Qasim was welcomed into the party fold by PDP patron Mufti Mohammed Sayeed and president Mehbooba Mufti, a party spokesman said.
"The PDP during its brief tenure had brought in fundamental changes in the entire state and Kargil and Leh had been the major beneficiaries of empowerment and development process," Qasim, a prominent academician from Kargil, was quoted as saying.
He was "impressed" by the functioning of the party and its "visionary leadership," the spokesman said.