These folks irradiated pollen at levels sufficient to incapacitate the paternal DNA but leave the pollen capable of extending a pollen tube and ‘fertilize’ the ovule, thus tricking the ovule into forming haploid seeds containing only the maternal genes.
They germinated their seeds by embryo rescue (culture medium containing supplemental nutrients and plant hormones) at a very early stage, 21 days and 35 days after fertilization, because seeds allowed to go to maturity did not germinate (for them - I suspect it was also somewhat a matter of convenience).
Be careful if you decide to try this yourself. The effective radiation dose was a minimum of 500 Gy from a cobalt source which is a pretty stiff amount of radiation, about 100 times more than it takes to kill a person.
I used to have a Cobalt Gamma Cell in my laboratory at the University. I did a number of experiments using it on roses, but all I produced were “monsters”. I guess they were similar to the descriptions of the first plants to appear at nuclear bomb sites.
I wonder if microwave radiation could be used. Those of you with microscopes could try germinating pollen in boron/sugar droplets after various time exposures to the microwaves to determine the maximum exposure before zero germination.
Interesting idea. I’ll give it a try later in the fall.
Notice in table 4 that they show that the pollen diameters for the haploids and a control tetraploid are consistent with the values that you and others have found.
Pseudo-fertilization is akin to performing wide crosses, which is another possible tool for breeders to induce haploidy. It wouldn’t be absurd too try dewberry, raspberry, blackberry, strawberry or potentilla pollen on roses for that purpose. Crosses of modern rose with roxburghii or the spins/foetidas would also be candidates as would crosses of New World species or close species to moderns, which are derived from Old World roses.
We were living-working in the same neighbourhood and first two were friends of mine. One is dead, the other retired I do not know where.
Quite often I looked at this work. Did not get plants or parts as it was Meilland’s funded so everything is lost now just as INRA la Gaudine is closed.
It is a revolutionnary idea, instead of bringing diploid species to tetraploid level, to bring modern tetraploid vars to diploid level. They just began breeding a few plants from dihaploid x diploid species before ending.
“It is a revolutionnary idea, instead of bringing diploid species to tetraploid level, to bring modern tetraploid vars to diploid level.”
This is why I have been inquiring a lot about the expression of both non-tea origin yellow and pelargonidin in diploids. I wanted to figure out if it was worth furthering new color tones into diploids. I am still unsure if the expression would be as saturated as they can be in tetraploids. I’d love to cross something like Coral Drift with Yellow Fairy just to see what the sprectum of color density would be like. My concern with diploids, and why I bring all of this up, is that they can easily become “more of the same” or easily lost among the sea of others with the same tones. Foliage, architecture and bloom style can perceptively change in a dramatic way with any differentiation in tone. People are drawn to roses because they can find a tone that matches them, whether it be blush white or deep bronze. I am guessing that both Kordes and Poulsen know the answer to my inquiry. I am also curious if the caninae family would express tones differently depending on which uneven arrangement was made. I wish I had an extra acre to experiment with that idea. I’d also love to see what radiation would do to the unusual meiosis behavior, lol.
lol, radiation scares me. My system is already screwed up enough as it is. It makes me wonder if roses were mass produced more north than California or Texas that there would be fewer cultivar sports produced. A lot of sports seem to come from California gardens but its hard to say anything since there are more rosarians in Califronia than most other states. I wonder where the sport that became Chicago Peace was originally grafted from? It was discovered in Chicago but that does not mean that the mutation itself originated in Chicago. Then again, UV radiation may have little to even do with sports. Who knows
Can one create a full-sized diploid miniature from diploids not related to any rose of the synstylae family and Rosa chinensis minima? An example could be something like [(Rosa rugosa x R. acicularis nipponensis) x (Hume’s Blush Tea-scented China x Rosa chinensis minima)].
I am curious as to the reliance of dwarfism from the synstylae influence. One aspect of this inquiry is that the vast majority of diploids are usually either ramblers close to the equator or North American/East Asian briars. I am curious as to what happens when tetraploids of other species and families are then set into the diploid constraint.
There are some triploids with more saturated yellow color than china/tea one.
Persica and acae are diploid sources for more saturated yellow. Former and its direct hybrids is too desease succeptible for me to be able to work with. I am waiting for someone breeding further persica at diploid level. Acae hybrids I got to date were sterile.
