PCR‐based diagnostics of Microdochium nivale and Tilletia tritici infecting winter wheat seeds*

UK cereal‐seed producers work under severe time constraints during the autumn harvest period. Management of seed health during seed production is restricted by the lack of prompt information from seed‐health assays. Currently, advisory testing is carried out using a lengthy agar‐plate test for Microdochium nivale (up to 7 days) and a seed‐washing/filtration method for Tilletia tritici (24 h). Although the T. tritici test can be completed within 1 day, the throughput for this test is restrictive. Polymerase chain reaction (PCR) assays for the detection of these two fungal pathogens of wheat have been developed, initially using purified fungal DNA, cultured mycelia and spores. The PCR Mimic technique, a form of competitive PCR, was chosen for the quantification of fungal infection. The development of simple DNA isolation methods for use with the PCR Mimic technique is described.