I don't know your father therefore I don't know his sensitivity, which is something very personal. Anyway I also think that the surname is just an etiquette. The genetical information in genes doesn't care at all about surnames of course. I know in some societies kids get a surname which is a mix of the surnames of their parents. Maybe this example could help your father understand that there's nothing privileged about a son rather than a daughter.
I will add that in my opinion even genes themselves worth little. I think the very difference is made by how much you love your kids (and everything else in your life). It's all about it, therefore if I decided to become a parent one day, I might prefer adoption: it's not a joke that worldly overpopulation is a serious issue, so why not prefering helping someone who already exist and is in an unlucky situation?
By the way, both the will of maintaining a surname as well as that of maintaining genes is in my view a little typical of animals in a certain sense. It's the preservation instinct. But acting as conscious human beings we understand those two things are not the point. Someone's mind is his/her very self.
But the very relevant thing in your case, in my opinion but not only for sure, is that no one can require from your life a strong decision (like becoming a parent) as if that were a duty of yours. Your life is yours and only you have the right to lead it. Feeling guilty in this case is totally wrong. You don't have to argue with your father, just tell him that surnames are not the key of anyone's identity and that you don't feel to become a parent. It's your decision, not anyone's else and you must feel free in making it.
I hope these reflections will help you clearing your ideas
In the end though there's another set of emotions you have to appease first. You own. You have to live your own life to your own heart and desires, not someone else's, or you will never find happiness yourself either and you will end up like your dad. Trying to live vicariously through you. In the end children don't own their parents a damn thing. Sure, parents put a lot of effort and money into raising you, but in the end you had no say in coming into this world. That was their choice. To put it very crudely they wanted a child for their own selfish reasons, either for cheap labor, to look after them in their own old age, or basically a glorified pet.
Try to live your own life and be happy. If you do that any parent should be proud of their children. If not, then its their loss, not yours.