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There’s a wave of groundwork being laid — genomic, cultural, and geospatial — for opportunity crops, but the governance, disease-pressure, market and environmental constraints that marginalized them in the first place are still very much active, and in some cases actively winning.
- Constraints on crop diversification under drought: Multi-scale evidence from California’s San Joaquin Valley. Consolidation, land tenure and water access limits farmers’ ability to switch crops.
- Fragmented urban food governance and impacts on the marginalisation of indigenous crops in Ghana. City plans sideline indigenous crops, and communities pay the price.
- Full Genome Characterization of the Causal Virus of Yellow Mosaic Disease in Mungbean Minicore Accessions. Technical barriers block the path from potential to harvest.
- Capsicum pubescens Ruiz & Pav.: evolutionary history, domestication, genetic resources and future opportunities for an overlooked Andean crop. Genomic evidence reveals substantial diversity in this overlooked Andean pepper but also major conservation gaps, particularly in Bolivia, highlighting opportunities for both crop improvement and biocultural conservation.
- Bitter vetch (Vicia ervilia (L.) Willd.): current research advances and future perspectives for a neglected legume crop. It was dropped because of anti-nutritional quirks, but should, and could, return for marginal lands.
- Genetic characterization of a global collection of common buckwheat to harness genetic resources for agricultural diversity. Hidden diversity is still out there.
- Genotype-by-sequencing of global hyacinth bean (Lablab purpureus) collections provides genomic resources for crop conservation and improvement. Diversity survives in farmer fields and genebanks.
- Wild Edible Greens Heritage in Western Crete and Its Resilience Across Greek Islands: The Role of Small-Scale Farming, Biodiversity, and Isolation. Small-scale farming sustains knowledge of wild edible greens across Greek islands, showing that opportunity crops depend on living farming cultures.
- African Crop Calendar: A geo-referenced dataset of crop growing seasons across diverse agro-ecological regions. Where (or should that be when) alternative crops might fit within agricultural systems.
Brainfood: Tree conservation from assisted migration to cryo
- 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.
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.
Conserving the tangle of grapevines
I think we may have already pointed to Conservation gap analysis for wild grapevines (Vitis L.) of the Americas, the latest in a series of papers by our friend Colin Khoury and a rotating assortment of colleagues on the conservation status of the crop wild relatives of the Americas, genepool by genepool. The authors compiled occurrence records for 38 wild American grapevine taxa, and used fancy GIS to infer the overall distribution and environmental niche of each. They then assessed the degree of representation of each taxon in genebanks and protected areas, and hence any remaining conservation gaps. Here’s the headline finding:
We categorize 25 of 38 of the taxa as urgent priority and 10 as high priority for improving ex situ conservation representation. Three taxa are assessed as urgent and 29 as high priority for enhancing in situ conservation. Further action, with emphasis on conservation gap hotspots, is needed to more comprehensively conserve wild Vitis native to the Americas.
Which is pretty clear.
Or is it?
What if “taxa” are perhaps not always the best units of conservation to use in assessing conservation efforts?
That may in fact be one of the implications of a paper that came out just a few weeks after that of Colin and friends: The dynamics of introgression and parallel adaptation across North American Vitis species.
These authors show that introgression and hybridization are pervasive and evolutionarily important across North American Vitis, based on genomic analysis of 639 accessions representing 48 species. About 14% of the average genome shows evidence of introgression, particularly associated with areas where species come into contact. Some taxa usually regarded as hybrid species are in fact better understood as ever-changing hybrid swarms, rather than distinct evolutionary lineages. Most importantly, the authors find that introgressed genetic variants have repeatedly contributed to adaptation in different species. The paper therefore portrays Vitis diversity as a reticulate network — or tangle — of species, populations and gene flow, rather than a set of discrete species.
This has important implications for conservation: hybrid zones and admixed populations may be really significant reservoirs of adaptive diversity. The framework of the first paper might potentially underestimate the conservation importance of regions where these occur, if they contain substantial genetic variation but aren’t well represented by the taxonomic units used in the gap analysis. For example, it might happen that two neighbouring species are reasonably well represented ex situ, but not from the specific regions where they hybridize and introgression occurs.
This suggests a useful next, synthetic step: take the geographic gaps from the first paper and overlay them with the evidence for introgression and gene flow networks from the second. The resulting map could identify not just under-collected species, but under-collected (or under-conserved in situ) evolutionary processes and genetic mixtures. That could be valuable for designing the next Vitis collecting mission.
The accessions in Spain fall mainly everywhere
My ex-colleagues at the Crop Trust have a very nice animation on the Genesys blog-type thing showing the progress of landrace collecting around the world over the past 125 years.
Do please read the post for the details of how it was done, and some observations on the results.
Here I just wanted to highlight something that has always intrigued me: how did Spain get so heavily collected? It’s really striking how in any global map of collecting localities, Spain looks like a solid carpet, with genebank accessions from practically every nook and cranny. More so than most neighbouring countries, I would say.
Well, it’s a little difficult to be sure because there’s no slider on the animation to take it backwards and forwards at will, but it looks like a burst of collecting first in the 40s, and then some filling in of gaps in the 80s, are responsible for the blanket coverage.
Maybe someone more familiar with the history of germplasm collecting in Spain can explain more.