毛竹和厚壁毛竹的核型分析及45S和5S rDNA的FISH分析

The karyotype and FISH analysis of 45S and 5S rDNA on the chromosomes of Phyllostachys edulis and Phyllostachys edulis ‘Pachyloen’

【目的】厚壁毛竹(Phyllostachys edulis‘Pachyloen’)是毛竹(Phyllostachys edulis)的栽培品种,是具有较高经济价值的优特种质。对毛竹与厚壁毛竹进行细胞遗传学研究,了解其核型特征。【方法】采用双色荧光原位杂交技术,对毛竹、厚壁毛竹进行了核型分析,利用45S和5S rDNA在其染色体上进行了物理定位。【结果】毛竹、厚壁毛竹的染色体数目都为48条,毛竹的染色体相对组成为2n=48=12L+10M_2+14M_1+12S,核型公式为2n=48=32m+12sm+4st(2SAT);厚壁毛竹的染色体相对组成为2n=48=12L+8M_2+16M_1+12S,核型公式为2n=48=34m+10sm+4st(2SAT)。毛竹与厚壁毛竹的染色体不对称系数分别为61.41%和59.55%,均属于"2B"型。荧光原位杂交(FISH)结果表明:毛竹、厚壁毛竹都有2个45S rDNA位点和4个5S rDNA位点。【结论】厚壁毛竹的染色体数量为48条,补充了毛竹的染色体为48条的循证依据;获得了毛竹、厚壁毛竹45S和5S rDNA荧光原位杂交核型,两者的45S和5S rDNA位点没有明显差异,具有相似的核型,显示其较近的亲缘关系。

【Objective】Phyllostachys edulis‘Pachyloen’is a cultivar of Phyllostachys edulis,which is an economically-important germplasm.Cytogenetic research on this germplasm provide a cytomolecular basis for genetic research on bamboo species.【Method】Karyotype analysis and physical localization of 45 S and 5 S rDNA on the chromosomes of Ph.edulis and Ph.edulis‘Pachyloen’were performed by double color fluorescence in situ hybridization(FISH).【Result】The results of karyotype analysis indicated that the chromosome number in the two materials was 2 n=48,the karyotype formula of Ph.edulis and Ph.edulis‘Pachyloen’was 2 n=48=32 m+12 sm+4 st(2 SAT)and 2 n=48=34 m+10 sm+4 st(2 SAT),respectively.The chromosome composition of relative length was 2 n=48=12 L+10 M2+14 M1+12 S and 2 n=48=12 L+8 M2+16 M1+12 S,respectively.The asymmetrical karyotype coefficients of Ph.edulis and Ph.edulis‘Pachyloen’were 61.41%and 59.55%,and their karyotypes were both of 2 B type.The results showed that there were 2 loci of 45 S rDNA and 4 loci of 5 S rDNA in both Ph.edulis and Ph.edulis‘Pachyloen’.【Conclusion】The chromosome number in the two materials is 2 n=48,the 45 S and 5 S rDNA loci of the two materials have no obvious differences,and the two varieties have similar karyotypes,which shows that they have close genetic relatedness.