Genome size variation in Deschampsia cespitosa sensu lato (Poaceae) in Eurasia

GREIMLER, JOSEF; TEMSCH, EVA M.; XUE, ZHIQING; WEISS-SCHNEEWEISS, HANNA; VOLKOVA, POLINA; PEINTINGER, MARKUS; WASOWICZ, PAWEL; SHANG, HUI; SCHANZER, IVAN; CHIAPELLA, JORGE O.

PLANT SYSTEMATICS AND EVOLUTION

SPRINGER WIEN

Año: 2022 vol. 308

0378-2697

The grass Deschampsia cespitosa is a variable taxon out of which many varieties, subspecies and endemic species havebeen separated. In this paper, the variation in genome size (GS) and ploidy of this grass including several of its subspeciesand two related species in Eurasia was investigated by flow cytometric (FCM) measurements. GS and ploidy data werealso related to specific environments and reproduction mode. Ploidy levels found by FCM were confirmed by chromosomecounts of diploid (2n = 28) and tetraploid (2n = 52) samples. Seminiferous (seed bearing) D. cespitosa was mainly diploid(GS between 3.754 and 5.438 pg/1C). GS variation in diploids showed a geographic pattern with a significant difference(H = 41,441, P < 0.001) between European (median = 4.377 pg) and Asian (median = 4.881 pg) accessions. Genome size(1C) in tetraploids ranged from 7.9426 to 9.0399 pg. Tetraploid seminiferous D. cespitosa was found mostly in disturbedhabitats in western and southern Europe, while tetraploids in Asia were registered in wet Arctic habitats. Genome size (1Cbetween 8.3278 and 8.8603 pg) of the pseudoviviparous plants (spikelets produce plantlets asexually) of wet habitats incentral and northern Europe indicated tetraploidy. A putative triploid (GS 6.6817 pg) was detected in Iceland. Summing up,we found a high variation in GS on the geographic scale with significant regional differences in diploid D. cespitosa. Amongthe tetraploids, the asexually reproducing plants were bound to specific habitats, while the seminiferous plants showed ahabitat preference similar to the diploids.