Evaluation des Performances Agronomiques et Comportement de 11 Hybrides et de 3 Lignées de Sorgho à L’anthracnose à la Station de Farako-Bâ à L’ouest du Burkina Faso

La présente étude porte sur l’évaluation des performances agronomiques des variétés de sorgho et leur comportement vis-à-vis de l’anthracnose à l’Ouest du Burkina Faso. Le dispositif expérimental utilisé est un bloc de Fisher complètement randomisé en 3 répétitions et 14 traitements correspond aux variétés. Le matériel végétal utilisé était constitué de 3 lignées et 11 hybrides de sorgho provenant respectivement du Burkina Faso et du Brésil. L’analyse phytosanitaire des graines a été réalisée selon la méthode du papier buvard. Les résultats ont montré que les hybrides ESFOEHN et KALATUR ont été les plus précoces. La lignée SARIASSO11 a enregistré la plus grande hauteur tandis que les hybrides ISQ223, KALATUR et ESFOEHN ont été semi naines. Les hybrides ISQ223 et BRG71098 ont enregistrés respectivement les rendements le plus élevé (4590 kg/ha) et le plus faible (1711 kg/ha). Les variétés ISR329, MSP332 et SARIASSO11 ont été les plus résistantes à l’anthracnose, cependant les variétés ESFOEHN et KALATUR ont été les plus sensibles. L’analyse phytosanitaire des graines issues des variétés testées a révélé la présence de Alternaria alternata, Exserohilium rostratum, Aspergilus sp, Rhizopus sp, Drechslera sp et Colletotrichum graminicola. Selon les performances agronomiques et le comportement des variétés à l’anthracnose, quatre groupes ont été identifiés. Des corrélations positives ont été obtenues entre la longueur des panicules et le rendement(r=0,55), entre le taux d’infection des semences au Colletotrichum graminicola et la sévérité de l’anthracnose (r=0,52) et entre la sévérité et incidence de l’anthracnose (r=0,92). Les résultats de cette étude servent de base pour le choix des variétés de sorgho performantes et résistantes à l’anthracnose au Burkina Faso.   The present study focuses on the evaluation of agronomic performance of sorghum varieties and their behaviour towards anthracnose in western of Burkina Faso. The experiments were laid out in a randomized complete block design with 3 replications and 14 treatments corresponding to the varieties. The plant material used consisted of 3 sorghum lines and 11 hybrids from Burkina Faso and Brazil respectively. Phytosanitary analysis of seeds was carried out using the blotting paper method. The results showed that ESFOEHN and KALATUR hybrids were the earliest. The SARIASSO11 line recorded the greatest height while ISQ223, KALATUR and ESFOEHN hybrids were semi-dwarf. The hybrids ISQ223 and BRG71098 had the highest (4590 kg/ha) and lowest (1711 kg/ha) yields respectively. Varieties ISR329, MSP332 and SARIASSO11 were the most resistant to anthracnose, while ESFOEHN and KALATUR were the most susceptible. Health analysis of seeds from tested varieties revealed the presence of Alternaria alternata, Exserohilium rostratum, Aspergilus sp, Rhizopus sp, Drechslera sp and Colletotrichum graminicola. According to agronomic performance and the behaviour of varieties to anthracnose, four groups were identified. Also, positive correlations were obtained between panicle length and yield (r=0.55), seed infection rate with Colletotrichum graminicola and anthracnose severity (r=0.52) and between anthracnose severity and incidence (r=0.92). The results of this study could serve as a basis for selection of efficient and anthracnose-resistant sorghum varieties in Burkina Faso

Evaluation des Performances Agronomiques et du Comportement de 11 Hybrides et de 3 Lignées de Sorgho (Sorghum bicolor (L) Moench) à l’Anthracnose à la Station de Farako-Bâ à l’Ouest du Burkina Faso

