Control of flowering time in temperate cereals: genes, domestication, and sustainable productivity

Abstract

The control of flowering is central to reproductive success in plants, and has a major impact on grain yield in crop species. The global importance of temperate cereal crops such as wheat and barley has meant emphasis has long been placed on understanding the genetics of flowering in order to enhance yield. Leads gained from the dissection of the molecular genetics of model species have combined with comparative genetic approaches, recently resulting in the isolation of the first flowering time genes in wheat and barley. This paper reviews the genetics and genes involved in cereal flowering pathways and the current understanding of how two of the principal genes, Vrn and Ppd, have been involved in domestication and adaptation to local environments, and the implications for future breeding programmes are discussed.

Detection of photoperiod responsive and non-responsive flowering time QTL in barley

“…The control of flowering time is central for the reproductive success of plants and has a major impact on grain yield (Cockram et al 2007, Sameri et al 2006, Sameri and Komatsuda 2007. Flowering is often restricted to a particular time of year.…”

Frequency of vernalization requirement associated dominant VRN-A1 gene and earliness related Esp-A1 candidate genes in advanced wheat mutant lines and effect of allele on flowering time

“…the cold period to induce the transition from the vegetative to the generative phase (VRN genes) and the photoperiod sensitivity (PPD genes) and poorly defined 'earliness per se' (eps) or 'narrow sense' earliness genes [15].…”

“…This variation has major implications for yield potential, abiotic and biotic stress tolerance/avoidance, interactions with agronomic interventions, and our ability for predictive breeding of germplasm adapted to specific environments [15].…”

“…It should be noted that standard wheat agriculture practices were followed. After harvesting M 5 plants, 15 …”

“…Varietal differences in flowering time other than those due to photoperiod and vernalization response have been observed in wheat [15]. Such genetic differences are termed ''earliness per se'', 'narrow-sense earliness' or 'intrinsic earliness'.…”