Isn bokken technique taught in aikido?
Yes, with qualifications. Not every aikido dojo offers qualified instruction in actual sword techniques. Many of them use bokken practice only as a way of better understanding the empty-handed techniques, as these techniques are grounded in kenjutsu. Ueshiba-sensei was trained in many styles of bujutsu, including kenjutsu, jojutsu and aikijutsu. He distilled and modified the myriad of techniques he knew into modern aikido. Most modern students do not have the time or inclination to learn the empty handed curriculum as well as bokken and jo, so the concentration tends to be on the aiki techniques. Even among those dojos which emphasize bokken, the techniques are somewhat different from kenjutsu. Ueshiba-sensei’s swordsmanship was excellent, incidentally. Should you ever get an opportunity to watch film of him with a bokken, take it.