- Graph-based pan-genome reveals structural variations associated with agronomic traits in mung bean. Pan-genome captures extensive structural variation missed by a single reference genome, providing new targets for mung bean improvement.
- Wild genes to the rescue: high-throughput genomics reveals the wild source of broomrape resistance in sunflower. Combining high-throughput root phenotyping with genomics identifies wild introgressions underlying broomrape resistance in sunflower and exposes valuable adaptive variation for breeding.
- Genomic insights into the local adaptation of spontaneous olive trees in the Mediterranean Basin highlight the need for conservation planning in the face of global change. Genomics of wild West Mediterranean olive trees reveals patterns of local adaptation across temperature and rainfall gradients that it will be important to conserve as climates change.
- Genetic regulation of major immunogenic protein accumulation in peanut seeds. Genomics provides targets for breeding peanuts with reduced allergenicity.
- Genomic elucidation of hybridization between Liberica and excelsa coffee and its implications for coffee crop development. Genomics confirms that Liberica and excelsa coffee readily hybridize and produce fertile, genetically diverse offspring with intermediate agronomic traits, a possible source of diversity to broaden coffee’s climate resilience.
- Simple sequence repeat (SSR) marker-based genetic diversity and population structure of large-leaf tea germplasm across four major tea-producing regions of Yunnan, China. Genomics of Yunnan’s large-leaf tea germplasm finds substantial genetic diversity but remarkably little regional differentiation, showing that seed propagation, natural crossing and human movement have maintained genetic connectivity across tea-growing regions.
- Measuring maternal line selection driven by differential survival in ex situ collections for plant conservation. A new method distinguishes random mortality from selection among maternal lines in ex situ collections, offering conservationists a way to detect whether plant deaths are systematically eroding the genetic variation they are trying to preserve. And no genomics involved.
The fruits of migration
As chance would have it, following my recent speculative foray into the possible connection between language and crop diversity, an essay by the great Andrea Wulf 1 has just appeared that tells the story of how a remarkable German naturalist used breadfruit and linguistics to work out Polynesian migration patterns long before DNA or archaeology could confirm them.
George Forster sailed with his father aboard the HMS Resolution on Cook’s second voyage (1772-1775) and encountered breadfruit across the South Pacific. He noticed that the trees were seedless and could only be propagated by root cuttings. And also that there didn’t seem to be wild breadfruit trees anywhere in the islands. That meant every tree he saw, and there were many of them, had been deliberately planted by people.
Digging through the university library back in Göttingen, Forster later found that wild, seeded breadfruit with little flesh do exist, but in Southeast Asia. If the Pacific islands only had the improved, seedless types, he reasoned, they must have been carried there by people. That was proof both of sophisticated Polynesian plant management and of a migration route running from Southeast Asia eastward across the Pacific.
Forster combined this with careful attention to language. He deduced that most Pacific languages he encountered were dialects of a single root language, with small, systematic sound shifts. He and his father also charted how the presence of Malay loanwords decreased the farther east an island was located, which suggested that islands closer to Southeast Asia — the home of Malay — were settled earlier.
Where his fellow naturalist Joseph Banks saw the breadfruit purely as an economic resource (later lobbying to transplant it to the West Indies to feed enslaved plantation workers, hence HMS Bounty and all that), Forster saw it as historical and ethnographic evidence. That’s a strikingly different, more humanistic and — to me at least — more appealing way of reading a plant.
Wulf then jumps forward to modern archaeology and genetics, which broadly confirm Forster’s reconstruction. There was an initial human population in the region of Papua New Guinea dating back 45,000 years. This was followed by a second, Austronesian-speaking wave migrating out of Taiwan and thereabouts around 3,500 years ago. They travelled by the stars in “outrigger or double-hulled canoes loaded with hogs, chickens, root vegetables, coconuts, bananas, and breadfruit seedlings.” And they mixed with the descendants of the earlier wave through Melanesia. Their own descendants eventually reached Fiji, Samoa, Tonga, and, much later, Tahiti, Hawaii, Easter Island and New Zealand.
The essay closes by tying this to Tongan historian Epeli Hau’ofa’s idea of “Oceania” — the Pacific not as scattered, isolated islands, lost in a vast ocean, but as one interconnected “sea of islands.” Exactly what Forster intuited two centuries before it became conventional wisdom.
We’ve blogged a lot about breadfruit over the years. Check out the archive. And in particular listen to the recently-retired Dr Diane Ragone describe her 40-year journey to understand this remarkable tree.
Fresh out of diversity
“Blueberries are a great example of agriculture as high-tech industry,” argues Daniel Hulls, the boss of AgDevCo, an investment fund. Driscoll’s, an American agribusiness giant, supplies seeds to farmers in Zimbabwe that are the result of years of cross-pollination. Polyethylene covers protect bushes. Storage rooms have optical sorting machines. To maximise profits, firms time production for the summer, after American supply dwindles but before Peru’s picks up.
According to a recent article in The Economist, quoted above, blueberries are just one of an increasing number of examples of Africa’s “industrialisation of fresh,” a concept developed by Christopher Cramer at SOAS with colleagues John Sender and Jonathan Di John. The article suggests that, if it is implemented properly, “there is huge potential for African agriculture to play the sort of role long envisioned for manufacturing.”
