Karyological patterns in the European endemic genus Soldanella L.: Absolute genome size variation uncorrelated with cytotype chromosome numbers. Issue 8 (8th August 2017)

• Record Type: Journal Article
• Authors: Štubňová, Eliška; Hodálová, Iva; Kučera, Jaromír; Mártonfiová, Lenka; Svitok, Marek; Slovák, Marek
• Is Part Of: American journal of botany. Volume 104:Issue 8(2017)
• Page Start: 1241
• Page End: 1253
• Publication Date: 2017-08-08
• Subjects: cytogeography -- dysploidy -- European mountain system -- genome size conservatism -- ITS -- PI flow cytometry -- Primulaceae -- rare cytotypes; Botany -- Periodicals; Botany; Electronic journals; Periodicals; 580
• DOI: 10.3732/ajb.1700153
• Languages: English
• ISSNs: 0002-9122

Abstract

Abstract : PREMISE OF THE STUDY: Detailed knowledge about the karyological diversity of organisms undoubtedly represents one of the crucial steps toward a better understanding of their evolutionary trends and history. We investigated the cytotype and absolute genome size (AGS) patterns in the European mountain‐dwelling genus Soldanella (Primulaceae) in light of its geographic distribution and ecological diversification. METHODS: Our chromosome number survey was based on 34 newly determined and 125 previously published chromosome counts. AGS was estimated on the basis of propidium iodide (PI) flow cytometry (299 individuals, 110 populations). KEY RESULTS: We confirmed the existence of two cytotypes with the same ploidy level, i.e., euploid 2 n = 40 and dysploid 2 n = 38. The overall infrageneric AGS variation ranged between 2.97 and 3.99 pg (25.6% variation). The 2 n = 40 cytotype harbors a modest amount of continuous AGS variation. With regard to its distribution area and ecology, the cytotype is ubiquitous. By contrast, the 2 n = 38 cytotype was detected only in six forest‐dwelling taxa with AGS variation segregated into three discrete, geographically separated groups. The AGS variation of the 2 n = 38 cytotype was strongly correlated with elevation and longitude. CONCLUSIONS: Despite the apparent morphological and ecological variation, members of the genus Soldanella have not undergone any pronounced cytotype and AGS diversification during their evolutionary history. The lack of correlation between chromosome numbers and AGS indicates that the evolutionary mechanism behind the origin of the dysploid cytotype 2n = 38 was a chromosomal fusion.