Gitai et al. 2014 (Article) Bromeliaceae, chromosomes

Chromosome numbers and DNA content in Bromeliaceae: additional data and critical review

Author(s):—JURAJ PAULE JAILSON GITAÍ

Publication:—Botanical Journal of the Linnean Society 176: 349–368.. (2014) — DOI

Abstract:—For the large Neotropical plant family Bromeliaceae, we provide new data on chromosome numbers, cytological features and genome size estimations, and combine them with data available in the literature. Root-tip chromosome counts for 46 species representing four subfamilies and a literature review of previously published data were carried out. Propidium iodide staining and flow cytometry were used to estimate absolute genome sizes in five subfamilies of Bromeliaceae, sampling 28 species. Most species were diploid with 2n = 50 in Bromelioideae,
Puyoideae and Pitcairnioideae, followed by 2n = 48 observed mainly in Tillandsioideae. Individual chromosome sizes varied more than tenfold, with the largest chromosomes observed in Tillandsioideae and the smallest in Bromelioideae. Genome sizes (2C-values) varied from 0.85 to 2.23 pg, with the largest genomes in Tillandsioideae. Genome evolution in Bromeliaceae relies on two main mechanisms: polyploidy and dysploidy. With the exception of Tillandsioideae, polyploidy is positively correlated with genome size. Dysploidy is suggested as the mechanism
responsible for the generation of the derived chromosome numbers, such as 2n = 32/34 or 2n = 48. The occurrence of B chromosomes in the dysploid genus Cryptanthus suggests ongoing speciation processes closely associated with chromosome rearrangements.