Evaluation of cowpea mini core accessions for resistance to flower bud thrips Megalurothrips sjostedti Trybom (Thysanoptera: Thripidae)

Open Access ArticleThe flower bud thrips, Megalurothrips sjostedti Trybom (Thysanoptera: Thripidae), is an economically important pest of cowpea in sub‐Saharan Africa. Varietal resistance is the most preferred, environmentally friendly, cost‐effective and sustainable option for controlling this pest. The objective of this study was to identify sources of resistance to M. sjostedti among mini core accessions from the largest world cowpea germplasm collection maintained at the International Institute of Tropical Agriculture (IITA). The study was conducted during the 2015 and 2016 cropping seasons where 365 accessions were screened under field conditions. Each accession was rated visually for thrips damage score, flower abortion rate, number of pods per plant and number of thrips per flower. The resistance levels observed in genotypes TVu8631, TVu16368, TVu8671 and TVu7325 were similar to that of the resistant check “Sanzisabinli” (called Sanzi) during both seasons. In addition, 56 mini core genotypes showed moderate resistance to thrips damage. High heritability values were associated with thrips damage scores at 65 days after planting (0.60), percentage of effective peduncles (0.59), flower bud abortion rate (0.59), number of pods per plant (0.51) and number of peduncles with pods (0.5). The accessions identified with good levels of resistance to flower bud thrips will be used in cowpea breeding programs to develop improved resistant varieties

Etude Comparative Des Produits Issus De La Transformation En Filature Des Fibres De Trois Nouvelles Variétés De Cotonnier

Résumé - Au Mali, comme ailleurs en Afrique, la sélection variétale est à la base du succès de la culture cotonnière. Le coton du Mali est presqu’entièrement exporté ; les fibres issues des variétés cultivées doivent répondre aux exigences du marché en termes de caractéristiques technologiques des fibres, facteurs clés du fonctionnement de la filature. Cette étude comparative a été réalisée sur trois nouvelles variétés de cotonniers A, B et C, issues d’un point d'expérimentation. L'objectif de l'étude est d’identifier les variétés ayant les meilleures performances variétales et industrielles pour la vulgarisation en production commerciale par les sociétés cotonnières. 1 échantillon représentatif de 100g de coton fibre, 20 échantillons de 5 m de rubans de carde, d’étirage et de 10 m de mèches, 30 échantillons de 100 m de fil et 40 échantillons de 500 mm de fil ont été respectivement prélevés par balle de chaque variété et à différentes étapes du processus de transformation par variété. Ces échantillons ont été testés sur des appareils de mesure dans les conditions requises au laboratoire de métrologie textile du CERFITEX, Ségou - Mali.L’analyse de variance (ANOVA) des données relatives aux fibres, rubans, mèches et fils et la comparaison de leurs principales caractéristiques de qualité à celle de la production mondiale avec l’application des USTER STATISTICS 2018 ont montré que les variétés de cotonnier A et B sont nettement meilleures que celle de C. Les performances variétales et industrielles de A et B, meilleures que celles de C sont recommandées à la vulgarisation Mots clés : Coton, caractéristiques technologiques, qualité, fibres, fils. [Comparative Study Of The Products Resulting From The Transformation Into Spinning Of The Fibers Of Three New Varieties Of Cotton]Abstract - In Mali, as elsewhere in Africa, varietal selection is the basis of the success of cotton growing. Cotton from Mali is almost entirely exported; fibers from cultivated varieties must meet market requirements in terms of the technological characteristics of fibers, key factors in the operation of the spinning mill. This comparative study was carried out on three new varieties of cotton A, B and C, from an experimental point. The objective of the study is to identify the varieties with the best varietal and industrial performance for popularization in commercial production by cotton companies. 1 representative sample of 100g of cotton fiber, 20 samples of 5m of carding and drawing slivers and 10m of rovings, 30 samples of 100m of yarn and 40 samples of 500mm of yarn were respectively taken per bale of each variety and at different stages of the transformation process by variety. These samples were tested on measuring devices under the required conditions at the CERFITEX textile metrology laboratory, Ségou - Mali.The analysis of variance (ANOVA) of fiber, sliver, roving and yarn data and the comparison of their main quality characteristics to that of world production with the application of USTER STATISTICS 2018 showed that cotton varieties A and B are clearly better than those of C. The varietal and industrial performances of A and B, better than that of C are recommended for popularisation Keywords : Cotton, technological characteristics, quality, fibres, yarns

