The answer is probably not. Low PR Backlinks will certainly not hurt your online presence but it will not do you any good either. You may have several low PR Backlinks yet it will not raise your PR as fast as a high PR Backlink would do.
However, you must keep in mind that having too many high PR Backlinks can make search engines suspicious. Make sure you are not being linked to by spam websites. Your best bet is to keep your site as natural looking as possible, hence have a mix of both high and low PR Backlink to avoid being considered spam.