Category: Biotechnology

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Trees in Kenya

There were two interesting articles about trees in Kenya in the Money section of this morning’s Daily Nation. Not online, though, so I’ll have to summarize. One piece describes how farmers in Nyeri are adopting a number of short-statured mango varieties from South Africa and Israel, apparently including things called Apple, Kent, Vydke and Tommy. This is not a mango-growing region, but these particular varieties have been found to be a good fit on the small farms of the area, to yield heavily and early, and to be good for juice. So now there’s no need to truck mangoes in from the coast. Good for Nyeri farmers, perhaps not so good for coast farmers? This may not be a zero-sum game: I don’t know enough about the supply of, and demand for, mango in Kenya to predict what will happen, but I would try to conserve those coastal varieties ex situ somewhere just to be on the safe side.

Then there was also a piece on how the Tree Biotechnology Project has been successful in cloning a number of indigenous trees (including for example Prunus africana, whose bark feeds a large international market for a prostate cancer drug) and providing planting materials to farmers. It seems previously the project’s focus has been on eucalypts. This is expected to take pressure off wild populations and contribute to reforestation, but there was nothing in the Daily Nation article about the downside of planting large areas of genetically identical clones. However, this is clearly a problem the project recognizes, as you can see for example by reading on page 28 of this brief on some of its activities:

Planting large areas of single clones will have the effect of decreasing rather than increasing biodiversity, and the risk of narrowing the genetic base needs to be managed to avoid growing pest and disease problems. Mondi has a policy to restrict planting of a single clone to no more than 5% of any planting area, and the project is adhering to this policy. In order to maintain biodiversity, the project team will select a wide range of local tree species of economic value and will feed these into the clonal production system through adaptive tissue culture research. Once the capacity to adapt the techniques of micro-propagation to different species is fully in place, there will be great potential for the project to multiply and disseminate a wide range of improved germplasm of different tree species, including those that are under threat of over-exploitation and extinction, such as ebony.

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White grapes are mutants

Thought that would get your attention. Actually, what the research summarized here revealed was that a couple of genes mutated independently thousands of years ago in the ancestor of the modern grapevine, whose berries were red. The resulting white variety proved to be the ancestor of almost all of the 3000 or so white grape varieties we have today. This discovery from CSIRO will apparently be useful in marker-assisted breeding.

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More tea, vicar?

You may remember an earlier – somewhat facetious – post on a possible threat to tea diversity in China. Now, from CropBiotech Update, there’s a summary of a far from facetious review paper on tea breeding in that country. Turns out that the China National Germplasm Tea Repositories can count on some 3000 tea germplasm accessions, and that over 200 improved varieties have been released. Some quite advanced biotechnological approaches are being used to speed up breeding. One of the things the researchers are looking at is developing cultivars with low or no caffeine, using RNAi. Personally, I think caffeine-free tea and coffee, like alcohol-free beer, are a bit like a one-legged man at a butt-kicking contest: useless. But the technology is cool.

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Rice stories

The BBC World Service is broadcasting a series of four programmes on the rice cultures of Asia, called Rice Bowl Tales. Starts 28 February, but if you miss it, it seems like the series has already aired on Radio National, and if you follow the link I’ve just given, you should be able to listen online or download audio files.

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Crop wild relatives underused

Are crop wild relatives (CWR) more trouble than they’re worth? There are certainly significant challenges involved in including them in breeding programmes, but you’d have thought that between the new molecular tools that are now out there, the greater numbers of CWR accessions in genebanks, and all the information about how useful CWRs can be, breeders would be falling over themselves to make those kinky inter-specific crosses. Well, according to a major review by our friends at Bioversity International (the outfit formerly known as the International Plant Genetic Resources Institute), the use of CWRs in breeding programmes has been steadily increasing in the past 20 years, but probably not as much as might have been expected. There’s been a number of papers recently on CWRs. This paper, also from Bioversity, looks at in situ conservation of CWR. Check out this for a discussion on the definition of the term, and, from some of the same people, there’s this overview of conservation and use of CWR, using a specific example. Here’s an example of conservation assessment and priority-setting for the wild relatives of the peanut. For a discussion of the possible effects of climate change on these species, see this.