Question

Why Electric field lines are said to originate from positive charge?????

Answer 1

This is just a convention. The field lines tell us how a positive test charge would move if placed on one of those field lines. Hence the field lines point away from positive charges and towards negative charges. But instead we could say we want the field lines to tell us how negative test charges move. Then the arrows would change direction and some unsuspecting person would ask the exact opposite question.