Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 2.54

MOLECULAR CHARACTERIZATION OF LOCAL POPULATIONS OF RADICCHIO (CICHORIUM INTYBUS L.) GROWN IN VENETO

M. BRAKE, G. BARCACCIA, M. LUCCHIN, P. PARRINI

Dipartimento di Agronomia Ambientale e Produzioni Vegetali, Università di Padova – Agripolis, via Romea 16, 35020 Legnaro, Padova, Italy

paolo.parrini@unipd.it

chicory, molecular markers, genetic similarity, genetic diversity

Red or variegated chicory (Cichorium intybus L.) native to, and very extensively cultivated in North-Eastern Italy, locally called “radicchio”, includes different types which represent valuable high-quality crops. The five major types of radicchio cultivated in the Veneto region were investigated by PCR-derived markers to evaluate the amount and partition of genetic variability in local populations and to set up a molecular reference system for the precise genetic identification of different types. Althought a clear-cut morphological differentiation among the five types does exist, their genetic identification is becoming increasingly important. Materials grown are usually represented by local populations known to possess a high variation and adaptation and maintained by farmers through phenotypical selection according to their own criteria.

The experimental material was repredented by 23 local populations, seven of “Rosso di Chioggia” (CH), eight of late “Rosso di Treviso” (TVT), three of early “Rosso di Treviso” (TVP), two “Rosso di Verona” (VR) and five of “Castelfranco” (CF). A total of 797 individual plant DNAs were assayed using random amplified polymorphic DNA markers (RAPD). Five selected operon decamer primers generated a total of 35 markers, 25 of which were polymorphic (71.4%). The genetic variation was shown to be much higher within than between populations. As a matter of fact, the total Nei’s genetic diversity (H_T) was 0.324, while that calculated for single populations (H_S) was, on average, 0.217. The high value of the fixation index (G_ST = 0.331) was consistent with a DNA polymorphism rate more pronounced within populations: the 67% of the total genetic variability observed can be attributed to within populations differences and around 33% is due to differences among the populations. The low value of gene flow (Nm = 1.013) confirms a little exchange of marker alleles among populations. Some type-specific markers that allow type discrimination were found. Further experiments and statistical analyses are in progress. The set up of a molecular reference system seems to be feasible for the precise identification of the single types of Veneto radicchio and suitable for the evaluation of the extent of natural hybridization there can occur between different types.