A precise regulation of flowering time is critical for plant reproductive success and for cereal crops to maximize grain production.

In wheat, barley, and other temperate cereals, vernalization genes play an important role in the acceleration of reproductive development after long periods of low temperatures during the winter (vernalization).

Scientists identified VERNALIZATION 4 (VRN-D4), a vernalization gene that was critical for the development of spring growth habit in the ancient wheats from South Asia.

VRN-D4 was expressed earlier than other VRN1 genes in the absence of vernalization; and induced mutations in this gene resulted in delayed flowering.

They show that mutations in regulatory regions of VRN-D4 are shared with other VRN-A1 alleles and can be used to modulate the vernalization response.

These previously unknown alleles provide breeders new tools to engineer wheat varieties better adapted to different or changing environments.