- WorldCuP: A database of checklists documenting the World’s Cultivated Plants and their distributions. Cool new database records 1,444,325 occurrences representing 91,358 accepted cultivated plant species across 2,718 regions in 156 countries. Geographic coverage is extensive but uneven, with notable gaps in parts of Africa, southwest and central Asia, and Oceania. Most of the taxa recorded are not in existing major crop and useful-plant databases.
- Integrating multiple disciplines to locate the origins of domestication of crops. Combining evidence from botany, biogeography, genetics, archaeology, linguistics, and history overturns the traditional Mesoamerican hypothesis for cacao origins, supporting domestication in western Amazonia, probably involving multiple events. Peach palm’s domestication is best placed in southwestern Amazonia. Cupuaçu remains unresolved. Now for the other 91,355 species.
- Plant Species Mentioned in Abrahamic Scriptures: Implications for Biodiversity and Traditional Agriculture and Horticulture. Olive, grapevine and fig, together with cereals such as wheat and barley, occur prominently across the three scriptural traditions examined, while date palm is particularly prominent in the Qur’an. Not clear whether scriptures qualify as checklists.
- Crop landrace conservation, status, challenges and motivations in Great Britain. A national inventory (checklist even) identifies 566 landrace populations maintained on farms by 197 growers, alongside 1,876 British-origin genebank accessions, representing a total of 1,201 distinct landraces. Cereal and vegetable landrace cultivation has gone up since 2004, but forage diversity is increasingly threatened. Climate change, labour shortages and lower yields are the main challenges reported by growers.
- An inventory, threat and conservation assessment of UK wheat landrace diversity. The UK currently has 27 wheat landrace varieties growing on more than 700 hectares, an increase in both variety numbers and cultivated area since 2009. Interviews with 50 farmers identify insufficient market demand and limited seed availability as key constraints. So, not climate change, labour shortages and lower yields.
- Strong differentiation between source and ex situ populations of rare plant species revealed by next-generation sequencing. Across four rare plant species, ex situ populations showed significant genetic differentiation from their wild sources despite only one generation in cultivation, while overall genetic diversity and inbreeding did not differ significantly. Unrepresentative seed collection, unconscious selection during propagation or genetic drift could explain the differences. Something to test on all those British landraces, labour permitting?
- Rethinking the vineyard of Santorini in a changing climate and preserving an historic wine region. Recommends a staged transition from vineyard recovery to ecological regeneration, prioritising soil organic matter, drought management and indigenous grapevine diversity. Sounds like lots of labour will be needed.
- Conservation dilemmas: Xylella fastidiosa and the future(s) of olive farming. In Puglia, disease management is pushing olive farming towards competing futures: intensive, mechanised production vs the preservation of ancient trees as cultural landscapes. The fate of traditional groves depends less on technical disease solutions than on whether markets, subsidies and labour arrangements make their continued care economically viable. Well that doesn’t sound promising. Maybe try prayer?
Weed all about it
I think I vaguely knew that USDA had a hemp collection, but I would definitely not have been able to tell you that it was located in Geneva, NY, that it may be the largest in the world, or that it only started in 2021. Fortunately, though, the researchers responsible for the collection organized a USDA Hemp Stakeholder Event at Cornell AgriTech on September 10, and the good people at the International Hemp Podcast are summarizing the proceedings in a series of four episodes. Episode 1 is out, and it includes those tidbits I began with, as well as lots of other interesting information, about hemp in particular but also more generally about how the US genebank system works. Well worth a listen.
But does USDA in fact have the largest hemp collection in the world? Well, the podcast says it has over 800 accessions, and GRIN does indeed return 871 (714 active, 92 available) hits. However, Genesys, which gets its USDA data from GRIN, says 569, which is at least closer to the “N > 600 accessions” on the webpage of the USDA Hemp Germplasm Laboratory. As it’s a fairly new collection, this all probably just means that its numbers go up fairly frequently and USDA just hasn’t updated either its website or its data on Genesys lately. Anyway, that would still give it more accessions than at VIR (491), though fewer than in Ukraine (610). That Ukraine number is split over two institutes, however. So it does look like USDA has managed to put together the world’s largest hemp collection in just 5 years. Pretty impressive. Too bad the podcast doesn’t go into how they did it.
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.
There’s gold in that thar rice story
Carolina Gold is another one of those stories that we kept coming back to, and that I now want to recap as part of our anniversary celebrations.
Before the U.S. Civil War, Carolina Gold was the dominant rice of the South Carolina Lowcountry, grown on vast plantations by enslaved Africans and generating much of Charleston’s wealth. The war, emancipation and a series of hurricanes then shattered that cruel system; commercial plantings dwindled and the last U.S. harvest is usually dated to 1927. But that wasn’t the end of the story, as it turns out.
I first wrote about the variety in 2007, asking where it had actually come from. New genetic evidence from a USDA study complicated the conventional story that it had arrived from Madagascar, pointing instead toward a West African source that fit rather better with the history of the transatlantic slave trade. Check out the string of comments on the post too.
I came back to the story in 2010, linking to an IRRI piece about how cultivation was revived in Carolina thanks to — wait for it — genebank samples. In 2016, there was an update on the revival. And then friend-of-the-blog Mike Jackson picked up the thread in 2017 with an account of “Civil War destruction … genebank redemption”.
He did us all a great service by telling the whole story in detail all in one place: the decline of rice cultivation after the Civil War, Carolina Gold’s near-disappearance, and its rescue when Savannah doctor Richard Schulze discovered seed in the USDA collection. Fourteen pounds supplied to Schulze eventually became 10,000 pounds by 1988. Mike checked Genesys and found 19 accessions carrying the Carolina Gold name, raising the next questions: how different are they, and which one was actually used for the rescue?
Along the way, I actually tasted the stuff! And Jeremy found a film featuring it.
By 2018, Carolina Gold had become the precedent for the comeback of another “lost” rice, this time in Trinidad.
For a blog about agricultural biodiversity, Carolina Gold, with its origin debates, near‑extinction, and then real‑world use of what genebanks kept alive, really is a near‑perfect subject. Can you find others in our archive?