Can Flowering Time Adapt Crops to a Warming World – Lessons from Wheat?

Empirical selection through time has allowed optimisation of wheat flowering to ensure maximum yields in a given region. Farmers and breeders have either directly or indirectly selected a complex of genes controlling floral transition, through preference for differing vernalization requirement (VRN genes), photoperiod sensitivity (PPD genes), and additional smaller effect earliness per se (Eps) loci to meet specific regional climatic conditions. Manipulation of flowering time is a key adaptation mechanism and is likely to be increasingly important under a climate change scenario, with global warming predicted to accelerate plant development and shorten lifecycles. Detailed knowledge of the interplay between the genetic control of flowering, allelic variants, epistatic interactions and phenotypic variation in varied growth conditions is necessary in order to identify key breeding targets.

Wheat (Triticum aestivum) is long day responsive, and possesses a vernalization requirement (in winter cultivars). Altering flowering time through manipulation of major genes provides a strategy to adapt elite varieties to the prospect of shorter, hotter, drier growing seasons. Understanding the precise phenotypic responses governed by known alleles of these genes may facilitate further manipulation of flowering to suit future permutations of climate. Additionally, identification of wheat orthologues of key flowering loci from model species may offer novel variation of particular relevance to a warming climate. Computational modelling could also offers the ability to assess and predict the effect of genotypic and phenotypic changes on yield potential, and interactions between climate and yield under current and forecast climatic conditions.