Variation between and within Trifolium repens L. populations collected from sown swards in Uruguay

摘要: Nineteen Trifolium repens L. (white clover) populations were collected in different parts of Uruguay (where conditions are marginal for the species) from swards sown 2–15 years earlier. Twenty five genotypes each population grown as spaced plants on a single site. Leaflet length and width, petiole length, plant height, diameter internode recorded. In second experiment, ten studied similar way. Large genetic correlations obtained among leaflet height one group, major diameter, minor another both experiments. Collection site characteristics that tended to result relatively short, small-leaved were: sowing cv. Bayucua or Santa Fe (rather than Zapican orYi); old sward; high available soil P; overgrazing; dry conditions. There was an indication that, some respects, there less variation within older younger swards. Overall heritabilities width low with intermediate. Genotypes (such Romero) survived 15 unfavourable could be useful breeding programme. Selection rather smaller-leaved types might enhance persistence.