center, I'm no expert but from experience with my one vuyl anything squishy is BAD. Cut it out the squishy ASAP and whatever roots look rotten and repot. I cant comment on culture because mine didn't make it. I tried to save as much as possible but didn't cut enough and the rot spread. I just cut it off a piece at a time until it was all gone instead of doing the radical surgery that might have saved it. Good luck!