Location: Hard Winter Wheat Genetics ResearchTitle: Mapping of quantitative trait loci for leaf rust resistance in the wheat population Ning7840 x Clark
|LI, CHUNLIAN - Kansas State University|
|LI, CHUNXIN - Kansas State University|
|CARVER, BRETT - Oklahoma State University|
|Bowden, Robert - Bob|
|WANG, ZHONGHUA - Northwest Agricultural & Forestry University|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/2/2017
Publication Date: 12/1/2017
Publication URL: http://handle.nal.usda.gov/10113/5860810
Citation: Li, C., Li, C., Carver, B., Bowden, R.L., Wang, Z., Bai, G. 2017. Mapping of quantitative trait loci for leaf rust resistance in the wheat population Ning7840 x Clark. Plant Disease. 2017(101):1974-1979. https://doi.org/10.1094/PDIS-12-16-1743-RE.
Interpretive Summary: Wheat leaf rust causes significant wheat yield losses worldwide. We investigated leaf rust resistance genes in a cross of ‘Ning7840’, which is a moderately resistant Chinese hard red wheat line, and ‘Clark’, which is a moderately susceptible soft red wheat line from Purdue University. We identified one major resistance gene in each of the parents. The major gene in Ning 7840 was confirmed to be Lr34, a well-known durable adult plant resistance gene. The major gene in Clark was tentatively identified as Lr74 and may also be an important gene for adult plant resistance. Each cultivar also contained one minor gene for resistance. The resistance genes showed an additive effect on leaf rust severity and can be used in combination to produce high levels of resistance to leaf rust.
Technical Abstract: Leaf rust, caused by Puccinia triticina, is an important fungal disease in wheat (Triticum aestivum L.) and causes significant yield losses worldwide. To determine quantitative trait loci (QTLs) responsible for leaf rust resistance, a recombinant inbred line (RIL) population developed from a cross of ‘Ning7840’ × ‘Clark’ was evaluated for leaf rust severity, and was genotyped for single nucleotide polymorphisms (SNPs) using 9K SNP chips, and with simple sequence repeat (SSR) markers. Two major QTLs on chromosome arms 7DS and 3BS, and two minor QTLs on chromosomes 5AS and 6AS showed a significant effect on leaf rust severity. The 7DS QTL from ‘Ning7840’ and the 3BS QTL from ‘Clark’ explained, respectively, about 35% and 18% of the phenotypic variation for leaf rust resistance. The QTL on 7DS was confirmed to be Lr34. The QTL on 3BS, QLr.hwwg-3B.1, was associated with adult-plant resistance and was provisionally identified as Lr74. QLr.hwwg-5AS and QLr.hwwg-6AS from Ning7840 and Clark, respectively, may correspond to previously described QTLs. Resistance was not detected in Ning7840 on 1BL, a region that was previously associated with adult plant resistance to leaf rust and a lesion mimic phenotype. Genotype analysis indicated that Lr34, QLr.hwwg-3BS.1 and QLr.hwwg-6AS had an additive effect on leaf rust severity. RILs with all three favorable alleles showed the highest resistance to leaf rust and the RILs with none of them showed the lowest resistance.