The molecular genetic regulation of vegetative-generative transition in wheat from environmental perspective.

The key to wide geographical distribution of wheat is its high adaptability. One of the most commonly used methods for studying adaptation is the investigation of transition between the vegetative-generative phase and the subsequent intensive stem elongation process. These processes are largely determined by changes in ambient temperature, the diurnal and annual periodicity of day length, and the composition of light spectrum. Many genes are involved in the perception of external environmental signals, forming a complex network of interconnections that are then integrated by a few integrator genes. This hierarchical cascade system ensures the precise occurrence of the developmental stages that enable maximum productivity. This review presents the interrelationship of molecular-genetic pathways (earliness per se, circadian/photoperiod length, vernalization - cold requirement, phytohormonal - gibberellic acid, light perception, ambient temperature perception and aging - miRNA) responsible for environmental adaptation in wheat. Detailed molecular genetic mapping of wheat adaptability will allow breeders to incorporate new alleles that will create varieties best adapted to local environmental conditions.