The keenness of gardeners to get involved in plant breeding has long been known. During the 1950s, tens of thousands of gardeners in the USA submitted marigolds to the Burpee seed company in a competition to find a white one. But, despite this, little plant breeding with gardeners has actually been done, suggesting they have been very hard to work with.
The biggest problem seems to be that there are millions of them with few commonalities even in a single country. This makes it difficult – but also all the more essential to appreciate this diversity and to gain representative samples.
Most gardeners also aren’t linked, for example, through an association. Fortunately, the World Wide Web has long solved this: websites, internet, social networks etc make it easy and cheap to work with many individuals.
Another problem of gardeners is that most have only small gardens so they can’t grow many plants – yet breeders usually want to grow hundreds, if not thousands, of these. But again, computers plus modern statistics can enable this to be an advantage, being able to analyse thousands of little bits of data to get a very broad ‘truth’, as long as there are a few standards included.
So, it is now practical. Here are the examples I’ve found.
The Guild of Oca Breeders
This web-based plant breeding club was started in the UK around 2015 by Dr Owen Glyn Smith at Plymouth University.
Oca is grown for its underground tuber and, like the potato, comes from the equatorial high Andes of S. America. As a result, it has evolved to produce tubers in the roughly 12 hr days experienced in the Tropics; in the UK it only begins to produce tubers in the autumn.
The Guild of Oca Breeders used PPB with gardeners to breed varieties of oca that develop tubers in the long days of a European summer. Gardeners were recruited using its website, making a small payment to be involved.
The Guild did all the crossing and grew the seedlings to produce tubers. It sent these to its members to grow in their gardens for their assessment and to return any really good ones.
Members signed the Open Source Seed Initiative pledge, so receiving plant material was a commitment to keeping the germplasm in the public domain.
Unfortunately, this initiative seems to have fallen foul of official regulations to prevent the spread of diseases on vegetatively-propagated planting material. Its website no longer functions and their facebook page has entries only up to 2019. Apart from this, the idea seems brilliant!
1000 Gardens Soybean Breeding Project
This soybean breeding project combined a German manufacturer of tofu called Taifun-Tofu GmbH, the German University of Hohenheim State Plant Breeding Institute and German gardeners.
The aims of the project are to expand the cultivation of soybeans in cooler regions of Germany by breeding cool-tolerant varieties suitable for tofu production.
A condition of being a part of the project is that the intellectual property rights of the breeding lines remained with Taifun-Tofu GmbH and the State Plant Breeding Institute.
In 2016, the project received online registrations from around 2,500 gardeners. About half remain committed, sending in their data (plant height, ripening date etc) online and posting their harvest by surface mail.
The beans were analysed by scientists and data shared online with the gardeners. This included lots of photographs (see below) and explanations to maintain interest (Wurschum et al., 2019). And it resulted in the release of two varieties of soya in 2019 1nd 2021, Tofina and Tori which yield well in northern Europe and which Taifun-Tofu GmBH are very pleased with: the approach works!
And these photos illustrate once again that everyone is enjoying themselves as well as doing something beneficial. But what seems truly ground-breaking about this project is its recruitment of so many gardeners via the internet! But it seems to have produced varieties suitable for processing into tofu rather than suiting gardeners. Inevitable perhaps, since Taifun-Tofu GmbH was driving the project.
Lettuce breeding with gardeners
Downy mildew (Bremia lactucae) is perhaps the most important diseases of lettuce. Over thirty strong and dominant resistance genes (Dm genes) able individually to control the disease have been identified in mainly wild lettuce species and these have been used, sometimes in combination with fungicide, to provide control. However, both means of control have been broken as more virulent strains have repeatedly and rapidly evolved. One way being tried of controlling the disease is to ‘stack’ several of these strong resistance genes in a single variety.
However, quantitative resistance based on the presence of many but weaker resistance genes has also been identified in mainly heirloom varieties of lettuce and may, like the example of Sarpo Mira potato and late blight, provide a more durable resistance. This is the route an organic, not-for-profit Swiss seed company, Sativa Rheinau AG, and gardeners throughout Europe have taken in the development of new lettuce varieties.
