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ARS Home » Southeast Area » Mississippi State, Mississippi » Crop Science Research Laboratory » Corn Host Plant Resistance Research » Research » Publications at this Location » Publication #341520

Research Project: Genetic Improvement of Maize with Enhanced Resistance to Aflatoxin and Insects

Location: Corn Host Plant Resistance Research

Title: Creation and Mapping of a New Mapping Population to Identify Novel QTLs for Aflatoxin Accumulation Resistance in Maize

Author
item OGUNOLA, OLUWASEUM - Mississippi State University
item Warburton, Marilyn
item Williams, William - Paul
item XU, WENWEI - Texas A&M Agrilife

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/12/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Aflatoxin is a secondary carcinogenic metabolite produced by Aspergillus flavus (Link:Fr) under favorable environmental conditions such as the hot and humid environments experienced annually in the Southern U.S and other countries. Aflatoxin accumulation in maize and other crops causes economic hardship to farmers and poses serious health issues in developing countries that lack the infrastructure for proper grain testing. Host plant resistance is the most efficient method of reducing aflatoxin accumulation in maize. Identification of maize (Zea mays L.) germplasm with resistance to aflatoxin accumulation is the first step in breeding for resistance. However, the quantitative nature of the trait makes it hard to transfer from resistant donor lines into elite cultivars. The use of molecular markers linked to quantitative trait loci (QTL) for resistance is one way to hasten this task, and some QTL have been identified to date. To identify novel QTL in a newly identified resistant maize line, a mapping population consisting of 238 F2:3 families was developed from CML69, an aflatoxin resistant inbred line from the Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT) and Va35, an aflatoxin susceptible inbred line adapted to the southern US. A total of 180 single nucleotide polymorphisms (SNP) markers spanning all 10 chromosomes in the maize genome was tested on the new QTL mapping population. Aflatoxin levels for each family were also determined in replicated field trials in four different locations. Results show that 72 SNP markers tested were polymorphic between the parents and were screened on all 238 families to create the initial genetic linkage map. These SNPs were mapped using the Joinmap software. Composite interval mapping (CIM) was carried out using the QTL cartographer to estimate the effect of each QTL on aflatoxin accumulation resistance. QTL results are presented here.