Inheritance of plant architecture traits in upland cotton (G. hirsutum L.).

To explore the genetic rule of plant architecture traits of cotton for providing theoretical references on improving cotton yield through plant architecture breeding,the major gene plus polygene mixed inheritance model was applied to analyze the inheritance of plant architecture traits with six generations of short-season cotton variety Baimian 2(P1) and middle-late maturing material TM-1(P2) in upland cotton(Gossypium hirsutum L.),and their F1,B1,B2 and F2.The results showed that fruit branch number,ratio of plant height to fruit branch length,and stem internode length were controlled by two major genes with additive-dominance-epistatic effects plus polygene with additive-dominance-epistatic effects(E-0 model).Effective fruit branches were controlled by two major genes with additive-dominance-epistatic effects(B-1 model).Plant height was controlled by one major gene with additive-dominance effects plus polygenes with additive-dominance-epistatic effects(D-0 model).Fruit branch length was controlled by one major gene with additive effects plus polygene with additive-dominance effects(D-2 model).Fruit branch internode length was controlled by polygene with additive-dominance-epistatic effects(C-0 model).Fruit node was controlled by two major genes with additive effects plus polygenes with additive-dominance effects(E-3 model).Fruit branch angle was controlled by one major gene with complete dominance effects plus polygenes with additive-dominance effects(D-3 model).Fruit branch number,plant height,stem internode length and fruit node were mainly controlled by major gene,while fruit branch angle was mainly controlled by polygene.Effective fruit branch number was typical major gene inheritance while fruit branch internode length was typical polygene inheritance.Fruit branch length and ratio of plant height to fruit branch length were controlled together by major gene and polygene.It was suggested single cross recombination or simple backcross could be adopted for the traits belonging to typical major gene inheritance or mainly controlled by major gene,polymerization backcross or recurrent selection to cumulate positive alleles could be adopted for the traits belonging to typical polygene inheritance or mainly controlled by polygene,and the relative effects of major gene and polygenes should be considered simutaneously for the traits controlled by both major gene and polygenes.