Structuration of alfalfa genetic diversity using agronomic and morphological characteristics. Relationship with RAPD markers.

摘要

Morphological and agronomic characteristics were studied in 46 tetraploid populations of Medicago sativa subsp. sativa and subsp. falcata [M. falcata] of diverse origin during 1994-97. Genetic diversity was analysed using principal component analysis and clusters were defined on the Euclidean distances. Wild populations of both subspecies were clustered together and characterized by slow regrowth after cutting, no growth during the winter, late spring growth and prostrate growth habit. Among the cultivated populations, genetic differentiation in 2 major clusters corresponding to the Mediterranean types and the Nordic types was observed. A population from Turkey exhibited characteristics intermediate between the 2 groups, with vigorous growth in the different seasons and high seed production. The relationship between the Euclidean distance based on morphological characteristics and the distance calculated from RAPD markers was analysed for 26 populations. This relationship was significant for themajor groups of variation, i.e. at the subspecies level, the relationship being not significant for the populations within groups.