DUBAI- An adviser to Iran's Supreme Leader Ayatollah Ali Khamenei joined the presidential race on Friday, with authorities keen to make the June vote a peaceful contrast to the upheaval that followed the disputed 2009 poll.Reformist groups have been suppressed or sidelined since then and the next president is likely to be picked from among a handful of politicians known for fealty to Khamenei, minimizing the chances of political rifts leading to post-election chaos.Lawmaker and former parliament speaker Gholam-Ali Haddad-Adel registered to run, state news agency IRNA reported, becoming the first of a trio of Khamenei loyalists to do so.Khamenei, who in theory stands above the political fray, is thought to want a reliable follower in the presidency after Mahmoud Ahmadinejad's two turbulent terms - and to thwart any attempt by the outgoing president to promote his own successor.