Analysis of the Qualitative-quantitative Geneticmodels of Orange Color Petal Tone Value in Tagetes erecta L.

Orange flower color is a useful indicator in Tagetes erecta L..It was used in correlative selection and purity test and was also used as a genetic traitmarker.In the present study the color quantified by tone value in order to investigate the geneticmodel of flower color.Six generations(P1,P2,F1,F2,B1and B2) from W217×W203 were analyzed with a mixed geneti cmodel for major genes and poly genes.Results showed that orange color in marigold was a quantitative trait and its inheritance fitted to a mixed genetic model of two major genes with additive-dominant-epistatic effects plus polygenes with additive-dominant-epistatic effects(E-0 model).Among them,the additive,dominant and epistatic effects of the two major genes were equally important.The effects and heritability of major genes were high with low environmental influence,and that of the polygenes were also relatively low.The estimated heritability rates of the two major genes were 49.13% in F2,84.23% in B1,74.41% in B2.The estimated inheritability rates of the polygenes were 48.25% in F2,18.24% in B2.