Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/13/2003
Publication Date: 10/13/2003
Citation: Gardner, H.D., Brooks, T.D., Williams, W.P., Windham, G.L., Hawkins, L.K., Luthe, D., Brown, R.L., Abbas, H.K. 2003. Investigation of gene effects on alfatoxin concentration in a segregation maize population [abstract]. 16th Annual Aflatoxin Elimination Workshop Proceedings. p. 68.
Technical Abstract: Approaches for using marker-assisted selection to enhance resistance to Aspergillus flavus infection and/or aflatoxin accumulation in corn (Zea mays L.) are under development. A number of environmental stresses have been linked to high levels of aflatoxin in maize, including drought stress, heat stress, insect damage, and nutrient deficiency. Candidate genes associated with increased tolerance were gathered from the literature for study. Genes selected included those coding for basal endosperm specific proteins, heat- and drought-stress related oxidases, pathogen specific signaling peptides, proteins involved in insect resistance, and water-stress related proteins. In addition, several candidate genes and potential gene sequences were contributed from other laboratories. Primers developed from the candidate sequences were screened over inbred parents segregating for resistance to aflatoxin build up in order to identify size polymorphisms. Those primers that were polymorphic were then used to screen a segregating maize population as part of a QTL study. Primer-derived sequences not obviously polymorphic in length were sequenced to determine the presence of single nucleotide polymorphisms. Finally, single marker analysis will be used to determine locus effect on aflatoxin accumulation. To date, the gene sequences glb2, mir3, and putative gene sequence hmc1a have had specific sequence regions amplified from their inbred parents Mp313E and B73. These have been screened for size polymorphism and await further marker development. In addition, some have been further sequenced to gain specific sequence information.