Anthers Drying Out Before Bursting

During the winter when my OP seedlings bloomed, I cut off the stamens in the morning and put them on a dry piece of paper. The next morning when I returned to them perhaps they ripened but they hadn’t burst spilling pollen they were hard a rock. Since then I have purchased florist roses to get the pollen and the same thing has happened with them turning hard.

I have some serious pollen gathering coming up and I am scared of not getting any pollen. What will change my experience so that I will be seeing and gathering the powdery pollen from now on and not dried out anthers?

I am very interested in this as well, as it happened to me last night. Harvested “Sharifa Asma” (I know it supposed to have weak seedlings, but as it has (from my perspective) many good qualities, I wanted to try) anthers yesterday evening (Nothing else ready for pollination). This morning, litte dried nubs.

Not all rose varieties produce a lot of pollen from their anthers. That’s one reason why we see the same roses frequently listed as male parents. In addition, just having dust doesn’t mean one has viable pollen. Last winter I collected lots of pollen (dust) from the florist cultivar ‘Grand Gala’. I looked at it under the microscope and tried a germination assay (15% sucrose 40ppm boric acid) and barely got any to germinate. Also most pollen grains were shriveled and aborted. After 4 hours in the pollen germination solution, a more fertile cultivar had pollen tubes about 30x the length of pollen grains, while the few grains that germinated of ‘Grand Gala’ were only ~10x the length of a grain.

Sometimes I get disappointed when roses that have traits I really love and would like to use as parents don’t cooperate. I hope you find these roses useful and can get more pollen from them. Yesterday I went to a cut florist rose grower and was able to collect almost open flowers on short unsalable stems of ‘Grand Gala’ and other roses. I’m hoping that the pollen will be more viable than the pollen I collected off of cut stems last winter that I’m sure were refrigerated for at least a week before I got them.

Take Care,

David

I recently came across a scientific literature article that stated that if the anthers were picked too green the pollen would not germinate, but the pollen would germinate after an acetone rinse. I have not yet tried this, but I have deposited fresh pollen on flowers with a acetone “slush” and did get hip set. If you are not familar with acetone, it is a very rapid evaporating solvent. If you try this, please read the precautions on the container.

So, Henry, you just wet the anthers with acetone and let it evaporate?

Yes, if it works. The acetone probably will have a long term negative effect on the pollen so you would want to use the pollen that day (not store it).

This was the reference (I had posted it earlier, do a search of this forum for organic and you will find the complete post.):

Authors: WAKI K; TAKEUCHI K Authors Address: FAC. AGRIC., TAMAGAWA UNIV., TAMAGAWAGAKUEN 6-1-1, MACHIDA-SHI, TOKYO 194, JPN. Title: POLLEN COLLECTING METHOD FOR ARTIFICIAL KIWIFRUIT POLLINATION 1. WASHING METHOD BY ORGANIC SOLVENTS Published in: Bulletin of the Faculty of Agriculture Tamagawa University, volumn 30, pages 59-72, (1990). Abstract: " Pollen collecting method for artificial kiwifruit pollination: 1. Washing method by organic solvents.To develop a labor-saving method for collecting pollen from Kiwifruit flowers, several procedures were examined; the following results were obtained. Pollen from pollen loads collected by honeybees showed a germination rate of 85%, but it was decreased to 40% after 4 days storage at a room temperature. When pollen loads were washed with successively decreasing concentrations of sucrose and finally with water, the germination rate was 78%. When pollen loads and pollen collected directly from flowers were washed with either 50%, 30% or 15% sucrose solution and then with water, their germination rates after drying were about 20%. This result suggests that these washing and drying methods are not suitable. The following 11 organic solvents out of 26 solvents used for washing showed high germination rates (over 50% of non-washed pollen): cyclohexane, n-pentane, isooctane, toluene, benzene, xylene, methyl acetate, ethyl acetate, diethyl ether, n-butyl alcohol and isoamyl alcohol. Pollen from early-stage male flowers did not germinate at all. But when it was washed with organic solvents after drying for 24 hours, its germination rate was as high as 77%. After 2 years of storing benzene-washed pollen at -17.degree. C, the germination rate was as high as 89%. Even when pollen was stored for 4 years below -17.degree. C, the germination ability was maintained to some extent (41% .apprx. 69%) when the pollen was washed with several solvents just after collection. Washing flowers with toluene, sucrose solution or water yielded more pollen than sifting although the latter two solvents reduced the germination rate considerably after drying. When toluene or benzene-washed pollen was used for hand pollination in the field, the percentage of fruit that set was high with no significant difference compared to non-washed pollen. The fruits obtained did not show any deterioration. Toluene and benzene are useful for obtaining pollen for artificial pollination."

Ok Henry, I tried this with nail polish thinner (butyl acetate, ethyl acetate and heptane) on some dried up anthers, and it did release the pollen! I used the pollen, but I also used some other pollens, just in case, so it will be hard to tell if the pollen was viable. The treated pollen came from a striped rose as opposed to the other pollens, so if I get stripes, there’s a fairly good chance it did work, I guess.

I’ll let you know if I get stripes (or nothing for that matter).

Nail polish remover didn’t work, by the way, since it has oils/proteins in it which slows down the evaporation and leaves an oily film.

Can you let us know the method you used for applying the

thinner?

Also, may I ask what striped rose you were using? I’m doing some striped breeding myself.

Thanks,

Chris Mauchline

I just barely covered the anthers in a tiny 1/2" cap-dish, and the solvent evaporated within 1 hour. The rose is “Tropical Sunset”.