Pcr-based Epidemiology And Diagnostics Of

tRNA genes are generally found clustered, head-to-tail in eubacterial, mitochondrial and chloroplastgenomes, and in assorted orientations in the genomes of species in other kingdoms. Unlike the tRNAgenes, their spacer regions evolve rapidly and vary in length between related species. PCR primersthat are derived from tRNA gene consensus sequences can be developed from each major group ofpathogenic fungi. When these primers are used for low stringency PCR, a species-specific fingerprintis generated that detects gene rearrangements and length polymorphisms in the spacers. In this 6-month feasibility project we will demonstrate that a set of tRNA gene consensus primers can bedeveloped for a major group of rusts that infect cereals. Intergenic spacers showing lengthpolymorphisms among related species or sub-species can be cloned and sequenced. Then a single pairof primers can be designed to detect the spacer length polymorphisms, a feature that makes these PCRproducts different from most conventional PCR. Such primers will find many uses inphytophatological diagnosis.