Identification of a leaf rust resistance gene Lr24 in the bread wheat (Triticum Aestivum L.) genotypes

Abstract

One of the most important pathogens of wheat is leaf rust caused by Puccinia triticina (syn. Puccinia recondita Rob. ex Desm. f.sp. tritici). It causes important yield decreases in bread wheat, mainly in the years with a high infection pressure of the pathogen. DNA marker-assisted selection (MAS) have been used for the identification of leaf rust (Lr) resistance genes into adapted commercial winter wheat cultivars and bred lines. 2 F1 hybrids, 2 Thatcher line and 14 cultivar which are used commonly in Turkey and have never been idenitify for resistance against leaf rust by SSR marker linked to the Lr24 gene. The SSR marker linked to resistance gene Lr24 was robust and highly specific for these gene and will be useful in marker-assisted selection in wheat. Markers for resistance gene, Lr24 was identified in laboratory as amplification products of 310 bp, respectively. Serial PCR experiments were carried out for determination of optimal PCR conditions for Lr24 gene in our labrotary. PCR conditions were as follows: 5 min at 94 degrees C, followed by 40 cycles of 1 min at 94 degrees C, 1 min 62 degrees C depending on the primer combination, and 1 min at 72 degrees C. The last step was incubation for 10 min at 72 degrees C. The primers used in the PCR runs were as follows: After analyzed 18 genotypes, Lr24 gene was not detected except Thatcher Lr24 (positive control line).