Shi F, Endo T R
Laboratory of Plant Genetics, Graduate School of Agriculture, Kyoto University, Japan.
Chromosoma. 2000;109(5):358-63. doi: 10.1007/s004120000085.
Chromosome 2C of Aegilops cylindrica induces chromosomal rearrangements in alien chromosome addition lines, as well as in euploid lines, of common wheat. To induce chromosomal rearrangements in barley chromosome 7H, reciprocal crosses were made between a mutation-inducing common wheat line that carries a pair of 7H chromosomes and one 2C chromosome and a 7H disomic addition line of common wheat. Many shrivelled seeds were included in the progeny, which was an indication of the occurrence of chromosome mutations. The chromosomal constitution of the viable progeny was examined by FISH (fluorescence in situ hybridization) using the barley subterminal repeat HvT01 as a probe. Structural changes of chromosome 7H were found in about 15% of the progeny of the reciprocal crosses. The aberrant 7H chromosomes were characterized by a combination of N-banding, FISH and genomic in situ hybridization. Mosaicism for aberrant 7H chromosomes was observed in seven plants. In total, 89 aberrant 7H chromosomes were identified in 82 plants, seven of which had double aberrations. More than half of the plants carried a simple deletion: four short-arm telosomes, one long-arm telosome, and 45 terminal deletions (23 in the short arm, 21 in the long arm, and one involving both arms). About 40% of the aberrations represented translocations between 7H and wheat chromosomes. Twenty of the translocations had wheat centromeres, 12 the 7H centromere, with translocation points in the 7HS (five) and in the 7HL (seven), and the remaining four were of Robertsonian type, three involving 7HS and one with 7HL. In addition, one translocation had a barley segment in an intercalary position of a wheat chromosome, and two were dicentric. The breakpoints of these aberrations were distributed along the entire length of chromosome 7H.
圆柱山羊草的2C染色体在普通小麦的异源染色体附加系以及整倍体系中都会诱导染色体重排。为了在大麦7H染色体上诱导染色体重排，在一个携带一对7H染色体和一条2C染色体的诱变普通小麦品系与普通小麦的7H二体附加系之间进行了正反交。后代中包含许多皱缩种子，这表明发生了染色体突变。使用大麦亚末端重复序列HvT01作为探针，通过荧光原位杂交（FISH）检测了存活后代的染色体组成。在正反交后代中约15%的个体中发现了7H染色体的结构变化。异常的7H染色体通过N带、FISH和基因组原位杂交进行了表征。在七株植物中观察到了异常7H染色体的嵌合体现象。总共在82株植物中鉴定出89条异常7H染色体，其中7条有双重畸变。超过一半的植物携带简单缺失：4条短臂端体、1条长臂端体和45个末端缺失（短臂23个，长臂21个，1个涉及双臂）。约40%的畸变代表7H与小麦染色体之间的易位。其中20个易位带有小麦着丝粒，12个带有7H着丝粒，易位点分别在7HS（5个）和7HL（7个），其余4个为罗伯逊易位类型，3个涉及7HS，1个涉及7HL。此外，一个易位在小麦染色体的中间位置有一个大麦片段，两个是双着丝粒的。这些畸变的断点分布在7H染色体的整个长度上。
