- The potential effect of megafaunal extinctions on modern conservation of horse chestnut Aesculus hippocastanum. The extinction of large seed-dispersing mammals (i.e. elephants) may explain why horse chestnut failed to recolonise Europe after the last ice age, pointing to assisted migration as a conservation option.
- Mapping melliferous tree species in Kenya via one-class classification with hyperspectral unsupervised domain adaptation. Hyperspectral remote imagery and fancy maths can accurately identify and locate Kenya’s honey trees, potentially supporting both conservation and beekeeping. Brave new world. Elephants not involved.
- Everyday agroecologies in the Mixteca Alta, Mexico: gendered knowledge and practices in homegarden agroecosystem management. Women’s knowledge helps sustain homegardens as reservoirs of agrobiodiversity and climate-adaptation spaces, embedding many interesting wild and cultivated trees, along with much else, in wider systems of knowledge and resource management.
- Integrative DNA barcoding and multimethod species delimitation reveal marker performance in the genus Ficus L. (Moraceae). Takes on the old taxonomic problem of where one fig species ends and another begins. Ficus is an especially resonant group for today’s tree-themed roundup: taxonomically challenging, ecologically consequential, economically and culturally important, tied to famously specialised pollination relationships. “Integrative” means the usefulness of a DNA marker must be tested against other evidence and against the particular boundaries one is trying to recognise.
- Chloroplast phylogeographic analysis guides the source tracing and conservation strategies of the endangered Magnolia kwangsiensis Moving down one biodiversity level, mapping maternal genetic structure helps identify appropriate seed sources for conservation and restoration, rather than treating all populations as genetically equivalent. Next comes feeding the seeds to passing elephants.
- Development of a simple and easily interpretable cultivar identification system using 18 insertion/deletion (InDel) markers in Japanese pummelo (Citrus maxima). Really simple markers can identify Japanese pummelo cultivars, and even reveal clues about their parentage.
- К 100-летию отдела генетических ресурсов плодовых культур ВИР. (On the 100th Anniversary of the Fruit Crop Genetic Resources Department of VIR). A century-long institutional case study in tree (ok, and shrub) conservation at scale: some 19,000 fruit, nut and berry accessions now held in field genebanks across ten Russian field stations, each sited in the climate zone that suits what it conserves.
- Cryopreservation strategies for trees: Leveraging organogenesis and somatic embryogenesis for effective conservation. Combining ultra-low-temperature storage with making shoots or roots from an explant tissue and making embryo-like structures from non-reproductive cells offers ways to emulate seeds when the real things cannot be easily stored in the usual way, field genebanks cannot be guaranteed to last 100 years, and there are no elephants around.
The plants that statistics forgot
FAO has just put out new guidance on capturing wild foods and neglected and underutilized species (NUS) in dietary surveys. It’s very much worth a look, even if your interest runs more to grain landraces on the farm than to greens gathered from the forest. The methodology is built to overcome a very real problem: standard dietary assessment tools are generally designed with the main staples in mind, so anything outside that narrow frame (think foraged, seasonal, localized, thinly documented) tends to fall straight through the cracks.
FAO’s fix is a set of very sensible, practical steps: engage local knowledge holders to compile inventories under their own names for things, survey markets to see what’s actually being sold and eaten, map harvest calendars against agroecological zones and seasons, and build simple identification tools (photobooks, reference databases) that let enumerators and communities work from a shared understanding of what they’re counting.
None of that machinery is specific to wild foods though. The same toolkit could easily be adapted to survey the diversity hiding in plain sight on farms: crops and landraces known only by a few, grown in a handful of villages, marginalized, on their way to be forgotten. And invisible to national crop statistics that only track the main crops and the most common named improved varieties, if that. A market survey designed to catch wild greens sold at the roadside works just as well for catching a local bean landrace in the same market. A harvest calendar built to track when forest foods peak works just as well for tracking when fonio gets planted or harvested, and why farmers still bother with it. Great for quantifying the opportunity presented by “opportunity crops.”
And there’s a useful downstream application: surveys built this way could help flag where crop diversity is thinning out on the ground, or where it’s abundant but under-represented in genebank holdings. In other words, the kind of gap analysis that ought to be steering germplasm collecting missions.
