Muchero W.,University of California at Riverside |
Muchero W.,Oak Ridge National Laboratory |
Roberts P.A.,University of California at Riverside |
Diop N.N.,University of California at Riverside |
And 8 more authors.
PLoS ONE | Year: 2013
The stay-green phenomenon is a key plant trait with wide usage in managing crop production under limited water conditions. This trait enhances delayed senescence, biomass, and grain yield under drought stress. In this study we sought to identify QTLs in cowpea (Vigna unguiculata) consistent across experiments conducted in Burkina Faso, Nigeria, Senegal, and the United States of America under limited water conditions. A panel of 383 diverse cowpea accessions and a recombinant inbred line population (RIL) were SNP genotyped using an Illumina 1536 GoldenGate assay. Phenotypic data from thirteen experiments conducted across the four countries were used to identify SNP-trait associations based on linkage disequilibrium association mapping, with bi-parental QTL mapping as a complementary strategy. We identified seven loci, five of which exhibited evidence suggesting pleiotropic effects (stay-green) between delayed senescence, biomass, and grain yield. Further, we provide evidence suggesting the existence of positive pleiotropy in cowpea based on positively correlated mean phenotypic values (0.34< r <0.87) and allele effects (0.07< r <0.86) for delayed senescence and grain yield across three African environments. Three of the five putative stay-green QTLs, Dro-1, 3, and 7 were identified in both RILs and diverse germplasm with resolutions of 3.2 cM or less for each of the three loci, suggesting that these may be valuable targets for marker-assisted breeding in cowpea. Also, the co-location of early vegetative delayed senescence with biomass and grain yield QTLs suggests the possibility of using delayed senescence at the seedling stage as a rapid screening tool for post-flowering drought tolerance in cowpea breeding. BLAST analysis using EST sequences harboring SNPs with the highest associations provided a genomic context for loci identified in this study in closely related common bean (Phaseolus vulgaris) and soybean (Glycine max) reference genomes. © 2013 Muchero et al.
Lucas M.R.,University of California at Riverside |
Huynh B.-L.,University of California at Riverside |
Vinholes P.S.,University of California at Riverside |
Cisse N.,Senegalese Institute of Agricultural Research |
And 4 more authors.
Frontiers in Plant Science | Year: 2013
Highly specific seed market classes for cowpea and other grain legumes exist because grain is most commonly cooked and consumed whole. Size, shape, color, and texture are critical features of these market classes and breeders target development of cultivars for market acceptance. Resistance to biotic and abiotic stresses that are absent from elite breeding material are often introgressed through crosses to landraces or wild relatives. When crosses are made between parents with different grain quality characteristics, recovery of progeny with acceptable or enhanced grain quality is problematic. Thus genetic markers for grain quality traits can help in pyramiding genes needed for specific market classes. Allelic variation dictating the inheritance of seed size can be tagged and used to assist the selection of large seeded lines. In this work we applied 1,536-plex SNP genotyping and knowledge of legume synteny to characterize regions of the cowpea genome associated with seed size. These marker-trait associations will enable breeders to use marker-based selection approaches to increase the frequency of progeny with large seed. For 804 individuals derived from eight bi-parental populations, QTL analysis was used to identify markers linked to 10 trait determinants. In addition, the population structure of 171 samples from the USDA core collection was identified and incorporated into a genome-wide association study which supported more than half of the trait-associated regions important in the bi-parental populations. Seven of the total 10 QTLs were supported based on synteny to seed size associated regions identified in the related legume soybean. In addition to delivering markers linked to major trait determinants in the context of modern breeding, we provide an analysis of the diversity of the USDA core collection of cowpea to identify genepools, migrants, admixture, and duplicates. © 2013 Lucas, Huynh, da Silva Vinholes, Cisse, Drabo, Ehlers, Roberts and Close.
