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ARS Home » Midwest Area » West Lafayette, Indiana » Crop Production and Pest Control Research » Research » Publications at this Location » Publication #402334
Research Project: Fungal Host-Pathogen Interactions and Disease Resistance in Cereal Crops

Location: Crop Production and Pest Control Research

Title: Genetic dissection using a nested-association mapping (NAM) population reveals quantitative trait loci (QTL) conferring resistance to Tar Spot in maize

Author
item Singh, Raksha
item Crane, Charles
item SHIM, SUJOUNG - Purdue University
item TELENKO, DARCY - Purdue University
item Goodwin, Stephen - Steve

Submitted to: Maize Genetics Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 2/15/2023
Publication Date: 3/16/2023
Citation: Singh, R., Crane, C.F., Shim, S., Telenko, D.E., Goodwin, S.B. 2023. Genetic dissection using a nested-association mapping (NAM) population reveals quantitative trait loci (QTL) conferring resistance to Tar Spot in maize. Maize Genetics Conference Abstracts. ABSTRACT.

Interpretive Summary: N/A

Technical Abstract: Tar spot, caused by the obligate fungal pathogen Phyllachora maydis, constitutes a major threat to corn production in North America, the Caribbean, Central and South America. Apart from a significant quantitative trait locus (QTL) on chromosome 8 that was mapped in tropical maize line populations, little is known regarding the genetics of maize resistance to P. maydis. Therefore, more research is required to identify additional sources of resistance against P. maydis populations in North America. Previously, we evaluated 26 parental inbred lines from the Nested Associated Mapping (NAM) population for tar spot resistance in Indiana in replicated field trials under natural infection. Our findings showed that inbred B73, the common parent of the NAM populations, was moderately susceptible. However, resistant inbred lines NC358, CML103, CML52, CML322, M162W, CML228, CML333, TZI8 and KI11, provided a potential germplasm source for genetic mapping of P. maydis resistance in maize. Next, we employed the B73 ' CML52 recombinant-inbred line (RIL) population to identify major quantitative trait loci for P. maydis resistance. A panel of 197 RIL lines derived from a cross of B73 ' CML52 was used to score tar spot disease phenotypes. Association mapping resulted in the detection of seven QTL on chromosomes 1, 2, 4, 5, 7, 8, and 9, including a major QTL on chromosome 9 and another moderately strong QTL on chromosome 2. Collectively, our findings revealed a novel QTL on chromosome 9 (qTL9) associated with P. maydis resistance. Future investigation involves the validation of qTL9 by simple-sequence repeat (SSR) marker analysis and the identification of candidate genes in the qTL9 region by differential gene expression analysis, which will provide insightful information to improve P. maydis resistance in maize.