 17 DAS. Results showed that all the cultivars were susceptible to single and mixed infections but to seemingly different extents. Germination of seeds was generally high before storage but was short lived indicating that conservation of infected seeds of the cultivars was impaired. Seeds of cultivars IT04K-267-8 and IT07K-222-2 recorded germination percentages of 54.6 and 53.7% respectively, while cultivars IT96D-610 and IT04K-291-2 had germination values of 52% which did not differ from each other. Viability of seeds amongst the 25 test cowpea cultivars from single infection with CPMoV alone and BICMV alone did not differ in some instances. Percent germination in cultivars IT98K-205-M8, IT90K-277-2 and IT07K-222-2 inoculated with BICMV + CPMoV were not much affected. Test of accelerated ageing germination (AAG) percentage for four weeks showed that seed vigour was greatly impaired in cultivars IT07K-292-2-10, IT06K-124 and IT90K-277-2 infected with BICMV + CPMoV compared to the lowest AAG percentage of 31.6 recorded in seeds of cultivar IT99K-377-1. Constant monitoring of legume fields through regular field sanitation and disease surveys to identify new and emerging viruses as facts obtained from this study are good starting point for legume virus diseases diagnosis.

Blackeye cowpea mosaic virus (BlCMV) is a major virus, infecting legumes with attendant huge losses. Cultivation of resistant varieties is the most effective and sustainable control strategy. Therefore, some groundnut (Arachis hypogaea) cultivars were evaluated against BlCMV in Minna, Southern Guinea savanna zone of Nigeria. The experiment was conducted at the Teaching and Research Farm, Federal University of Technology, Minna. It was arranged as infected and uninfected using Randomised Complete Block Design (RCBD) with three replications. Groundnut seeds were sowed in the second week of August, 2015. Seedlings were inoculated by sap transmission at 10 days after sowing. Disease incidence, severity, growth and yield attributes were recorded. Data were subjected to analysis of variance (ANOVA) and means separated at p≤0.05 probability level. Disease incidence varied significantly p<0.05 from 28.3 to 60.3 % at one week after inoculation (WAI) and 44.7 to 100 % at 2 WAI. ICGV 91317 which expressed mild infection (symptom score = 2) at 9 WAI also exhibited the lowest leaf diameter reduction (3.6 %) at that growth stage. FDRF7-82 which had the lowest reduction in number of leaves per plant at 3 and 6WAI (10.7 and 9.6 %, respectively) also exhibited the lowest reduction in fresh haulm weight per plant (42.2 %). None of the cultivars exhibited consistent reactions, FDRF7-82 and ICGV 91317 had an appreciable combination of growth and yield attributes under BlCMV infection. However, these cultivars could be improved upon either through conventional or molecular breeding by coding with desirable genes. The cultivars which were adversely affected by BlCMV disease could so be improved genetically through appropriate gene introgression from the resistant cultivars.Keywords: Blackeye cowpea mosaic virus; disease incidence and severity; growth and yield; groundnut