Ronda Rousey's trainer says he's not bothered by the scathing verbal attack Ronda's mom directed at him over the weekend ... saying Ronda's opinion is the only one that really matters.
Ronda's mom AnnMaria De Mars went on Submission Radio and launched new insults at Edmond Tarvedyan -- calling him an "idiot" and a "fraud" ... and begging her daughter to cut ties with him.
But Tervadyan tells TMZ Sports ... he can't focus his energy worrying about what Ronda's mom thinks -- he's got more important things at hand .