Understanding the genetic diversity and evolutionary history of plant pathogens is crucial for effective disease management strategies. Sunflower downy mildew, caused by the oomycete Plasmopara halstedii , is a worldwide threat to the sunflower oil crop. We aimed to explain through phylogenomic studies how downy mildew resistance breakdown occurred recurrently in the last decades in France, leading to new virulence profiles. W...

Aim Studies assessing large‐scale patterns of microbial diversity have predominantly focused on free‐living microorganisms, often failing to link observed patterns to established theories regarding the maintenance of global diversity patterns. We aimed to determine whether foliar fungi on two closely related grass hosts— Heteropogon contortus and Themeda triandra —display a commonly observed latitudinal gradient in species ric...

There is growing evidence that the Earth's climate is undergoing profound changes that are affecting biodiversity worldwide. This gives rise to the pressing need to develop robust predictions on how species will respond in order to inform conservation strategies and allow managers to adapt mitigation measures accordingly. While predictions have begun to emerge on how species at the extremes of the so‐called slow‐fast continuum...

Understanding landscape changes is central to predicting evolutionary trajectories and defining conservation practices. While human‐driven deforestation is intense throughout Madagascar, exceptions in areas such as the Loky‐Manambato region (north) raise questions regarding the causes and age of forest fragmentation. The Loky‐Manambato region also harbours a rich and endemic flora, whose evolutionary origin remains poorly unde...

C 4 photosynthesis is a complex trait that boosts productivity in warm environments. Paradoxically, it evolved independently in numerous plant lineages, despite requiring specialised leaf anatomy. The anatomical modifications underlying C 4 evolution have previously been evaluated through interspecific comparisons, which capture numerous changes besides those needed for C 4 functionality. Here, we quantify the anatomical chang...

Aim Grasses (Poaceae) are found in all major habitats of Madagascar and have a particular importance in C 4 grasslands, whose origins are controversial. We aimed to estimate the number, age and origins of endemic grass lineages in the Madagascar region, and to compare the diversification of C 3 and C 4 taxa. Location Madagascar and the surrounding Indian Ocean islands, integrated within a global dataset. Methods We estimated 1...

Aim Successful colonization after long‐distance dispersal ( LDD ) depends on the availability of suitable habitats and competitive ability. In this study, we address the hypothesis that two widely distributed sister grass lineages (broad‐ and fine‐leaved Loliinae; hereafter BL and FL ) that differ in their habitat requirements and competitive ability also differ in their biogeographic history, with particular reference to LDD...

Understanding the evolutionary mechanisms generating parallel genomic divergence patterns among replicate ecotype pairs remains an important challenge in speciation research. We investigated the genomic divergence between the anadromous parasitic river lamprey (Lampetra fluviatilis) and the freshwater‐resident nonparasitic brook lamprey ( Lampetra planeri ) in nine population pairs displaying variable levels of geographic conn...

Physiological novelties are often studied at macro‐evolutionary scales such that their micro‐evolutionary origins remain poorly understood. Here, we test the hypothesis that key components of a complex trait can evolve in isolation and later be combined by gene flow. We use C 4 photosynthesis as a study system, a derived physiology that increases plant productivity in warm, dry conditions. The grass Alloteropsis semialata incl...

Aim Greater understanding of the processes underlying biological invasions is required to determine and predict invasion risk. Two subspecies of olive ( Olea europaea subsp. europaea and Olea europaea subsp. cuspidata ) have been introduced into Australia from the Mediterranean Basin and southern Africa during the 19th century. Our aim was to determine to what extent the native environmental niches of these two olive subspecie...

Adaptation to changing environments often requires novel traits, but how such traits directly affect the ecological niche remains poorly understood. Multiple plant lineages have evolved C 4 photosynthesis, a combination of anatomical and biochemical novelties predicted to increase productivity in warm and arid conditions. Here, we infer the dispersal history across geographical and environmental space in the only known species...