Preheat oven to 350°.
Lightly spoon flour into dry measuring cups, and level with a knife. Combine flour and the next 3 ingredients (through 1/4 teaspoon salt) in a large bowl. Combine yogurt, oil, syrup, honey, and vanilla. Add yogurt mixture to flour mixture, stirring just until moist. Fold in fruit, sunflower seeds, and rind.
Spoon batter into 4 (6-inch) loaf pans coated with cooking spray. Bake at 350° for 35 minutes or until a wooden pick inserted in center comes out clean. Remove from pans; cool completely on wire rack.