Gigantea the largest seeded species is a diploid. Pollen or stomata guard cells are said to be more reliable.
About full expression miniature away from synstilae it was done: Paul raised at least one involving foliolosa as I did. If I remember well some were bred from rugosa also.
In my opinion synstilae are very very close to chinenses and banksiae as all are interbreeding without loss of fertility.
Paul’s hybrid is from several synstylae backgrounds. Anything from originating Moore will likely have heavy synstylae influence. If you look at Elfinglo, a selfling of Little Chief, you can definitely see the influence. I actually find Paul’s hybrid to be very beautiful but it is not what I meant because it is a 3’+ shrub. I meant a full sized modern miniature (like, for example, Magic Carrousel since the world is familiar with it) without the usage of any synstylae genetics.
I think there is a paper floating around showing the relative relation of most species. It was posted on here at one time. It might contain info for gigantea, bract, banksia, chinensis, etc. What was interesting to me is that the majority of diploids usually fall into certain specific groupings. It makes things difficult, lol.
I wonder if Rosa ecae can help produce mauve on the diploid level like Rosa foetida did on the tetraploid level.
“I meant a full sized modern miniature (like, for example, Magic Carrousel since the world is familiar with it) without the usage of any synstylae genetics.”
What do you blame about synstylae genetics?
There are a lot of phylogenic tree.
Different ones according to what was considered.
Bracteata is with very few others in a group of its own. Its F1 hybrids fertility excepted for closely related is low to poor.
Acae has a lot of untaped potential I am trying to explore. Here again fertility and reccurence without loosing color are problems.
I’m not blaming anything. I am mostly curious as to pathways into the future, and how what would affect what and to what extent. In otherwords, I am trying to look (as best we can) before leaping. And, also, looking at ways in which we can minimize lost time or potential since hybridizing is partially a game of massive patience. I also want to see what could be missed, if possible.
Regarding miniatures, I was initially curious if something entirely new could be invented in terms of a class archetype. Synstylae is such a strong influence on the various miniature classes that it is difficult to seperate out mentally. A huge surge is going around the world in terms of “sustainability” etc where modern form and design is being edged out to anything simplistic and green washed. I had wondered if it was possible to attain something within that narrow vision that was also useful in the modern, small gardens of today. I was imagining something upright but chaotic in it’s branching habit (like most briars) to 2’ or so, with semi-double crepe paper blooms of a sweet prairie scent. It would repeat bloom, look great near any type of drought-tolerant ornamental grass type and have a fall foliage and hip display. Personally, it is not my type of taste, but I could see that something of that nature could be easily employed in many ways. I often see the Flower Carpet series planted next to random ornamental grasses and there is a huge mismatch between the two schema because the Flower Carpet series usually employs (some better than others) the rounded nature plant with shiny foliage and random clusters of blooms everywhere. Sometimes I am still amazed it is 2010 and Potetilla fruiticosa ‘Gold Star’ still sells in massive quantities.
Yeah, Rosa ecae seems like a royal pain in the … to work with. My crop science buddy had a chart showing me statistical probability per generation of breeding out blackspot alone from Rosa foetida. It was some insane number. I am unsure how the ploidy would affect the inheritance of any of the traits we are seeking and avoiding. If it is anything like Rosa foetida, which seems possible, it looks like an uphill battle, especially given the fertility difference between Rosa foetida and Rosa ecae.
Seedlings of Prairie Peace segregated by size in a classic recessive pattern of 1:3, as did seedlings from R. acicularis. I noticed the pattern in other spins as well, so I suspect that ‘miniature’ may come about easily in nature and can be amplified by judicious crosses.
I kept a couple of the small acicularis seedlings to see what comes of them.
I often find that modern vars mostly synstilae/chinenses phenotype is too dominant. So I share your concern.
My answer to this fact in order of preserving specific features is going back to species and/or staying away from mainstream moderns.
In my climate miniatures are too desease prone to be bred for. I agree that in easier climates introducing miniaturizing genes in reccurent species or close to species vars is quite tempting.
Jadae UV radiation should only be a really small part of what causes sports in roses. Chlorophyll somehow provides some protection for plants. I am not sure how, but I do know when they try to do UV radiation it is important to grow plants in the dark for a while. Also the states with the highest uv radiation are the states with the higher elevation. I would think most of california would be around sea level.
