Growth and phosphorus productivity of non-mycorrhizal Pinus pinaster seedlings: Comparison of three populations and seven full-sib families within a population
Abstract:Growth and nutrition of hydroponically cultivated pine seedlings ( Pinus pinaster Ait.) were investigated at various phosphorus (P) availabilities. P was added either with free access or at a relative addition rate of 0.02 and 0.04 day -1 . Laboratory observations were compared with adult growth performances in the field in two sets of experiments: the first with three contrasting populations, the second with seven full-sib families within a population. Significant differences in P productivity (growth rate per unit P in the plant) and in maximal relative growth rate were observed in both experiments, but correlation with adult performances was restricted to populations. Selection for nutrient-related traits would thus be possible, but understanding of the relationship between growth and nutrition needs further evaluation. The minimum P concentration in the seedlings supporting maximum growth ([P]optimum) varied from 2.2 to 3.8 mg g -1 DM, which is in agreement with values obtained in other species. The root/shoot ratio increased with P limitation, with a marked tendency for the population with the highest adult height performance. Inversely, within families, seedlings identified as the best performers for adult growth invested more biomass in shoots than in roots with P stress.
Document Type: Research Article
Affiliations: 1: Unité de Recherche EPHYSE, Ecologie fonctionnelle et Physique de l'environnement, Institut National de la Recherche Agronomique, Cestas, France 2: CESBIO, Unité mixte CNES-CNRS-UPS-IRD-UMR 5126, Toulouse, France
Publication date: May 1, 2005