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Clonal propagation enables favourable crop genotypes to be rapidly selected and multiplied. However, the absence of sexual propagation can lead to low genetic diversity and accumulation of deleterious mutations, which may eventually render crops less resilient to pathogens or environmental change. To better understand this trade‐off, we characterize the domestication and contemporary genetic diversity of Enset (Ensete ventricosum), an indigenous African relative of bananas (Musa) and a principal starch staple for 20 million Ethiopians. Wild enset reproduction occurs strictly by sexual outcrossing, but for cultivation, it is propagated clonally and associated with diversification and specialization into hundreds of named landraces. We applied tGBS sequencing to generate genome‐wide genotypes for 192 accessions from across enset's cultivated distribution, and surveyed 1340 farmers on enset agronomic traits. Overall, reduced heterozygosity in the domesticated lineage was consistent with a domestication bottleneck that retained 37% of wild diversity. However, an excess of putatively deleterious missense mutations at low frequency present as heterozygotes suggested an accumulation of mutational load in clonal domesticated lineages. Our evidence indicates that the major domesticated lineages initially arose through historic sexual recombination associated with a domestication bottleneck, followed by the amplification of favourable genotypes through an extended period of clonal propagation. Among domesticated lineages, we found a significant phylogenetic signal for multiple farmer‐identified food, nutrition and disease resistance traits and little evidence of contemporary recombination. The development of future‐climate adapted genotypes may require crop breeding, but outcrossing risks exposing deleterious alleles as homozygotes. This trade‐off may partly explain the ubiquity and persistence of clonal propagation over recent centuries of comparative climate stability. [ABSTRACT FROM AUTHOR]

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Understanding hybridization and introgression between natural plant populations can give important insights into the origins of cultivated species. Recent studies suggest differences in ploidy might not create such strong reproductive barriers as once thought, and thus studies into cultivated origins should examine all co‐occurring taxa, including those with contrasting ploidy levels. Here, we characterized hybridization between Chrysanthemum indicum L., Chrysanthemum vestitum (Hemsley) Ling and Chrysanthemum vestitum var. latifolium (Zhou & Chen), the most important wild species involved in the origins of cultivated chrysanthemums. We analyzed the population structure of 317 Chrysanthemum accessions based on 13 microsatellite markers and sequenced chloroplast trnL‐trnF for a subset of 103 Chrysanthemum accessions. We identified three distinct genetic clusters, corresponding to the three taxa. We detected 20 hybrids between species of different ploidy levels, of which 19 were between C. indicum (4x) and C. vestitum (6x) and one was between C. indicum and C. vestitum var. latifolium (6x). Fourteen hybrids between C. indicum and C. vestitum were from one of the five study sites. Chrysanthemum vestitum and C. vestitum var. latifolium share only one chloroplast haplotype. The substantially different number of hybrids between hybridizing species was likely due to different levels of reproductive isolation coupled with environmental selection against hybrids. In addition, human activities could play a role in the different patterns of hybridization among populations. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Digitized molecular data are vital to numerous aspects of scientific research and genetic resource use. The Convention on Biological Diversity currently refers to this as "Digital Sequence Information" (DSI), a term not widely adopted by science and lacking a clear definition. There are concerns over the access to genetic resources and absence of benefit sharing by provider countries. Open access to DSI might exacerbate this, which is leading to increasing policy interventions and restricted access to genetic resources and DSI. We analyze current international debate and proposed solutions and provide case studies of DSI use producing tangible benefits for the provider countries and scientific research, demonstrating the importance of open access DSI to achieving conservation goals. Summary: Substantial advances in DNA sequencing over the last decades hold great potential to enhance food security and sustainable use of global biodiversity, benefiting the world's poorest people. Digital Sequence Information (DSI) plays a crucial role in catalyzing research applications that can contribute to international societal and biodiversity conservation targets. However, benefit sharing relating to DSI is difficult to identify and hindered by the lack of clear international governance and legislation, which in turn has led to a reluctance to make DSI publicly and freely available. Critically, no precise definition exists under the Convention on Biological Diversity (CBD), the Nagoya Protocol (NP), or the International Treaty for Plant Genetic Resources for Food and Agriculture (ITPGRFA). The key difference between DSI and biological resources, for which access and use are highly regulated under those frameworks, is that information is nonphysical. Information can be replicated and used without movement of, or access to, physical specimens. Thus, regulating the use of DSI is extremely challenging and remains controversial. Here, we review the regulation of DSI and the possible future steps by the international community, in the context of the benefit‐sharing obligations of the CBD, NP, and ITPGRFA. We highlight how multilateral agreements work in practice and are a solution to this impasse. We provide case studies demonstrating how the Royal Botanic Gardens, Kew, and its collaborators address the uncertainty surrounding the use of DSI, illustrating tangible and equitable benefits that have arisen from such use. We conclude that open access to DSI is needed for scientific research and international policy. [ABSTRACT FROM AUTHOR]

