wet spots and white streaks in claro walnut

[gobywalnut]

We seem to get a lot of wet spots and white streaks in some of our walnut. I have been told that it may be a bacteria. The surrounding wood is dry to 8% and the white streaks read 25-30% on the meter. No matter how long the wood is in the kiln, the white streaks remain. I have noticed that if the boards are left out in the sun the streaks will darken up and even disappear. Does anyone know the cause of these streaks?