高山红景天同源四倍体诱导与鉴定研究

目的 获得高山红景天同源四倍体无性体系。方法 秋水仙素诱导种子加倍，通过多次组培再生进行嵌合体分离，采用气孔大小与密度测量、染色体计数和流式细胞学分析进行倍性鉴定。结果 秋水仙素质量分数与处理时间对种子萌发率、幼苗死亡率及诱变率均有十分明显的影响，0.2%秋水仙素处理露白种子72 h的萌发率、幼苗死亡率及诱变率分别为18.2%、73.6%、68.7%；倍性变异植株气孔明显增大，气孔密度变小；正常二倍体染色体数目为2n＝2x＝26，四倍体染色体数为 2n＝4x＝52，发现非整倍体的存在；倍性变异植株经3次再生纯化后获得纯合四倍体无性系，流式细胞学检测无嵌合体存在。结论 秋水仙素处理高山红景天种子获得同源四倍体具有可行性。

Autotetraploid induction and identification of Rhodiola sachalinensis

Objective To obtain autotetraploid clones of Rhodiola sachalinensis. Methods Germplasm with doubled chromosomes was acquired according to colchicine soaking seeds, and ploidy was identified according to stomata size and density measurements, chromosome counting and flow cytometry analysis. Chimera was purified after several times of regenerations. Results Colchicine concentration and treatment duration had significant effect on seed germination rate, seedling death rate and ploidy mutation rates, and they were 18.2%, 73.6%, and 68.7%, respectively after the seeds were soaked in 0.2% colchicine solution for 72 h. Stomata diameter was promoted and density was declined significantly in morphological variation plantlets; normal diploid chromosome number was 2n = 2x = 26, and tetraploid chromosome number was 2n = 4x = 52. Meanwhile, aneuploidy was found in the population of plantlets after colchicine soaking, leaves of ploidy mutation plantlets were used as explants to regenerate to tube plants, and homozygous clones were obained after three regeneration and purification cycles. There was no chimera in the homozygous clones according to flow cytometry analysis. Conclusion It is feasible to obtain autotetraploid according to colchicine treatment on seeds of R. sachalinensis.