Yes?

Selective breeding to get plants with different characteristics inherently involves modifying the genes of the plant. Genes that lead to unwanted traits are bred out, and genes that lead to desirable traits are promoted.

A plant that undergoes this process has been genetically modified from its wild, undomesticated counterpart. It is a GMO (in its broadest definition).

Bananas are actually a really interesting plant and I recommend reading about the work being done even today to breed new disease resistant varieties, mostly involving mutation breeding (selective breeding with radiation to speed things along).