New Zealand Journal of Agricultural Research abstracts

---

Morphogenetic adaptation to defoliation and soil fertility in perennial ryegrass (Lolium perenne)

L. HAZARD

INRA
Station d'Amélioration des Plantes Fourragères
86600 Lusignan, France

Present address: INRA, Centre de Recherches de Toulouse, Auzeville B.P.27, 31326 Castanet-Tolosan Cedex, France

D. J. BARKER*
H. S. EASTON+

AgResearch
Grasslands Research Centre
Private Bag 11008
Palmerston North, New Zealand

*Present address: Dept of Horticulture and Crop Sciences, The Ohio State University, Columbus, Ohio 43210, USA.

Abstract  Morphogenetic adaptation, plasticity, and mortality of four perennial ryegrass populations, representing different selection histories, were compared in response to soil fertility and to defoliation severity. In a second experiment, morphogenetic adaptation and plasticity in response to defoliation frequency were studied in two divergent sub-populations. Genetic variability was found between ryegrass populations for leaf appearance and elongation rates, leaf size, and tiller number. All populations exhibited plasticity in response to defoliation severity and soil fertility. There was no genetic variation for plasticity, the morphological response to the environment. Morphogenetic differences between populations remained constant across environments and resulted in differential mortality under the most severe defoliation. Both leaf length and rate of leaf appearance were positively correlated with greater mortality. The ryegrass ideotype for hill country is a compromise between yield and persistence.

Keywords  Lolium perenne; hill country; leaf growth; plasticity; mortality; tiller density

New Zealand Journal of Agricultural Research, 2001, Vol. 44: 1-12

0028-8233/01/4401-0001 $7.00/0 (c) The Royal Society of New Zealand 2001

PDF file of entire paper: medium quality (892K); (scanned from paper original: notes about this process)

---

This year's abstracts | Journal home page | All abstracts | Publishing home page