L’anthracnose est l’une des principales maladies fongiques du sorgho au Burkina Faso. La présente étude porte sur l’évaluation des performances agronomiques de 11 variétés de sorgho et de leur comportement vis-à-vis de l’anthracnose l’Ouest du Burkina Faso. Le dispositif expérimental utilisé est un bloc de Fisher complètement randomisé en 3 répétitions et 14 traitements correspondant aux variétés. Le matériel végétal utilisé a été constitué de 3 lignées et de 11 hybrides de sorgho provenant respectivement du Burkina Faso et du Brésil. L’analyse phytosanitaire des graines a été réalisée, selon la méthode du papier buvard. Les résultats ont montré que les hybrides ESFOEHN et KALATUR ont été les plus précoces. La lignée SARIASSO11 a enregistré la plus grande hauteur, tandis que les hybrides ISQ223, KALATUR et ESFOEHN ont été semi naines. Les hybrides ISQ223 et BRG71098 ont enregistrés, respectivement, les rendements le plus élevé (4590 kg/ha) et le plus faible (1711 kg/ha). Les variétés ISR329, MSP332 et SARIASSO11 ont été les plus résistantes à l’anthracnose, cependant, les variétés ESFOEHN et KALATUR ont été les plus sensibles. L’analyse phytosanitaire des graines, issues des variétés testées, a révélé la présence de Alternaria alternata, Exserohilium rostratum, Aspergilus sp, Rhizopus sp, Drechslera sp et Colletotrichum graminicola. Selon les performances agronomiques et le comportement des différentes variétés à l’anthracnose, quatre groupes ont été identifiés. Des corrélations positives ont été obtenues entre la longueur des panicules et le rendement(r=0,55), entre le taux d’infection des semences au Colletotrichum graminicola et la sévérité de l’anthracnose (r=0,52) et entre la sévérité et incidence de l’anthracnose (r=0,92). Les résultats de cette étude peuvent servir de base pour le choix des variétés de sorgho performantes et résistantes à l’anthracnose au Burkina Faso.   Anthracnose is one of the main fungal diseases of sorghum in Burkina Faso. The present study focuses on the evaluation of agronomic performance of sorghum varieties and their behaviour towards anthracnose in western of Burkina Faso. The experiments were laid out in a randomized complete block design with 3 replications and 14 treatments corresponding to the varieties. The plant material used consisted of 3 sorghum lines and 11 hybrids from Burkina Faso and Brazil respectively. Phytosanitary analysis of seeds was carried out using the blotting paper method. The results showed that ESFOEHN and KALATUR hybrids were the earliest. The SARIASSO11 line recorded the greatest height while ISQ223, KALATUR and ESFOEHN hybrids were semi-dwarf. The hybrids ISQ223 and BRG71098 had the highest (4590 kg/ha) and lowest (1711 kg/ha) yields respectively. Varieties ISR329, MSP332 and SARIASSO11 were the most resistant to anthracnose, while ESFOEHN and KALATUR were the most susceptible. Health analysis of seeds from tested varieties revealed the presence of Alternaria alternata, Exserohilium rostratum, Aspergilus sp, Rhizopus sp, Drechslera sp and Colletotrichum graminicola. According to agronomic performance and the behaviour of varieties to anthracnose, four groups were identified. Also, positive correlations were obtained between panicle length and yield (r=0.55), seed infection rate with Colletotrichum graminicola and anthracnose severity (r=0.52) and between anthracnose severity and incidence (r=0.92). The results of this study could serve as a basis for selection of efficient and anthracnose-resistant sorghum varieties in Burkina Faso

Evaluation des Performances Agronomiques et Comportement de 11 Hybrides et de 3 Lignées de Sorgho à L’anthracnose à la Station de Farako-Bâ à L’ouest du Burkina Faso

La présente étude porte sur l’évaluation des performances agronomiques des variétés de sorgho et leur comportement vis-à-vis de l’anthracnose à l’Ouest du Burkina Faso. Le dispositif expérimental utilisé est un bloc de Fisher complètement randomisé en 3 répétitions et 14 traitements correspond aux variétés. Le matériel végétal utilisé était constitué de 3 lignées et 11 hybrides de sorgho provenant respectivement du Burkina Faso et du Brésil. L’analyse phytosanitaire des graines a été réalisée selon la méthode du papier buvard. Les résultats ont montré que les hybrides ESFOEHN et KALATUR ont été les plus précoces. La lignée SARIASSO11 a enregistré la plus grande hauteur tandis que les hybrides ISQ223, KALATUR et ESFOEHN ont été semi naines. Les hybrides ISQ223 et BRG71098 ont enregistrés respectivement les rendements le plus élevé (4590 kg/ha) et le plus faible (1711 kg/ha). Les variétés ISR329, MSP332 et SARIASSO11 ont été les plus résistantes à l’anthracnose, cependant les variétés ESFOEHN et KALATUR ont été les plus sensibles. L’analyse phytosanitaire des graines issues des variétés testées a révélé la présence de Alternaria alternata, Exserohilium rostratum, Aspergilus sp, Rhizopus sp, Drechslera sp et Colletotrichum graminicola. Selon les performances agronomiques et le comportement des variétés à l’anthracnose, quatre groupes ont été identifiés. Des corrélations positives ont été obtenues entre la longueur des panicules et le rendement(r=0,55), entre le taux d’infection des semences au Colletotrichum graminicola et la sévérité de l’anthracnose (r=0,52) et entre la sévérité et incidence de l’anthracnose (r=0,92). Les résultats de cette étude servent de base pour le choix des variétés de sorgho performantes et résistantes à l’anthracnose au Burkina Faso.   The present study focuses on the evaluation of agronomic performance of sorghum varieties and their behaviour towards anthracnose in western of Burkina Faso. The experiments were laid out in a randomized complete block design with 3 replications and 14 treatments corresponding to the varieties. The plant material used consisted of 3 sorghum lines and 11 hybrids from Burkina Faso and Brazil respectively. Phytosanitary analysis of seeds was carried out using the blotting paper method. The results showed that ESFOEHN and KALATUR hybrids were the earliest. The SARIASSO11 line recorded the greatest height while ISQ223, KALATUR and ESFOEHN hybrids were semi-dwarf. The hybrids ISQ223 and BRG71098 had the highest (4590 kg/ha) and lowest (1711 kg/ha) yields respectively. Varieties ISR329, MSP332 and SARIASSO11 were the most resistant to anthracnose, while ESFOEHN and KALATUR were the most susceptible. Health analysis of seeds from tested varieties revealed the presence of Alternaria alternata, Exserohilium rostratum, Aspergilus sp, Rhizopus sp, Drechslera sp and Colletotrichum graminicola. According to agronomic performance and the behaviour of varieties to anthracnose, four groups were identified. Also, positive correlations were obtained between panicle length and yield (r=0.55), seed infection rate with Colletotrichum graminicola and anthracnose severity (r=0.52) and between anthracnose severity and incidence (r=0.92). The results of this study could serve as a basis for selection of efficient and anthracnose-resistant sorghum varieties in Burkina Faso