An in situ intercomparison exercise on passive samplers for the monitoring of metals, polycyclic aromatic hydrocarbons and pesticides in surface water

An intercomparison exercise on passive samplers (PSs) was organized in summer 2010 for the measurement of selected metals, polycyclic aromatic hydrocarbons (PAHs) and pesticides in surface waters. Various PSs were used and compared at 2 rivers sites and one marine lagoon. A total of 24 laboratories participated. We present selected significant outputs from this exercise, including discussion on quality assurance and quality control for PSs, the interlaboratory variability of field blanks, time weighted average water concentrations and its uncertainties, the representativity of DGT samples, the ability of PSs to lower limits of detection, PAH fingerprints in various PSs compared with spot samples, and the relevance of the permeability reference compounds (PRC) approach for POCIS with pesticides. These in situ intercomparison exercises should enable to progress on the harmonization of practices for the use of passive sampling, especially for priority chemical monitoring and regulatory programs in compliance with the Water Framework Directive (WFD) and Marine Strategy Framework Directive (MSFD)

Entomologie.

Les principaux rabageurs de la culture cotonnière du C-4; Suivi des ravageurs dans l'écosystème et prise de décision; Méthodes de lutte intégrée; Lutte variétale; Contrôle chimique et techniques d'application; Techiques d'appliction des produits.bitstream/item/142479/1/Entomologie.pdfCOTON-4. Idioma: Francês e Português

Adaptive values of wild X cultivated sorghum (Sorghum bicolor (L.) Moench) hybrids in generations F1, F2, and F3

Gene flow between cultivated and their wild relatives is one of the main ecological concerns associated with the introduction genetically modified (GM) cultivars. GM sorghum cultivar has been developed and its commercial production may be possible in the near future. The rate of gene flow depends on the fitness of wild 9 cultivated sorghum hybrids. The study aimed at estimating adaptive values of wild 9 cultivated sorghum hybrids in generations F1, F2, and F3 compared to their parents. Artificial crosses of four wild sorghums, five cultivated sorghums, and two male sterile lines were made to produce the F1 generation, which were advanced to F2 and F3. Each hybrid generation and their respective parents were evaluated for their adaptive value at two sites in a randomised complete block design with seven replicates. The resulting progenies did not show serious fitness penalties. Some hybrids were as fit as their respective wild parents and no consistent differences exist between the three generations studied. Thus, the resultant wild 9 cultivated hybrids may act as avenue for introgression

Quantitative trait loci for head bug resistance in sorghum

An experiment was conducted during the 1997/99 cropping seasons, in Mali, France, to study the inheritance for resistance to head bug (Eurystylus oldi) of sorghum progenies using quantitative trait loci (QTL) maps. Cultivars Malisor 84-7 (resistant) and S 34 (susceptible) were used as parents. To build the sorghum genetic map, 345 restriction fragment length polymorphism (RFLP) probes in combination with 6 restriction enzymes (BamHI, DraI, EcoRI, EcoRV, HindIII and SstI) were screened for their ability to reveal polymorphism. Thousand kernel weight (TKW) and germination rate at grain maturity were measured. Head bug damage was assessed visually on a 1 to 9 scale on the infested part of the panicle (NOTF2). Among the 345 RFLP probes, 81 revealed polymorphism between the parents. Additionally, 14 microsatellite markers gave amplification products. The genetic map based on Malisor 84-7 × S 34 includes 13 linkage groups (LGs) covering a total distance of 1160 cM. Three significant and 7 putative QTLs were detected. One QTL for TKW reduction that accounted for 13% of the phenotypic variation was detected on LG C2. For this QTL, resistance is conditioned by the Malisor 84-7 allele and is dominant. Two QTLs were detected on LG D and LG E for visual damage score under natural head bug infestation, explaining 16 and 26% of the phenotypic variation for this trait, respectively. Resistance from the QTL on LG D is conditioned by the S 34 allele, whereas resistance from the QTL on LG E is provided by the Malisor 84-7 allele. In both cases, resistance is recessive. No significant QTLs were detected for NOTF2 and germination rate, but co-localization of 2 putative QTLs for these traits was observed on LG G2, and in both cases, resistance is conditioned by the S 34 allele

