Rapid identification of transformed wheat using a half-seed PCR assay.

A simple, nondestructive PCR-based screening method has been developed for identifying putative transgenic soft white winter wheat (Triticum aestivum L.) carrying the coat protein gene of wheat streak mosaic virus. Removal of the endosperm end of individual seed provided sufficient material for DNA extraction and PCR. DNA from seed is more free of the secondary, metabolites found in leaf tissue that can inhibit both PCR and restriction digests required for Southern analysis. The half-seed PCR assay has comparable accuracy to the leaf-tissue PCR assay and hence can be used as an accurate and rapid method for identifying transformed lines before planting. Germination of the remaining seed portion showed germination rates comparable to whole-seed controls. A slight delay in growth from the first-leaf through the first-tiller stage was observed in the half-seed-derived plants, as compared to plants grown from whole seed.