东方山羊草、尾状山羊草中染色体配对控制机制的存在和作用

Discovery of Mechanisms on Homoeologous Chromosome Pairing in Aegilops aucheri and Ae.caudata

直接杂交与幼胚培养方法结合获得了小麦与东方山羊草、尾状山羊草属间杂种。Ｆ１杂种细胞遗传学研究发现，东方山羊草的染色体组显著促进部分同源染色体配对，完全掩盖了小麦ｐｈ１ｂ基因的作用，尾状山羊草的染色体组一定程度抑制部分同源染色体配对，尤其强烈抑制小麦ｐｈ１ｂ基因的作用。表明东方山羊草的Ｓ染色体组上存在类似于小麦的ｐｈ１ｂ基因。

egilops aucheri and Ae.caudata as male parents were crossed with Chinese Spring and its mutants ph1b line,ph2a line and ph2b line,respectively.The immature embryos were excised to culture on N6 medium 12～15 days after pollination for obtaining the F1 hybrids.Meiotic study of the hybrids revealed that the F1 plants between the four common wheats and Ae.aucheri had 10.87,13.60,11.00 and 12.48 chiasmata per cell at metaphase I respectively,but those between the four common wheats and Ae.caudata only had 3.45,3.43,5.51 and 6.35 chiasmata per cell at MI respectively.The results indicated that the genome S of Ae.aucheri carried ph1b-like gene promoting significantly homoeologous chromosome pairing.Its function was much stronger than that of ph1b in common wheat,but the genome C of Ae.caudata carried Ph1-like gene supressing chromosome pairing.