The repetitive landscape of Arachis glandulifera (Leguminosae) investigated by low-depth Illumina sequencing. SSR markers assessed for peanut smut disease resistance.

SAMOLUK, SERGIO S.; CHAVARRO, CAROLINA; CHALUP, L.; BERTIOLI, D.J; JACKSON S; ROBLEDO, G; J. G. SEIJO

Córdoba

Conferencia; 9th International Conference of the Peanut Research Community on Advances in Arachis through Genomics and Biotechnology (AAGB-2017); 2017

International Peanut Genome Initiative

II was previously shown that changes in Ihe repetitive genome fraclion were a primary driving force in genome differentiation belween Ihe A and B genomes of section Arachis. However, to fully undersland Ihe role of the repelitive sequences in Ihe evolulion of Arachis species, addilional dala including species having differenl genomes are needed. Here we analyze Ihe repetilive componenl of A. glandulifera, which is Ihe only wild diploid species (2n =2x = 20, C-value: 1315 Mbp) of the O genome. For this purpose, low-coverage IlIumina whole genome shotgun sequencing reads from A. glandulifera was generated. A tolal of 635 Mbp of sequence dala was used lo perform a low-coverage graph-based cluslering approach implemenled in Ihe RepealExplorer software. This analysis showed Ihal aboul 72 % of Ihe genome is composed of repetilive sequences.The L TR-retroelemenls make up most of Ihe repelilive ONA (57 %), particularly the Ty3-gypsy superfamily, as observed in Ihe A and B genomes. Tandem repeats (microsalelliles, salelliles and rONA) were the second mosl abundant (8 %) repelitive sequences. Among the satO NAs, the CL8 was the most represented. The chromosome distribution by FISH of this satONA showed that this sequence localized to most of Ihe OAP¡+ heterochromatic bands, suggesting Ihal it is likely the major component of Ihese chromosomal regions. This work provides insights into the chromosome structure and repetitive composition ofA. glanduliferagenome, and evidence thal satDNAs may have played a key role in the genome diversification of section Arachis.