Aa BBCCDD AAb BCc DD Aabb Cc Dd

����� Aa. BBCCDD AAb. BCc. DD Aabb. Cc. Dd Aa. BBCCdd aa. Bd. Cc. Dd aa. BBCCDd AAbb. Cc. Dd Aabbcc. Dd ……. . Aabbccdd ������ heterogenous population

������������ inbreeding depression ��� heterosis ����������� non addtive gene action

�� Hardy-Weinberg ������ A=p ��� a=q Genotype: AA 2 Aa aa ������ : pxp 2(p x q) q x q 2 2 p 2 pq q

�� Hardy-Weinberg ������ �� genotype ������ 2 2 AA = p = 0. 55 = 0. 3 Aa = 2 pq = 2(0. 55 x 0. 45) = 0. 5

Inbreeding depression ��� heterosis inbreeding depression ������������ �������

Inbreeding depression ������ ��� F 1 ������ F 2 ���� inbreeding depression = F 1 – F 2 ������

Heterosis ���������� heterosis 1. Dominance hypothesis ����� dominance gene ������� Aabb. CCDd x Aa. BBcc. Dd

Heterosis 2. Overdominance hypothesis Intra-allelic interaction hypothesis ������� overdominance AABBCCDD x aabbccdd Aa. Bb. Cc. Dd

Heterosis AA aa Aa

Mass selection w/o progeny testing xxxxxxxxxxx xxxxxxxxxxx xxxxxxxxxxx xxxxxxxxxxx ����� 1 ������ 10% ����� 2 ������ 10%

������ 2. ������������ (Mass selection with progeny testing) - ������ (ear-to-row method)

Ear-to-row method xxxxxxxxxxxxxx ��� �� 1 x x x x 2 x x x ����� x x x x x ����� 3 x x x x

Ear-to-row-to-ear method xxxxxxxxxxxxxxxxxxxxxxxx ����� 1 ����� 2

Ear-to-row-to-ear method ����� 3 ����