Benjamin's Excellent Adventure
3 August 2016
This week, I’d like to use this blog to introduce a new colleague here at the Crop Trust. His name is Dr Benjamin Kilian, and he’ll be working on our project on crop wild relatives, mainly looking after the pre-breeding component. But rather than reviewing Benjamin’s career, which you can always do by googling anyway, what I thought I’d do here is talk about two scientific papers which have just come out, which he was involved in writing. They’re both on barley, and they tell fascinating stories about its career.
The first paper is entitled “Genomic analysis of 6,000-year-old cultivated grain illuminates the domestication history of barley.” The researchers were able to extract and sequence DNA from 10 ancient grains of barley from an archaeological site on the shores of the Dead Sea called Yoram Cave, in Israel. The technology for doing this is getting better all the time. You may have heard about recent successes in extracting ancient DNA from human remains also dating back to the Neolithic and even much earlier times. But it’s still tricky. In particular, you have to be very careful about contamination, and ancient DNA is always to some extent degraded. That makes it difficult to compare with the much better quality DNA from fresh specimens. Imagine trying to find the really significant differences between digital photographs of the same place taken at two different items, but where one of the photos has some pixels missing or otherwise corrupted.
But that’s exactly what Benjamin and the other co-authors did. They also extracted DNA from 267 wild and landrace barley genebank accessions originally collected from all over Europe, Asia, North Africa and Ethiopia, and compared it with the ancient DNA. Out of all those more modern accessions, the ancient barley was most similar to material, both wild and cultivated, from the southern Levant and Egypt. That means that barley at least has remained relatively unchanged genetically in the region. That’s pretty astounding, if you think of all the changes that the Middle East has seen in the last several thousand years.
The other paper looks in more detail at the diversity of those 267 genebank accessions, diversity not just at the level of DNA but also traits like plant height and days to flowering. There must be reasons for the genetic stability of barley in the Levant, and this study tried to tease them out. One of the more interesting results was that there was a very close association between particular combinations of environmental conditions, specific morphological traits, and bits of DNA.
These papers are great examples of material from genebanks being used to investigate the genetic history of a crop. Such research is interesting in its own right, but it also helps breeders use genebanks. If a breeder is interested in barley adapted to particular stresses, or with particular traits, she can just look for particular bits of DNA, which is much easier than growing the actual barley plants in large agronomic trials under different conditions.
The crop wild relatives pre-breeding projects will be generating a lot of exactly these kinds of data, and it’s one of our aims to make them all as easily accessible as possible to breeders everywhere. Benjamin is just the guy to make that happen. He’ll be busy though. Apart from barley, we have pre-breeding projects on 18 other crops, involving 44 institutions in 27 countries. Welcome, Benjamin! Now get back to work.