I experimented with the different gradient styles from Linear to Rectangular to Radial, but ultimately I chose Sunburst (0, 0, invert checked, 50/50, 0/0, link center unchecked) as I was kind of going for that watermelon wedge slice look.  This font that I used, Vitamin, doesn't show off the rind as much as I would have liked but I am happy with the overall coloration of the gradient.  You picked really nice shades for this watermelon gradient.

I tried to figure out how to rotate the watermelon seed in the tube settings but I couldn't figure out how to do it so all my seeds are standing straight up LOL.  I suppose I could have selected them and rotated them but I thought for sure there would be some kind of setting for the tube that would randomly rotate the tube.  If you know of such a setting, then please let me know.  I don't work with the Tube Tool very much, so I enjoyed trying something new.

I used the Eye Candy 3 Glass settings from Kes' Glass Text Tutorial to give my text some gloss.  I tried beveling the text first but no matter which bevel settings I used the text stopped looking like watermelon, so I omitted the bevel.

The effect is very subtle but I've actually animated the gradient fill.  At first I tried PSP Noise, but it made the gradient look dirty, so I tried a different technique using Texture Effects/Mosaic Glass (95, 95, symmetric checked, 95, 85, 3, 7); I changed grout diffusion value to create the movement.  So even though this effect is subtle at least the colors of the pixels match the gradient.  The effect is kind of like Toadies Blast 'Em.  I also animated the outline of my text with PSP Noise.