Almost eighteen months in the making, or 80 years, depending on how you look at it, yesterday saw the publication of a gargantuan review of the literature on crop genetic erosion. ((A common topic on here of course.))
The team reviewed hundreds of primary literature sources published over the last 80 years that examine potential crop diversity loss, also called “genetic erosion”. The global collaborative effort found that 95% of all studies reported diversity change, and almost 80% found evidence of loss.
The most interesting (but, to be fair, unsurprising) thing to me though, apart from our evidence base still being fairly limited for many crops and regions, was the variation in the magnitude of loss, which depended hugely “on species, taxonomic and geographic scale, and region, as well as analytical approach.”
What’s to be done? Well, I won’t kid you, it won’t be easy.
Reversing the trajectory of crop genetic erosion requires more profound change – no less than reorganizing global agriculture, and food systems, and even the human societies they nourish, to become diversity-supportive processes… Crop diversity must be valued not only as a genetic resource to be exploited, but just as much for its cultural and ecological values… This implies a (re)integration of species, varietal and genetic diversity into agricultural systems, both temporally and spatially, as well as the (re)establishment of local autonomy and markets supporting the processes that foster the ongoing evolution of this diversity.
So let’s roll up our sleeves, yes? As, for example ((Don’t @ me, I know there are many more examples, this is just what’s been in the news in the past couple of weeks.)), Vijay Jardhari and his friends have done in Uttarakhand. And Vivien Sansour is doing in Palestine. And Charity Lanoi is doing in Kenya. And Hamidou Falalou and his ICRISAT colleagues are doing in Chad. And as the Svalbard Global Seed Vault hopes to do in the next few months up in the Arctic.
Because, as a nicely complementary paper by Moises Exposito-Alonso and co-authors also pointed out in the past few days, though referring to 19 wild plant and animal species, “over 10% of genetic diversity may be extinct” already.
https://twitter.com/mexpositoalonso/status/1449158576975482880
I did my usual on this epic review – looked at the references. I can’t find anything credited to Zhu et al. 2000 is actually in the his paper (which is actually about varietal mixtures in monoculture) intraspecific variation. It is a rubbish paper anyway.
Also Thormann et al. (2019) which claims “In 1975, the International Board for Plant Genetic Resources created the first internationally linked system of genebanks”. They didn’t. That was done by the TAC Beltsville proposal in 1972 (I worked in three of them over the years). The IBPGR Base Collections were a disaster, paid for pro rata by IBPGR donors in return for getting a Base Collection and eventually coveted by FAO on the reasonable argument:” Why should we not run this system”. This eventually gave us the ITPGRFA. I pulled the CIAT collections out of the system as we were doing the work and IBPGR was getting the funding.
Then there is the Lopez‑Ridaura et al. that showed that Maize-legume intercrops in Guatemala gave higher yields than maize – we knew that – the legume component provides the nitrogen.
They were the first three papers I checked – I can’t take any more, there are hundreds.