Re: Unusual Sport

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The photo of Pat Mora's sport is indeed different. I have tried to come up with some possible explanations for the unusual pattern of LI and LII tissue. Let me start off the discussion of possible causes for the variegation pattern with several assumptions which may affect the analysis of the causes.

Assumptions:

1. That the parent of 'Embroidery' (Aden) is Green Velveteen and not the otherway around as stated in the HostaSports.com Library
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2. That the ruffled edges of 'Embroidery' is due to the presumption that it may be a 4-2-2 cytochimera which causes the ruffling in the green outer edge. I suggested this in a talk given in 1997 Winter Scientific Meeting in Chicago. This is speculation, please understand.

3. That the LI/LII tissue cytochimera may have been induced by radiation by the originator. This also is pure speculation on my part, but may be a reasonable assumption.

4. That 'Embroidery' has been propagated widely by now. I know that two labs have propagated it (Scolnick and Ventatesh in Florida for Khlem) and perhaps Shady Oaks also. The more it is propagated, the more variable the end product may become  because of more chances for mutations of several types..

5. That several mechanisms may have occurred within the plant tissue undergoing micropropagation. These mechanisms must have occurred in an exact sequence to give the specific pattern of variegation which has been displayed in the photo. Some mutations may have occurred without being observed in tissue culture.

6. That LI and LII layers remain distinct with 'Embroidery' while in tissue culture with the exception that tissue displacement/replacement may have occurred  at one specific time while the cultivar was  being micropropagated.

With these assumptions being accepted, the following sequences of changes may have occurred to explain the pattern of variegation observed in Pat Mora's unusual sport:

Step 1. Green Velveteen may have undergone a chloroplast mutation which created upon complete sorting out of unmutated and mutated plastids, a periclinal sport with a green center and a white edge.

Step 2 . A tissue transfer took place with cell initials of LII displacing the position of LI, and LI replacing the position of LII. The chimera now has a green edge and a white center.

Step 3. A mutation creating a 4-2-2 cytochimaral sport may have been created in a major cell initial in the unmutated green LII cell, creating a green ruffled edge. The media portion of the leaf was unchanged, being white..

Step 4. After a number of years of micropropagation, a nuclear mutation may have occurred changing the ability of one cell which happened to be a cell initial in the apex of the meristem within the white LI tissue to begin again to synthesize chlorophyll once more in a portion of the white tissue layer. At the time of the photo, incomplete sorting out is suggested as the current situation,  since some of the tissue is striated with alternating patterns of green and white tissue on some leaves and a larger area of green LII cells  on one of the other  leaves appearing, giving the LI layer,  cells of two different types,  green and white.. . I would not be surprised to see more green tissue next year with the white area of the leaves   being reduced in size in future years.

How is that for a diagnosis? Of course, other mechanism changes may have occurred instead of those I have suggested. Aren't hosta wonderful? Just about anything may have occurred.

Jim Hawes
 
 

Bill Meyer wrote:

Hi Sports Fans,         The picture attached here was sent to hostapix by Pat Mora. It shows a division of 'Embroidery' in which a green center is appearing inside the whitish center, which is something I've only seen before in 'Royal Tiara'. Given that we understand Hosta to have only two layers, how can we explain this? Has a third layer come into existance through mutation? Or is this new tissue some L1 that has become trapped inside the L2? This is one of the strangest things hostas do. The appearance of a third color in a hosta leaf is not uncommon, but this usually occurs as streaking or patches of another color. What does it tell us that it apparently can form a stable-appearing pattern?                                                                                .............Bill Meyer