My understanding of Av genetics is more than a bit fuzzy, but I'll give it a shot. Chimera AVs have two sets of DNA, and they express this through stripes on the flowers (more rarely through the foliage); they're always 'pinwheel' -- stripes down the middle of the petals, and the main color on the sides. One set of DNA is in the 'skin' of the plant, and the other is in the inside tissues. When you grow babies from leaves, the new plants grow from the external tissue, which means it only gets one set of DNA, and therefore one color. When you grow plants from suckers and the crown, obviously it gets both sets. This whole arrangement is pretty unstable, and plants can revert to one or the other color, especially when stressed (you forget to water, bug attack, etc.). Got it? Korina the Konfused ~embrace the confusion~ ÂNever trust anything that can think for itself if you canÂt see *where it keeps its brain*! ~Arthur Weasley

You're welcome. I've read about "sports" in roses and other plants, and cases of "sports" reverting back and forth. If the change originated from a genetic mutation, the odds against going back and forth (i.e. a change in the DNA sequence at the exact same point, and then again back to normal, and then again to the "sport") are astronomical. What's more likely, in my mind, is that the undifferentiated cells in the meristem (the part of plant tissue which can be induced to form just about anything else) must undergo differentiation, which involves mechanisms regulating gene expression. These mechanisms involve how the DNA is folded, which molecules attach and where, etc. which result in some genes having "easier access" for transcription than others. And this process is more prone to both "errors" and "reversions" than actual changes in DNA sequence. What's interesting to me is how this explains moss roses, which are claimed to have originated as "sports" among centifolias and Quatre Saisons. The ancestral species of damasks includes R. fedtschenkoana, which has similar mossy growths. Most damasks lack this phenotype, but the genes for it are still there -- perhaps genes from R. gallica and/or R. moschata interfere with this expression, but in the first mossy "sports", those interfering genes were "silenced" or otherwise reduced in expression, allowing the effects of "moss" to reappear. Centifolias are thought to be a complex mix of roses, including damasks, and so it seems reasonable to assume that they similarly inherited genes responsible for the "mossiness" in R. fedtschenkoana as well as the "interfering" genes from the other species, and so also contained the potential for re-expression if their "interfering" genes were similarly silenced or reduced in expression. The further breeding of mosses from these sports allowed for selection of higher degrees of "mossiness" than is found in R. fedtschenkoana. It would be interesting to see if healthier moss roses could be bred by using R. fedtschenkoana with existing moss roses, since the wild species doesn't seem to be as prone to mildew as the domesticated moss roses are. Off-topic, but if the proposed parentage of damasks is correct, perhaps breeders can "re-make" damasks by putting R. fedtschenkoana pollen onto the OGR 'Dupontii' which is claimed to be a R. gallica X R. moschata (or vice versa) cross. Or, perhaps even more interestingly, one could try using one of the purple gallicas with "Secret Garden Musk Climber" instead of pure R. moschata, and selfing the offspring, hoping to find a purple-flowered repeat-blooming plant, and then put R. fedtschenkoana pollen on that, and selfing those offspring. Maybe we could get a repeat-blooming purple-flowered damask from scratch. :-) ~Christopher

Dear Kevin, Hi! From your original description it appears that you are describing a sectoral chimera, a section or kind of pie shaped portion of the growing point bearing a mutation (either in all three layers of the meristem or even just one) and you get a section of tissue showing a different color for instance. I notice this rather commonly in blooms where there is a petal section or section of a whole bloom with a distinct color mutation. The challenge in this situation is to propagate a new plant from the mutated part to stably maintain the new mutation as a complete plant. As Karl describes, there's different types of chimeras depending on if the mutation is in a complete layer of the meristem or not. Chimera just means that there are some genetically different cells in the growing point. Depending on how the genetically distinct portions are arranged will depend on how stable the chimera is and how it is expressed in the plant tissue because the different layers give rise to different tissues. For instance most of the petal tissue is derrived from layer II and then just the outer layer of cells typically from layer I. Depending on the layer mutated and which layer is giving rise to various tissues, the ability to observe a chimera will be influenced. For instance, a mutation for flower color in layer III that is maintained as a periclinal chimera will not be expressed as long as the layers of the meristem is intact. If someone roots a stem cutting of this branch (adventitious roots typically come from from Layer III derrived cells) and then someone takes a root cutting and stimulates an adventitious shoot, the mutation from that once chimera can be expressed since all three layers of the new meristem from the root cutting will have come from layer III cells. Chimeras are interesting and they are common in plants. Identifying stable ones and / or isolating interesting mutations from them to make stable sports is often a challenge. I had a rose seedling that had streaks of variegation in the foliage this past spring. It appeared to be due to a periclinal chimera where layer II of the meristem was unable to produce chlorophyll. It was somewhat unstable and not that attractive unfortunately. The sectoral chimeras, like what you seem to have described, are generally pretty unstable. In the growing point there is a battle for one section of the chimera in a layer or layers to battle the other until one finally overtakes the whole layer(s). As Karl described with striped blooms that's in essence a type of chimera as well because the different colored petal portions have a slightly different genetic makeup. No one has really done the genetics to conclude how gene expression is influenced, but it is generally throught to be due to transposible elements / viruses and not really differing genetics between layers of the meristem. Within layer II of the meristem sections of DNA are periodically jumping out of a color gene, allowing it to express itself. For instance, you can have an anthocyanin gene for red color with a transposible element in it blocking its expression so you see white. In petal tissue this transposible element is often stimulated to transpose (move out of the gene and insert somewhere else) allowing for the anthocyanin gene to express itself in the orginal cell and cells that divide from that cell leading to a widening streak of color. Sincerely, David

Hi everyone, Sorry I've been away but we are in the middle of a major remodel, and my whole house/world has been turned upside down and torn apart. They've been ripping/ tearing down the chimney/fireplace, and have taken off the whole backside of our house (except for the drywall). Needless to say, it's been crazy here, and I haven't really been home, because the baby cant be around the construction while they are inside the house. But to answer some of your questions: A color break virus usually comes from another plant that is infected with a virus (and there are several types out there). It gets transfered to the plumeria via insects, gardening tools, water from watering cans, etc. It very well can be fatal to the plant (plumeria) but not always. It depends on the actual plant/ cultivar whether or not it'll survive. Princess Victoria is the most well known plumie with the virus, and is not negatively affected by it. But other strains can die from it (or have adverse reactions to it and not be healthy) Different people do different things with their plumies that have the color break virus. Some people destroy the plant, others don't do anything different with it, and then there are others that separate the infected plumeria from their other plants/plumeria. I have chosen to separate my plumie from the rest of my collection, so I have a smaller chance in one of my other plumerias getting infected. I also have tools/supplies that I ONLY use for the infected plumie, and I dont use them on any of my other plants. Karen B: I only have one plumie with the CBV...It's my Lavendar Splash, and it's the same plant that I posted a picture of before. The virus is just coming through stronger now, compared to when I first noticed the color variance. Musarojo: I purchased my Lavendar Splash from Green Thumb, and it came from C-Stars Nursery, which is known for color breaks in a lot of their plumies. Hope this helps, and I'm glad you enjoyed the pictures. I'll add more as new flowers pop up with the color break :) Joanna