Genetic Analysis on Yield-related Traits and Its Application for Breeding of Zea mays L.

A genetic analysis on the yield-related traits of Zea mays L.was conducted by using the mixed major genes and polygene inheritance models.The joint analytic method on the P1,P2,F1,B1,B2 and F2 generations of two crosses made from 3 inbred lines of the maize,which was newly bred by the Agricultural Sciences Institute of Riparian of Jiangsu Yangtze,was applied for the study.The results indicated that the weight per ear of maize was controlled by two pairs of major genes and the polygenes with additive-dominance-epistatic effects.And,the trait was mainly governed by the major genes in both crosses.The ear length was controlled by the additive-dominance-epistasis polygenes in the cross S1×S3;whereas in the cross S3×S7,the trait was controlled by one additive-dominance major-gene as well as the additive-dominance-epistasis polygenes.The ear diameter was controlled by one additive-dominance major-gene and the additive-dominance-epistasis polygenes in the cross S1×S3;whereas in the cross S3×S7,the trait was controlled by one wholly dominance major-gene and the additive-dominance polygenes.Both ear length and diameter were mostly governed by polygenes.The cob diameter was controlled by two additive-dominance-epistasis major-genes and the additive-dominance polygenes in the cross S1×S3;whereas in the cross S3×S7,the trait was controlled by two additive-dominance-epistasis major-genes and the additive-dominance-epistasis polygenes,and was mainly governed by polygenes.The cob diameter,weight per ear and ear diameter were mostly affected by their additive genetic components.Therefore,to use favorable allele polymerization would be effective for breeding and/or early generation selection.Nevertheless,to obtain the high phenotypic individuals with the ear length trait ought to take place in the late generation stage,as its main genetic components were non-additive.And the F1 generation of the two traits,due to the superdominance effect,could produce the high phenotypic cross combinations.