I have some trouble propagating new trees from my Fukushu. I have done 4 attempts already on 3 different rootstocks (PT, Swingle & Aurantium) and always the same results. Around grafting after one week the rootstock start to sap oozing. I know that usually sap oozing is a defensive method against infestation. All tools was desinfected after every grafting and also in the same time I have done multiple grafts using different varieties but the Fukushu grafts always fails. I suspect that my Fukushu is carrying some kind of desease but I have no idea what the heck could be.

PT rootstock, here the budwood already died:


Swingle rootstock:







Here is my Fukushu tree. I can't see any sign what could let me to think that my tree is ill:


Please, if anybody has any idea or any advice what can I do or what could be is welcome! Thanks in advance!