Sb is not on chromosome 2

6. Sb is not on chromosome 2.

Genes	Phase	XY	Xy	xY	xy	Total	% Recomb.
Lg₁ Sb	RS	288	95	76	35	494	50
Gl₂ Sb	RS	288	92	78	36	494	50

sb x trisome 2:

	Sb	sb
Culture 1	6	3
Culture 2	187	63
Culture 3	126	20
	319	86

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.

J. Shafer