SDS-Page characterization of some elite cowpea (Vigna unguiculata L. Walp) varieties

The shortcomings of genotype x environment interaction  necessitated the use of molecular methods in characterizing many plant species and in determining their phylogenetic relationships. In this study, some selected cowpea lines (27 varieties) from Obafemi Awolowo University, Ile – Ife, the Institute of Agricultural Research (IAR), Samaru, Kaduna and Genetic Resource Centre, IITA, Ibadan were characterized using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) profiling. The protein banding profiles of the 27 cowpea varieties were scored and subjected to cluster analysis using Ward's minimum-variance method (WMVM) for dendrogram grouping. The dendrogram generated from the SDS-PAGE profiles grouped the varieties into seven clusters at 52% similarity coefficient. Hence, the biochemical characterization revealed more precise discrimination among the 27 cowpea varieties studied. Keywords: Cowpea, electrophoretic banding profiles, dendrogram grouping, total protein

Interrelationships between grain yield and other physiological traits of cowpea cultivars

Adequate knowledge of the interrelationships among physiological traits is essential in planning and evaluating breeding programmes for cowpea improvement. The objective of this study was to determine the interrelationships among physiological traits of thirty cowpea cultivars and identify suitable traits for indirect selection for improved crop yield. The study was conducted for two consecutive growing seasons at the Obafemi Awolowo University, Teaching and Research Farm, Ile-Ife in Nigeria. Combined analysis of variance, cluster analysis and genotype-bytrait (GT) analysis were carried out on the measured traits. Results showed significant genotype differences for all phenological and morphological traits, except grain yield and associated yield components. The GT biplot analysis revealed close associations among the phenological traits. Grain yield was positively correlated with all morphological traits except the two peduncle traits and negatively correlated with flowering traits. IT98-131-1 was the best cultivar based on multiple traits and was identified as the ideal cultivar that can be used as a reference check. Seed growth rate, yield growth rate, yield per plant, and pod weight were identified as traits that are most appropriate for indirect selection for improved grain yield of cowpea.La connaissance ad\ue9quate des relations mutuelles parmi les traits physiologiques est essentielle dans planification et l\u2019\ue9valuation des programmes d\u2019am\ue9lioration du petit pois. L\u2019objectif de cette \ue9tude \ue9tait de d\ue9terminer les relations mutuelles parmi les traits physiologiques de trente cultivars de petit pois et d\u2019identifier des traits appropri\ue9s pour la s\ue9lection indirecte de cultures \ue0 rendement am\ue9lior\ue9. L\u2019\ue9tude \ue9tait conduite en deux consecutives saisons de culture \ue0 l\u2019Universit\ue9 Obafemi Awolowo, une Ferme de Recherche et d\u2019\ue9ducation, Ile-Ife au Nigeria. L\u2019analyse de la variance combine, l\u2019analyse par groupement et l\u2019analyse du g\ue9notype par trait, \ue9tait conduit sur les traits m\ue9sur\ue9s. Les r\ue9sultats ont montr\ue9 des diff\ue9rences g\ue9notypiques significatives pour tous les traits ph\ue9nologiques et morphologiques, except\ue9 le rendement en grain et les composants associ\ue9s aux rendements. L\u2019analyse de biplot GT a r\ue9v\ue9l\ue9 des associations proches parmi les traits ph\ue9nologiques. Le rendement en grain \ue9tait positivement corr\ue9l\ue9 avec tous tous les traits morphologiques except\ue9 les deux traits de p\ue9doncules et n\ue9gativement correl\ue9 avec les traits de floraison. IT98-131-1 \ue9tait le meilleur cultivar bas\ue9 sur de traits multiples et \ue9tait identifi\ue9 comme un cultivar ideal qui peut \ueatre utilis\ue9 comme un mat\ue9riel de reference. Le taux de croissance, le taux de rendement, le rendement par plant, et le poids de gousses \ue9taient identifi\ue9s comme des traits appropri\ue9s \ue0 la s\ue9lection indirect pour l\u2019am\ue9lioration du rendemen en grain du petit pois

Interrelationships between grain yield and other physiological traits of cowpea cultivars

