Powdery Mildew on Lilac - dangerous to Tomatoes?

[JRinPA]

This week I twice pruned a few tomato leaves that had what appeared to be powdery mildew on them.

Yesterday I realized the lilac bush nearby has the same stuff on the leaves, hanging right next to the garden.





Question - I have read "on the internet" that powdery mildew is plant specific, such that it does not spread between plants of different types. If two different plants near each other both have powdery mildew, it is due to the moist shady conditions growing two slightly different fungi.

My mom tells me every lilac bush she can recall gets that stuff on the leaves in late summer...but she has no idea whether it will affect tomatos.

So...any thoughts?

I have been sorely tempted to cut down that lilac just to allow more sunlight and circulation. It has gone untrimmed for some years and is pretty large. It is nice looking in the spring and the cardinals love to perch there.