- Ancient farmers didn’t have to wait for the genetic diversity that made domestication possible. They selected from variation already present in wild plants, including the ancestors of rice and maize. Domestication was as much about spotting (or happening upon) useful differences as creating new ones.
- English colonists in America called Indigenous dogs “wolves,” revealing as much about colonial perceptions as about the animals themselves. This history of Indigenous dogs shows how unfamiliar animals were classified through peculiarly European ideas about wildness.
- Austria is bringing forgotten apple varieties back to life. Saving old varieties in genebanks is one thing: getting people to grow, sell and eat them is another, but it can be done. Or at least tried.
- Jordan’s olive-oil heritage centres on traditional varieties such as Nabali and ancient Rumi trees, but most production is consumed locally, leaving exports limited and making provenance, cultivar and harvest date important indicators for buyers. Compare and contrast with Austrian apples.
- Small island developing states have distinctive food cultures and ingredients, but face particular challenges in building sustainable and resilient food systems. FAO’s A Taste of SIDS explores the connections between island food, biodiversity and culinary heritage. Nice to see diversity within crops considered, though a few local variety names would have been nice.
The gourd, the bred and the citrus
Jeremy’s latest newsletter includes a link to a piece on the domestication of cucurbits1 that reminded him of a classic of evolutionary biology and reminded me that I meant to link to The Botanist in the Kitchen’s own autumnal foray into Halloween pumpkins et al. It also alerted me to what promises to be a phenomenal eight-part exploration of citrus diversity in Sicily by Erik Grouger.
Give farmers room to grow
Farmers conserve and improve the crop diversity around them. They have been doing it for millennia. Their livelihoods depend on it. But how much more might they be able to do?
Consider the coconut. Farmers know which palms have characteristics they value, but with ordinary open pollination they can choose the mother but not the father of future coconuts. A recent paper proposes relatively simple techniques that would allow farmers to control pollination and thus choose both parents and produce more predictable seednuts. It won’t turn them into breeders, but it could help them produce — and maybe even sell — better planting material.
Tamarind presents a different version of the same problem. Much of the African crop still comes from scattered, semi-wild trees. Harvesters know which trees are best, but turning a particularly good tree into a reliable source of planting material is hard. Seedlings don’t necessarily reproduce the parent’s characteristics, and tamarind takes years to mature. Grafting and other forms of vegetative propagation exist, but have not been widely adopted, according to a recent review.
There’s a nice example from southern Africa that gives a glimpse of what might be. Researchers are identifying exceptionally productive wild fruit trees in the miombo woodlands and cloning them through grafting and air-layering. A tree that might otherwise take around a dozen years to fruit can produce within four or five when propagated this way.
But it doesn’t have to be a researcher doing that. A farmer or harvester who knows a particularly productive tree, or one with especially good fruit, could propagate it through cloning rather than relying on whatever seedlings happen to arise.
Coconut and tamarind aren’t the same, and neither are the technologies needed. But the principle is similar. We sometimes fall into the error of thinking that conserving and improving crop diversity are things done for farmers, whether in a genebank, a breeding programme or a research station. But they already do these things. Sometimes they just need a little room to try doing them a little bit differently.
Nibbles: Bacon kitchen garden, Bison diversity, African herbaria, Mycorrhiza, China wild rice genebank, African seed laws
- Sir Nathaniel Bacon’s painting records the arrival of American crops in early modern England. And the cookmaid gets equal billing.
- North America’s bison survived near-extinction, but how much of its genetic diversity is left? Past and present DNA is helping reconstruct what was lost, with implications for how what remains is conserved and managed.
- China’s wild rice collection in Hainan now holds more than 15,000 samples. A genetic treasure trove, but its value ultimately depends on what breeders can make of it. Much like what’s left of bison diversity.
- Mycorrhizal fungi form vast underground networks that support plant life and store carbon. A new global map begins to show their extent, and just how much of this biodiversity remains overlooked.
- Africa’s herbaria hold centuries of botanical history, much of it still effectively invisible. Specimens can reveal shifting plant distributions and overlooked species. First, though, someone has to do the painstaking work of getting the data online.
- Africa has done painstaking work on seed laws, but getting good seed to farmers remains hard in practice. The gap between policy and delivery is stark, and commercial companies need to work alongside farmer-managed seed systems, not pretend they don’t exist.
The apples of our eye
Apples have been another recurring obsession on the blog, maybe because they make the conservation problem unusually tangible, and immediate. Pretty much everyone thinks they know what an apple is, but the diversity hidden behind that word is enormous, and not much visible in supermarkets. A lot of it may have disappeared, but you can pretty much guarantee a slew of heritage apple stories in the press come autumn (and so it begins), so I guess people care. Here’s a selection of posts about apples spanning 15 years. There’s a lot more out there in the archive for you to explore.
