PCR detection of Hordeum bulbosum introgressions in an H. vulgare background using a retrotransposon-like sequence.

Retrotransposon-like sequences are ideal tools for initial screening assays to distinguish between closely related species because of their ubiquitous presence, high copy number, chromosome coverage and rapid sequence evolution. A retrotransposon-like sequence, pSc119.1, cloned from Secale cereale (rye) has been used to obtain PCR primers that are capable of detecting small introgressions of Hordeum bulbosum (bulbous barley grass) chromatin in a Hordeum vulgare (cultivated barley) background. Combining this PCR-based assay with a crude but effective high-throughput DNA extraction has enabled the rapid identification of plants possessing H. bulbosumintrogressions from large numbers of progeny from H. vulgarex H. bulbosumcrosses. These plants are then further characterized by more-refined cytological, molecular and pathological techniques to locate and map the introgressed chromatin and to evaluate their disease resistance.