When populations of a rare species are small, isolated and declining under climate change, some populations may become locally maladapted. Detecting this maladaptation may allow effective rapid conservation interventions, even if based on incomplete knowledge. Population maladaptation may be estimated by finding genome–environment associations (GEA) between allele frequencies and environmental variables across a local species range, and identifying populations whose allele frequencies do not fit with these trends. We can then design assisted gene flow strategies for maladapted populations, to adjust their allele frequencies, entailing lower levels of intervention than with undirected conservation action. Here, we investigate this strategy in Scottish populations of the montane plant dwarf birch (Betula nana). In genome‐wide restriction site‐associated single nucleotide polymorphism (SNP) data, we found 267 significant associations between SNP loci and environmental variables. We ranked populations by maladaptation estimated using allele frequency deviation from the general trends at these loci; this gave a different prioritization for conservation action than the Shapely Index, which seeks to preserve rare neutral variation. Populations estimated to be maladapted in their allele frequencies at loci associated with annual mean temperature were found to have reduced catkin production. Using an environmental niche modelling (ENM) approach, we found annual mean temperature (35%), and mean diurnal range (15%), to be important predictors of the dwarf birch distribution. Intriguingly, there was a significant correlation between the number of loci associated with each environmental variable in the GEA and the importance of that variable in the ENM. Together, these results suggest that the same environmental variables determine both adaptive genetic variation and species range in Scottish dwarf birch. We suggest an assisted gene flow strategy that aims to maximize the local adaptation of dwarf birch populations under climate change by matching allele frequencies to current and future environments. [ABSTRACT FROM AUTHOR]

Past reproductive interactions among incompletely isolated species may leave behind a trail of introgressed alleles, shedding light on historical range movements. Betula pubescens is a widespread native tetraploid tree species in Britain, occupying habitats intermediate to those of its native diploid relatives, B. pendula and B. nana. Genotyping 1134 trees from the three species at 12 microsatellite loci, we found evidence of introgression from both diploid species into B. pubescens, despite the ploidy difference. Surprisingly, introgression from B. nana, a dwarf species whose present range is highly restricted in northern, high-altitude peat bogs, was greater than introgression from B. pendula, which is morphologically similar to B. pubescens and has a substantially overlapping range. A cline of introgression from B. nana was found extending into B. pubescens populations far to the south of the current B. nana range. We suggest that this genetic pattern is a footprint of a historical decline and/or northwards shift in the range of B. nana populations due to climate warming in the Holocene. This is consistent with pollen records that show a broader, more southerly distribution of B. nana in the past. Ecological niche modelling predicts that B. nana is adapted to a larger range than it currently occupies, suggesting additional factors such as grazing and hybridization may have exacerbated its decline. We found very little introgression between B. nana and B. pendula, despite both being diploid, perhaps because their distributions in the past have rarely overlapped. Future conservation of B. nana may partly depend on minimization of hybridization with B. pubescens, and avoidance of planting B. pendula near B. nana populations. [ABSTRACT FROM AUTHOR]

Habitat fragmentation represents an unprecedented threat to global biodiversity. Understanding the range at which individuals and populations can become reproductively isolated is vital to ecosystem management and the maintenance of genetic diversity. Here, I demonstrate an improved rapid assessment protocol for empirically measuring the settling velocity of pollen. I find significant differences in pollen settling velocity between species, suggesting different dispersal distances and population structures. It is also found that Stokes' law is a reasonable theoretical predictor of pollen settling velocity in many cases. These findings predict that plant genetic connectivity is spatially localized, raisings concerns for highly fragmented populations. This method should provide a means of rapidly assessing species and populations at increased risk of erosion to genetic diversity. [ABSTRACT FROM AUTHOR]

Intensifying agriculture to spare land for nature could help meet competing food security and biodiversity conservation goals. However, this approach neglects and undervalues agrobiodiversity, currently maintained by millions of smallholder farmers. For intensification to be sustainable and land sparing to be achieved equitably, we must conserve high-agrobiodiversity landscapes., Competing Interests: Declaration of interests There are no interests to declare., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)