Abstract：A F1 hybrid was obtained by crossing mutant 11A-47 with orange petal and a wild type
of flowering Chinese cabbage〔 Brassica campestris L. ssp. chinensis（L.）Makino var. utilis Tsen et
Lee〕with yellow petal．After the population of F 1，F2，BC1，BC1′ were taken as experiment materials．
Seeds of 6 generations were vernalized at 4 ℃ for 15 days，and cotyledon colors were investigated to
study the hereditary law of orange petal．Meanwhile，molecular markers linked to or gene in Chinese
cabbage were applied to determine the characteristics of orange petal gene in flowering Chinese
cabbage．Results showed that the ratio of orange with green cotyledons was 1∶3 in F2 progeny, χ2=
1.938 9 ＜ χ20.05=3.841．The ratio of orange with green cotyledons was 1∶1 in BC1′ progeny，χ2=
1.369 7 ＜ χ20.05=3.841．Therefore，orange petal gene in flowering Chinese cabbage is qualitative trait，
and is controlled by a pair of recessive gene．Orange petal gene in flowering Chinese cabbage was probably
different from gene in Chinese cabbage by molecular markers．
