Just how far are we from the efficient and effective global system of genebanks that has been on the horizon since at least 1996? Maybe a little closer, thanks partly to efforts by the Global Crop Diversity Trust and Bioversity International to help all those myriad genebanks and their managers to forge a common position. Five years after the Trust began, two of its staff ((Including our very own Luigi Guarino.)) and a colleague from Bioversity have published an assessment of where things stand. ((Khoury, C., Laliberté, B., & Guarino, L. (2010). Trends in ex situ conservation of plant genetic resources: a review of global crop and regional conservation strategies Genetic Resources and Crop Evolution DOI: 10.1007/s10722-010-9534-z)) Bottom line: Good effort, could try harder.
The report is based on 18 crop strategies and 8 regional strategies, undertaken by the Trust in concert with shed-loads of experts in an attempt to collate what is known and what isn’t. From their consideration of all extant strategies the authors isolate eight themes. In their paper they treat each in detail. I have the luxury of picking cherries.
Regeneration is probably the greatest single threat to the safety of wheat accessions held in globally important genebanks.
And what holds for wheat in globally important genebanks holds for other crops and other genebanks too. Keeping what you have alive is crucial, but it isn’t just the lack of skilled staff that is holding things up. Research is needed to know how best to regenerate and multiply some species, especially wild relatives. And of course while regeneration is the sine qua non of a functioning genebank, it is also fundamental to so many other activities, like having enough stuff to send out, gathering the characterization and evaluation data that make stuff worth sending out, and cleaning up the diseases that make stuff not worth sending out. So regeneration is the number one priority.
Number two, for me, has to be information systems, although it ranks No. 5 in the paper. No need to go into details, except to say that the only way out of genebank database hell is to build information systems that allow different searching styles and different social styles alike to find what they are looking for.
And finally, a little something on user priorities. Information plays a part here. The paper says that:
The greatest constraint on utilization of plant genetic resources by researchers, taxonomists, breeders, farmers, and other users of germplasm presented in the strategies is the lack of accession level information … especially for useful traits.
Well, yes. And am I mistaken, or is this a highly disguised pat on the back?
In order to increase use, there is a continuing need for the creation of greater awareness among policy makers and the general public of the value of crop diversity collections and the global interdependence on those collections for agricultural research.
E non solo, as they say in Italy.
Thanks for a good summary of the key points of the paper, Jeremy. Just one clarification. The Trust did not really “undertake” the strategies. It initiated the process and funded them, but they were undertaken by the relevant crop and regional communities.
The authors note that “regeneration is a relatively costly procedure” and that technologies are needed to “extend the time interval between regenerations”. This, surely, is where genebanks should put their efforts, into avoiding the need for regeneration in the first place. The four factors that determine storage life of orthodox seeds are seed moisture content, storage temperature, species and initial seed viability, ie viability at the time of banking. For accessions of the same species stored to international standards, very small differences in initial viability will have a big effect on the time taken for viability to fall to the regeneration standard. Poor handling in the field, particularly during a long collecting trip, may cause considerable loss of viability (and hence reduce storage potential) by the time collections arrive at the seed bank. Likewise, all the effort put into regenerating collections may be wasted if the freshly-harvested material is not handled appropriately.
Well-handled collections should not require frequent regeneration. Ellis and Hong (2007) used the viability equations to predict that maize stored at 6%mc and -20ºC would take 340 years for viability to fall from 85% to 80%. Even wheat, a shorter-lived species, would take 86 years.
Ellis, R.H. & Hong, T.D. (2007) Quantitative response of the longevity of seed of twelve crops to temperature and moisture in hermetic storage. Seed Science and Technology, 35, 432-444
All true Kate, and undeniable. But bear in mind too that Khoury et al. specifically say that regeneration also enables many other good things to happen, for example characterization and evaluation. So there’s a trade-off. If you have plenty of seed collected, you can store some under your ideal conditions and evaluate the rest. But if there has to be a choice, I expect it would make sense to store what you have, as well as you can, and regenerate as soon as conditions allow (rather than necessitate) to get the other benefits.
Agreed, Kate, all collectors should collect properly, all genebanks should store properly. We know how to do this, as you point out. Unfortunately, for one reason or another, the recommended procedures have not always been followed in the past, and standards continue not to be met, hence the need for regeneration. I’m sure in some cases re-collection would be more cost-effective process than regeneration, but this may not be possible any more.
Totally agree on the importance of characterization and evaluation, and yes, if you haven’t got enough material for characterization, you need to multiply. But that’s not the same as having to regenerate collections because of poor viability. Let’s hope current regeneration efforts are now following recommended procedures…
Otherwise, thanks for the pointer to the Khoury et al paper, a useful overview of the themes in the various crop and regional strategies. And thanks for the blog, one of the best.