DIVERSITY OF THE REPETITIVE DNA FRACTION IN Solanum betaceum Cav. (SOLANACEAE)

SADER, MARIELA; VAIO, MAGDALENA; LOPEZ, A; URDAMPILLETA, J. D.

Cordoba

Congreso; LI Congreso de la Sociedad Argentina de Genética; 2023

Sociedad Argentina de Genetica

Tree tomato (Solanum betaceum Cav.) is native to the Andean region (between 600 and 3,200 m a.s.l.) of South America and is found today in a semi-wild state in northwestern Argentina. Is popular in this region for its consumption in juices and as fresh fruit. Wild fruits can be collected almost all year round, which constitutes an important supplement to balance the necessary nutrients in the diet, having highly valued properties. However, in Argentina the tree tomato is rarely used. Solanum betaceum has 2n=24 chromosomes, and a large genome size (2C = 23 pg). To understand the repetitive fraction composition in this species, we analyzed the repetitive genomefraction using Repeat Explorer and localized the most abundant repeats by Fluorescence In SituHybridization (FISH). The Solanum betaceum genome (with 75% of repeats) showed high proportions of the LTR-retrotransposon Ty3/gypsy-Tekay (54%) followed by Ty3/gypsy-Athila (7.5%). Satellites abundance represents 0.85% of the repetitive fraction with seven different families. The most abundant satellites, SbeSat1 and SbeSat2, were mapped on mitotic chromosomes and revealed a subtelomeric and pericentromeric distribution, sometimes colocalized with heterochromatic CMA+ bands. Consistent with previous studies in other Solanaceae species, S.betaceum showed an accumulation of repetitive DNA sequences, especially retrotransposons, but a relative low abundance of satDNA.