Interesting. Is it even a Turbinicarpus? It doesn't look like one, the stigma would usually stick out beyond the stamens. It also looks liked your grafted plant may be flowering while it still has juvenile spination and also pupping very early. T. gracilis without adult spines? One of the Gymnocactus?

shurbs n bulbs

Thank you very much for your comment.
It seems I should wait until the cactus becomes a mature plant.
I also attach a cactus photo, which I think it is an alonsoi. I sowed seeds same time and grafted same day.

Frank

Here is a link that might be useful: alonsoi