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

Salsomaggiore Terme, Italy - 26/29 September, 2001

ISBN 88-900622-1-5

Poster Abstract

AFLP ANALYSIS IS AN EFFECTIVE TOOL TO DISCRIMINATE THE ITALIAN ALFALFA ECOTYPES

BUSTI A., PUPILLI F., MOLINARI L.

Istituto di Ricerche sul Miglioramento Genetico delle Piante Foraggere-CNR, Via della Madonna Alta 130, 06128 Perugia, Italy

F.Pupilli@irmgpf.pg.cnr.it

Medicago sativa, AFLP, cultivar identification

The cultivars of the most important forage species are formed by heterogeneous outcrossing populations for which it is difficult if not impossible to find molecular markers that are present in all the individuals of a cultivar and absent in all the individuals of another one. Alfalfa (Medicago sativa L.) is the most important forage crop in temperate environments. It is an outcrossing, seed propagated species with an autotetraploid genetic architecture. In Italy a significant percentage of cultivated Alfalfa is represented by local landraces or ecotypes, which may have a wide genetic base. The aim of the present research, carried out in the frame of the project “Caratterizzazione di ecotipi di erba medica iscritti al registro varietale”, was to distinguish the 15 Italian ecotypes formerly registered at the Italian Seed Agency, through AFLP analysis. A well established bulk strategy was used and 90 primer combination were screened for their capacity to reveal ecotype-specific bands. Three independent bulks of 100 plants were taken as representative of the total genetic variability of each ecotype. Thirty bands specifically present or absent in single ecotypes and therefore defined as ecotype-specific, were revealed by 23 primer combinations. The two narrow base varieties used as control, were the most easily distinguishable as expected. Among the ecotypes, Campania was identified by 9 bands followed by Romagnola with 5, Sardegna, Polesana, Vogherese e Italia Centrale with 3 bands each. Although no ecotype-specific bands were found from the other ecotypes their could be differentiated by combinations of markers . The phenogram generated by the UPGMA analysis showed three main clusters corresponding to the ecotypes adapted in Northern, Central and Southern Italy even if some ecotypes such as Sicilia and Sardegna clustered with Northern ecotypes. These unexpected clustering could be ascribed to the fact that Sicilia and Sardegna were the unique ecotype taken as representative of their respective adaptation areas compared to the other ecotypes for which the best performing of 5-10 accessions was considered. Therefore Sicilia and Sardegna might not represent effectively their respective adaptation areas. In conclusion AFLP markers were proved efficient to distinguish the former Italian Alfalfa ecotypes and could be used for the seed certification procedures.