Re: Hosta Sports, continued...

Andrew:

>I'm just curious, Joe, why you are so firmly convinced that mitotic
>recombinations is NOT be a viable explanation for SOME Hosta sports

I don't believe that I ever said that mitotic recombination could 
never be the cause of a green edge on a yellow hosta.  However, the 
chances of that are so low that we can pretty much dismiss it as a 
casual cause of green edges developing on yellow hostas.  Besides 
mitotic recombination there is also chromosome loss/damage, point 
mutations and transposible elements.  Ben has not shown any proof that 
mitotic recombination is the cause of green edges on yellow hostas, or 
even any evidence for it.  All the other possible explinations are 
just as viable.  Personally, I think transposible elements are more 
likely the cause.

>...particularly for more stable ones like Great Expectations which is 
>a periclinal chimera,

Great Expectations sported from an all green/blue leafed hosta.  So, 
where did the yellow come from?  The open pollinated seedlings that I 
grew last year, about half were yellowish while the rest were green.  
Didn't appear to be maternal inheritance to me.  I did have an all 
yellow leafed sport of GE that survived while it was attached to the 
main crown, but it didn't survive after I seperated it from the mother 
plant.  

>I don't know why a mitotic recombination for Abiqua Recluse would 
>only offer one variety of a green edged sport. 

If you have a plant that is Yy and you have a mitotic recombination 
then you get two cells, one of which is YY and one which is yy.  
However, if you have a lot of genes between the Y gene and the end of 
the chromosome that are heterozygous, they will also show up as 
recessive phenotypes.  However, to have have any significent effect on 
the appearance of the green edge they would have to be genes that 
somehow influence/control the green edge.  The cells that develop the 
yy geneotype should be green just like any regular green leafed hosta. 
However, when you look at sports in hostas you see a LOT of different 
sports that would be difficult to explain by mitotic recombination.  

Joe Halinar

---------------------------------------------------------------------
To sign-off this list, send email to majordomo@mallorn.com with the
message text UNSUBSCRIBE HOSTA-OPEN
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index