Karyotypes and physical mapping of ribosomal DNA with Oligo-Probes in Eranthis sect. Eranthis (Ranunculaceae)

Abstract

A comparative karyotype analysis of four species of yellow-flowered Eranthis sect. Eranthis, i.e., E. bulgarica, E. cilicica, E. hyemalis, and E. longistipitata from different areas, has been carried out for the first time. All the studied specimens had somatic chromosome number 2n = 16 with basic chromosome number x = 8. Karyotypes of the investigated plants included five pairs of metacentric chromosomes and three pairs of submetacentric/subtelocentric chromosomes. The chromosome sets of the investigated species differ mainly in the ratio of submetacentric/subtelocentric chromosomes, their relative lengths, and arm ratios. A new oligonucleotide probe was developed and tested to detect 45S rDNA clusters. Using this probe and an oligonucleotide probe to 5S rDNA, 45S and 5S rDNA clusters were localized for the first time on chromosomes of E. cilicica, E. hyemalis, and E. longistipitata. Major 45S rDNA clusters were identified on satellite chromosomes in all the species; in E. cilicica, minor clusters were also identified in the terminal regions of one metacentric chromosome pair. The number and distribution of 5S rDNA clusters is more specific. In E. cilicica, two major clusters were identified in the pericentromeric region of a pair of metacentric chromosomes. Two major clusters in the pericentromeric region of a pair of submetacentric chromosomes and two major clusters in the interstitial region of a pair of metacentric chromosomes were observed in E. longistipitata. E. hyemalis has many clusters of different sizes, localized mainly in the pericentromeric regions. Summarizing new data on the karyotype structure of E. sect. Eranthis and previously obtained data on E. sect. Shibateranthis allowed conclusions to be formed about the clear interspecific karyological differences of the genus Eranthis. © 2023 by the authors.National Science Foundation, NSF: 32011530072; Ministry of Education, MOE: 2023R1A6C101B022; Korea Basic Science Institute, KBSI; Russian Science Foundation, RSF: 23-14-00230Most of the co-authors, who are not co-researchers on the RSF project No. 23-14-00230, carried out work on data analysis and revision of the text (5% of the effort in this study) within the framework of the state task for NSF 32011530072 and Korea Basic Science Institute (National Research Facilities and Equipment Center) grant funded by the Ministry of Education (Grant No. 2023R1A6C101B022). Collection materials, all work on the data and writing the manuscript (95% of the effort in this study) were funded by the Russian Science Foundation project Scientific Foundation No. 23-14-00230, https://rscf.ru/project/23-14-00230/ (accessed on 20 April 2021) (for its participants who are co-authors of this study)