saving seeds from plants infected with Aster yellows?

[gilbert]

All the cucurbits in my garden have been infected by phytoplasmas causing Aster yellows; the growing points have become fat with little balls of tiny leaves and flowers crowded around them, and jagged edged yellowish leaves. 

I'm trying to create and maintain landraces of these plants. Can I save these seeds, or will they carry the virus? The plants were healthy up until a week or so ago.