GA flight instructor reported unusual attitude event during instrument training with student.

Narrative

In moderate continuous turbulence when performing the course reversal on the RNAV 19 approach into 9D4 with a 50 kt. wind out of the southwest my Student disconnected the autopilot when he thought it wasn't going to be able to complete the parallel entry to the final approach course. He initiated a steeper turn than the autopilot had and then went heads down to look at the approach plate. I was also head down looking at the approach plate when I noticed increasing positive G-forces and looked at the instruments. We were in a 45 degree bank losing 2;000 FPM of altitude. I immediately called bank angle twice and shielded the controls as the learner recovered. We lost 800 feet and ended up well below the minimum altitude for that segment of the approach. ATC notified us of a low altitude alert; by which time we were already recovered in a stable climb. There is an antenna in the area that reaches 1927 feet MSL; less than 600 feet lower than our lowest altitude. Although this was a poignant lesson for the student on the importance of maintaining an instrument scan; our safety margin was fairly low. An incorrect recovery input could have quickly turned the upset into a disaster. The aircraft does not have an aural warning when the autopilot is disconnected; which would've helped both of us be aware that the aircraft was being hand flown. In its absence; I recommend pilots announce themselves that they are disengaging the autopilot which will help them and their crew be more vigilant to maintain control.