0 avis
Unravelling the genetic and environmental control of root system architecture traits in grapevine rootstocksusing the structural root model, Archisimple
Archive ouverte
Edité par CCSD -
International audience. Root system architecture (RSA) defines the spatial distribution of roots in the soil over time. It is shaped by genetically driven growth and developmental processes, which are highly modulated by internal and exogenous cues. Since RSA largely determines the ability of a plant to access water and nutrients, it represents a promising target for breeding plants more tolerant to the future adverse environments. In perennial grafted plants, rootstock genetic variation in RSA and their consequences for soil resource capture has not been studied a lot mainly because of the difficulty to phenotype large root systems in situ. In grapevine rootstocks only few robust quantitative trait loci (QTLs) have been identified for RSA traits (i.e. total root number, length, or biomass) and in general they explain a low percentage of the phenotypic variance. A better understanding of the genetic determinants of RSA as well as its plasticity is important in any grapevine rootstock breeding program. By dissecting RSA into its underpinning components (e.g. root emission, axial elongation, radial growth, branching, or tropism) and identifying the relationships between them, functional-structural 3D root models are promising tools for analysing the diversity and complexity of RSA phenotypes with Genotype × Environment interactions. The model parameters are assumed to be simpler traits, less influenced by the environment, and consequently with less polygenic architectures than the integrative RSA traits they drive. Root models can serve as a basis for the development in silico of root ideotypes by highlighting the physiological mechanisms and parameters that most likely influence the RSA fitness. Based on this principle, we provide here an overview of our original work on RSA phenotyping and model-assisted trait dissection in grapevine. First, we calibrated the root model, Archisimple (Pagès et al., 2014) on a set of rootstocks grown in containers and assess its value to simulate several RSA traits measured at the root system level. Secondly, using the parameters of Archisimple as phenotyping traits, we aimed to identify the relevant traits underlying genotypic diversity among the 138 genotypes and the 2 parents of a mapping progeny derived from an inter-specific cross between Vitis vinifera cv. Cabernet-Sauvignon × V. riparia cv.Gloire de Montpellier grown in the field for 2 years. Broad-sense heritability and QTLs analyses were carried out for model parameters and variables outputs with a consensus map, and compared with other QTLs obtained on classical used RSA descriptors. The preliminary results give new insights on the genetic control of RSA in grapevine rootstocks.
Consulter en ligne
Suggestions
Du même auteur