Let’s start at the beginning, or as close to it as the genetics can get us. In 2016’s The Adam and Eve of apples?, I discussed the wild apple forests of southeastern Kazakhstan, where all of the world’s apple varieties can be traced back to an ancestral population of Malus sieversii — spread, if you believe the more colourful tellings, by bears eating the sweetest fruit and pooping the seeds around the forest. As usual, though, the genetics turned out to be more interesting than the headline. The cultivated apple isn’t a simple straight line from one mother tree; it’s the product of a long history of movement, hybridization and exchange between wild and domesticated populations all along the old trade routes out of Central Asia.
But those forests are in danger. Back in 2009, in Wild fruit relatives threatened in Central Asia, I looked at how the wild relatives of apples and other crops were vanishing along with their habitat. Among them was Malus niedzwetzkyana, the remarkable red-fleshed apple of Kyrgyzstan. These aren’t just obscure wild trees: they represented genetic diversity that has already made its way into cultivated apples, and might still have something to offer breeders. That red-fleshed apple came back a year later in Not the world’s first red apple. A new red-fleshed variety was being breathlessly presented in the press as a novelty — not GM, just 15 years of patient crossing and 20,000 rejected seedlings — but nature had got there first. M. niedzwetzkyana has been doing red flesh for millennia.
The cultivated stock has its own story of loss. In 2009’s Saving an apple a day, I looked at the loss of American apple varieties, and at the people trying to rescue what remained. Thousands of named varieties had once been grown in the United States; only a fraction survived in orchards, collections and the memories of the people who knew what they tasted like. It was a nice illustration of a familiar conservation paradox: you can lose a lot of diversity without even noticing, because the supermarket keeps selling you apples.
However, that same year, a study added a wrinkle to the “thousands lost” narrative. In Lost apples found, Jeremy pushed back a little on the standard version of the story — the one where 6,800 of 7,100 named 19th-century American apple varieties are simply gone. A team from the University of Arizona and USDA had gone looking for ghosts among old apple trees on historic farmsteads in Arizona, Utah and New Mexico. Only 34 of the resulting genotypes matched a known variety. The other 110, spread across 160 trees, matched nothing on record. Some of those are probably unnamed seedlings that never had a name to lose in the first place. But some, surely, are the supposedly lost varieties everyone had given up on. Not extinct, just lurking.
Seven years on, the USDA apple folks came back with another version of the answer. In As American as apples, Gayle Volk summarized her and Adam Henk’s trawl through historic nursery catalogues, which turned up 891 named apple cultivars grown in the US before 1908. They went looking for the 150 that seemed to matter most. The payoff: 90% are still findable today, safely tucked away in genebanks, private collections or specialist nurseries. Only 51 high-priority cultivars remained unaccounted for in any collection. For now.
The lesson isn’t that genetic erosion doesn’t happen. It plainly does, and 30 fruit nurseries vanishing a year is not nothing. No, the lesson is that “extinct” is much harder to prove than “endangered,” and pomologists with their equivalent of a swab kit keep turning out to be more patient, and luckier, than we have any right to hope.
Conserving what’s left, of course, depends on people as much as on collections and gene sequencers. In 2014, I offered up Irish eyes smiling about apple conservation. The post was prompted by Michael Hennerty’s beautiful book on the Irish apple, but the real story was the people who had nurtured the 68 varieties documented in the book over the years. Conservation often depends on a motley collection of people keeping things alive long enough for some fancy institution to discover that they matter. A few years later, Jeremy went into much more detail on Irish apples on his podcast.
Institutions, though, can be just as precarious as the work of any orchard-keeper or amateur gardener. Across the Irish Sea, the story of the UK’s apple collection showed just how fragile even a major national genebank can be. The National Fruit Collection at Brogdale in Kent, with its hundreds of apple varieties, came under threat when its funding was thrown into doubt, prompting a succession of stories about sales, new management and relocations. Oh, and royalty. Anyway, the collection is fine, but the saga was a reminder that conservation is not just about keeping things alive. You have to keep them alive with enough institutional resilience that they can survive the next crisis.
Taken together, these posts highlight a sometimes overlooked aspect of safeguarding agrobiodiversity. Conservation is not just putting varieties safely into collections, nor, on the other hand, is it just protecting wild populations from destruction. Apples show that the two are connected — or should be. These are, in the jargon, complementary conservation strategies. The diversity in a genebank has a history outside it, and the diversity out in the wild and in farms may only have a future in a genebank. We really do need both, it’s not just mom and apple pie rhetoric.