Adopted dog scared of boyfriend

Question
Hi there,
My boyfriend and I adopted a dog yesterday.  Tesla a 10 month old shepard/husky mix.  When we picked her up yesterday, she was perfectly sweet to both of us and sat in the back seat with my boyfriend.
But at some point yesterday the dog became deahtly afraid of him. (we're not sure when it even happend. i've been around them both the whole time and he didn't do anything to scare her) Shes now scared to be in the room alone with him, and growls at him if he approaches and i'm not petting her already. We've been telling her "no" when she starts, and she stops and will let him feed her, pet her, but she does so submissively-tail down, ears back, won't make eye contact.
He's now been the only one giving her treats and I won't praise her unless shes being nice to him.
Will this help? Or do we need to go about this a different way?

Thanks so much!
Tesla is a sweetheart and we just want her to be happy, not scared!

Answer
Some dogs that have not had extensive social contact with men are afraid, mainly because they are larger, louder, and tend to approach dogs in a frontal, direct way.  Avoid punishing her at all for growling.  That's her early warning system, and if you scare her enough to make her stop growling, she has nothing but a snap left to increase distance between her and scary things.  It can take a newly rescued dog weeks to acclimate to new surroundings, so be patient.  The dog you see today may not be the dog you end up with.  Example - my hound, rescued at age 2, was afraid of my boyfriend, trash cans, and his own leash.  Now, he is a registered therapy dog!  That's not to say your dog will progress that dramatically, but your initial instincts to have your boyfriend give her treats was partially correct.  What I recommend is for him to feed her all her meals for the next three weeks or so (while you give her nothing, even though it's hard!).  Otherwise, he should not approach her, he should wait for her to come investigate him.  When she does, he should avoid reaching for her.  Have him just drop a treat onto the floor and not make direct eye contact.  Later, once she is comfortable with him, he can start teaching her to look at him when he says her name.  Lessons for that (attention) can be found at www.clickerlessons.com.  I would use a marker word, like "yes", rather than a clicker, for such a fearful dog.  There will be plenty of time later to see if she can tolerate the clicker noise.  For now, your object is to make her trust both of you.  Do NOT force her to interact with people she doesn't know.  Instead, get them to toss treats to her onto the floor from a distance.  That way, she can learn that their intentions are good.  The more you repeat that, the more she learns that most people mean her no harm.