possible, MOSFET can conduct in reverse direction because drain and source are interchangeable depending on the potential on them. If R1 is the load, i think u need to control the bias voltage of Q1 instead of GND. But I m not sure wat is the circuit performing. For me, it seems like u wan to use 2 voltage source to drive the load.
if the arrow is the current flow, then it's not reverse conduction.
cause it is a PMOS, the VSG =(15-0) > |Vtp| , and VSD=(15-13)=2 < VSG-|VTP| , so it is in triode region.
Well, since the PMOS FET is in linear region, it is acting like a resistor. Well, the indication seems fine because, the current is going in to a lower voltage source. There does not seem any problem as far as I know.