摘要
以普通小麦第四部分同源染色体组的１３个ＲＦＬＰ（限制性片段长度多态性）标记为探针，通过原位杂交进行了物理定位和４Ａ染色体重排的物理特征研究。ＲＦＬＰ分析确定的标记所在的染色体臂和原位杂交结果相一致。位于４ＡＬ上的９个ＲＦＬＰ探针有６个的杂交点集中分布在距着丝点约６０％～７０％的区域内。本结果支持了４Ａ染色体来自于双重易位的假说，第一次易位产生的４ＡＬ／５ＡＬ染色体又和７ＢＳ发生易位，现在的４Ａ染色体结构为４ＡＬ／５ＡＬ／７ＢＳ，保留在４Ａ的５ＡＬ、７ＢＳ染色体片段约分别为０５μｍ、２２μｍ。所用ＲＦＬＰ标记杂交点聚集的区段分布于染色体臂的近端部，可能和易位断点及染色体的交换重组有关。４ＡＬ上Ｃ－带距着丝点的相对距离和各标记杂交点集中区段距着丝点的相对距离接近。
n situ hybridization with biotin-labelled DNA was used to determine the physical location of 13 RFLP (restriction fragment length polymorphism) markers from homoeologous group 4 in wheat (T.aestivum).The results showed all probes hybridized to the corresponding chromosomal arms indicated with the RFLP analysis.The six among nine probes were concentrated in the proximal 60%～70% on chromosome 4AL.It confirms the hypothesis that the present 4A is a consequence of double translocation.Following the first translocation of 4A and 5A,the chromosome 4AL/5AL experienced another interchromosomal exchange with 7BS.The chromosomal structure of the present 4A is 4AL/5AL/7BS.The chromosomal fragment remaining on 4AL from 5AL,7BS was about 05μm and 22μm in length,respectively.The fact that the probes were distributed on subterminal region may related to translocation breakpoints and chromosome recombination.The relative distance of C-banding and physical distance of concentrated markers of in situ hybridization were very close to each other on 4AL.
关键词
小麦
原位杂交
染色体重排
insituhybridization,Chromosomal rearrangement,Translocation,Wheat (T.aestivum)
