Characterization of Blast Resistance in a Diverse Rice Panel from Sub-Saharan Africa.

There is a recent unparalleled increase in demand for rice in sub-Saharan Africa, yet its production is affected by blast disease. Characterization of blast resistance in adapted African rice cultivars can provide important information to guide growers and rice breeders. We used molecular markers for known blast resistance genes (Pi genes; n = 21) to group African rice genotypes (n = 240) into similarity clusters. We then used greenhouse-based assays to challenge representative rice genotypes (n = 56) with African isolates (n = 8) of Magnaporthe oryzae which varied in virulence and genetic lineage. The markers grouped rice cultivars into five blast resistance clusters (BRC) which differed in foliar disease severity. Using stepwise regression, we found that the Pi genes associated with reduced blast severity were Pi50 and Pi65, whereas Pik-p, Piz-t, and Pik were associated with increased susceptibility. All rice genotypes in the most resistant cluster, BRC 4, possessed Pi50 and Pi65, the only genes that were significantly associated with reduced foliar blast severity. Cultivar IRAT109, which contains Piz-t, was resistant against seven African M. oryzae isolates, whereas ARICA 17 was susceptible to eight isolates. The popular Basmati 217 and Basmati 370 were among the most susceptible genotypes. These findings indicate that most tested genes were not effective against African blast pathogen collections. Pyramiding genes in the Pi2/9 multifamily blast resistance cluster on chromosome 6 and Pi65 on chromosome 11 could confer broad-spectrum resistance capabilities. To gain further insights into genomic regions associated with blast resistance, gene mapping could be conducted with resident blast pathogen collections. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Integrated Strategies for Durable Rice Blast Resistance in Sub-Saharan Africa.

Rice is a key food security crop in Africa. The importance of rice has led to increasing country-specific, regional, and multinational efforts to develop germplasm and policy initiatives to boost production for a more food-secure continent. Currently, this critically important cereal crop is predominantly cultivated by small-scale farmers under suboptimal conditions in most parts of sub-Saharan Africa (SSA). Rice blast disease, caused by the fungus Magnaporthe oryzae, represents one of the major biotic constraints to rice production under small-scale farming systems of Africa, and developing durable disease resistance is therefore of critical importance. In this review, we provide an overview of the major advances by a multinational collaborative research effort to enhance sustainable rice production across SSA and how it is affected by advances in regional policy. As part of the multinational effort, we highlight the importance of joint international partnerships in tackling multiple crop production constraints through integrated research and outreach programs. More specifically, we highlight recent progress in establishing international networks for rice blast disease surveillance, farmer engagement, monitoring pathogen virulence spectra, and the establishment of regionally based blast resistance breeding programs. To develop blast-resistant, high yielding rice varieties for Africa, we have established a breeding pipeline that utilizes real-time data of pathogen diversity and virulence spectra, to identify major and minor blast resistance genes for introgression into locally adapted rice cultivars. In addition, the project has developed a package to support sustainable rice production through regular stakeholder engagement, training of agricultural extension officers, and establishment of plant clinics.

Structure of African Populations of Pyricularia oryzae from Rice.

Rice 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.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

[Prevalence and factors associated with malnutrition in infants aged 6 to 23 months admitted to paediatric emergencies department at the Yalgado Ouédraogo University Hospital in Burkina Faso]. / Prevalence et facteurs associes a la malnutrition des nourrissons ages de 6 a 23 mois admis aux urgences pediatriques du Centre Hospitalier Universitaire Yalgado Ouedraogo, Burkina Faso.

