Creation of a core-collection of the species Cynara cardunculus L.

CRIPPA, I.; MARTIN, E.A.; COINTRY, E.L.; CRAVERO, V.P.

La Plata

Simposio; IX International Symposium on Artichoke, Cardoon and their wild relatives; 2015

ISHS

The aim of this work was to create a core-collection of the species Cynara cardunculus L. in order to preserve its variability with the less redundancy. To achieve this, 52 accessions belonging to the three botanical varieties (scolymus, altilis and sylvestris) were characterized. Quantitative and qualitative morpho-vegetative traits were evaluated. Also a molecular characterization was performed using SRAP (Sequence Related Amplified Polymorphism) and SSR (Single Sequence Repeats) markers. Variation parameters like Total Number of Bands (NB), Number of Polymorphic Bands (PB), Polymorphic Information Content (PIC), Shannon-Waver index (SW) and Heterozygosity index (H) were estimated with both kind of markers and Effective Number of Alleles just with SSR markers. The results of these parameters confirmed the presence of variation both intra and inter-accessions. Morphological and molecular analyses showed to be complementary. To construct the core-collection, two stratification criteria were applied previous to the cluster analysis: the first one includes all the accessions together (E1) whereas the second one divides them by botanical varieties (E2). Afterwards, to determine how many accessions of each group will be included in the core collection, three strategies were considered (fixed (F), logarithmic (Ln) and proportional (Pr)). Also M strategy was applied, which not only defines the number of accessions that will be included, but also identifies which accessions will form the core-collection. Seven different core-collections were designed. Three of them were performed using the stratification criteria E1 combining with the three sampling strategies (F, Ln, Pr), other three, by E2 combined with each one sampling strategies and the last collection using strategy M through the software PowerCore (PC). All core-collections were validated comparing their values with those of the initial collection for several parameters obtained from the morphological (Mean Values Differences, Percentage of Differences in Mean Values, Percentage of Differences in Variance, Range-matching Percentage and Percentage of Variation Coefficient for all the phenotypic traits) and molecular characterization (NB, PB, PIC, SW and H). Validation allowed determine that the core-collection performed using the strategy E1Pr is that best represent the initial diversity, retaining 36% of the accessions.