2. The Concept of Heterosis Hybrid heterosis and hybrid vigor Types of Heterosis: 1)vegetative, 2) productive adaptive Measurement of Heterosis p 118-119 (1)Mid-parent heterosis (2)Over-parent heterosis 3)Over-standard (Over check heterosis) (4)Heterotic Index
2. The Concept of Heterosis ▪ Hybrid heterosis and Hybrid vigor ▪ Types of Heterosis: 1) vegetative, 2) productive 3)adaptive ▪ Measurement of Heterosis p. 118-119 (1) Mid-parent heterosis (2) Over-parent heterosis (3) Over-standard (Over check heterosis) (4) Heterotic Index
3. The characteristics of heterotic Performance in plants (1)Multiple-character Phenomenon (2) Related to Parental Genetic Difference 3 ) Related to Parental homozygosity (4) Environment Dependent (5) Depression of Heterosis in F2 and later generations 4. The fixation of heterosis P.120
3. The Characteristics of Heterotic Performance in Plants (1) Multiple-character Phenomenon (2) Related to Parental Genetic Difference (3) Related to Parental Homozygosity (4) Environment Dependent (5) Depression of Heterosis in F2 and later generations 4. The Fixation of Heterosis P.120
82 Genetic Basis of Heterosis 杂种优势的遗传基础 1. The dominance Hypothesis P1 AABBccddee x aabbCcdDee P2 10+10+5+5+10=40 5+5+10+10+5=35 AaBbccddEe 10+10+10+10+10=50 F1 F1>PI. P2
§2 Genetic Basis of Heterosis 杂种优势的遗传基础 1. The Dominance Hypothesis P1 AABBccddEE x aabbCCDDee P2 AaBbCcDdEe F1 10+10+5+5+10=40 5+5+10+10+5=35 10+10+10+10+10=50 F1 > P1, P2
2. The over-dominance hypothesis P1 aja1bjb deel x a2a2b2b2C2C2d2d2e2e, p2 (12) a1a2b1b2Cc2dd2ejez F1 where: a a2, a2a,, b1b2>b,b1 b,b
2. The Over-dominance Hypothesis P1 a1a1b1b1c1c1d1d1e1e1 x a2a2b2b2c2c2d2d2e2e2 P2 a1a2b1b2c1c2d1d2e1e2 F1 (12) (10) (20) where: a1a2 > a1a1 , a2a2 ; b1b2 > b1b1 , b2b2 …