Question

You find 3 trees where each tree gives a
different coloured fruit: red, pink or orange. You perform crosses between all
three trees and get the following results:

P: red x pink ---F1: ½ red: ½ pink
P: red x orange --- F1: ½ red: ½ orange
P: pink x orange---F1: ¼ red: ¼ pink: ¼ orange:
¼ pale yellow

Are any of the plants true-breeding? How many different alleles for
fruit colour exist within these three trees?