Analysis on Genetic Model of Major Gene Plus Polygene for Cob Diameter of Maize

LI Jing; CHEN Shilin?; ZHANG Huaisheng; WANG Tiegu

Abstract：The mixed genetic model of major gene plus polygene for plant quantitative traits was used to investigate the inheritance of cob diameter,taking P1 ,P2 ,B1 ,B2 ,F1 and F2 generations of Ji 533/PH6WC (crossⅠ),Ji 533 / H5818 (crossⅡ) and 2394 / PH6WC (crossⅢ) as experimental material. The re-sults showed that the cob diameter of crossⅠaccorded with E-5 model,controlled by two fully dominant major genes plus additive-dominance polygenes,so it was affected by major gene and polygenes. The opti-mal model of cross Ⅱ was A-4 model,controlled by a pair of negative completely dominant major gene, and the highest selecting efficiency was in B1 generation. CrossⅢaccorded with D-4 model,controlled by a pair of negative completely dominant major gene plus additive-dominance polygenes, but the multiple genes were not detected in B2 generation. For crossⅠ,the major gene heritability of cob diameter in three separating generations was 6. 0%,42. 5% and 75. 0%,respectively,while the polygene heritability was 71. 4%,37. 5% and 5. 0%. For cross Ⅱ,the major gene heritability of cob diameter in three separating generations was 63. 0%,54. 6% and 54. 2%,respectively. For crossⅢ,the major gene heritability of cob diameter in three separating generations was 7. 0%,40. 5% and 17. 8%,respectively,while the polygene heritability was 47. 5%,0 and 50. 4%,respectively.