A multivariate analysis of variation in genome size and endoreduplication in angiosperms reveals strong phylogenetic signal and association with phenotypic traits

Abstract

SummaryGenome size (C-value) and endopolyploidy (endoreduplication index, EI) are known to correlate with various morphological and ecological traits, in addition to phylogenetic placement. A phylogenetically controlled multivariate analysis was used to explore the relationships between DNA content and phenotype in angiosperms.Seeds from 41 angiosperm species (17 families) were grown in a common glasshouse experiment. Genome size (2C-value and 1Cx-value) and EI (in four tissues: leaf, stem, root, petal) were determined using flow cytometry. The phylogenetic signal was calculated for each measure of DNA content, and phylogenetic canonical correlation analysis (PCCA) explored how the variation in genome size and EI was correlated with 18 morphological and ecological traits.Phylogenetic signal (k) was strongest for EI in all tissues, and k was stronger for the 2C-value than the 1Cx-value. PCCA revealed that EI was correlated with pollen length, stem height, seed mass, dispersal mechanism, arbuscular mycorrhizal association, life history and flowering time, and EI and genome size were both correlated with stem height and life history.PCCA provided an effective way to explore multiple factors of DNA content variation and phenotypic traits in a phylogenetic context. Traits that were correlated significantly with DNA content were linked to plant competitive ability.

Endopolyploidy Patterns in Organs of Trifolium Species (Fabaceae)

“…Annuals and biennials are more frequently endopolyploid than perennials are (Barow and Meister, 2003). In angiosperms a negative correlation between endopolyploidization and genome size has been observed (Nagl, 1976;de Rocher et al, 1990;Barow and Meister, 2003;Bainard et al, 2012). Jovtchev et al (2006) demonstrated a highly positive correlation between DNA content and nuclear volume and a significant positive correlation between nuclear volume and cell volume.…”

“…Low endopolyploidy degree in leaf has been found in other Fabaceae species (Bainard et al, 2012;Barow and Meister, 2003). Fabaceae species show considerably lower cycle values than other polysomatic species, for example those in Cucurbitaceae, Chenopodiaceae (Barow and Meister, 2003) and Brassicaceae (Bainard et al, 2012;Barow and Meister, 2003).…”

“…3) also indicated that T. montanum and T. repens are closer to each other than either of them to T. pratense. Barow and Meister (2003) and Bainard et al (2012) pointed to taxonomic position as the most important factor leading to the occurrence of endopolyploidy, and Bainard et al (2012) reported that endopolyploidy degree correlates with various morphological and ecological traits, in addition to phylogenetic position.…”

“…DNA endoreduplication might be seen as an evolutionary alternative which compensates a deficiency in the phylogenetically determined nuclear DNA amount in some species (Nagl, 1976). Bainard et al (2012) found a correlation between both genome size and endoreduplication and some phenotypic traits. However, phylogeny and life strategy have a stronger impact on endopolyploidy than genome size (Barow and Meister, 2003;Jovtchev et al, 2006).…”

“…Fabaceae is a family with several polysomatic species (Kondorosi et al, 2000;Barow and Meister, 2003;Kocová and Mártonfi, 2011;Bainard et al, 2012). Trifolium L., with more than 250 species, is one of the largest genera in Fabaceae (Zohary and Heller, 1984).…”