Category: Genebanks

Posted on

Critically endangered cassava wild relative delays rotting

Here’s something else I learned at this workshop I’m attending on the state of plant genetic resources conservation and use in Latin America:

Dramatically delayed PPD [postharvest physiological deterioration] was found in Manihot walkerae, a wild relative of cassava found in Mexico and USA (state of Texas) (Fregene and Mba 2004). An accession of M. walkerae (MWal 001) was crossed extensively to elite cassava varieties. A single successful genotype was found with delayed PPD. The storage roots of the hybrid remained intact a month after harvest. Backcrosses of this hybrid to elite progenitors of the CIAT cassava gene pools and selfed (S1) populations were made for genetic mapping of the delayed PPD traits.

This came up during a discussion of the importance of collecting and conserving crop wild relatives. I had no idea the Manihot genus went as far north as Texas. Walker’s manioc turns out to be extremely endangered:

Until recently, it was believed that this species was represented in the U. S. by a single plant in the wild, discovered in Hidalgo County in 1990. In 1995, Walker’s manioc was located in three different areas on the Lower Rio Grande National Wildlife Refuge in Starr and Hidalgo Counties.

It is known from only a couple of populations in Mexico. I don’t give much for its chances in the wild. But there is material in the San Antonio Botanical Garden. And some of its genes are now in some cultivated varieties.

Posted on

Nibbles: Databases, Hell squared, Genebanks, Goats, Olives, Safe movement, Pouteria, Roman wine

Posted on

Nibbles: Fraxinus, Sheep, Fish, Potato, Chickens, Eden, Microlivestock, Saliva, Mashua, Vine

Posted on

Millennial beans

beans

Nice enough beans, ((And thanks to Bisse for letting me use her flickr pic.)) but is the story circulating about them really true?

The story of Anasazi beans varies, depending on who is telling it. In popular mythology, the beans were uncovered by an anthropologist, who discovered a 1,500 year old tightly sealed jar of the beans at a dig in New Mexico. Some of the beans germinated, and the new variety of bean entered cultivation again.

I tried to track the story down, and the closest I got to paydirt, I think, was a passage in Beans: A History by Ken Albala. But even that is pretty vague really. Archaeologists from UCLA somewhere in the midwest in the 1980s, or maybe 1950s, uncover a clay pot sealed with pine tar which they carbon date to 500 BCE. Some of the beans sprout and an intrepid businessman markets them. Yeah, right. To go back to the source of the previous quote:

Since most botanists agree that most beans are unable to germinate after approximately 50 years, it is more probable that the beans remained in constant cultivation in the Southwest, probably in Native American gardens, and that they were picked up by companies looking for new “boutique beans.”

There are plenty of companies marketing Anasazi beans now. But actually it is not impossible for legume seeds to keep their viability for more than 50 years — that’s what genebanks are for. And the dry, relatively cool conditions of an Arizona cave might just be good enough to ensure the survival of a few beans for centuries.