Müller et al. 2019 (Article)

Bromeliaceae subfamilies show divergent trends of genome size evolution

Author(s):—L.B. Müller, G. Zotz & D.C. Albach

Corresponding email:—lilian-lee.mueller-fischer@univie.ac.at

Publication:—Scientific Reports 9 (5136): 1-12. (2019) — DOI

Abstract:—Genome size is known to vary widely across plants. Yet, the evolutionary drivers and consequences
of genome size variation across organisms are far from understood. We investigated genome size
variation and evolution in two major subfamilies of the Neotropical family Bromeliaceae by determining
new genome size values for 83 species, testing phylogenetic signal in genome size variation, and
assessing the fit to different evolutionary models. For a subset of epiphytic bromeliad species, we
also evaluated the relationship of genome size with thermal traits and relative growth rate (RGR),
respectively. Genome size variation in Bromelioideae appears to be evolutionary conserved, while
genome size among Tillandsioideae varies considerably, not just due to polyploidy but arguably also
due to environmental factors. The subfamilies show fundamental differences in genome size and RGR:
Bromelioideae have, on average, lower genome sizes than Tillandsioideae and at the same time exhibit
higher RGR. We attribute this to different resource use strategies in the subfamilies. Analyses among
subfamilies, however, revealed unexpected positive relationships between RGR and genome size, which
might be explained by the nutrient regime during cultivation. Future research should test whether there
is indeed a trade-off between genome size and growth efficiency as a function of nutrient supply.