Wow this is a really cool project you are working on... I really don't know that much about the Dominant and Recessives of watermelons but i am really curious about what you are doing... Could you keep me posted on your work as it progresses..... You can email me at:
harry_johnson1234@hotmail.com. Thank you and i will do some research for you and try to come up with an answer.

Jumsmith

Another way to approach this goal is to grow the tasty mellon, grow lots of it. Do what ever it takes to get them to fruit production as early as possible. Isolate the ones with the largest fruit (by removing the inferior ones). Remove all the first crop of fruit from all the plants. Remove all the plants that produce small fruit (you'll see and compare them before they are fully grown). Only allow the biggest fruited plants to breed and produce fruit. After of couple of seasons you should have isolated the genes for size and taste. I'm not a geneticist but I always thought that sweetness was influenced by soil and weather. I also think you would need to use the pollen as quickly as possible and not store it - so you need flowers on both plants blooming at the same time.