Kentucky Small Grain Growers Association

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Research Report: Understanding the Genetic Basis of Wheat Development

By David Van Sanford and Carrie Knott

Full Report (PDF)

The objective of this project is to increase our understanding of the genes that affect the vernalization and photoperiod response in wheat. We hope to reduce growers’ risk of freeze damage and yield losses by fine tuning our planting date recommendations based on the photoperiod and vernalization genes a variety has.

The development of the wheat plant through harvest maturity is controlled by genes with both large and small effects.  The large effect genes are those that control response to vernalization—the cold period required for winter wheat to flower— and photoperiod or daylength. This is  important because late spring freezes are common in Kentucky. Varieties like Truman will not flower until daylength is long enough for them to shift into reproductive growth. Truman’s photoperiod sensitivity is associated with a maturity date that is too late for Kentucky growers. We want to combine this sensitivity with earlier maturity.

Based on the 2017 data, the long vernalizing genes were better (higher yields) in our environment, but this varied some with the photoperiod genes that were present in a line. In a line like Truman, for example, which is photoperiod sensitive (i.e., requires a long day in order to flower), the short vernalizing genes did not lower yield. This tells us that photoperiod sensitivity is more important that vernalization sensitivity in our environment, though this is not necessarily true in southern states like GA.

The picture is a complex one and we hope that a second year of data will produce the information we need to provide growers with planting date recommendations that are based on the photoperiod and vernalization profiles of different wheat varieties.