Many routes to stayfresh cassava

Luigi wondered whether there was a connection between my recent report of a cassava that did not show post-harvest physiological degradation (PPD, or rotting for the rest of us) and his own post on the same subject in March of this year. So we asked the CIAT blogger.

So what’s the story? Did the high carotene trait come from M. walkerae? Or some other place? It would be great if you could tie these loose ends up for us.

And he did, by asking the CIAT researcher.

There is a connection as Luigi suggests. In the article we have just submitted there are four different sources of tolerance to PPD:

1) High carotenes

2) Induced mutations

3) Tolerance from a wild relative (Manihot walkerae)

4) Waxy starch genotypes.

The tolerance from high carotene clones is not coming from M. walkerae. It is an entirely different source and an entirely new chemical basis for the tolerance as well. As it turns out the tolerance from M. walkerae (which is real and is there) is not as good as the one we have seen in yellow rooted cassava.

Thanks to Neil, and to Hernán, and to Luigi’s elephantine memory. We’ll be on the lookout for that paper.

What’s yellow, nutritious and doesn’t rot?

If you answered PPD-free carotene-rich cassava roots, then you obviously got to the CIAT blog before we did. There’s a great story about the kind of serendipitous result that makes scientific research so exciting. CIAT has been developing a yellow cassava, which they call an “egg-yolk” variety, in the hope that the extra carotenes would help to rectify the vitamin A deficiencies that plague so many poor people. Roots were sent off for analysis (the results are very promising) but some of those roots were forgotten in a store-room for two months.

They should have been “totally spoiled and rotten,” because cassava roots are prone to something called post-harvest physiological degradation (PPD) that destroys them within a couple of days of harvest. It seems that the anti-oxidant activity of the carotenes — which had faded away in the stored specimens — had somehow protected them from PPD.

This is a huge breakthough for cassava breeders, growers and processors. Read more at CIAT.

Nibbles: European agricultural origins, Drought, Native American ranching, Sorghum, Anthocyanins in apples, Dog coat, Pear cider