Plasticity in Vegetative Growth over Contrasted Growing Sites of an F1 Olive Tree Progeny during Its Juvenile Phase

Abstract

Climatic changes impact fruit tree growth and severely limit their production. Investigating the tree ability to cope with environmental variations is thus necessary to adapt breeding and management strategies in order to ensure sustainable production. In this study, we assessed the genetic parameters and genotype by environment interaction (GxE) during the early tree growth. One hundred and twenty olive seedlings derived from the cross ‘Olivière’ x ‘Arbequina’ were examined across two sites with contrasted environments, accounting for ontogenetic trends over three years. Models including the year of growth, branching order, environment, genotype effects, and their interactions were built with variance function and covariance structure of residuals when necessary. After selection of a model, broad sense heritabilities were estimated. Despite strong environmental effect on most traits, no GxE was found. Moreover, the internal structure of traits co-variation was similar in both sites. Ontogenetic growth variation, related to (i) the overall tree form and (ii) the growth and branching habit at growth unit scale, was not altered by the environment. Finally, a moderate to strong genetic control was identified for traits at the whole tree scale and at internode scale. Among all studied traits, the maximal internode length exhibited the highest heritability (H2 = 0.74). Considering the determinant role of this trait in tree architecture and its stability across environments, this study consolidates its relevance for breeding.

On the origins and domestication of the olive: a review and perspectives

“…The power to detect genes under positive selection associated with olive domestication will be enhanced by large-scale phenotyping efforts spanning multiple years in several environments and including replicates of wild and cultivated individuals in collections or common gardens (e.g. Belaj et al, 2012;El Bakkali et al, 2013;Ben Sadok et al, 2015;León et al, 2016). Over the last 10 years, segregating progenies have been used to identify genomic regions associated with agronomic traits [quantitative trait loci (QTLs) for olive oil quality, fruiting, growth and tree architecture], but the precise genes responsible for these trait variations remain unknown (e.g.…”

“…Both in the wild (e.g. García-Verdugo et al, 2009;Granado-Yela et al, 2011;Rubio de Casas et al, 2011) and in common gardens (Rubio de Casas et al, 2011;Ben Sadok et al, 2015;León et al, 2016), strong environment effects have been demonstrated on many traits of wild olives and cross progeny. Little is known about the ecological and genomic basis of this phenotypic variation (e.g.…”

Genetic Variation of Morphological Traits and Transpiration in an Apple Core Collection under Well-Watered Conditions: Towards the Identification of Morphotypes with High Water Use Efficiency

“…Since these traits are highly heritable ( Fig 2A ) they could be easily implemented as secondary traits in apple-breeding programs. The internode maximum length has been recently proposed as an important morphological trait due to its stability among different environments [ 40 ]. We also identified a group of 17 genotypes with high WUE ( Table 6 ).…”

High-resolution genetic linkage map of European pear (Pyrus communis) and QTL fine-mapping of vegetative budbreak time

“…GxE in the context of plant breeding is denoted as phenotype plasticity. Breeders aim to produce new cultivars with stable phenotypes in different climatic regions [ 25 , 26 ]. Selection of new cultivars is usually made in the targeted region.…”

“…GxE related to important agricultural annual crops has been reported. However, very few studies have been carried out on the GxE effect on fruit tree traits [ 25 ].…”