Molecular fingerprinting and hybridity authentication in cowpea using single nucleotide polymorphism based kompetitive Allele-Specific PCR assay

Open Access Journal; Published online: 05 Oct 2021Optimization of a breeding program for increased genetic gain requires quality assurance (QA) and quality control (QC) at key phases of the breeding process. One vital phase in a breeding program that requires QC and QA is the choice of parents and successful hybridizations to combine parental attributes and create variations. The objective of this study was to determine parental diversity and confirm hybridity of cowpea F1 progenies using KASP (Kompetitive Allele-Specific PCR)-based single nucleotide polymorphism (SNP) markers. A total of 1,436 F1 plants were derived from crossing 220 cowpea breeding lines and landraces to 2 elite sister lines IT99K-573-1-1 and IT99K-573-2-1 as male parents, constituting 225 cross combinations. The progenies and the parents were genotyped with 17 QC SNP markers via high-throughput KASP genotyping assay. The QC markers differentiated the parents with mean efficiency of 37.90% and a range of 3.4–82.8%, revealing unique fingerprints of the parents. Neighbor-Joining cladogram divided the 222 parents into 3 clusters. Genetic distances between parents ranged from 0 to 3.74 with a mean of 2.41. Principal component analysis (PCA) depicted a considerable overlap between parents and F1 progenies with more scatters among parents than the F1s. The differentiation among parents and F1s was best contributed to by 82% of the markers. As expected, parents and F1s showed a significant contrast in proportion of heterozygous individuals, with mean values of 0.02 and 0.32, respectively. KASP markers detected true hybridity with 100% success rate in 72% of the populations. Overall, 79% of the putative F1 plants were true hybrids, 14% were selfed plants, and 7% were undetermined due to missing data and lack of marker polymorphism between parents. The study demonstrated an effective application of KASP-based SNP assay in fingerprinting, confirmation of hybridity, and early detection of false F1 plants. The results further uncovered the need to deploy markers as a QC step in a breeding program

Cowpea (Vigna unguiculata): Genetics, genomics and breeding

Article purchased; Published online: 9 May 2018Cowpea, Vigna unguiculata (L.), is an important grain legume grown in the tropics where it constitutes a valuable source of protein in the diets of millions of people. Some abiotic and biotic stresses adversely affect its productivity. A review of the genetics, genomics and breeding of cowpea is presented in this article. Cowpea breeding programmes have studied intensively qualitative and quantitative genetics of the crop to better enhance its improvement. A number of initiatives including Tropical Legumes projects have contributed to the development of cowpea genomic resources. Recent progress in the development of consensus genetic map containing 37,372 SNPs mapped to 3,280 bins will strengthen cowpea trait discovery pipeline. Several informative markers associated with quantitative trait loci (QTL) related to desirable attributes of cowpea were generated. Cowpea genetic improvement activities aim at the development of drought tolerant, phosphorus use efficient, bacterial blight and virus resistant lines through exploiting available genetic resources as well as deployment of modern breeding tools that will enhance genetic gain when grown by sub‐Saharan Africa farmers

Climate change adaptation in conflict-affected countries:A systematic assessment of evidence

People affected by conflict are particularly vulnerable to climate shocks and climate change, yet little is known about climate change adaptation in fragile contexts. While climate events are one of the many contributing drivers of conflict, feedback from conflict increases vulnerability, thereby creating conditions for a vicious cycle of conflict. In this study, we carry out a systematic review of peer-reviewed literature, taking from the Global Adaptation Mapping Initiative (GAMI) dataset to documenting climate change adaptation occurring in 15 conflict-affected countries and compare the findings with records of climate adaptation finance flows and climate-related disasters in each country. Academic literature is sparse for most conflict-affected countries, and available studies tend to have a narrow focus, particularly on agriculture-related adaptation in rural contexts and adaptation by low-income actors. In contrast, multilateral and bilateral funding for climate change adaptation addresses a greater diversity of adaptation needs, including water systems, humanitarian programming, and urban areas. Even among the conflict-affected countries selected, we find disparity, with several countries being the focus of substantial research and funding, and others seeing little to none. Results indicate that people in conflict-affected contexts are adapting to climate change, but there is a pressing need for diverse scholarship across various sectors that documents a broader range of adaptation types and their results