Three seed lots, obtained from different 'foundation farms', for each of th
e alfalfa, Medicago sativa L., ecotypes 'Vogherese' and 'Maremmana', togeth
er with the variety 'Iside' as a control, were studied to test the possibil
ity of distinguishing them through restriction fragment length polymorphism
analysis. Twenty plants per seed lot were analysed with 25 DNA probes that
yielded 155 informative polymorphic fragments. Variance partitioning showe
d that within-population Variability accounted for nearly 98% of the total
variance, while a small but significant contribution to the total Variance
was due to among-lot variability. 'Vogherese' was more homogeneous than 'Ma
remmana', as a consequence of the greater environmental homogeneity of the
adaptation area of the former ecotype compared with the latter. Bulk analys
is yielded eight variety-specific bands, 12 bands present in both ecotypes
and absent in the variety and one band specific of 'Maremmana'. Results are
discussed in relation to the practical use of molecular markers for alfalf
a ecotype identification.