P. Annicchiarico et al., Heritability of, and genetic correlations among, forage and seed yield traits in Ladino white clover, PLANT BREED, 118(4), 1999, pp. 341-346
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.