tulip color breaking

totototo@telus.net totototo@telus.net
Mon, 02 Feb 2009 11:10:33 PST
On 2 Feb 2009, at 10:08, Kenneth Hixson wrote:

> Color breaking [and foliar variegation] occurs in a variety of plants, and is
> not always caused by virus. 

To emphasize that point, a couple of analogous examples in other types of 

1. Indian corn with multi-colored kernels on one cob. This is the phenomenon 
that inspired Barbara McClintock to do her Nobel prize-winning work on the 
regulation of genetic expression.

2. An ordinary pussycat (meow!) with a coat that is partly colored, partly 
white, or one that's multicolored (i.e. a calico). 

While simple Mendelian genetics was a good start, as time has gone on, it's 
become clear that it's not all about simple dominant and recessive alleles. 
Also, extra-nuclear factors have been found to play important roles in the 
expression of genes. Google "epigenetic" for further leads.

Rodger Whitlock
Victoria, British Columbia, Canada
Maritime Zone 8, a cool Mediterranean climate
on beautiful Vancouver Island


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