Although the green revolution adapted a handful of crops to homogeneous and high-input industrialized agriculture, much of the global population still relies on the local production of variable crop cultivars by low-input smallholder farms. This diversity of unhomogenized crops1, like that of the grain and bioenergy crop sorghum2-5, offers raw materials for genetic gain and cultivar improvement. However, breeding efforts can be constrained by highly specialized traits and breeding targets6. Here, to bridge this diversity, we constructed a 33-member pangenome reference and a diversity panel across 1,984 cultivars and landraces. We leveraged these resources to explore the complex interplay among historical contingency, ongoing adaptation and previously uncharacterized structural diversity. Specifically, our analyses conclusively demonstrated multiple nested and deeply diverged structural variants in the domestication gene SHATTERING1, which distinguish the previously established multicentric origin of sorghum. We then applied landscape genomics to reveal how gene flow and secondary contact created the complex genetic mosaic in contemporary breeding networks. As proof of concept for pangenome-accelerated trait discovery, we connected biosynthetic gene cluster structural variation to phenotypic leaf concentration of the cyanogenic glucoside dhurrin. Combined, these approaches will accelerate breeding and trait discovery and provide a framework for similar applications in other crops.
Au Niger et dans les pays sahéliens, l’insécurité alimentaire résulte de la péjoration climatique consécutive à la dégradation des terres et à la croissance démographique exponentielle. La résilience de la population entraine la mise en culture des bas-fonds pour la production maraîchère. L’objectif de cette étude était de réaliser une étude diachronique du paysage de la Commune de Doguéraoua située dans la vallée Maggia pour des périodes allant de 1993 à 2023 afin de déterminer la dynamique d’occupation de sol et l’expansion des cultures maraichères. Ainsi, des images Landsat ont été téléchargées afin de produire des cartes d’occupation des sols à l’aide logiciels ArcGIS 10.8 de la société ESRI. L’analyse des matrices de transition générées a permis de déterminer la superficie globale (78217 ha soit 100%). L’analyse de la dynamique de l’occupation a montré que les aires de culture maraichère ont évolué de 1993 à 2013 de 7,16% à 8,74% et de 14,60% en 2023. Ces résultats ont montré l’augmentation des aires des cultures pluviales et maraichères aux détriments des steppes, des glacis et des plateaux. Ces transformations des formations naturelles en culture confirment la volonté des populations à la diversification de la production alimentaire particulièrement ces dernières années pour la production de l’oignon. In Niger and other Sahelian countries, food insecurity is the result of climate deterioration caused by land degradation and exponential population growth. The resilience of the population has led to the cultivation of low-lying land for vegetable production. The objective of this study was to conduct a diachronic study of the landscape of the commune of Doguéraoua, located in the Maggia Valley, for the period from 1993 to 2023, in order to determine the dynamics of land use and the expansion of vegetable cultivation. Landsat images were downloaded to produce land use maps using ESRI's ArcGIS 10.8 software. Analysis of the transition matrices generated made it possible to determine the total area (78,217 ha, or 100%). Analysis of land use dynamics showed that market gardening areas increased from 7.16% to 8.74% between 1993 and 2013, and to 14.60% in 2023. These results show an increase in the area of rain-fed and market gardening crops at the expense of steppes, glacis, and plateaus. These transformations of natural formations into cultivated land confirm the population's desire to diversify food production, particularly in recent years for onion production.
The tobacco cyst nematode, Globodera tabacum, is considered a serious and important pest of shade and broadleaf tobacco. In our study we provide phylogenetic analyses of 51 COI and 66 ITS rRNA gene sequences of G. tabacum populations from different geographical areas using statistical parsimony. These sequences included 17 new COI and 34 new ITS rRNA gene sequences obtained from 19 samples from the USA, France, Spain and Italy. Statistical parsimony COI gene sequence network confirmed that G. tabacum is a polytypic species consisting of four subspecies rather than three as previously reported. The four subspecies include the three known subspecies: G. tabacum tabacum, G. t. virginiae and G. t. solanacearum and a new subspecies, G. tabacum argentinensis subsp. n. Maximal intraspecific COI gene sequence diversity for G. tabacum was 14.1%. If COI gene sequences clearly differentiated subspecies showing large genetic distance between them, the statistical parsimony analysis of the ITS rRNA gene sequences differentiate four subspecies based on a few nucleotides only. Moreover, this discrimination could be compromised by the presence of recombinant ITS rRNA gene sequences due to subspecies hybridisation. The new subspecies, G. t. argentinensis subsp. n., presently found in Argentina and Italy, is proposed and morphologically described.
Cette recherche examine les différences morpho-zootechniques entre les moutons Kababich du désert soudanais et les moutons Balami du Sahel nigérien en fonction de l'âge. L'objectif est de déterminer leur complémentarité génétique pour améliorer la production de viande ovine de façon durable au Niger. Au total 22 caractéristiques morphologiques ont été mesurées chez 419 animaux, dont 217 moutons Kababich et 202 moutons Balami, répartis en trois groupes d'âge (18, 24 et 30 à 36 mois). Les résultats montrent une influence significative de l’âge et de la race sur la majorité des caractères étudiés. Aux âges de 18 et 24 mois, les moutons Balami présentent des mensurations corporelles supérieures, traduisant une croissance précoce et un fort potentiel boucher. À l’inverse, les moutons Kababich se distinguent par le développement marqué des caractères caudaux en fin de croissance (30-36 mois), reflétant une meilleure capacité d’adaptation aux milieux arides. Cette différenciation met en évidence une forte complémentarité morpho-fonctionnelle, suggérant que des programmes de croisement contrôlés Kababich x Balami pourraient améliorer durablement la productivité ovine et les revenus des éleveurs nigériens. Mots-clés: mouton Kababich, mouton Balami, morpho-zootechniques, productivité ovine, Niger
Flooding is a dominant constraint to rice production in lowland and floodplain ecosystems, where stress intensity, timing, and duration vary widely across agroecological zones. This review synthesizes current knowledge on flooding typologies affecting rice, including anaerobic germination failure, flash flooding, stagnant flooding, and deep-water submergence, and critically examines how rice plants respond at physiological, anatomical, and molecular levels. We integrate evidence on key adaptive mechanisms, including anaerobic metabolism during germination, SUB1-mediated quiescence under short-term submergence, SNORKEL-driven internode elongation in deep-water environments, aerenchyma development, leaf gas films, and antioxidant defense systems. Particular emphasis is placed on the genetic architecture underpinning these responses, highlighting the successes and limitations of the SUB1 locus and the necessity of multitrait pyramiding to address prolonged, deep, or sequential flooding events. Drawing on case studies from Africa and Asia, the review demonstrates that flooding impacts are strongly context-specific, shaped by rainfall variability, hydrology, soil properties, and water management infrastructure, with disproportionate socioeconomic consequences for smallholder farmers. We argue that reliance on single-gene solutions is insufficient under climate change scenarios that intensify flood unpredictability. Instead, resilient rice systems require an integrated strategy combining stress-tolerant varieties, adaptive crop and nutrient management, and climate-informed decision-making. By consolidating physiological insights, breeding advances, and regional flood dynamics, this review provides a targeted framework for developing rice varieties and management options tailored to diverse flooding regimes, with direct implications for food security in flood-prone regions.
