Genome size and chromosome number of ten plant species from Kerguelen Islands

• Published in: Polar Biology
• Main Authors: Siljak-Yakovlev, Sonja, Lamy, Françoise, Takvorian, Najat, Valentin, Nicolas, Gouesbet, Valérie, Hennion, Françoise, Robert, Thierry
• Other Authors: Ecologie Systématique et Evolution (ESE), AgroParisTech-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Cytométrie (CYTO), Département Plateforme (PF I2BC), Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Ecosystèmes, biodiversité, évolution Rennes (ECOBIO), Université de Rennes (UR)-Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Supported by the French Polar Institute (IPEV). This research was also supported by CNRS IRP grant “AntarctPlantAdapt” (F. Hennion)., IPEV 1116 PlantEvol
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: evolution; polyploidy; Flow cytometry; 2C DNA value; Genome size; nuclear-dna content; angiosperms; brassicaceae; c-values; climate; constraint hypothesis; Endemic species; festuca-pallens; indian-ocean; Ploidy level; Sub-Antarctic flora; [SDV]Life Sciences [q-bio]; Antarc*; Antarctic; Kerguelen Islands; Polar Biology
• Online Access: https://hal.science/hal-02985456; https://hal.science/hal-02985456/document; https://hal.science/hal-02985456/file/Siljak-Yakovlev%20et%20al-2020-Genome%20size%20and%20chromosome%20number%20of%20ten%20plant%20species-clean%20Revised%20Manuscript.pdf; https://doi.org/10.1007/s00300-020-02755-7

Place: New York Publisher: Springer WOS:000578347700001 International audience Kerguelen Islands harbor a unique, probably very ancient flora with a high rate of endemism. However, the evolutionary history and characteristics of this flora still require investigation. This concerns in particular genome size and ploidy level variation, despite the evolutionary and ecological significance of those traits. Here we report the first assessment of genome size, using flow cytometry, for eight plant species of which two are endemics of Kerguelen Islands and four of the South Indian Ocean Province. The 2C DNA value ranged from 1.08 pg for Pringlea antiscorbutica to 11.88 pg for Ranunculus biternatus. The chromosome numbers of Colobanthus kerguelensis (2n = 80), Lyallia kerguelensis (2n = 96) and Poa kerguelensis (2n = 28) were also reported in this study for the first time. Overall, our data allowed to infer that all Kerguelen studied species are polyploid (from tetra- to octopolyploid). Intra-genus comparisons showed significant differences of 2C DNA values among Poa and among Ranunculus species, despite their identical ploidy level. In addition, our data highlight the existence of an intraspecific variability of genome size for the two octoploid species Colobanthus kerguelensis and Lyallia kerguelensis. Finally, our data also support the hypothesis regarding which polyploidy may have played a major role in the adaptation of flowering plants to high latitudes, as it has been suggested for arctic species.