Quantitative analysis of the phenotypic variability of shoot architecture in two grapevine (Vitis vinifera) cultivars

Louarn Gaëtan, Guédon Yann, Lecoeur Jérémie, Lebon Eric. 2007. Quantitative analysis of the phenotypic variability of shoot architecture in two grapevine (Vitis vinifera) cultivars. Annals of Botany, 99 : 425-437.

Résumé : - Background and Aims Plant architecture and its interaction with agronomic practices and environmental constraints are determinants of the structure of the canopy, which is involved in carbon acquisition and fruit quality development. A framework for the quantitative analysis of grapevine (Vitis vinifera) shoot architecture, based on a set of topological and geometrical parameters, was developed for the identification of differences between cultivars and the origins of phenotypic variability. - Methods Two commercial cultivars ('Grenache N', 'Syrah') with different shoot architectures were grown in pots, in well-irrigated conditions. Shoot topology was analysed, using a hidden semi-Markov chain and variable-order Markov chains to identify deviations from the normal pattern of succession of phytomer types (P0-P1-P2), together with kinematic analysis of shoot axis development. Shoot geometry was characterized by final internode and individual leaf area measurements. - Key Results Shoot architecture differed significantly between cultivars. Secondary leaf area and axis length were greater for 'Syrah'. Secondary leaf area distribution along the main axis also differed between cultivars, with secondary leaves preferentially located towards the basal part of the shoot in 'Syrah'. The main factors leading to differences in leaf area between the cultivars were: (a) slight differences in main shoot structure, with the supplementary PO phytomer on the lower part of the shoot in 'Grenache N', which bears a short branch; and (b) an higher rate and duration of development of branches bearing by P1-P2 phytomers related to P0 ones at the bottom of the shoot in 'Syrah'. Differences in axis length were accounted for principally by differences in individual internode morphology, with 'Syrah' having significantly longer internodes. This trait, together with a smaller shoot diameter, may account for the characteristic 'droopy' habit of 'Syrah' shoots. - Conclusions This study highlights the architectural parameters involved in the phenotypic variability of shoot architecture in two grapevine cultivars. Differences in primary shoot structure and in branch development potential accounted for the main differences in leaf area distribution between the two cultivars. By contrast, shoot shape seemed to be controlled by differences in axis length due principally to differences in internode length.

Mots-clés Agrovoc : Vitis vinifera, analyse quantitative, phénotype, variété, organogénèse, morphogénèse, ramification, port de la plante, variation génétique

Mots-clés complémentaires : Architecture végétale

Classification Agris : F62 - Physiologie végétale - Croissance et développement
F50 - Anatomie et morphologie des plantes
F30 - Génétique et amélioration des plantes

Champ stratégique Cirad : Axe 1 (2005-2013) - Intensification écologique

Auteurs et affiliations

• Louarn Gaëtan, CIRAD-AMIS-AGRONOMIE (FRA)
• Guédon Yann, CIRAD-AMIS-UMR AMAP (FRA)
• Lecoeur Jérémie, INRA (FRA)
• Lebon Eric, INRA (FRA)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/537436/)

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