Bananas are a good example they are all clones, 95% of banana exports come from a single cultivated variety, the Cavendish.
https://en.wikipedia.org/wiki/Cavendish_banana: "After years of attempting to keep it out of the Americas, in mid-2019, Panama disease Tropical Race 4 (TR4), was discovered on banana farms in the coastal Caribbean region. With no fungicide effective against TR4, the Cavendish may meet the same fate as the Gros Michel."