Abstrait

Identification and Quantification of Tilletia caries and T. controversa in Seed Samples and Discrimination of the Two Species

Zgraja G, Kramer S, Jonitz A and Wagner W

The stinking or common bunt, caused by Tilletia caries, and the wheat dwarf bunt, caused by T. controversa Kühn, are major seed born diseases in cereals and grassland species (Graminaceae). Contamination levels are routinely controlled by certification bodies or official control laboratories. We report several PCR assays which were developed for the identification and quantification of Tilletia spp. in contaminated wheat and spelt samples. A 140 bp segment of the ITS region is amplified with qualitative PCR for screening purposes or with real-time PCR for quantification. The method was validated successfully both in-house and in a proficiency test in comparison with other established methods. In addition a PCR-RFLP was developed for species discrimination. Using HinfI as restriction endonuclease the PRB2 sequence of T. caries is digested into three fragments whereas there are only two in T. controversa. In routine analyses and monitoring of seed lots or feed materials this PCR approach is a suitable alternative for the time-consuming and laborious traditional microscopic methods.