Love is a strong, complex emotion that, at times, seems to have more control over us than we have over it - and we don't always choose the people we love in certain relationships outside of family - it just happens, and we love many different people for many different reasons. We don't get to choose our family either, of course - but a family relationship, usually, is such a strong bond and our love for one another so ingrained; that even though sometimes we don't even like certain family members, have been hurt or even betrayed by them, - we still love them and are much more forgiving.
So, do you have to trust someone to love them? I would have to say that trust is very important and would affect the quality of your love for that person. Eventually, I believe if trust became an issue, that lack of trust would erode the love. For love to be strong and positive, trust is an important component. Can love transcend the issue of trust at times? I believe that depends on the reason why trust became an issue in the first place and the impact it had on you and the relationship and how forgiving you can be, or should be - trust can be regained, but it takes time and a lot of work. But a person will take the time and will work at it, if the love is really there and worth saving - so yes, love can sometimes transcend the issue of trust.
Love, and relationships, are complicated - and there are no simple answers.