ARS | Publication request: MOLECULAR CHARACTERIZATION OF THE LANGDON DURUM-TRITICUM DICOCCOIDES CHROMOSOME SUBSTITUTION LINES USING TARGET REGION AMPLIFICATION POLYMORPHISM (TRAP) MARKERS.

Submitted to: Wheat Genetics International Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 20, 2003
Publication Date: September 1, 2003
Citation: XU, S.S., HU, J., FARIS, J.D. MOLECULAR CHARACTERIZATION OF THE LANGDON DURUM-TRITICUM DICOCCOIDES CHROMOSOME SUBSTITUTION LINES USING TARGET REGION AMPLIFICATION POLYMORPHISM (TRAP) MARKERS.. WHEAT GENETICS INTERNATIONAL SYMPOSIUM PROCEEDINGS. 2003. VOL. 1:91-94.

Interpretive Summary: Wild emmer wheat is the tetraploid progenitor of cultivated durum and bread wheat. It possesses many interesting traits such as disease and pest resistance and high protein content. In an effort to transfer the desirable traits from wild emmer to durum wheat, Dr. L.R. Joppa (ARS retired) developed a complete set of 14 chromosome substitution lines from wild emmer line PI 481521 in the background of durum wheat cultivar 'Langdon'. In each of the substitution lines, a pair of chromosomes from PI 481521 was substituted for a pair of native homologous chromosomes in Langdon. To facilitate the transfer of the desirable traits into durum wheat, we employed the newly developed marker technique, known as TRAP, to develop chromosome-specific molecular markers using the Langdon durum-wild emmer substitution lines. In this study, 642 chromosome-specific molecular markers have been developed. The study showed that the TRAP marker technique is efficient in generating chromosome-specific markers in tetraploid wheat and the technique provides an efficient approach for confirming and maintaining the substitution lines. In addition, the new molecular markers developed in this study will be useful for chromosome identification, genome characterization, tagging genes that govern desirable traits, high-throughput mapping of segregating wheat populations, and other genetic studies.

Technical Abstract: Triticum turgidum L. var. dicoccoides (DIC), known as wild emmer, is the tetraploid progenitor of durum and bread wheat. Wild emmer has many useful traits such as pest resistance and high protein content. To facilitate the transfer of the desirable traits into durum wheat, we employed the newly developed TRAP (target region amplification polymorphism) marker technique to develop chromosome-specific molecular markers using a complete set of Langdon durum-Triticum dicoccoides [LDN (DIC)] substitution lines recently developed by Dr. L.R. Joppa (ARS retired). The TRAP technique employs one fixed primer of known sequence in combination with a random primer to amplify genomic fragments. In this study, 642 chromosome-specific markers have been developed. The results showed that the TRAP marker technique is efficient in generating chromosome-specific markers in tetraploid wheat and the technique generated approximately 17 markers per PCR reaction, ranging from 4 to 30. Therefore, the TRAP marker technique provides an efficient approach for confirming and maintaining LDN (DIC) substitution lines. In addition, the TRAP markers developed in this study will be useful for genome characterization, tagging genes that govern desirable traits, high-throughput mapping of segregating wheat populations, and other genetic studies.