cell biology - What is the difference between "dikaryotic" and "heterokaryotic" states in the sexual lifecyles of fungi?

dikaryotic does - by definition - mean that there are exactly two nuclei in the cells, it does not say that the two nuclei are genetically distinct!
heterokaryotic does also mean only one thing: the nuclei (the number is not important) are genetically distinct.

that's the reason why, for example webster, writes "heterokaryotic dikaryon".

in fact the nuclei are distinct in almost all cases, that's why some only write "dikaryon"