Morphological and molecular diversity of the wild carrot Daucus pusillus: implications for classification and ex situ conservation

IBAÑEZ, V; CAMADRO, E.L.; SALA, C; MASUELLI, R. W.

BOTANY

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Ottawa; Año: 2014 p. 1 - 12

1916-2790

Daucus pusillus and D. montevidensis are wild carrots from the Americas with unresolved taxonomic 1 status. An 2 investigation was carried out with accessions of D. pusillus/D. montevidensis from Argentina for a) morphological and 3 molecular (AFLP and ISSR) characterization, b) analysis of congruence of morphological and molecular variation, and c) 4 comparison of diversity for the ITS region with that reported for a North American accession of D. pusillus. Twelve 5 accessions of D. pusillus/montevidensis -representing their geographical distribution in Argentina-, and one accession of 6 each wild D. carota and D. montanus -as outgroups- were included. In the multivariate analysis of morphological diversity, 7 two accessions were clearly differentiated; this result is not sustained by multivariate analysis of molecular diversity. Based 8 on multivariate and AMOVA analyses, D. pusillus/montevidensis accessions were separated at the molecular level into two 9 groups, associated with geographical origin. Since this result is not supported by morphology, the segregation into two taxa 10 seems unjustified. In all accessions, ITS and 5.8S rDNA regions had identical sequences, which differ in one nucleotide 11 from the corresponding sequence of the North American accession. According to the combined results, D. pusillus would 12 be a single taxon distributed from North to South America, and D. montevidensis a nomenclatural synonym. Autogamy of 13 D. pusillus and its highly structured genetic diversity (Fst=0.86) allows the application of a geographically targeted 14 approach for germplasm exploration, conservation and eventual use in pre-breeding.