It may be correct technically but the sentence is difficult to read because it lacks organization. There should not be a comma after "that". An extra comma is needed after "situations". But really, the whole thing needs to be reorganized, broken into two sentences, and simplified for the sake of readability: "It’s stated in the lecture that few among the genetically uniform modified trees would survive during novel situations for which the modification isn’t designed. By contrast, normal trees can survive crises on account of their genetic diversity."

"On account of genetic diversity, unlike normal trees which can survive through crisis, few among the modified trees would survive during novel situations. For this modification isn't designed to be genetically uniformed."