Transfer characteristic of p-channel JFET
Considering the output characteristic of the n channel JFET, can we
  somehow obtain the same characteristic only for the p-channel type of
  this transistor?


It's not practical because the manufacturing tolerances for any specific N channel JFET are so wide to make it a worthless exercise. See below from the 2N5486 data sheet: -



The above describes the channel resistance against temperature WHEN the voltage across gate and source is zero.

If you picked out one device that had Vgs(off) = -1V then you'd use the top curve but who knows what device you have grabbed from the handy bag of JFETs. It could easily be a device whose Vgs(off) was -8V

Because of this, Fairchild (and other suppliers) have basically created three part names for the same device because the tolerances are so wide. If you read the data sheet there are: -


2N5484 having a Vgs(off) between -0.3 and 3.0 volts
2N5485 having a Vgs(off) between -0.5 and 4.0 volts
2N5486 having a Vgs(off) between -2.0 and 6.0 volts


Irrespective of all that, they are still anticipating that some may have a characteristic that is -8.0 volts! It's not unknown on Fairchild data sheets to have made a typo and actually meant -6.0V.

So, trying to characterize a P ch JFET from an N ch device is fruitless