Development of a sequence-characterized amplified region marker for diagnosis of dwarf bunt of wheat and detection of Tilletia controversa Kühn.

AIMS

Dwarf bunt of wheat, caused by Tilletia controversa Kühn, is a destructive disease on wheat as well as an important international quarantined disease in many countries. The objective of this investigation was to develop a diagnostic molecular marker generated from amplified fragment length polymorphism (AFLP) for rapid identification of T. controversa.

METHODS AND RESULTS

A total of 30 primer combinations were tested by AFLP to detect DNA polymorphisms between T. controversa and related species. The primer combination E08/M02 generated a polymorphic pattern displaying a 451-bp DNA fragment specific for T. controversa. The marker was converted into a sequence-characterized amplified region (SCAR), and specific primers (SC-01(49)/SC-02(415)), designed for use in PCR detection assays, amplified a unique DNA fragment in all isolates of T. controversa, but not in the related pathogens. The detection limit with the primer set SC-01(49)/SC-02(415) was 10 ng of DNA which could be obtained from 11 microg of teliospores in a 25-microl PCR reaction.

CONCLUSIONS

An approach to distinguish T. controversa from similar pathogenic fungi has been developed based on the use of a SCAR marker.

SIGNIFICANCE AND IMPACT OF THE STUDY

Development of the simple, high throughput assay kit for the rapid diagnosis of dwarf bunt of wheat and detection of T. controversa is anticipated in further studies.