The Southern part of India happens to be the actual point of origin of the banana plant and would therefore be the site with the greatest genetic diversity of both edible and wild inedible banana species. Same way Kazakhstan happens to be the origin of apples and used to have the most genetic variation until some Soviet era dictator decided to have much of the forests that were the gene bank for apple varieties cleared to grow cotton instead.

Of note, many have forgotten, but rice suffered from a pandemic blight in the 1980s that was saved only because a particular species of wild rice, coincidentally found in South India, happened to have disease resistant genes.