how can i delete pictures from itune interface on my Iphone

If you placed the photos onto your phone by syncing them from a computer using iTunes, you delete them by syncing again but with different selections/settings on the photos tab of iTunes. See the quote below from Sync photos from your computer to your iOS device using iTunes - Apple Support

1. In iTunes, locate and click on your device.
2. Click Photos.
3. Choose "Selected albums" and deselect the albums or collections you want to delete.
   To delete all synced photos, deselect "Sync Photos from" and, when asked, click "Remove photos."
4. Click Apply.

Learn how to delete photos and video synced from iTunes when you can't access the originals.