不同倍性柳枝稷45S rDNA的染色体定位研究  

Chromosome Localization of 45S rDNA in Panicum virgatum Cultivars with Different Ploidy

作　　者：王璐[1] 王晓遇 张媛[1] 罗向荣 徐阳菁 张平冬[1] WANG Lu;WANG Xiao-yu;ZHANG Yuan;LUO Xiang-rong;XU Yang-jing;ZHANG Ping-dong(National Engineering Laboratory for Forest Tree Breeding,Beijing Forestry University,Beijing 100083)

机构地区：[1]北京林业大学林木育种国家工程实验室,北京100083

出　　处：《植物遗传资源学报》2020年第5期1287-1294,共8页Journal of Plant Genetic Resources

基　　金：北京市大学生创新创业项目(S201910022112);北京林业大学教育教学研究项目(BJFU2018JY045)。

摘　　要：以3个四倍体和6个八倍体栽培品种的根尖为材料,利用荧光原位杂交技术,在核型分析的基础上,开展了不同倍性柳枝稷45S rDNA的染色体定位研究。研究结果表明,四倍体柳枝稷核型公式为2n=4x=36=32m(SAT)+4sm,且45S rDNA在四倍体柳枝稷染色体上分布稳定,位于3号染色体顶端。八倍体柳枝稷栽培品种以及同一栽培品种不同个体间45S rDNA信号分布位置和数目差异较大,可大致分为四类:第Ⅰ类为较强的45S rDNA信号分别分布于染色体两臂的顶端;第Ⅱ类为较强的45S rDNA信号位于染色体一臂内部,第Ⅲ类为较强的45S rDNA信号位于染色体一臂的顶端,第Ⅳ类为较弱的45S rDNA位于染色体一臂内部。八倍体柳枝稷不同栽培品种以及同一栽培品种不同个体间45S rDNA信号复杂性的成因可能与染色体同源重组以及染色体结构变异密切相关。Panicum virgatum L. is an important biomass energy plant. Its straw is rich in lignocellulose which can be used as raw material for ethanol production. An investigation on chromosome localization and distribution of 45 S rDNA in P. virgatum cultivars with different ploidy would promote the cytogenetic study of the species. In this investigation,chromosome localization of 45 S rDNA and karyotype analysis were conducted by fluorescence in situ hybridization using root tips of three tetraploids and six octaploids as materials. The results indicated that the karyotype formula of the tetraploids was 2 n=4 x=36=32 m(SAT)+ 4 sm,and 45 S rDNA was invariably located at one end of chromosome 3. Significant differences in number of chromosomes and location of 45 S rDNA signals were found among different octaploid cultivars or different individuals of the same octaploid cultivar. Four types of 45 S rDNA distribution in the octaploid cultivars existed. The first type had a strong 45 S rDNA signal at the end of both arms of the chromosome. The second type had a strong 45 S rDNA signal within one arm of the chromosome. The third type had a strong 45 S rDNA signal at the end of one arm of the chromosome. The fourth type had a weak 45 S rDNA signal within one arm of the chromosome. The complexity of the models of 45 S rDNA signal distribution among different octaploid cultivars or different individuals of the same octaploid cultivar is inferred to be closely correlated to homologous recombination and structure variation of the chromosoms.

关 键 词：柳枝稷 45S rDNA 染色体核型 荧光原位杂交 染色体结构变异 

分 类 号：S578[农业科学—作物学]