中文摘要：

目的：获得高山红景天同源四倍体新材料。方法：用高山红景天愈伤组织原生质体为材料,进行了40%PEG6000介导的原生质体融合,对融合后原生质体进行了低密度、低融点琼脂包埋培养。按原生质体大小对融合原生质体进行了活体标记,建立了起源于单个原生质体的单细胞姊妹系,获得同源四倍体材料。结果：新生子细胞、中期细胞及其原生质体的直径RD与RM均与公式RD=0.793 7RM大致相符。未融合的二倍体、两原生质体融合产物直径的变化范围分别为16.7μm≤R〈21.3μm,21.0μm≤R′〈26.8μm,两者直径范围存在部分重叠。融合原生质体培养时,接种密度以1×104个/mL为宜,在此密度条件下植板率为20.3%,单细胞起源的姊妹系微克隆生长迅速,易于进行标记、彼此分离并继续培养;染色体计数的结果表明,二倍体、四倍体单细胞姊妹系再生植株染色体数目分别为26,52,不同节位叶片经流式细胞仪检测了DNA含量,证实没有嵌合体的存在。结论：本研究为高山红景天多倍体育种提供了科学依据。

英文摘要：

Objective： To acquire homozygous tetraploid germplasm of Rhodiola sachalinensis.Method： PEG-mediated protoplast fusions were conducted using callus of Rh.sachalinensis as materials.Protoplast fusion products were embedded and cultured in low-density,low-melting-point agar and marked according to the protoplast size,and single-celled sister lines were established to acquire genetically homozygous tetraploid germplasm.Result： RD and RM of newborn daughter cells or protoplasm,metaphase cells or protoplasm were approximately in line with the formula RD=0.793 7RM.The change range in diameter of the diploid cells without fusion,two protoplasts fusion product were： 16.7 μm≤R21.3 μm,21.0 μm≤R′26.8 μm respectively.There is an overlap between the two diameter ranges.The protoplast inoculation density of 1× 104 cells·mL-1 was appropriate when protoplasts were anchored by low-intensity,low-melting-point agar.Under the conditions of this density,plating efficiency was high and single cell origin of the sister lines microclones grew rapidly,and it was easy to mark the single cell microclones,and separate from each other to subculture.The chromosome counts results showed that chromosome numbers of diploid and tetraploid of single cell lines were 26 and 52,respectively.The result from flow cytometry assay showed that there is no presence of chimerism in single-cell regeneration plantlets.Conclusion： The results of this study provide a scientific basis for polyploid breeding of Rh.sachalinensis.