1. There is an indication of linkage between interchange 1-9c (breaks near P₁ and wx-13-T), and the dominant white cap (W^c), a small backcross population having:

W^c = 12 normals + 29 semisteriles; yellow cap = 27 normals + 18 semisteriles; or about 35% c.o. � 5% S.E.