Inventaire Des Nématodes Parasites et Mycorhization Naturelle de l’Igname (Dioscorea spp.) Dans La Région Centrale Du Togo

L'igname, Dioscorea spp. est une culture très importante au Togo avec plusieurs espèces cultivées. Toutefois, le complexe D. cayennensis- rotundata est le plus répandu dans les exploitations. Malheureusement, les nématodes sont des parasites majeurs qui entravent sa production. A cet effet, cette étude a été conduite dans trois préfectures de la région centrale du Togo dans le but d’identifier les nématodes parasites qui font intrusion dans les champs d’igname et d’évaluer la mycorhization naturelle de la plante. Des prélèvements de sol et de racines ainsi que l’inspection des tubercules d’igname pour les dégâts de fissuration et de galles dues aux nématodes ont été effectués à différents endroits de différents champs d’igname dans chaque préfecture. Des échantillons de sol et de racines ramenés au laboratoire, ont été extraits des nématodes et identifiés sur la base de critères morphologiques en utilisant les clés d’identification. Le taux de mycorhization a été évalué par la coloration des racines. Les résultats ont révélé la présence des genres Scutellonema, Meloïdogyne, Aphelenchoides et Xiphinema dans les champs avec Scutellonema spp. et Meloidogyne spp. comme nématodes majeurs sur les ignames. L’évaluation des dégâts visuels des nématodes sur les tubercules a montré que les taux de fissures causées par Scutellonema spp. vont de 80 à 100% alors que les taux de galles causées par Meloidogyne spp. sont de 60 à 70%. Le taux de mycorhization naturelle des plantes d’ignames va de 10 à 86,66% en milieu naturel de culture en fonction des sites et des cultivars. Cette étude est la première réalisée en milieu paysan au Togo pour inventorier la diversité des nématodes de l’igname. Les résultats de cette étude servent de base à l’élaboration des stratégies de gestion des nématodes pour une production durable de l’igname. Yam, Dioscorea spp. is an important crop in Togo with several cultivated species. However, D. cayennensis- rotundata complex is the most widespread in the exploitations. Unfortunately, the nematodes are major pests that hindered its production. Therefore, this study was conducted in three different counties in central region of Togo. The objectives were to identify the parasitic nematodes associated with yam crop, to evaluate the damage of these parasitic and the natural mycorhization of the yam. Soil and root were sampled and inspection of yam tubers for nematode cracking and gall damage were done at different locations of different yam fields in each county. From soil and root samples taken into the laboratory were extracted the nematodes and identified based on morphological criteria using the identification keys. The rate of mycorrhization was assessed by staining of the roots. The results revealed the presence of the genus Scutellonema, Meloïdogyne, Aphelenchoides and Xiphinema in the fields and showed that Scutellonema spp. and Meloidogyne spp. are the major parasitic nematodes of yam in the areas of the study. The assessment of the visual damages of the nematodes on the tubers showed that the crack rates due to Scutellonema spp. were between 80 and 100% while the gall rates due to Meloidogyne spp. varied between 60 and 70%. The frequency of natural mycorhization of yams ranging from 10 to 86, 66% and is related to the site and the variety. This study could be the first carried out in Togo to inventory the nematodes diversity of the yam. These results will contribute to nematodes management strategies elaboration for durable production of yam