I have tried microwaving pollen. I was not really all that scientific about it. Microwaving at lower power for a few minutes did not seem to have much affect on pollen fertility and none of the resulting seedlings were kept but the crosses were not all that great anyways. For example I crossed Rise N Shine with pollen from Black Jade. Can we say powdery mildew. On the regular setting of power the pollen failed to fertilize anything after two minutes of microwaving. I was planning to try more this past spring but forgot all about it. One important thing to remember is different microwaves have different level of powers.
Maybe some one could try using the glow in the dark hands in watches.
A possible explanation for all the sports in california besides shear number of roses could be radium in the soil. A lot of the western states have heavy radium. Some areas have such high natural level that if it were in an eastern state they would not allow a building to be built upon it but since it is in say wyoming or colorado they allow a higher level before they say you can not build on the property (at least when it comes to commercial sites). I am pretty sure California may also have higher radium and other metals in their soils like Colorado, Wyoming, Utah, Nevada and Arizona has but I am not certain.
When we talk about radiation, we need to distinguish ionizing radiation (X-ray, far UV, gamma rays) from common radiation (sunlight, infrared, microwave,heat). Mutations happen when DNA gets damaged by breaking some part of it and a mistake happens when trying to fix the damage. Until that failure of repair point we never will know what happened, so genetically there’s no mutation. It takes a high energy photon to do that kind of damage (to break bonds in the DNA). The UV that should be screened by ozone (shorter wavelength than 260 nm) is the lowest energy kind that can damage DNA. And plants use anthocyanins, carotenoids, and chlorophyll to prevent most UV damage. With yeast it is possible to measure the rate of UV at different times of day, different altitudes, different degrees of cloudiness, smog or ozone layer. They lack those protection mechanisms. There are a bunch of papers on that subject out there somewhere.
Radon does its damage only when very close up. You have to breathe it into your lungs for it to damage them. So probably it won’t make much difference to plants that there is radon in the soil. And heavy metals like uranium are not taken up into plants. So that’s not a worry. Strontium-90 might be if we had it falling down from the skies like in the '50s & '60s. It behaves like calcium. That’s why it’s so bad in milk.
It is much easier to make mutations with chemicals like mustard gas, but again, they’re not too likely to get into the plant without reacting on its surface first. And plants resist many animal and human carcinogens because they do a different kind of metabolism to inactivate them, so they don’t have them anywhere near the cells making eggs and pollen.
Pollen is protected from UV by its yellow color. So X-ray, and gamma rays are basically the only tools we have to produce enough damage to the DNA that it becomes unrepairable. Or perhaps some strong alkylating agents like mustard gas, but that would be nasty to get near. Radiation from, for instance, a dental X-ray machine leaves no residual. Same with a medical Cobalt-60 source. People with connections to a lab have used such things on seeds, yeast or pollen.
Thanks for the info Larry. So you do not think high levels of radium in the soils could cause these mutations? Or is it more likely to only effect root stocks that have direct contact in the soil.
Another question is the vast majority of sports coming from the 50s and 60s or is their no correlation with this time period? If their is a correlation with the time period why do we not see it in other areas. Would it be Californias proximity to Nevada where they did a lot of testing of nukes?
Also Larry do you think microwaving pollen would have an effect on pollen genetics or do you think it could be wasted effort?
I subscribed to Organic Gardening and Farming for decades. Back in the seventies or eighties I think, they had a lot of articles about planting in metal cans in that the metal attracted something (electrical charges?) which enhanced growth.
Shortly thereafter, they did some articles on naturally ocurring mutations ocurring in farmer’s fields. Apparently farmers had noticed in some of their fields there would be areas or “spots” where there was an increase in apparent plant mutations. Further testing with meters showed that these areas had higher meter readings. ( I don’t remember what the meter was said to read-electrical energy, radiation etc.?) Apparently, energy (electrical or charges of some sort, leave the earth’s surface in a band and then like a rainbow arc and reenter the earth at another spot. They concluded that this was the reason certain areas had higher occurrences of plant mutations.
Sorry I can’t remember more; it was over 3 decades ago; maybe some of the physicists or geologists can jump in.
