2. Combination of parents (1) Significance Key to successful breeding: (2)Principles 1)More advantages, less disadvantages; Complementary 2)Large genetic differences 3)High combining a bility GCA: Additive gene effects SCA: Heterosis effects(non-additive) Good cultivars are not always good parents 4)Salient objective characters in one or both parents, with a high inheritability 5)Select one locally popularized cultivar as one of the parents 3) Successful Selection and combination of parents in cross breeding Tab6-1,p.902. Combination of Parents (1) Significance Key to successful breeding: (2) Principles 1) More advantages, less disadvantages; Complementary 2) Large genetic differences 3) High Combining ability: GCA: Additive gene effects SCA: Heterosis effects (non-additive) Good cultivars are not always good parents 4) Salient objective characters in one or both parents, with a high inheritability 5) Select one locally popularized cultivar as one of the parents (3) Successful Selection and combination of parents in cross breeding Tab. 6-1, p. 90