普通小麦栽培品种丰抗13的4B—1D染色体易位的鉴定

通过细胞学观察,在普通小麦栽培品种“丰抗13”和“京红1号”的杂交后代中,发现有多价体出现,这就表明有染色体易位发生。为进一步弄清究竟是哪条染色体发生了易位,我们采用单体测交方法,观察鉴定所有各单体系F_1的花粉母细胞第一次减数分裂中期Ⅰ(以下简称PMCs中Ⅰ)染色体构型。从鉴定结果发现,凡2n=42的F_1 PMCs中Ⅰ出现19~Ⅱ 1~Ⅳ,而2n=41的F_1PMCs中Ⅰ的染色体构型不同,单体与易位有关的两个单体系4B和1D F_1 PMCs中的Ⅰ构型中有部分呈现为19个二价体加1个三价体,即19~Ⅱ 1~Ⅲ,没有单价体,而其余各单体系F_1 PMCs中Ⅰ构型则表现为18个二价体,1个四价体和1个单价体,即18~Ⅱ 1~Ⅰ 1~Ⅳ。因此,可以肯定“丰抗13”存在1个染色体易位,其有关染色体就是4B和1D。

IDENTIFICATION OF CHROMOSOMAL TRANSLOCATION 4B-1D IN CV. FENGKANG NO. 13 OF COMMON WHEAT

The meiotic configurations at metaphase I show often one chain or ring quadrivalent in hybrids between CV. Fengkang No. 13 and Beijing Red No. 1 , this indicates that the two chromosomes are involved in one reciprocal translocation. 21 monosomic plants of Beijing Red No. 1 were used as female parents in crosses with Fengkang No. 13. All monosomic families Fl PMCs at metaphase 1 were observed to analyze the chromosomal configuration. The meiotic behaviour of monosomic offspring shows different chromosome configurations depending on whether the monosomic chromosome is or is not involved in a translocation. Configurations at metaphase 1 of monosomic 4B and 1D in FlPMCs exhibit 19 bivalents and 1 trvalent, without any univalent. Configurations at mctaphase I of monosomic families Fl except mono-4B and lD exhibit 18 bivalents, 1 Quadrivalent and 1 univalentt. The results obtained indicate clearly that the two chromosomes involved in this reciprocal translocation arc 4B and lD.