Molecular mapping of Aegilops speltoides derived leaf rust resistance gene Lr28 in wheat

Abstract

In a segregating homozygous F 2 population of bread wheat involving a leaf rust resistance gene Lr28 derived from Aegilops speltoides, six randomly amplified polymorphic DNA (RAPD) markers, three each in coupling and repulsion phase were identified as linked to Lr28, mapped to a region spanning 32 cM including the locus. The F 2 and F 3 populations were studied in the phytotron challenged with the most virulent pathotype 77-5 of leaf rust. A coupling phase linked RAPD marker S464 721 and a repulsion phase linked RAPD marker S326 550 flanked the gene Lr28 by a distance of 2.4 ± 0.016 cM on either side. The flanking markers genetically worked as co-dominant markers when analyzed together after separate amplification in the F 2 population by distinguishing the homozygotes from the heterozygotes and increased the efficiency of marker assisted selection by reducing the false positives and negatives. One of the three RAPD markers, S421 640 was converted to locus specific SCAR marker SCS421 640 which was further truncated by designing primers internal from both ends of the original RAPD amplicon to eliminate a non-specific amplification of nearly same size. The truncated polymorphic sequence characterized amplified region marker (TPSCAR) SCS421 570 was 70 bp smaller, but resulted in a single band polymorphism specific to Lr28 resistance. The TPSCAR marker was validated for its specificity to the gene Lr28 in nine different genetic backgrounds and on 43 of the 50 Lr genes of both native and alien origin, suggesting the utility of the SCAR markers in pyramiding leaf rust resistance genes in wheat.

Physiological specialization of wheat leaf rust (Puccinia triticina Eriks.) in the Czech Republic in 2009-2011

“…Virulence to Lr9 was found neither in the Czech Republic in 2005-2008(Hanzalová 2010 nor in Germany and in Russia in 2001-2003(Lind & Gultyaeva 2007. In Slovakia virulence to Lr9 was recorded in 2008 (Hanzalová et al 2012).…”

“…DNA quality was verified by electrophoresis in 0.8% agarose gel, stained with ethidium bromide, visualized under UV light and compared with ladder Lambda DNA/HindIII (Fermentas, Vilnius, Lithuania). The genes Lr10, Lr24, Lr26, Lr28, Lr34, and Lr37 were tested by PCR with published primers marking these genes according to de Froidmont (1998), Helguera et al (2003), Cherukuri et al (2005), Gupta et al (2006), Lagudah et al (2006), Gultyaeva et al (2009). The reactions were carried out in the Veriti thermal cycler (Applied Biosystems, Foster City, USA).…”

Identification and Validation of a Microsatellite Marker for the Seedling Resistance Gene Lr24 in Bread Wheat

“…A SCAR marker developed by Cherukuri et al, [22] in the same laboratory is currently being successfully employed to track the transfer and establishment of this gene in different genetic background. A PCR-based DNA-STS marker, six RFLP markers completely linked to Lr24 -one inherited as a codominant marker (PSR1205), one in coupling phase (PSR1203), and four in repulsion phase (PSR388, PSR904, PSR931, PSR1067) were reported to be inherited with Lr24.…”

New Phytotron for Studying the Effect of Climate Change on Plant Pathogens

“…At present, at least in Europe, several kinds of phytotrons are already in use for studying the effect of environmental conditions and stresses on plant diseases, but in most cases experiments were carried out in small chambers, on seedlings or small plants, without monitoring and controlling carbon dioxide concentration and not specifically designed for studying plant-pathogens interactions, in particular on foliar diseases [Tani 1996;Thiel 1996;Uprety 1998;Schmadel-Hagebolling 1998;Gutierrez 2000;Grote 2001;Yazaki 2004;Cherukuri 2005;Luedemann 2005;Pritsch 2005]. Consequently, available phytotrons are not really suited to study the effect of climate change on plant disease or there is no scientific evidence of the possibility to use commercially available chambers for such purposes.…”