Wetenschap - 7 juli 2011

Collecting spinach

Chris Kik, head curator of the gene bank at the Dutch Centre for Genetic Resources (CGN) returned last weekend from a one-man expedition through Azerbaijan, Georgia and Armenia.


Foto: .

And what he brought back was a suitcase stuffed with 53 linen bags of seed from wild and locally cultivated spinach varieties. This material is intended to inject new life into plant breeding companies, but, emphasizes Kik, collecting these specimens is also important for safeguarding biodiversity. 'It may not seem such a big harvest if you've been away for over four weeks, but I can assure you, it was a long process and hard work, at 35 degrees', says Kik. 'They are not particularly attractive  little plants, and they are also grazed by goats and sheep.' To find potential growing places, Kik consulted the local people, who collect wild spinach as an early spring vegetable.
Kik: 'At the CGN we want to focus especially on vegetables because they are underrepresented in gene banks worldwide. What is more, over the past couple of decades the Netherlands has developed into a major player in the field of vegetable breeding.' Plant breeding companies are very eager to get hold of fresh material for spinach, says Kik, and especially that of two wild varieties that are thought to have interesting genetic characteristics.

Protection against wolf
These two varieties occur in different regions: one in the area of the southern Caucasus currently being studied, and the other further into Asia, in Tajikistan among other places. Kik already went there in 2008, to beef up his gene bank. Two spinach-collecting expeditions in three years? Kik: 'Companies insisted on it. There is an urgent need, for instance, for new genes to resist the disease known as 'wolf', a fungus-like affliction in spinach that keeps taking new forms. I also think the material collected now will be useful for developing drought resistance and salt tolerance.'
These things take time: 'the breeding companies are now very busy working on the material from the 2008 expedition; that takes ten years'. CGN staff first dry the collected seeds and then distribute them among the companies that financed the expedition. They in turn grow the seeds and propagate them. They keep some of their harvest for their own use and some of it is sent to gene banks in the countries of origin. The rest is sealed in portions of 50 to 100 seeds and stored in the cool store in Wageningen, in the biggest spinach gene bank in the world. A new request for material is granted almost every day.

Biocultural heritage
Breeding and long-term food security are not the only goals of his trips, says Kik. 'By collecting wild spinach varieties we are making a contribution to the maintenance of biodiversity.' In central Asia, for example, wild spinach grows beside fields which are neither fertilized nor irrigated. If agriculture is intensified there too, the wild spinach varieties will die out. And the CGN is preserving biocultural heritage, says Kik. Of the 53 bags of seed that he collected on this trip, 29 were filled with wild spinach seeds and 14 with the seeds of local varieties of the species that is common here too, but which has been adapted by generations of Caucasian farmers to the conditions in their vegetable gardens. 'Those local varieties often disappear eventually. We are preserving them for the future.'