INTRODUCTION: Despite the implementation of various nutritional interventions, access to healthy food in sufficient quantity for the population remain challenging in Burkina Faso. The objective of this study was to assess the nutritional status of infants aged 6-23 months and to identify factors associated with malnutrition. PATIENTS AND METHODS: From 1st May to 31th July 2016, we conducted a cross-sectional study at Yalgado Ouedraogo University Hospital paediatric department. Infants aged 6 to 23 months admitted to the paediatric emergency department were enrolled. Factors associated with malnutrition were identified using multivariate logistic regression. RESULTS: A total of 295 infants were included, at an average age of 13 months (standard deviation: 5.1 months). The prevalence of wasting was 15%, 13% was stuntingand 7% was underweight. The majority of mothers (69%) were unaware of exclusive breastfeeding and only 22% knew the importance of colostrum. In multivariate analysis age ≥ 12 months increased the odds of wasting (adjusted odds ratio [aOR]: 2.3, 95% confidence interval: 1.1-4.7), while knowledge of exclusive breastfeeding reduced the risk of wasting (aOR: 0.4, 95% CI 0.2-0.9). In addition, age ≥12 months (aOR: 0.08, 95% CI: 0.03-0.22), female gender (aOR: 0.31, 95% CI: 0.12-0.77) and absence of dietary restrictions (aOR: 0.13, 95% CI: 0.05-0.3) significantly reduced the odds of stunting. CONCLUSION: The prevalence of malnutrition remains high in paediatric department in Burkina Faso. Routine screening and adequate management of malnutrition, coupled with the promotion of optimal nutritional practices in childhood, is needed to improve child healthcare.

INTRODUCTION: Les pratiques d'alimentation constituentle facteur essentiel déterminant l'état nutritionnel des enfants.L'objectif de cette étude était d'évaluer l'état nutritionnel des nourrissons âgés de 6 à 23 mois admis dans le département de pédiatrie du CHU-YO et d'identifier les facteurs associés à la malnutrition. PATIENTS ET MÉTHODE: Nous avons mené une étude transversale chez des nourrissons âgés de 6 à 23 mois admis dans le service des urgences pédiatriques au Centre Hospitalier Universitaire Yalgado Ouédraogo entre le 1er mai et le 31 juillet 2016.Les facteurs associés à la malnutrition ont été identifiés par une régression logistique. RÉSULTATS: Au total 295 nourrissons ont été inclus, à un âge moyen 13 mois(Ecart type :5,1 mois).Les prévalences de la malnutrition étaient de15% pour la malnutrition aiguë, 13% pour la malnutritionchronique et 7% pour l'insuffisance pondérale. En analyse multivariée un âge ≥ 12 mois augmentait le risque de malnutrition aiguë (Rapport de cote ajusté (RCa) : 2,3 ; Intervalle de confiance à 95% : 1,1-4,7) tandis que la connaissance de l'allaitement maternel exclusif réduisait le risque de malnutrition aiguë (RCa : 0,4 ; IC95% 0,2-0,9). De plus, un âge ≥12 mois (RCa : 0,08,IC95% : 0,03-0,22), le sexe féminin (RCa : 0.31 IC95% : 0,12-0,77) et l'absence d'interdits alimentaires (RCa : 0,13 ; IC95% : 0,05-0,3) réduisait le risque d'êtreen malnutrition chronique chez les nourrissons. CONCLUSION: La prévalence de la malnutrition carentielle reste élevée en milieu hospitalier au CHU YO. La promotion des pratiques nutritionnelles optimales du nourrisson sont nécessaires pour améliorer la prise en charge des nourrissons dans le centre.

A geospatial database of drought occurrence in inland valleys in Mali, Burkina Faso and Nigeria.

The data described in this article are related to drought occurrence in inland valleys and farmers adaptation strategies. The data were collected in 300 inland valleys distributed in 14 regions of West Africa. The data were collected in two phases. In the first phase, 300 inland valleys were identified in 14 regions and their locations were determined with handheld GPS devices. Questionnaires and informal interviews were administered to inland valleys users to collect data on physical and socio-economic characteristics, hydrology, farmers experience with drought affecting rice production in inland valleys and adaptation strategies. In the second phase, the locations of the inland valleys were imported in a GIS environment and were used to extract additional parameters on soil characteristics and water demand from the Shuttle Radar Topography Mission (SRTM), Africa Soil Information Service (africasoils.net) and POWER database (http://power.larc.nasa.gov). In total, the dataset contains 41 variables divided into seven themes: farmers' experience with drought, adaptive management of rice farmers to drought, physical characteristics, hydrology, management practices, socio-economic characteristics and weather data of inland valleys.