Mammillaria luethyi seed production

Hi, I want to start my experience in this forum asking something about one of my favourite plants, M. luethyi. Last year I had only a plant in flower but it produced some seeds that I tried to sow, without results, but that was interesting because I used to think that this specie was autosterile. This year happened the same thing. I know that, in nature, seeds of M. luethyi are kept in the body of the plant for years, so, when it's the best time for keep them out the plants and sow and how the scarification of the seeds has to be done?

Hi Luca,

First of all, welcome to this forum. It has become less active over the last 5 years (the same happened to the German Kakteenforum, which has a subforum dedicated to mammillarias). I think that Facebook has 'taken over' much of these forums. I am surprised that your M. luethyi is self-fertile, but it is not impossible. I used to have a plant of M. tepexicensis which was also self-fertile (the other 3 were not).
Harvesting of M. luethyi seeds. I harvest mine during the growing season. This year it was somewhere in July. After harvesting, there is a hole in the plant, and therefore I prefer to harvest the seeds during a dry sunny period in order to prevent rotting.
Germination: I had not much success with M. luethyi. On the German Kakteenforum an interesting method was recently described by Franz Dankwart, see https://www.kakteenforum.com/t38344-aussaat-schwer-keimender-kakteen-insbesondere-mammillarien. He keeps the dry seeds for 1 to 2 weeks at 50 °C, then sows them, and gets quite good results. This probably mimics nature, where this species (and others with cryptocarpic fruits) grow on barren gravel fields, where the sun can make the substrate very hot. I will try Dankwart's method next year.
On https://cactiguide.com/forum/viewtopic.php?t=20291 you can read about someone's experiments with M. theresae, using wet paper.

Regards,

Wolter.

You could also try the method described in this video: https://www.youtube.com/watch?v=BbeXw2xafrc&t=52s

It might be a bit tricky to cut off a small piece of the seed and not of your fingers.

Wolter.

The process involving paper is very interesting and I think I will try. It's curious that this specimen of M. luethyi is autofertile, it produces lots of seeds by herself. Thanks Wolter, I will share with you the method and the results

Ok, nothing popped outfrom the seeds. Now I will try to damage the external tegument and then leave them in a solution of GA3 and water. Let's see if it works

On the German cactus forum there is a subject about difficultly germinating mammillarias. See https://www.kakteenforum.com/t38344-aussaat-schwer-keimender-kakteen-insbesondere-mammillarien. The method mentioned by Franz Dankwart involves heating the seeds prior to sowing. I am experimenting with this method. It worked very well for M. tetrancistra (also works for Pediocactus and Sclerocactus), but not yet for M. roemeri and M. roczekii, possibly because I sow in pumice/vermiculite and when that is allowed to stand with water, the water becomes slightly basic. I probably need a slightly acidic environment, i.e. having peat in the substrate (Dankwart's substrate contains peat). To be continued.

Wolter.

I tried the method of heating too but it didn't work, maybe the seeds are too fresh and the fenolic substances under the integument are more active

I'm sorry for posting that link to the German cactus forum. I had forgotten that I had already mentioned it in a previous mail. I don't know what your substrate is, but I think that it should preferably contain peat (but not cocopeat, which is not acidic).

Yes, I rode about the fact that acidic substrate helps germination and so I will use peat in the soil. I have big hopes about the method with scarification and GA3, at university I am working with a PHd botanist who suggested me that. He said that this method works well with alpine pioneer plants, and I think that could work for luethyi and other mammillaria because they are mountain plants of extreme climate too, with similar strategy about seed germination in function of preserving the species

Yes, I rode about the fact that acidic substrate helps germination and so I will use peat in the soil. I have big hopes about the method with scarification and GA3, at university I am working with a PHd botanist who suggested me that. He said that this method works well with alpine pioneer plants, and I think that could work for luethyi and other mammillaria because they are mountain plants of extreme climate too, with similar strategy about seed germination in function of preserving the species

Basically, there will be two compounds in these seeds, a germination inhibitor (abscisic acid, ABA) and a germination promoter (gibberellic acid, GA3). You have to get rid of ABA in order to get germination. In nature the ABA will get washed out by rain (after the seed has been 'cracked' by long dry heat), and such a rainy period is also the perfect time for GA3 to do its job.

I have to do it artificially, because where I live it's so cold now and it doesn't rain, it snows. I would lire to try it naturally but I'm too impatient, spring is too far