Genetic determinism of anatomical and hydraulic traits within an apple progeny

Pierre-Eric P.-E. Lauri (1) , Olivier O. Gorza (1) , Hervé H. Cochard (2) , Sébastien S. Martinez (1) , Jean-Marc J.-M. Celton (1) , Veronique V. Ripetti (1) , Marc M. Lartaud (1) , Xaver X. Bry (3) , Evelyne E. Costes (1) , Catherine C. Trottier (3, 4)

1 UMR AGAP - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales
2 PIAF - Laboratoire de Physique et Physiologie Intégratives de l'Arbre Fruitier et Forestier
3 I3M - Institut de Mathématiques et de Modélisation de Montpellier
4 UPVM - Université Paul-Valéry - Montpellier 3

The apple tree is known to have an isohydric behaviour, maintaining rather constant leaf water potential in soil with low water status and/or under high evaporative demand. However, little is known on the xylem water transport from roots to leaves from the two perspectives of efficiency and safety, and on its genetic variability. We analysed 16 traits related to hydraulic efficiency and safety, and anatomical traits in apple stems, and the relationships between them. Most variables were found heritable, and we investigated the determinism underlying their genetic control through a quantitative trait loci (QTL) analysis on 90 genotypes from the same progeny. Principal component analysis (PCA) revealed that all traits related to efficiency, whether hydraulic conductivity, vessel number and area or wood area, were included in the first PC, whereas the second PC included the safety variables, thus confirming the absence of trade-off between these two sets of traits. Our results demonstrated that clustered variables were characterized by common genomic regions. Together with previous results on the same progeny, our study substantiated that hydraulic efficiency traits co-localized with traits identified for tree growth and fruit production.

Mots clés: xylem cavitation; x domestica borkh; prunus persica trees; malus pumila mill; hydraulique; xylem vessel; xylem safety; xylem efficiency; wood area; qtl; pith area; hydraulic conductivity; heritability; cavitation; malus domestica; stress induced cavitation; complex architectural traits; beech fagus sylvatica; vulnerability curves; physiological traits; different rootstocks

Domaines: Ecologie, Environnement

Pierre-Eric P.-E. Lauri, Olivier O. Gorza, Hervé H. Cochard, Sébastien S. Martinez, Jean-Marc J.-M. Celton, et al.. Genetic determinism of anatomical and hydraulic traits within an apple progeny. Plant, Cell and Environment, 2011, 34 (8), pp.1276-1290. ⟨10.1111/j.1365-3040.2011.02328.x⟩. ⟨hal-00964804⟩