Heritability of, and genetic correlations among, forage and seed yield traits in Ladino white clover

Sixteen white clover genotypes and their half-sib progenies were grown in p ure stand. Each clover progeny was also grown in a mixed stand that also in cluded three grass varieties of different species. Dry matter (DM) yield wa s measured over 2 years and seed yield at the second year. Competitive abil ity of clover families was defined as the ratio between mixed stand and pur e stand for clover DM yield. Narrow-sense heritability from parent-offsprin g regression of pure stand data was high to moderate (h(2) > 0.50) for DM y ield, seed yield and most of their components. Persistence as predicted by stolen density showed negative genetic correlations with seed yield (r(g) = -0.70) and DM yield (r(g) = -0.60), whereas seed yield and DM yield tended towards a negative correlation (r(g) = -0.45). Sizes of different vegetati ve or reproductive organs were generally correlated positively. Evidence wa s provided that the set of parent genotypes represents well the genetic var iation available within the Ladino gene pool. The results highlighted the d ifficulty of combining relatively short-term DM yield, persistence and seed yield into a unique plant type. Differences in competitive ability emerged only in the second year, better ability being related mainly to petiole le ngth among the traits assessed in pure stand.