The relationship between productivity and some components of canopy structure in ryegrass (Lolium spp.)

Abstract

Experiments were carried out to measure the components of canopy structure (on young spaced seedlings), their heritabilities and relationship to sward yield in the F1 generation of a diallel cross between six ryegrass populations.Considerable differences existed between parent populations in both leaf length and tiller angle, but little difference existed in leaf angle. All the components of canopy structure were highly heritable, tiller angle, leaf length and leaf rigidity showing narrow sense heritabilities greater than 0·75.There were large differences in yield between F1 families, moreover, when (a) Lolium perenne families, (6) L. multiflorum families and (c) L. perenne x L. mvltiflorum families were considered separately, leaf length and a composite character derived from leaf length and tiller angle (all measured on young spaced seedlings) were closely related to yield under sward conditions.The plant breeding implications of these results are discussed.