Parental lines are selected from mildew-tolerant traditional varieties by plant breeders at Sativa and crossed. Then, “In order for the lettuce to come into contact with a large number of different mildew strains, it is necessary for the lettuce lines to be cultivated at a large number of [garden] locations in Central Europe.”
Like the soybean project, some 1,200 gardeners were involved by 2020 but what is really impressive with this project is that, like the Dwarf Tomato Project, it has become international with gardeners in many European countries involved and a French website.
Like the soybean project, they include photographs and explanations on the project’s websites and feedback to the gardeners to maintain their enthusiasm.
Because Sativa Rheinau AG is a small company, the participatory breeding must cover its costs! And it already breeds vegetable varieties for gardeners conventionally and therefore understands these costs.
Sativa Rheinhau also says it is intending PPB to be a part of their future! The method is clearly practical.
Overall progress of PPB with gardeners
The above three examples are farsighted and extraordinarily hopeful. It’s taken a long time but the idea of using modern methods to link with gardeners as individuals seems so simple and logical. But, although each example tries very hard to involve gardeners in activities, gardeners are still not in charge. They aren’t even asked what crop they want to improve and how they want it improved!
This is because the projects are led by the interests of the organisers. But it would have occurred if the gardeners provided the leadership.
In the UK, there are lots of gardeners and gardening organisations of different forms and sizes. And some, like the National Allotment Society, the Royal Horticultural Society and large-circulation gardening magazines have large resources. But none of them seem to ask gardeners how they want their crops improved genetically.
My allotment plot (above) is in a site of over a hundred and fifty plots. The site is managed by a society which also manages two others, so perhaps three hundred plots in total. It has a shop, Facebook website and most members are on at least email, phone etc so we are relatively easy to contact.
And bigger cities have bigger organisations with more sites: the Greater London Authority looks after 763 allotment and community growing sites! There are also regional associations, for example, The Yorkshire Allotments and Gardens Federation.
Even higher, there is the UK National Allotment Society (NSALG). And NSALG belongs to the Europe-wide International Office of Allotment and Leisure Gardens (Office International du Coin de Terre et des Jardins Familiaux) in Paris.
In its newsletter, I came across the statistics that Dresden in Germany, with a population of around half a million people, has 25,000 allotments in 366 sites and occupying 793 ha and Hamburg, with a population of nearly two million people has 34,780 allotments in 312 sites occupying 1,829 ha.
My allotment society also doubles as a horticultural society and there are also about three thousand such local societies in England affiliated to the Royal Horticultural Society (RHS), with hundreds of thousands of members. The RHS includes “Understanding and promoting the benefits, use [my italics] and conservation of plant genetic resources in UK gardens” as an aim on its website.
There are also several horticultural colleges and universities with horticultural leanings dotted across the UK, at least some of which would surely be interested in partnering gardeners for PPB and, no small point, welcome joint project proposals. There is also the National Institute of Agricultural Botany including “NIAB EMR, at East Malling in Kent [working] on perennial fruit crops. [Its] research programme is based on genetics, genomics and breeding [my italics]”.
Please note that all the above organisations are either not-for-profit or are funded through charitable or national (taxpayer-funded) projects so they should have few concerns about working in partnership with gardeners or about the commercial aspects of ownership, e.g., of genetic resources. We also have several small retail companies which have ethical aims, for example, Real Seeds provides advice on seed saving, not the action of a seeding company wanting to make excessive profit.
And many other developed countries have a similar range of organisations with breeding expertise with a desire to serve gardeners either as members, taxpayers or customers and without the encumbrances of the desire for profit at all costs.
But, if PPB is so good (which it truly seems to be), as a UK citizen, I do feel it is strange that it is not happening in the UK. We are supposed to be a nation of gardening enthusiasts, we have even funded PPB in developing countries! I have seen the idea of PPB with gardeners mentioned, there was the Guild of Oca Breeders but nothing with firm foundations has yet occurred.
However, this has happened in other European countries like Germany, Austria and The Netherlands and it seems certain that we too will realise how there are now very easy ways of linking us, collectively we are powerful, and we deserve varieties that are suited to us, not suited to commercial growers and seed merchants.
We just need to do it!