MORPHOLOGICAL AND ARCHITECTURAL TRAITS ON FRUIT TREES WHICH COULD BE RELEVANT FOR GENETIC STUDIES: A REVIEW

Abstract

Presently, the integration of morphological and architectural traits in fruit tree breeding programs, is a major goal for INRA research programs. During the last decade, the architectural development of several species has been investigated at INRA Montpellier, mostly in apple, apricot and olive trees. The existence of morphological characters which are specific to genotypes has been highlighted and used to qualitatively classify the intra-specific genotypes in terms of tree morphology and to promote new agronomic practices. Genotypic differences were quantitatively demonstrated in both shoot morphology, including shoot dimensions and geometry and branching process. Studying the inheritance of morphological traits relies on an estimation of the respective effects of genotype and environment and their possible interactions. Because the comparison of successive years integrates both different climatic conditions and the evolution of traits with plant development, these effects cannot be easily separated in perennial woody plants. This paper illustrates how growth and branching evolve during tree ontogeny. It will also present some possible strategies for capturing the genetic part from fruit tree architectural variation. This will be developed on different traits and developmental stages, attempting to address the following questions: how many years must be described, where in the trees?