title: Congruence between morphological and molecular markers inferred from the analysis of the intra-morphotype genetic diversity and the spatial structure of Oxalis tuberosa Mol.
abstract: Oxalis tuberosa is an important crop cultivated in the highest Andean zones. A germplasm collection is maintained ex situ by CIP, which has developed a morphological markers system to classify the accessions into morphotypes, i.e. groups of morphologically identical accessions. However, their genetic uniformity is currently unknown. The ISSR technique was used in two experiments to determine the relationships between both morphological and molecular markers systems. The intra-morphotype genetic diversity, the spatial structures of the diversity and the congruence between both markers systems were determined. In the first experience, 44 accessions representing five morphotypes, clearly distinct from each other, were analyzed. At the molecular level, the accessions exactly clustered according to their morphotypes. However, a genetic variability was observed inside each morphotype. In the second experiment, 34 accessions gradually differing from each other on morphological base were analyzed. The morphological clustering showed no geographical structure. On the opposite, the molecular analysis showed that the genetic structure was slightly related to the collection site. The correlation between both markers systems was weak but significant. The lack of perfect congruence between morphological and molecular data suggests that the morphological system may be useful for the morphotypes management but is not appropriate to study the genetic structure of the oca. The spatial structure of the genetic diversity can be related to the evolution of the species and the discordance between the morphological and molecular structures may result from similar selection pressures at different places leading to similar forms with a different genetic background.
authors: Département de Biologie Appliquée et Productions Agricoles, Ecophysiologie et Amélioration Végétale, Université Catholique de Louvain, Place Croix du Sud, 2 bte 11, 1348 Louvain-La-Neuve, Belgium. pissard@ecav.ucl.ac.be
authors: Audrey
authors: A
authors: Pissard
authors: Carlos
authors: C
authors: Arbizu
authors: Marc
authors: M
authors: Ghislain
authors: Anne-Michèle
authors: AM
authors: Faux
authors: Sébastien
authors: S
authors: Paulet
authors: Pierre
authors: P
authors: Bertin
mesh_terms: D005819:Genetic Markers / Q000235:genetics; D014644:Genetic Variation; D019684:Magnoliopsida / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics*; D018598:Minisatellite Repeats; D010802:Phylogeny; D015203:Reproducibility of Results; D017422:Sequence Analysis, DNA / Q000379:methods
chemical_list: D005819:Genetic Markers