由题知两对性状独立遗传,所以分开考虑,抗病:感病=3:1说明抗病为显性且亲本基因型为Aa×Aa,无芒:有芒=1:1,判断不了显隐性,但知道亲本基因型为Bb×bb,所以亲本为AaBb×Aabb,F1为1/8AABb1/8AAbb1/4AaBb1/4Aabb1/8aaBb1/8aabbF1抗病无芒基因型为(设无芒显性)1/3AABb2/3AaBb(这两个基因型比例为1:2)感病有芒为aabbF2中2/6AaBb2/6Aabb1/6aaBb1/6aabb所以答案选A