V.H.Beaumont、T.R.Rocheford和J.M.Widholm在美国伊利诺依大学,作出了玉米花药培养过程中同形成胚相关的基因的图谱。伊利诺依大学的研究人员进行了三种不同的杂交,并分析了产生的F1代植株离体成胚的能力。还用RFLP分析了F1代植株。Beaumont等人发现:玉米小孢子离体形成胚的能力与6个染色体区域相关。除了一个以外,其余的5个染色体区域都靠近在母株上萌发突变的 V. H. Beaumont, T. R. Rocheford and J. M. Widholm, at the University of Illinois, USA, made maps of genes involved in embryogenesis in popcorn cultures. Researchers at the University of Illinois conducted three different crosses and analyzed the ability of the F1 plants generated in vitro to embryogenesis. F1 plants were also analyzed by RFLP. Beaumont et al. Found that the ability of microspore maize to form embryos ex vivo is associated with six chromosomal regions. With the exception of one, the remaining five chromosomal regions are all near germinal mutations on the mother plant