Adequate knowledge of the interrelationships among physiological traits is essential in planning and evaluating breeding programmes for cowpea improvement. The objective of this study was to determine the interrelationships among physiological traits of thirty cowpea cultivars and identify suitable traits for indirect selection for improved crop yield. The study was conducted for two consecutive growing seasons at the Obafemi Awolowo University, Teaching and Research Farm, Ile-Ife in Nigeria. Combined analysis of variance, cluster analysis and genotype-bytrait (GT) analysis were carried out on the measured traits. Results showed significant genotype differences for all phenological and morphological traits, except grain yield and associated yield components. The GT biplot analysis revealed close associations among the phenological traits. Grain yield was positively correlated with all morphological traits except the two peduncle traits and negatively correlated with flowering traits. IT98-131-1 was the best cultivar based on multiple traits and was identified as the ideal cultivar that can be used as a reference check. Seed growth rate, yield growth rate, yield per plant, and pod weight were identified as traits that are most appropriate for indirect selection for improved grain yield of cowpea.La connaissance adéquate des relations mutuelles parmi les traits physiologiques est essentielle dans planification et l’évaluation des programmes d’amélioration du petit pois. L’objectif de cette étude était de déterminer les relations mutuelles parmi les traits physiologiques de trente cultivars de petit pois et d’identifier des traits appropriés pour la sélection indirecte de cultures à rendement amélioré. L’étude était conduite en deux consecutives saisons de culture à l’Université Obafemi Awolowo, une Ferme de Recherche et d’éducation, Ile-Ife au Nigeria. L’analyse de la variance combine, l’analyse par groupement et l’analyse du génotype par trait, était conduit sur les traits mésurés. Les résultats ont montré des différences génotypiques significatives pour tous les traits phénologiques et morphologiques, excepté le rendement en grain et les composants associés aux rendements. L’analyse de biplot GT a révélé des associations proches parmi les traits phénologiques. Le rendement en grain était positivement corrélé avec tous tous les traits morphologiques excepté les deux traits de pédoncules et négativement correlé avec les traits de floraison. IT98-131-1 était le meilleur cultivar basé sur de traits multiples et était identifié comme un cultivar ideal qui peut être utilisé comme un matériel de reference. Le taux de croissance, le taux de rendement, le rendement par plant, et le poids de gousses étaient identifiés comme des traits appropriés à la sélection indirect pour l’amélioration du rendemen en grain du petit pois

Genetic analysis of thrips resistance in cowpea (Vigna unguiculata [L.] Walp.)

Published online: 29 August 2017Flower bud thrips, Megalurothrips sjostedti is the most severe field pest of cowpea that causes massive flower abortion which eventually results to substantial yield reduction in Africa. There is paucity of information on the mode of gene actions controlling inheritance of resistance to flower bud thrips in cowpea in the literature. The objectives of study were to assess the genetic variability for thrips resistance among the cowpea germplasm, determined the mode of inheritance of genes that conferred resistance and both broad and narrow-sense heritability estimates for the inheritance of thrips resistance in cowpea. Twelve cowpea lines were used in crosses in the screen house at IITA, Ibadan. The mating was accomplished using North Carolina design II to generate 48F1 hybrids, which were eventually evaluated with the parents. Data on number of peduncles, number of pods and number of thrips per flower were recorded and subjected to analysis of variance using random model by SAS 9.2. Significant variability was observed for most agronomic and thrip-adaptive traits among the cowpea germplasm, parental-lines and F1 genotypes evaluated. General combining ability (GCA) and specific combining ability (SCA) mean squares were significant (P < 0.01) for number of pods per plant and other traits under the research environment. The GCA effect accounted for 68.82–80.07% of the total variation among hybrids for all traits except days to flowering; SCA explained less than 50% of the total variation. Narrow-sense heritability estimates ranged from 7.53 (days to flower) to 63.92% (number of peduncles per plant). Additive gene action largely controlled the inheritance of yield components and other traits under thrips infestation and these traits were moderately heritable

Nutritional and antioxidant profiles of pumpkin (Cucurbita pepoLinn.) immature and mature fruits as influenced by NPK fertilizer

This study evaluated the influence of NPK fertilizer on protein, fibre, ash, fat, carbohydrate, antioxidantactivities and antioxidant phenolic compounds in immature and mature fruits of pumpkin. The treatmentconsisted of six NPK levels (0, 50, 100, 150, 200 and 250 kg/ha), and was replicated six times in a random-ized complete block design (RCBD). Proximate analysis and antioxidant assays were done using standardanalytical methods. At control and lower NPK rates, the proximate compositions and antioxidant profileof pumpkin fruits decreased with increasing NPK fertilizer. Between the control and the highest fertilizerrate, proximate compositions decreased by 7–62% while the antioxidant profile decreased by 13–79% forboth immature and mature fruits. Across all the measured parameters, mature fruit had higher proximatecontents and higher antioxidant concentrations. For the high health value of pumpkin fruits to be main-tained, little or no NPK fertilizer should be applie