FAO’s framing kind of gestures at this already: wild, managed and cultivated aren’t three separate boxes but points on a continuum. A methodology built to navigate that blurriness for wild foods is also a methodology that ought to work for navigating the blurriness at the cultivated end. It would be a shame if this toolkit stayed confined to the wild-food side of the spectrum when the conceptual heavy lifting behind it applies just as well to neglected cultivated diversity.
Crops made, and remade
Two new studies of very different crops – banana and chrysanthemum, of all things – end up telling surprisingly similar, deliciously complicated stories. For these crops, domestication was not once and done, so to speak. They were both repeatedly remade as people moved them through landscapes containing new wild diversity.
In the banana study, the authors suggest that a partly domesticated Musa acuminata lineage from New Guinea was carried westwards through Southeast Asia, encountering and hybridizing again and again with different local wild bananas along the way. Each encounter added new genetic material to an already changing crop, helping produce the genomic mosaics found in mainland Southeast Asian bananas today.
The chrysanthemum study reveals a strikingly parallel history: cultivated plants originating in China were introduced to Japan, where they encountered local wild populations and acquired new genetic diversity, before later movements to Europe and further breeding reshaped the crop again.
The papers also show that an essentially similar process played out somewhat differently in the two crops. In banana, repeated hybridization appears to have been important in the building of the crop itself, as domesticated or partly domesticated plants became the starting material for successive encounters with wild Musa. In chrysanthemum, genomic analysis reveals a more complex network of relationships among multiple wild and cultivated groups, with C. indicum among the important ancestral contributors. In this genetic cauldron, hybridization and introgression repeatedly diversified an established cultivated genepool, contributing to traits such as flower form, colour and plant architecture.
Taken together, these papers challenge the familiar “funnel,” or bottleneck, image of domestication: a one-way downward slide from diverse wild relative to genetically narrow crop. Instead, they point to a more stop-start, two-way, non-linear, geographically contingent process, in which (semi-)cultivated plants continue to encounter, absorb and be reshaped by wild diversity.
In both banana and chrysanthemum — and probably many other cases — wild relatives have been more active, continuous participants in creating the diversity of the crops we know today than we sometimes give them credit for. Or I have given them credit for at any rate.
That argues for treating the wild genepool not simply as a reservoir from which to fish out useful genes one at a time. The historical evidence suggests that crops have benefited in the past from repeatedly absorbing larger chunks of wild genetic diversity, allowing selection to reconstruct useful combinations. Might it be worth trying to make that happen again? Is anyone out there doing pre-breeding explicitly with an eye to the past?
Nibbles: Mango breeding, Cambodian peppers, Cold genes, Geechee cowpea, Navajo genebank
- Blue mangoes.
- Kampot pepper.
- Antarctic flowering plant.
- Sapelo Island red pea.
- Navajo seed data.
Brainfood: Biodiversity works through relationships
- Plant diversity modifies multi-trophic interactions in croplands, grasslands and forests. Increasing plant diversity changes the interactions between plants, herbivores and their natural enemies, but exactly how depends on the ecosystem. Diversification’s pest-suppression magic looks like a farming-specific trick, not a universal law.
- High-resolution carbon and biodiversity mapping shows correlated losses across space and agricultural products. Carbon loss and biodiversity loss from farming turn out to hit the same ground: two-thirds of both concentrated on one-third of agricultural land, with beef and milk alone responsible for 41% of the biodiversity damage. Good news for anyone hoping one policy lever could do double duty.
- Harnessing agri-food system microbiomes for sustainability and human health. Soil to gut, it’s all one network, linking ecosystem function, food production and human health across the entire agri-food system.
- Breeding for beneficial microbial associations. If microbiomes matter that much, why not breed for them? A proposed framework pairs crop traits that recruit good microbes (root exudates, architecture) with soil practices that keep those microbes around, since good genetics on ruined soil gets you nowhere. This means designing crops as participants in ecological networks rather than as isolated organisms.
- Host genetics and social relationships jointly shape fitness-associated microbiome variation in a population of feral horses. Nature’s own microbiome-breeding program: seven years of horse poop from Sable Island shows gut microbes predict winter survival, and related horses share microbes more than chance allows. So the functional unit of adaptation is the animal plus its microbiome.