Clues from genetic variability in Ipheion (Allioideae) using genotyping-by-sequencing

AGOSTINA SASSONE ; DIEGO HOJSGAARD; JONATAN BRASSAC; GIUSSANI, L. M.; FRANK BLATTNER

Natal

Congreso; 6th International Conference on Comparative Biology of Monocotyledons ? Monocots VI, 2nd World Congress of Bromeliaceae Evolution ? Bromevo II and the 7th International Symposium on Grass Systematics and Evolution; 2018

Federal University of Rio Grande do Norte (UFRN)

The tribe Leucocoryneae is monophyletic and includes 6 genera and about 100 species occurring only in South America. The genus Ipheion comprises three species: I. sessile, I. tweedieanum and I. uniflorum distributed in the Pampean region (Argentina, Uruguay, and Brasil). The species are morphologically differentiated and earlier molecular studies indicate a single origin during Middle Miocene. For the first time, a population-level analysis was carried out for Ipheion using genome-wide single-nucleotide polymorphism (SNP) data from genotyping-by-sequencing (GBS), a next-generation sequencing method. This approach allowed us to investigate phylogenetic relationships and genomic variability among natural populations of Ipheion. In 93 analyzed individuals a total of 2,424 loci were retained after filtering, and a concatenated matrix of 240,568 bp length was generated. The level of missing data was lower than 90%. Phylogenetic analyses provided robust relationships and showed that Ipheion is composed of three genetically, cytogenetic and morphologically differentiated entities that agree with previously defined species. We found that I. sessile and I. tweedieanum might have diverged from within I. uniflorum. Chromosome rearrangements and polyploidization are the major drivers of speciation within Ipheion promoting reproductive isolation among sympatric/parapatric populations.