VARIATION FOR DRY-MATTER YIELD, SEED YIELD AND OTHER AGRONOMIC TRAITSIN LADINO WHITE CLOVER LANDRACES AND NATURAL-POPULATIONS

A set of Ladino white clover ecotypes including the last available lan draces and some natural populations collected from old permanent meado ws, together with some white clover varieties of various origins, were evaluated as monocultures for dry matter (DM) and seed yield assessed in separate field experiments. Other agronomic traits were also recor ded. The best performing variety,'Espanso', was significantly outyield ed by some ecotypes for DM and seed production. Compared to landraces, natural populations yielded on average far less seed but as much DM a nd tended towards higher persistence indicating that domestication of the native Ladino at the farm level only improved seed yield of the cr op. Natural populations showed, besides lower values of most seed yiel d components, a distinct canopy architecture characterized by smaller leaves, longer internodes and denser stolons. Seed weight proved the b est character discriminating between the two ecotype groups. Significa nt variation for most traits was found both among landraces, in which it was mostly relatable to differences among provenances, and among na tural populations. The relations between the main multivariate pattern s of phenotypic variation and a set of environment collecting variable s suggested that evolutive adaptation to different agronomic practices was a major determinant of the overall variation found in landraces. Evidence is provided that a relevant part of the variation observed am ong ecotypes for some important traits could be genetic.