Hi everybody,
If a cleric has got the talent "Divine Defiance", can he cast Dispel Magic to counterspell a blast spell, using this talent?
PHB does not underline what kind of spell can be dispelled by this particular magic.
(e.g. A wizard spells Fire Ball against a clerical, can he counterspell that with Dispel Magic using the talent?)
More Generally, can Dispel Magic be used against a blast magic (with or without Divine Defiance) or it need to a appropriate counter?
Thanks for the attention. 
I think you need this forum instead. The one you're in is for Fifth Edition.
While true that this is a 5e forum, I can still answer this.
The feat doesn't give you a counterspell on its own, so to speak - it lets you cast a counterspell (including dispel) as an immediate action instead of as a readied action, by spending a turn attempt. Normally you need to anticipate spells by saying "I ready an action to counterspell if he starts casting a spell". Divine Defiance lets you do it instead as an immediate action by spending a turn attempt. The rest of the counterspell system is unchanged - you either need to cast the same spell (in which case you automatically counter it; note that you need Spellcraft to ID the spell to use) or a dispel (in which case you need to succeed on the dispel check). The only thing that's different is you spent a turn attempt to do it as an immediate action instead of as a readied standard action.
The "kind" of spell never matters, as arcane and divine magic are transparent. This is generally true no matter what system of magic you're using in 3e: unless an effect specifically says it only works with one kind of magic (i.e. "expend an arcane spell slot") or relies on mechanics that are unique to one type of magic (i.e. "expend power points", unique to psionics), all magic is the same. If you have Burning Hands as a Fire domain cleric, you can counterspell a wizard's Burning Hands just fine with it, and the wizard's Dispel Magic might be able to counterspell your Flame Strike.
Dispel spells can counter anything, but they need a a dispel check instead of being automatic. Stronger dispels have higher bonuses on the check. There are also a few spells that use the same sort of mechanic as Dispel, but can't be used to counterspell (Dispel Ward or Arcane Turmoil can't replicate the Counterspell version of Dispel Magic (only the targeted or area version), and Dispel Psionics has identical wording but lacks a counterspell option).
Be advised that counterspelling in general is seen as a bad strategy, although Divine Defiance changes things a bit. I'd suggest reading this.