6. Sb is not on chromosome 2.
sb x trisome 2:
If sb were on chromosome 2 there should be about 30 sb plants; if on some other chromosome, about 100.
Notes: Sb is generally readily classifiable, though quite variable. Many of the plants are fully fertile. Usually the ratio is about as expected, though in two of my cultures the ratio was about 8:l (F2 seed). This was not due to lethalness of sb, for nearly all of the seeds grew. In A B Pl plants the slitting of the blades seemed less developed than in green plants.