小麦×高粱的受精率和小麦单倍体的诱导(简报)

THE FREQUENCY OF FERTILIZATION AND PRODUC-TION OF HAPLOID WHEAT PLANTS IN WHEAT x SORGHUM CROSSES

远缘杂交无论在植物遗传学理论的建立还是在新品种的培育上都是一项十分有用的技术,特别在小麦上成绩更为突出。近来发现小麦不但和其亲缘属(如山羊草属、偃麦草属,赖草属等)植物可以杂交,而且和亲缘关系较远的植物种属如玉米、珍珠栗、大刍草、摩擦禾等杂交也有很高的成胚率,并且通过杂种胚发育过程中父本染色体的消失,可以获得小麦单倍体。

When the hexaploid wheat (Triticum aestivum) variety Chinese Spring was pollinated with sorghum (Sorghum vulgare), pollen germinated readily and grew well in the wheat stigma. In a sample of 230 florets, 57 (24.8%) had only an embryo, 5 (2.2%) had only an endosperm and 22 (9.6%) had both. In those florets where an endosperm is present it is always highly abnormal. The hybrid embryos were karyotypically unstable and eliminated sor- ghum chromosomes early in development, giving rise to haploid wheat embryos. It is necessary to use the embryo rescue method for development of embryo and recover plants from wheat x sorghum crosses. Of the 159 florets from wheat x sorghum dissected, 38 embryos were obtained and 19 plants recovered on the medium. Root tip cell chromosome counts showed that all the plants regenerated from embryo rescue contained 21 chromosomes (haploid).