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Chemistry-based tracing techniques are increasingly used for combating illegal timber trade, but they are currently limited by the small and fragmented reference datasets available. We introduce a model that integrates data from multiple tree genera while accounting for statistical differences between them. Our model accurately predicts the harvest location even when relevant data are unavailable in some areas, by leveraging data from other genera. Our approach could lower reference sampling costs and enable tracing in situations where new samples cannot be collected, such as during armed conflict. Chemistry-based techniques for identifying the harvest location of timber are becoming increasingly important for enforcing timber trade regulations. However, their application has been limited by the need for reference samples from all species across all areas of interest. We investigate whether combining reference data from multiple taxonomic groups can improve timber harvest location determination in regions where reference data is scarce by using the shared natural variability in isotopic composition across species. We extend the harvest location model of Mortier et al. to jointly model isotope ratios and trace element concentrations in wood from different genera. This is achieved by a new covariance function that accounts for shared patterns of spatial variation between genera. We evaluate our approach on 1020 tree samples from four economically important genera (Betula, Fagus, Pinus, Quercus) across 12 Eastern European countries. The multi-genus model substantially outperforms the single-genus model when little or no data for that genus is available in the focus area. When data from all genera are available across the study area, the multi-genus model achieves similar performance to the single-genus model. Our approach strengthens the applicability of timber tracing methods by enabling accurate predictions in areas where sample collection is not currently feasible due to political, logistical and/or security-related challenges, provided that pre-existing samples from other genera are available.
Fonio (Digitaria exilis (Kippist) Stapf) is an underutilized cereal whose genetic diversity is largely conserved through traditional seed systems managed by smallholder farmers in West Africa. Preserving this diversity is critical for climate adaptation, food security, and future crop improvement, yet empirical evidence on farmer-managed fonio landraces remains limited. This study characterizes farmer-saved fonio landraces and associated seed management practices in Northern Ghana, with emphasis on their role in on-farm conservation of crop genetic resources. Using a stratified random sampling approach, 110 fonio farmers were surveyed across Chereponi, Saboba, Gushegu, Tatale, and Zabzugu districts using structured questionnaires to document identified landraces, seed sources, duration of seed possession, trait preferences, and production practices. The results revealed that fonio cultivation is dominated by farmer-maintained landraces, with Yadema, Kpeintike, Ugabuja, Ipuja and Lipuima being the most cultivated. Most farmers (93
A new species of Buchnera L. is described, Buchnera hirsutorepens, from south-eastern Democratic Republic of the Congo, and central and eastern Zambia. Buchnera hirsutorepens is split from Buchnera prorepens Engl. Gilg, which is also redescribed here, its range now encompassing Angola and Western Zambia. These two species are unique in the genus Buchnera in their prostrate habit and axillary flowers. They can be separated from each other by differences in indumentum of the inflorescence and leaves, bract shape, pedicel length and relative length of the corolla tube to the calyx. A distribution map of georeferenced specimen localities of the two species is provided, along with information on their habitat and ecology, and an evaluation of their conservation status based on IUCN guidelines and criteria.
Trichoderma fungi support sustainable agriculture by suppressing plant diseases and improving crop performance. However, emerging pathogenicity of Trichoderma warrants further ecological and genetic characterization. Here we used machine learning to correlate genomic data from 37 Trichoderma strains with over 140 phenotypic traits, spanning metabolic versatility, biotic interactions, stress tolerance and reproductive strategies. We determined Trichoderma to be an ancient, genetically cohesive and physiologically diverse genus with spores capable of germination in water and dispersal via air and water droplets. Metabolic preferences indicate universal adaptation to mycoparasitism and to niches like arboreal microbial mats, alongside broader saprotrophic versatility. Our analyses are consistent with character displacement among close relatives and convergent evolution in distant lineages, with both processes shaping ecological plasticity and traits including dispersal modes, terrestrialization or endophytism. Our findings reveal that while some Trichoderma species show traits of biosafety concern, its vast ecophysiological diversity enables the development of safe, targeted bioeffectors.
BACKGROUND AND AIMS:Isoetales is a clade of lycopsids that evolved colossal arborescent forms during their Palaeozoic prime but today are represented solely by the small, herbaceous monogeneric Isoetes. Despite the differences in scale of taxa in the clade, the rooting system of all members consists of two parts; rootlets develop from a rhizomorph in a regular pattern termed rhizotaxy. Rhizomorphs are highly diverse in morphology, leading to different terms being used to describe aspects of rhizotaxy in contrasting lineages. Here we set out to investigate the degree to which rhizotaxy was conserved among taxa, aiming to provide a standard geometric definition and developmental interpretation of rhizotaxy. METHODS:We developed a pipeline to quantitatively describe rhizotaxy. This pipeline allowed rootlet arrangement to be captured in 3D, before being visualized on a 2D lattice to which Delaunay triangulation could be applied. This approach offers a standard quantitative method of comparing rhizotaxy across disparate rhizomorphs. Next, to investigate the evolution and development of rhizotaxy we applied our pipeline to 3D reconstructions we generated of the rooting system of the extinct Carboniferous lycopsid, Oxroadia. Finally, we made direct observations of rootlet development in Isoetes using time-course imaging. KEY RESULTS:We demonstrate that rhizotaxy can be described as an equilateral triangular lattice for all members of the Isoetales, including Oxroadia. By combining evidence from direct observation of rootlet development in Isoetes with inferences of rootlet development and the early stages of sporophyte ontogeny of Oxroadia, we conclude that the conserved rhizotaxy developed through the process of rootlet intercalation. CONCLUSIONS:We provide a single geometric definition and predicted developmental mechanism for rhizotaxy that applies to all Isoetales. Our findings call into question the literal interpretation that the rhizomorph is a modified shoot.
