This is what I don't understand about 'New Dawn'.

If ‘New Dawn’ is the repeating sport of ‘Dr. W. Van Fleet’, a once bloomer, does that mean ‘Dr. W. Van Fleet’ has two recessive repeat blooming chromosomes as well? Hopefully I’m making sense. This is what I don’t understand. If it takes two recessive chromosomes to produce repeat blooming roses, how is it possible for ‘Dr. W. Van Fleet’ to produce such a sport when it is itself has one chromosome, as I assume for right now, for repeat blooming. Is it possible that DWVF has two recessive chromosomes, but they regulated by another factor such as perhaps a 3rd chromosome that may turn it on and off the repeating expression like a light switch? Or Could it be possible that ‘New Dawn’ is a seedling of DWVF instead a sport? I’ve heard that it is a fertile triploid, but may it is actually a tetraploid. Does anyone know if its’ ploidy has been actually counted? Maybe people call it a triploid because everyone is just assuming that it is.