大白菜橘红色和紫色遗传分析

以球内叶橘红色的大白菜和外叶紫色的普通白菜（小白菜）为亲本进行杂交、自交和回交，研究大白菜橘红色、紫色2对基因的遗传规律。结果表明：球内叶橘红色的大白菜和外叶紫色的普通白菜杂交，F1植株颜色为非橘红心-紫色|在F2群体中出现4种基因型，非橘红心-紫色、非橘红心-非紫色、橘红心-紫色、橘红心-非紫色，比例接近9∶3∶3∶1，其中获得橘红心-紫色基因型ororPr-的概率为18.75%，获得纯合橘红心-紫色基因型ororPrPr的概率为6.25%|在BC1群体中，4种基因型之比接近1∶1∶1∶1|BC2群体中，全部植株颜色为非橘红心-紫色。x2检测结果进一步证明：球内叶橘红色的大白菜和外叶紫色的普通白菜杂交后代球内叶橘红色和外叶紫色为非连锁、互为独立遗传、自由组合的2对基因，二者分别位于不同的染色体上。球内叶橘红色基因or已定位在A基因组1号染色体末端，据此推断，来源于外叶紫色的普通白菜的紫色基因不在1号染色体上，而是在A基因组其他染色体上。

Genetic Relationship between Chinese Cabbage with Orange Color in Inner Head and Purple Color in Leaf

F1，F2，BC1 and BC2 generations were obtained through crossing，self-crossing and backcrossing by Chinese cabbage（Brassica campestris L. ssp. pekinensis）of orange color in inner head with pakchoi〔Brassica campestris L. ssp. chinensis（L.）Makino var. communis Tsen et Lee〕of purple color in leaf，in order to study the genetic relationship between inner head color and leaf color．Results showed that colors of F1 hybrids were non orange-purple colors．The ratios of 4 genotypes were close to 9 non orange-purple∶3 non orange-non purple∶3 orange-purple∶1 orange-non purple for F2 progenies．The ratio of orange-purple genotype ororPr- was close to 18.75%，of which was close to 6.25% for pure orange-purple genotype ororPrPr．For BC1 progenies，the ratios of 4 genotypes were close to 1 non orange-purple∶1 non orange-non purple∶1 orange-purple∶1 orange-non purple．For BC2 progenies，all plants owned non orange-purple colors．Results of x2 test deeply showed that the genetic relationship between inner head color and leaf color on Chinese cabbage and pakchoi was not linked，which controlled by 2 independent genes．Orange gene or was located on the end of chromosome 1 in A genome．Purple gene was located on some chromosomes except chromosome 1，which or gene was located．