普通小麦-簇毛麦6V代换系45S rDNA和5S rDNA位点的FISH分析

FISH Analysis of 45S rDNA and 5S rDNA Gene Loci in a Wheat-Haynaldia villosa 6V Substitution Line

采用顺序基因组原位杂交和双色荧光原位杂交技术,对普通小麦-簇毛麦6V代换系K0736的45S rDNA和5S rDNA基因位点进行了分析。结果表明,该代换系2n=42,有1对簇毛麦6V染色体,为6V/6A代换系,45S rDNA位点有8对,位于7对染色体上。5S rDNA位点有6对,分别位于6对染色体上。在1AS、1BS、5DS的端部同时存在45S rDNA和5S rDNA位点,并在物理位置上紧密相邻。同时讨论了rDNA位点的数目和分布位置存在变异的可能因素。

Sequential genomic in situ hybridization（GISH）and double color fluorescence in situ hybridization（FISH）techniques were used to map physically 45S rDNA and 5S rDNA gene loci in a wheat-H.villosa 6V/6A substitution line.The results indicated that eight pairs of 45S rDNA loci were detected on seven pairs of wheat chromosomes,and six pairs of 5S rDNA loci were detected on six pairs of wheat chromosomes,respectively.Both 45S and 5S rDNA signals were collocated closely on the terminal region of the short arm of chromosomes 1A,1B and 5D.At the same time,we discussed the possible factors of variation about the two types of rDNA in locus number and location in wheat-H.villosa 6V/6A substitution line.