It’s a striking phrase. “Fresh” sounds like the very opposite of industrial. Fresh food is perishable, seasonal and associated with local production. Yet, increasingly, fresh fruit and vegetables are being made to behave like industrial commodities. Agribusiness is using breeding, controlled production, refrigeration, packaging, logistics and retail systems to make perishable foods standardized, predictable and available almost anywhere, anytime.
Think of a supermarket apple. It needs to look right, travel well, resist bruising, ripen predictably and remain edible in storage for months. The tomato needs to survive harvesting, packing and a long journey without losing its appearance. The strawberry needs a shelf life that would have seemed miraculous a generation ago. “Fresh” has become something that can be engineered.
There are obvious benefits. Longer shelf lives can reduce waste, extend markets and make nutritious foods available far beyond their traditional growing seasons. Even foods based on so-called neglected and underutilized species — making them truly “opportunity crops.” That could be good for agrobiodiversity.
But there is a less visible consequence that is not so good: the characteristics that make a crop useful to an industrial fresh-food system can also narrow the range of diversity that gets grown.
Industrialized fresh-produce chains tend to reward uniformity. Grading standards, packing-line specifications, and retailer contracts all push toward a narrow set of varieties that perform consistently — the right size, the right shelf life, the right appearance under fluorescent light. That’s efficient for the production process Cramer et al. and The Economist extol, but it’s also potentially a quiet mechanism of genetic erosion: the traits that make a variety a good fit for industrial handling are not necessarily the traits that make it resilient, nutritious, or adapted to marginal land. A diverse production landscape can narrow disastrously once it’s plugged into export-oriented industrial supply chains.
Uniformity is valuable. Predictability is valuable. Long shelf life is valuable. But genetic diversity is valuable too. And not always for the same reasons.
Genebanks maintain thousands of crop varieties that may not meet the specifications of industrial supply chains. At least now. Some may have unusual flavours or colours; others may be poorly suited to long-distance transport. But they may also contain genes for disease resistance, heat tolerance, drought adaptation, nutritional quality, novel textures or other traits that could become valuable as production conditions and consumer preferences change.
The paradox — or is it the conundrum — is that the more successfully we industrialize “fresh”, the more important it will become to conserve the diversity that industrial systems tend to leave behind.
The fresh food in the supermarket may look reassuringly abundant. The genetic diversity behind it is another matter. The Economist could have pointed out that the industrialisation of fresh selects for what works now. For the system to be sustainable, you need genebanks to preserve what might work next.
Nibbles: Festivals, Wheat breeding, Cowpea, Community seed bank, Mint diversity
- Festivals, rituals and seed-saving go hand in hand, as this photo essay on Koraput’s Adivasis shows for World Indigenous Peoples Day.
- Speaking of unlikely alliances, Israeli and Palestinian researchers have teamed up on wheat that can take the heat in a warming, drying Middle East.
- Not to be outdone in the resilience stakes, the cowpea shrugs off both drought and flooding, according to FAO.
- If all this talk of resilient crops has you inspired, here’s a how-to on starting your own community seed bank, in South Africa or anywhere else for that matter.
- And for when preservation is really about nostalgia: Romania’s Buzau genebank is keeping childhood mint flavours alive, chocolate, clove and vanilla notes included.
Brainfood: Avocado history, Brazil commuity seedbanks, Citizen science, Agroecology double, Indigenous knowledge, Turkish seeds, Swiss biodiversity
- Ethnobotanical and genetic assessments of Central American avocado landraces reveal novel sources of biodiversity and ancient migration patterns. DNA from landraces, and interviews with farmers, show that people transported and cultivated avocados across the Americas long before European contact, with landraces from lowland Nicaragua and Honduras in particular showing evidence of ancient migration from South America.
- The Circle of Seeds: An Ethnography of Seed Guardianship and the Making of Agroecological Futures in Paraná, Brazil. Community seed banks depend on relationships of care, reciprocity and collective labour, especially among women farmers, and not just on knowing how to store seeds properly. Though that helps, clearly.
- iNaturalist as a Tool to Improve Agroecological Biodiversity Knowledge: An Ecuadorian Case Study. A citizen science platform can strengthen agroecological biodiversity knowledge, but more efforts are needed to engage farmers.
- Are agroecological practices pro-poor? Evidence from smallholder farms in Zimbabwe. Farmers using agroecological practices were generally wealthier and their farms were more diverse in crop and livestock species, but the association between the use of improved practices and diet outcomes was inconsistent.
- Regenerative agriculture for dietary diversity and food security in Zambia. Agroecological practices were positively correlated with improved dietary quality and food security, including (though not exclusively) through farm production diversity. No word on the wealth of the farmers involved.
- Indigenous Peoples’ knowledge systems and practices for climate survival. Indigenous knowledge systems, including of farmers, offer tested approaches to climate adaptation and resilience that warrant a central place in responses to environmental change.
- Guardians of Agricultural Biodiversity: Farmer Perceptions and Sustainability of Local Seed Varieties in Turkish Highlands. Farmers continue to maintain local seed varieties, driven as much by social, cultural and market considerations as by agronomic performance. But they need support.
- Religion, spirituality and faith of Swiss farmers in relation to biodiversity-linked farming behaviour. Farmers’ religious and spiritual values can shape biodiversity-friendly management decisions, showing personal belief systems are important in conservation. Even in Switzerland.