Re:Hosta Variegation (continued)
Jim Anderson and others interested,
This post is number seven in a series of chronological posts on the nise
listserver, discussing Hosta Variegation. It is unfortunate that we did
not include hosta-open in distribution at the beginning. I have taken
the liberty of including hosta-open (it is not too late to catch up).. I
hope it is alright with participants.I apologize to hosta-open Robins
for the oversight. This post is a continuation of a discussion of the
evening of August 7, 1999. Jim Anderson had asked a question (number 1)
regarding similarities/differences between variegation in daylilies and
hostas. I had declined to participate in this question because of my
limited familiarity in daylilies.
A second question dealt with H. 'Striptease'. Jim A. asked why there
were three colors, one being a fine white line between the viridescent
white center tissue and the dark green border tissue? I pleaded
ignorance. But then after thinking about it overnight, I wondered if
this tissue might represent an exception to the conventional wisdom
that colors in variegated hostas are due to the two layers of distinct
tissue per Dermen and Vaughn.
According to the work of Schmid(1924) , the outer shoot apical layers
can divide anticlinally ( 90 degrees from the perimeter of the leaf)
and produce a meristem with a stratified "tunica-corpus" organization of
cell layers.Dermen(1950) has defined these as L1 and L2. They grow and
differentiate into border and central tissue in the leaf.
Tillney-Bassett(1986) indicated that both two and three layers are
common in monocots. Speculation on my part is that the thin white
border between tissues may be derived from the third layer that may be
possible according to mentioned cytological classical research....Could
Since one can not easily determine if a plant is a specific chimera via
histological examination by microscopy, the ususal method of arriving at
explanations is to examine the leaf's morphological characteristics
since they are usually an expression of the histological structure
which exists in the meristem, i.e. we deduce meristematic structure by
phenotypical expression of organs derived from the meristem..
A third point posed by Jim A. asked for comments regarding his
observations that a "base color" seemed to predominate when streaked
hostas "reverted" to final stable forms.I raised the question of 1/
the need for an understanding of the origin of streaked hostas and...
2 and 3/ the need for an understanding of the basis of the green
and yellow (and white) colors in hostas. I summarized the concepts
defined by Jones(1934) wherein chimeras (multicolored adjacent tissues)
are a result of mutations within specific cells which create two or more
colors within cells and subsequent, corresponding tissues.
At this point, I am willing to continue in a simple dissertation of my
views and interpretations of what I have found that cytologist claim to
be the explanation for streakiness in variegation patterns and the role
they play in the development of chimeras of several types. But I do not
want to go ahead of others in this discussion. I will hold my
discussion in abeyance for others to comment as they wish. I will
resume later when timing seems appropriate.
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