You could probably have genes from one of them inserted into the other by a genetic engineer. For example you could probably get an orange flavoured banana.
It does't much matter about the relatedness for this process. Some quite extradinary combinations have been done.
Daffodil yellow has been inserted into rice making a rice high in vitamin A.
A fish antifreeze has been put into tomatos to make them frost resistant. Unfortunately the tomatos tasted fishy so it didn't catch on.
A jellyfish gene has been inserted into mice, dogs and marmosets making glow in the dark animals.