More on the Grand Canyon’s super-sunflower

Here’s some more information on that sunflower from Supai that I blogged about yesterday. There was a huge storm last night and I was stuck indoors with not much to do, so I tried to see if I could track down the accessions in question. They’re not for sale from Native Seed/SEARCH, though they are surely in their seed bank. So I went to GRIN, guessing that duplicates of the material had probably been deposited in the USDA system.

A quick text search on “Helianthus Supai” in GRIN’s “Accession area queries” page yielded 5 PI numbers. However, only 4 are “active.” It seems there may not be enough seed available for the fifth. Incidentally, there are also accessions of maize, devil’s horn and Cercis occidentalis from this site.

Now, I could click on each of the sunflower entries and look at the available evaluation data under “Observations” to track down the specific accession with rust resistance, but there is also another way. You can go to GRIN’s “Evaluation/characterization query” page, select sunflower, go to the descriptor list, and find the specific descriptors concerning rust resistance, one of which happens to have the code RUSTNUM3. ((The 3 refers to the particular race of the rust fungus Puccinia helianthi against which the material was tested.))

It turns out that of about 1000 sunflower accessions in the US National Plant Germplasm System for which there are rust data (out of a total of over 2500), only 8 have a RUSTNUM3 value of 100, meaning they are resistant to the fungus. And PI432512, collected by Gary Nabham in 1978 from Supai, is one of them.

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