Re: RE: Red-toned rebloomers (was RE: First 08 rebloomers)

Actually I don't know or think anybody has done a count on how many yellows, oranges and pinks actually carry the Dominant I gene, but that might be a fair assumption.  I realy wouldn't expect many pure whites at all. It would depend on the other parent.  I have found many yellows and such are white because they are recessive whites.  They tend to have brownish tints as they open or at the hafts after opening.   So you just have to be careful and observe.  Some are not so obvious even if you are looking for the traits.  Breeding behavior will be the conclusion unfortunately for some. 

Since 'Golden Immortal' was mentioned earlier I will use it as an example.  In appeartance it looks like it is yellow with a Dominant white gene as it has no anhocyanin pigments or tints.  However, I crossed it with 'Matrix'  and got lots of seeds and about 70 plants.  Absolutely none were pure white or even what I would call Dominant white (with carotenoid), one anthocyanin plicata, a couple carotenoid plicatas all were yellow to some extent with some degree of anthoycyanin except for two which had minimal markings at the hafts.  I am concluding it is a recessive white based on it's breeding behavior.

Keep in mind no one has mentioned another few wrinkles in this genetic tapestry.  Just because a blue isn't showing any carotenoid in the flower doesn't mean that the carotenoid intensifiers are not still there.  And just because a blue doesn't express carotenoid doesn't mean that it doesn't have four copies for lycopene production.  The lycopene genes are independent of the carotenoid genes (probably).   It simply means if there isn't any carotenoid present in the flower the lycopene genes cannot modify it to look pink.  

I think we can also surmise that there is a dosage effect with carotenoid expression with more copies of the gene leading to deeper and brighter colors.  So the further you breed away from the carotenoid intensity the less carotenoid you will get. So for example,  A bright and intense yellow X a blue you might get pale yellows and blue and red/browns/purples.  That is assuming the blue does not carry any carotnoid intensifiers.  If you then crossed one of those yellow seedlings to the same blue plant you would get many more blues and blues with yellow and brown/red/purple shadings and very few yellows.

In my opinion in reality it doesn't really pay to worry too much about how many copies of a gene a plant has except for the basics as with lycopene, plicatas and carotenoid amoenas which for all intents and purposes have to have four copies to express properly.  Many times it is the surprises along the way that are the most worthy.  

My approach has been to create my own seedlings that I know will have genetic backround that I want and work with those to compliment pedigrees of other Registered plants of known backround or potential.

Anyone more knowledgable on these genetics feel free to comment or contradict what I generally have observed in my seedlings over the years.

Paul Archer




-----Original Message-----
>From: Ann Head <jac@labdude.com>
>Sent: Jun 8, 2008 4:29 AM
>To: iris@hort.net
>Subject: Re: [iris] RE: Red-toned rebloomers (was RE:  First 08  rebloomers)
>
>Paul Archer wrote:
>>I would cross your reds to rose-pinks, mauves and red-violets.  The 
>>closer you get to blue the harder it is to get the pinker 
>>shades.  Purples can work too.  Just be careful that the purple is 
>>not a combination of blue and a carotenoid.
>
>>You can also use yellows (and oranges definately) that have at least 
>>one lycopene (flamingo pink) parent or has been known to produce 
>>lycopene pinks.  Yellows and oranges can give purples, maroons and 
>>browns if combined with blues and purples.
>
>As I understand it, most yellows, pinks, etc. carry a dominant I gene 
>that inhibits expression of anthocyanin.  So in a cross between 
>yellow/orange and blue/purple, you would expect at least half the 
>seedlings to be shades of yellow or white?  With many more 
>yellows/whites than that if the carotenoid parent is carrying more 
>than one copy of I.  Is it known how many copies of I most 
>yellows/pinks do generally carry?
>
>>A blue or purple could be used if you look at it's pedigree and know 
>>that one of its parents is a rose-pink,mauve shade or 
>>red-violet.  Then it will be recessive and can reappear, but you 
>>would need to grow enough seedlings to increase your chances of 
>>getting something you want.
>>
>>Not to complicate or confuse but if you have a plant that is 
>>purplish because of carotenoid AND anthocycnin presence just make 
>>sure it has both a lycopene parent (or potential) and a rose-pink 
>>parent and see what happens as the genes get all mixed up and throw 
>>all sorts of shades.  Then when you have a few seedlings that are 
>>close or you like from that cross you can cross them amoung themselves.
>
>Thank you, Paul.  You have definitely provided much food for thought.
>
>Ann
>
>South Australia
>
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