Re: HYB: TB: yellow patterns?

Never say never is true.
But in this case there are a few things going on to be aware of. First, is that the pumila spot would appear to be only on the 8 chromosome set from pumila, and the variagata spot appears to only be on the 12 chromosome set. With each spot we can have inculison or exclusion of pigment from this spot, in both pumila and variagata. There have been some pictures posted of SDB and IB with both pumila spot including cartenoid, and variagat spot excluded, to give a yellow pumila spot with a rim in the variagata spot cartenoid excluded.
In SDB, the 8 chromosome set have the glaciata form of the plicata allele and the 12 chromosome set can have all three identified plicata alleles. So SDB plicatas operate as diploid in plicata inheritence. In SDB, they are are not true tetraploids, but amphidiploids, with 8 chromosome sets pairing with 8, and 12 pairing with 12. Only in the MDB and in IB do we get the imbalanced pairing. With fertile IB's there may be some funny gene counts going on. Their hasn't been any gene counts to be sure what is happening. I have suspected that some fertile IB may actually be tall SDB genetically, so not realy an uneven IB.
It is only with fertile MDB or IB with unbalanced pairs, can we expect there to be the possibility of gene crossovers, and by this get pumila spot genes into the 12 chromosome set.
What this means is that the patterns seen with SDB and IB are very unlikely with a 12/12/12/12 chromosome TB. I have seen a number of IB at TB height, so you could get a TB imposter with this pattern, but the flowers would be not TB size.
I keep hoping to see a crossover on plicata alleles to 8 chromosome set, but so far no luck. Same with pumila spot onto 12 chromosome set. 

Chuck Chapman




Date: Sun, 15 Mar 2009 09:24:31 -0500
From: Linda Mann <lmann@lock-net.com>
Subject: [iris] Re: HYB: TB: yellow patterns?

I didn't mean that - I meant keeping the "variegata spot" area (or in
this case it's not anthocyanin as in the variegata spot, it would be
yellow), but adding a yellow rim to it. So beard and spot would be
yellow, rim yellow, with wide white "band" in between. I wouldn't mind
a white stripe from the beard, splitting the pumilla type yellow spot.
In a TB.

PEACH SPOT has part of the pattern, but not the outer rim of pigment.
Plus, as I recall, it has some anthocyanin in the spot?
Griff, would you post the photo you sent me of the MDB seedling you sent 
that has the pattern I'm looking for? I deleted it. It is close, tho
I'd like to find something with a wider yellow rim.

<I don't think such a pattern can exist. This pattern involves
exclusion of cartenoid pigment from "variagata spot" area, so the
pigment would not be present at end of beard.>

- --
Linda Mann east Tennessee USA zone 7/8

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