Thanks to Danny Hunter for pointing to two recent posts at CABI’s blog, one on bovine spongiform encephalopathy (mad cow disease to you and me), the other on bluetongue disease. BSE seems to be running its course and to be more or less under control, even though many mysteries still surround it. Bluetongue, however, is altogether more menacing, because it seems to have reached Britain at least partly as a result of climate change, which has allowed the midges that spread the virus to expand their range. This could be the start of something big. I don’t believe there is any resistance associated with different breeds of cattle, but I could be wrong.
Agrobiodiversity in China
Back now from Kunming and Beijing, I discover that there is a rather massive Sino-German collaboration on Sustainable Management of Agrobiodiversity. It apparently runs from June 2005 to May 2009, and is certainly casting its net wide in both Hunan and the island province of Hainan. The project web site is rather neat, although I personally found the content just a little confusing. It is hard to get a sense of timing, and the use of acronyms is downright confusing. I clicked on PVP Training in Hunan Province Successfully Held fully expecting it to be about plant variety protection, only to discover it was about participatory village planning. Still, that’s minor. There’s plenty to explore and I’m sure the project will have an impact. Now, if only I can persuade the project to establish an RSS feed and to change the name of one of the organisations the web site links to, I’ll be even happier.
p.s. Just to pull all my recent posts from China together (just in case someone somewhere is Googling “china agrobiodiversity”) here they are:
Bottlegourd to the rescue
Zucchini yellow mosaic virus (ZYMV) does not, alas, restrict itself to zucchini, or even courgettes. It attacks most cucurbits, including cucumbers, melons, pumpkins, squash, bottlegourds and watermelons. One of those, however, the bottlegourd Lagenaria siceraria may also hold the antidote to ZYMV. Scientists at the Agricultural Research Service of the USDA grew seeds of 190 different accessions from a USDA genebank and inoculated the seedlings with virus.
To their surprise, 36 accessions of the 190 screened—33 from India alone—were completely resistant to ZYMV infection, and another 64 accessions were partially resistant. They also found that ZYMV resistance is heritable in crosses between different bottlegourd accessions, enabling the development of bottlegourd varieties with enhanced virus resistance.
Breeding resistance from Lagenaria into other cucurbits may be difficult, although if they can isolate the gene(s) responsible other options become possible. And even they may not be needed. Growers can graft watermelons, for example, onto bottlegourd rootstocks and benefit from the resistance that way.
p.s. I shouldn’t get snitty, of course, but Wikipedia’s entry on bottlegourd in China is bizarre in the extreme. I’m not going to wonder what a “remedy for health” is, though it sounds to me a lot like a disease. I am going to wonder why there is absolutely no mention of the presence absolutely everywhere of a jillion small bottlegourds as good luck charms. The Buddha used one to carry “life’s essentials”.
Intensifying rice
WWF has a news release today announcing the publication of a study on the System of Rice Intensification (SRI), a set of practices initially developed in Madagascar in the 1980s. ((If you’re wondering why WWF is publishing a report on agriculture: “WWF is focusing on sustainable agriculture efforts for cotton, sugar and rice, some of the most consuming crops for which alternative techniques can result in a strong yield and water savings.”))
The system is based on eight principles which are different to conventional rice cultivation. They include developing nutrient-rich and un-flooded nurseries instead of flooded ones; ensuring wider spacing between rice seedlings; preferring composts or manure to synthetic fertilizers; and managing water carefully to avoid that the plants’ roots are not saturated.
The WWF study says SRI is more water-efficient and productive: in India, yields have apparently risen by 30%, while water use has decreased by 40%. No word on its effects on local agrobiodiversity. Yet. But methane emissions are supposed to go down. Nevertheless, there has been some criticism of SRI in the past.
Linking archaeology and agrobiodiversity
It was probably a silly thing to say. A couple of days ago I briefly mentioned the models that researchers have built, based on present-day genetic data on Europeans, to understand the rate and pattern of human movement into the continent during the Neolithic. And I made the throw-away comment that I wasn’t aware of similar models for crops. I sort of instantly regretted it, and last night did some googling.
At first I thought perhaps I was right after all. I found a recent (2006) paper whose abstract says:
Thus far, no attempts have been made to track the movement of the founder genetic stocks of the first crop plants from their core area based on the genetic structure of living plants.
Further on, though, the authors say they’ve done just that for wheat. And I also found reference to a “Domestication of Europe” project which sought
to determine the extent to which phylogeographical analysis of modern landraces of barley and wheat, combined with examination of ancient DNA in preserved specimens, can reveal genetic information pertaining to the spread and establishment of cereal cultivation from its points of origin in Southwest Asia into and through Europe.
I think the project must have run from 2003-2006. The Glyn Daniel Laboratory for Archaeogenetics at Cambridge was one of the labs involved, and some of the work, and other related research projects, is described on its website.
So there are people out there trying to link up the archaeology and human genetics of agricultural spread in Europe with the genetics of crops and livestock. Is it too early for a Grand Synthesis?