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 - 2.09

VARIATION AMONG ITALIAN ALFALFA ECOTYPES BY MEANS OF BIO-AGRONOMIC CHARACTERS AND AMPLIFIED FRAGMENTS LENGTH POLYMORPHISM ANALYSES

M. CARELLI*, F. PUPILLI**, A. BUSTI**, M. ZACCARDELLI***, G. GNOCCHI*, P. GAUDENZI*, C. SCOTTI*

*) Istituto Sperimentale Colture Foraggere, Lodi, Italy

**) Istituto di Genetica Vegetale, CNR, Perugia, Italy

***) Istituto Sperimentale Colture Industriali, Battipaglia, Italy

alfalfa, ecotypes, AFLP markers

The 14 Italian alfalfa ecotypes, each represented by a variable number (1-21) of accessions corresponding to different ‘foundation’ farms, were evaluated in a cold greenhouse at Lodi for 3-years culture together with check cultivars. Plant material (480 plants/ accession) was organised in a randomized block design with 5 blocks; irrigation was non-limiting. Four cuts were made in the sowing year, eight and three cuts respectively in the 1^st and 2^nd productive year. Dry matter, mortality, stem height and earliness were recorded at plot basis. For this study, the highest yielding accession was chosen to represent each of the different ecotypes; besides, two varieties with different genetic origin were included as well. AFLP analyses were performed on 3 independent bulks/accession, each bulk deriving from mixing 100 plantlets (one trifoliate leaf/plantlet).

The variation among ecotypes for vigour (DMY), estimated on 15 cuttings, was highly significant and mainly related to the production in summer cuttings and to the response to autumn conditions. Final mortality was correlated with the total production (r=0.75 **) and showed a highly significant variation among ecotypes. In both cases, however, the variation appeared continuous, with a group of ecotypes from the central-eastern Po Valley showing the highest productivity and the lowest mortality values. AFLP analyses, performed with different selective primers, generated 20 and 61 polymorphic bands that, once combined, produced a unique pattern per ecotype. The genetic distances among ecotypes, estimated on AFLP data, ranged from 0.0154 to 0.2269; UPGMA dendrogram indicated a relative genetic similarity value of about 0.84 for the clusters including all the ecotypes and the check cultivar Lodi. The molecular data seem then to confirm an important common background for the Italian alfalfa ecotypes with the possibility, however, of distinguishing them on the basis of the different frequencies of specific fragments.