Whole-genome sequences of Bipolaris bicolor , Curvularia hawaiiensis , Curvularia spicifera , and Exserohilum rostratum isolated from rice in Burkina Faso, France, Mali, and Pakistan

International audienceABSTRACT Different fungal species of the Pleosporaceae family infect rice, causing similar symptoms. Reference genomic sequences are useful tools to study the evolution of these species and to develop accurate molecular diagnostic tools. Here, we report the complete genome sequences of Bipolaris bicolor , Curvularia hawaiiensis , Curvularia spicifera, and Exserohilum rostratum

Spatiotemporal Survey of Multiple Rice Diseases in Irrigated Areas Compared to Rainfed Lowlands in the Western Burkina Faso

International audienceMultiple constraints affect rice yields in West Africa. Among these constraints are viral, bacterial, and fungal pathogens. We aimed to describe the spatiotemporal patterns of occurrence and incidence of multiple rice diseases in farmers’ fields in contrasting rice growing systems in the western Burkina Faso. For this purpose, we selected a set of three pairs of sites, each comprising an irrigated area and a neighboring rainfed lowland, and studied them over four consecutive years. We first performed interviews with the rice farmers to better characterize the management practices at the different sites. This study revealed that the transplanting of rice and the possibility of growing rice twice a year are restricted to irrigated areas, while other practices, such as the use of registered rice cultivars, fertilization, and pesticides, are not specific but differ between the two rice growing systems. Then, we performed symptom observations at these study sites to monitor the following four diseases: yellow mottle disease, Bacterial Leaf Streak (BLS), rice leaf blast, and brown spot. The infection rates were found to be higher in irrigated areas than in rainfed lowlands, both when analyzing all observed symptoms together (any of the four diseases) and when specifically considering each of the two diseases: BLS and rice leaf blast. Brown spot was particularly prevalent in all six study sites, while yellow mottle disease was particularly structured geographically. Various diseases were frequently found together in the same field (co-occurrence) or even on the same plant (coinfection), especially in irrigated areas

The impact of the rice production system (irrigated vs lowland) on root-associated microbiome from farmer's fields in western Burkina Faso

International audienceDue to their potential applications for food safety, there is a growing interest in rice root-associated microbial communities, but some systems remain understudied. Here, we compare the assemblage of root-associated microbiota in rice sampled in 19 small farmer's fields from irrigated and rainfed lowlands in Burkina Faso, using an amplicon metabarcoding approach of the 16S rRNA gene (prokaryotes, three plant samples per field) and ITS (fungi, one sample per field). In addition to the expected structure by root compartments (root vs rhizosphere) and geographical zones, we showed that the rice production system is a major driver of microbiome structure. In irrigated systems, we found a higher diversity of prokaryotic communities from the rhizosphere and more complex co-occurrence networks, compared to rainfed lowlands, while fungal communities exhibited an opposite pattern (higher richness in rainfed lowlands). Core taxa were different between the two systems, and indicator species were identified: mostly within Bacillaceae in rainfed lowlands, and within Burkholderiaceae and Moraxellaceae in irrigated areas. Finally, a higher abundance in rainfed lowlands was found for mycorrhizal fungi (both compartments) and rhizobia (rhizosphere only). Our results highlight deep microbiome differences induced by contrasted rice production systems that should consequently be considered for microbial engineering applications

Structure of African Populations of Pyricularia oryzae from Rice

International audienceRice blast, caused by the filamentous ascomycete Pyricularia oryzae, is one of the most devastating diseases of rice. Four genetic clusters were previously identified, and three have a large geographic distribution. Asia is the center of diversity and the origin of most migrations to other continents, and sexual reproduction persisted only in the South China-Laos-North Thailand region, which was identified as the putative center of origin of all P. oryzae populations on rice. Despite the importance of rice blast disease, little is known about the diversity and the population structure of the pathogen in Africa (including Madagascar). The present study was intended to describe the structure of African populations of P. oryzae and identify the relationship between African and worldwide genetic clusters. A set of 2,057 strains (937 African and 1,120 Madagascan strains) were genotyped with 12 simple sequence repeat markers to assess the diversity and the population structure of P. oryzae. Four genetic clusters were identified in Africa and Madagascar. All four clusters previously identified are present in Africa. Populations from West Africa, East Africa, and Madagascar are highly differentiated. The geographic structure is consistent with limited dispersion and with some migration events between neighboring countries. The two mating types are present in Africa with a dominance of Mat1.2, but no female-fertile strain was detected, supporting the absence of sexual reproduction on this continent. This study showed an unsuspected high level of genetic diversity of P. oryzae in Africa and suggested several independent introductions