Preheat oven to 350 degrees F. Grease the bottom and 1/2 inch up the sides of an 8x4x2-inch loaf pan; set aside. In a large bowl stir together flour, the 1 cup sugar, the baking powder, and salt. Make a well in the center of flour mixture; set aside.
In a medium bowl combine egg, milk, oil, tangerine peel, 2 tablespoons tangerine juice, and poppy seeds. Add egg mixture all at once to flour mixture. Stir just until moistened (batter should be lumpy). Spoon batter into the prepared loaf pan, spreading evenly.
Bake for 50 to 55 minutes or until a wooden toothpick inserted near the center comes out clean. Cool in pan on a wire rack for 10 minutes.
Meanwhile, for tangerine glaze, in a small saucepan combine the 2 tablespoons sugar, 2 tablespoons tangerine juice, and butter. Cook and stir over medium-low heat until butter is melted and sugar is dissolved.
Remove bread from pan. Poke holes in top of warm bread with a wooden skewer; slowly brush with tangerine glaze. Cool completely on a wire rack. Wrap and store overnight before slicing.