Winter is a time to plan the next seasons outdoor activities. As you can see from my other posts, this season I am interested in increasing my chromosome doubling options.
I would like methods that are relatively safe and can be done without complicated laboratory equipment. For example being able to dilute something until a color is barely visible is preferrable to a method that requires weighing out a sample on a sensitive balance. Also a method where the results are onvious is preferred to one that requies a laboratory chromosome count.
Along those lines I wonder what can be done with coffee?
Title: Chromosome doubling of haploids of common wheat with caffeine.
Authors: Thomas, Julian; Chen, Qin; Howes, Niel
Authors Address: Lethbridge Res. Centre, Box 3000, Lethbridge, AB T1J 4B1, Canada.
Published in: Genome, volumn 40, pages 552-558,(1997).
Abstract: “Treatment of dividing plant cells with caffeine inhibits their cytokinesis, thereby inducing the formation of binucleate cells that contain polyploid nuclei. This study was undertaken to determine whether caffeine treatments would induce chromosome doubling and seed set in haploids of common wheat (Triticum aestivum L. em. Thell.) through the further development of diploid nuclei. Ten sterile wheat haploid plants, obtained through the agency of corn (Zea mays L.) pollination, were multiplied by vegetative propagation (subdivision of well-tillered plants) to produce about 50 crowns per haploid. Washed and trimmed crowns were treated with 0.3, 1.0, 3.0, and 10.0 g cntdot L-1 caffeine for 3, 6, 12, and 24 h. While treatment with 0.3 g cntdot L-1 caffeine did not restore fertility, higher concentrations of caffeine resulted in pollen shedding and substantial seed set compared with untreated controls. Many combinations of caffeine concentration and duration produced comparable results; however, treatment with 3 g cntdot L-1 for 24 h was the most effective caffeine treatment on the basis of the number of seeds recovered, as well as the size and incidence of fertile sectors. Compared with a standard colchicine treatment (3-h immersion in 2 g cntdot L-1 colchicine dissolved in 0.5% dimethyl sulfoxide), all caffeine treatments produced fewer seeds, principally because colchicine-doubled sectors were often large, while caffeine-doubled sectors were numerous but generally small. In conclusion, caffeine produced useful numbers of seeds for all clones; gliadin banding patterns and chromosome counts indicated that genetic and cytogenetic stability of the doubling process were equal or superior for caffeine compared with colchicine.”
I’ve thought about using Surflan as a doubling agent, but I’d be even more comfortable using this! (I was going to say that someone finally found a good use for coffee, but realized that would offend too many 
Question: What amount of coffee dilution would give you the percents used in this study?
Another thought: Aren’t pills whose main ingredient is caffeine sold OTC?
Chris Mauchline
SE PA, zone 6
Related questions:
Does the world really need rose hybridizers whose chromosomes have been doubled by the use of coffee?
What would be the objective of doubling the hybridizer’s chromosomes? To increase hardiness? To increase disease resistance? To increase productivity?
How would doubleness be identified? Is the presence of doubled chromosomes in a hybridizer indicated by stunted growth, or by tallness, or by expansiveness?
Once it is known that the hybridizer’s chromosomes have been doubled, should the hybridizer be tested for duplicity or for other fitness before being allowed to supply genetic material in a breeding operation?
If caffeine doubles chromosomes, I must be at least octoploid by now…
I had no success using caffeine last year. I used caffeine pills used for dieting, although I don’t quite remember the solution strength. I used many methods of application as possible, including DMSO, vassaline, agar, and plain water.
This may be a silly question but I’ve never come across concentration expressed as “3 g cntdot L-1”, so could someone tell me what the “cntdot” means. I’m guessing maybe that it’s something like “contained in”?? thanks
Enrique, how about mixing it with a light foliar feed? Or, Hmm. somehow used during a process of callusing?
Tom, I also am not familar with “cntdot”. An on line dictionary search did not report a hit. Google finds many useages of it, but I did not find a definition among the hits.
I got in touch with some of my chemist friends here at school, and this is the apparent solution to the mystery of cntdot.
“cntdot” seems to be the abbreviation for “center dot” and it refers to any character that can not be readily used in the text of a document! For example in the article below related to:
“The effects of low-doses of fentanyl, buprenorphine and pentazocine on circulatory responses to endotracheal intubation”
The article linked below mentions (among others like it) “0. 5 mg cntdot kg-1 of pentazocine”: this should be read as “0.5 milligrams per kilogram (body weight of the subject) of pentazocine (the drug).”
Link: www.coretext.org/Coretext/Gbphbibl.nsf/0/e345681cf236c30e0025674d002f4bf8?OpenDocument
Thanks Peter, it is sad that the editor allowed such a “slang” to be put into what is supposed to be written in formal English.
I had no success using caffeine last year. I used caffeine
pills used for dieting, although I don’t quite remember
the solution strength. I used many methods of application
as possible, including DMSO, vassaline, agar, and plain
water.
Enrique,
As you said, you don’t remember the solution strength. Do you think you approached 3g of caffeine per Liter? This to me sounds like a lot of pills.
Chris Mauchline
I can’t remember the brand, or how much it contained. But I I think I made a very strong concentrated paste, then a watery solution. Well, I may retry it again next year. I would I would love to see if I could get some crosses of diploid species and try to get a fertile tetraploid such as R. foliolosa x R. wichuraiana poteriifolia or, if possible, R. abyssinica…