Investigation of nuclear DNA contents of Lycoris species (Amaryllidaceae) with different chromosome number by flow cytometry

摘要

The chromosome number and karyotype of Lycoris genus display great variability. Flow cytometry was used to estimate 1Cx-values with the aim to analyze the genome size of Lycoris species with different basic chromosome numbers. Three Lycoris species with x=11, three Lycoris species with x=8 and two hybridization origination species, L. straminea (2n=19) and L. haywardii (2n=22) were quantified by flow cytometry in this study. The results demonstrated that: (1) the 1Cx-values of Lycoris lines with x=11 ranged from 20.22 pg to 25.46 pg, among which, L. radiata var. pumila and L. radiata (triploid) are markedly smaller than the other species with x=11. (2) The 1Cx-values of L. aurea , L. chinensis and L. longituba with x=8 were close, which were 30.40 pg, 32. 42 pg and 31.40 pg respectively, much larger than those with x=11, suggesting different origin between Lycoris species with x=11 and x=8. (3) The 1C DNA contents of L. straminea and L. haywardii were 26.97 pg and 23.96 pg respectively, which were close to the averages of their hypothetic parental lines, well proofing their hybridization origination. To our knowledge, the data may be helpful for the evolution studies of Lycoris genus.