AlternAP: Genetic mechanisms underlying alternate cropping in apple (Malus x domestica)

Promoting an environmentally safe and economically competitive fruit tree industry in Europe is challenging because fruit production is fragile in front of global warming and is prone to alternate bearing, which is defined as a high cropping year followed by a low (or nil) cropping. In AlternApp, we investigate new avenues on the genetic and environmental control of floral induction in apple tree to open perspectives for innovative material selection.

Date de début de projet

01/03/2015

Date de fin du projet

28/02/2018

Objectives

In apple tree, the existence of a genetic determinism of floral induction (FI) has been demonstrated in an apple segregating population. First candidate genes (CGs) were revealed which support the assumption of hormonal control of FI, involving developing fruits. But the role of nutritional competition between reproductive and vegetative growth, must also be considered. This project aims at deciphering these two main assumptions by histological, eco-physiological, genetic and genomics approaches. Expected outputs are new and high standing results on FI in apple tree in relation to their alternate bearing behavior and more applied results linked to the discovery of allelic variation in key genes that could be used in breeding programs.

Location

Montpellier-Hohenheim-Dresde

Description

AlternApp is organized in four main WPs, three dedicated to the scientific goals of the project, and one dedicated to project and outputs management. The first WP (WP1) corresponds to phenotypic data collection, calculation of statistical descriptors and mixed models to capture the nature, biennial, irregular or regular, of the different genotypes. QTL detection is also be part of this which final aim is to highlight favorable alleles and a set of CGs located in QTL regions.  The second WP (WP2) focuses on the physiological processes linked to CGs and aims at deciphering two main assumptions underlined in the literature: carbohydrates and/or hormonal control of the bearing nature of genotypes. WP3 focuses on producing molecular data to obtain (1) a high density genetic map of the studied population in WP1; (2) discover positional and expressional CGs. A transversal WP (WP0) concerns the project management, including scientific management (partners meeting), results communication (publication strategy, participation to congress, student training) and administrative management (budget).

Partnership

France : INRA-Montpellier, INRA-Clermont-Ferrand, Univ. Grenoble ; Allemagne : Univ. Hohenheim, Julius Khun Institute (Dresde)

Team

Architecture and functioning of fruit species (AFEF)

Fundings

158 k€ (partie ANR)

Keywords

alternance de production, pommier, charge en fruits, carbohydrates, gibbérellines, histologie, RNA-seq par capture