Using Paecilomyces lilacinus (fungus nematicide) as replacement method to fight against nematodes of tomato for a sustainable production in urban and peri-urban areas (Dakar, Senegal) [Utilisation de Paecilomyces lilacinus (Champignon Nématicide) comme method de remplacement pour la Lutte contre les Nématodes de la Tomate, en vue d'une Production Durable dans les Zones Urbaines et Périurbaines (Dakar, Sénégal)]
Diarra K.,Cheikh Anta Diop University |
Mbodj I.,Cheikh Anta Diop University |
Kooyman C.,Agir pour lEducation et la Sante Foundation |
Niang Y.,Senegalese Institute of Agricultural Research
Acta Horticulturae | Year: 2014
Agricultural activities, especially horticulture, will become increasingly important in areas now classified as urban or suburban. In Senegal, the practice of urban horticulture is particularly important since the agricultural sector still has the difficult task of providing jobs, incomes and food security in much of the population. It is essential to identify the risks posed by urban and peri-urban horticulture and to provide solutions for farmers as well as research opportunities for scientists to ensure the sustainability of the system. The aim of this study was to compare the effects of 5 types of treatments on tomato (Lycopersicon esculentum 'Mongal', sensitive to nematodes) by analyzing their impact on the yield in kg, the number of fruits and the level of attack by Meloidogyne javanica at the ISRA research center (CDH) close to Dakar, Senegal under pesticide-free conditions. The experimental design was set in a completely randomized block with 5 treatments and 3 repetitions. The product used was PL Gold®, which contains the fungus Paecilomyces lilacinus (PL) and is proposed by the Foundation "Agir pour l'Education et la Santé" for the west African market to control Meloidogyne javanica. The five treatments were: PL1 (0.5 kg/ha), PL2 (1 kg/ha) and PL3 (1.5 kg/ha), a control with Carbofuran (WC) (50 kg/ha) and an untreated control. PL3 was the most effective treatment since seedlings in this treatment were not attacked by M. javanica. All the other treatments were susceptible to M. javanica. With regard to the agronomic parameters, seedlings in the PL2 treatment sprouted earlier and gave higher fruit yield. The WC treatment gave a better yield (92 t/ha) followed by PL2 (89 t/ha). The effect of the PL2 treatment in terms of yield, agronomic performance and level of attack by M. javanica (40% reduction of attack) is discussed in this paper. The use of PL2 (a biological treatment) as an alternative to WC (chemical treatment) is suggested to improve the sustainability of soil fertility and crop productivity.
Belko N.,Regional Research Center for the Improvement of Crops Adaptation to Drought |
Belko N.,University of Ouagadougou |
Cisse N.,Regional Research Center for the Improvement of Crops Adaptation to Drought |
Cisse N.,Senegalese Institute of Agricultural Research |
And 6 more authors.
Crop Science | Year: 2014
Available drought-tolerant cowpeas [Vigna unguiculata (L.) Walp.] are few, and identification of additional genotypes with even greater tolerance to drought would enable breeders to develop cultivars with higher and more stable yields across the semiarid ecologies where this crop is grown. The objectives of this work were to evaluate the effects of drought on the growth and reproduction of a diverse set of cowpea germplasm and select drought-tolerant and high-yielding genotypes using stress tolerance indices. Thirty short- and 30 medium-duration genotypes were separately assessed in adjacent drought-stressed (DS) and nonstressed (NS) environments in a randomized complete block design with three replications. Selection indices, including stress tolerance index (STI) and geometric mean productivity (GMP), were estimated considering grain yield under NS and DS environments and the stress intensity. Overall, the medium-duration genotypes had higher yields than the short-duration ones under both DS and NS conditions. On average, fodder and grain yields were 40 and 65% less under DS conditions and maturity occurred 4 d earlier. IT85F-3139, IT93K-693-2, IT97K-499-39, IT93K-503-1, IT96D-610, IT97K-207-15, KVx-61-1, KVx-403, KVx-421-25, and Mouride had the highest grain yields under both DS and NS environments and were identified as the most drought-tolerant and high-yielding genotypes based on their rank in terms of STI and GMP values. Therefore, these cultivars may be valuable parents for breeding programs whose objectives include developing drought-tolerant cowpea cultivars. © Crop Science Society of America.
Effect of agro-ecological zones and contiguous basin crops of groundnut (Arachis hypogaea) on the structuring and genetic diversity of Caryedon serratus (Coleoptera: Chrysomelidae, Bruchinae) in the sub-region of West Africa
Diome T.,University Ca |
Diome T.,Institute Of Recherche Pour Le Developpement |
Ndong A.,University Ca |
Ndong A.,Institute Of Recherche Pour Le Developpement |
And 10 more authors.
Journal of Asia-Pacific Entomology | Year: 2013
Caryedon serratus is found in different agro-ecological and agro-climatic zones, and its damage to groundnuts can vary up to an 80% quantitative loss of yield. This study seeks to demonstrate the effects of different agro-ecological refer to so as to very quickly process the content zones and the presence or absence of groundnut cultivation on the structure and genetic distribution of C. serratus in West Africa. Portions of the cytochrome b and 28S ribosomal genes of C. serratus were sequenced, using samples from four countries that represent different agro-ecological and agro-climatic sub-regions of West Africa. The results showed 37 haplotypes for the cytochrome b and 7 haplotypes for the 28S ribosomal gene. Although genetic diversity was different between agro-ecological zones tests show no significant differences in structuring according to agro-ecological zone. These tests, as well as the phylogenetic relationships that our results imply, indicate that there is a genetic differentiation between individuals from groundnut culturing areas compared to those from areas where the cultivation of groundnuts is absent or low. © 2013 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society.