ARS | Publication request: Identification of gene markers in aflatoxin-resistant maize germplasm for marker-assisted breeding

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: June 22, 2011
Publication Date: October 3, 2011
Citation: Brown, R.L., Menkir, A., Chen, Z.-Y., Luo, M., Bhatnagar, D. 2011. Identification of gene markers in aflatoxin-resistant maize germplasm for marker-assisted breeding. In: Guevara-Gonzalez, R.G., editor. Aflatoxins - Biochemistry and Molecular Biology. Rijeka, Croatia: Intech Open Access Publishers. pp 91-106.

Technical Abstract: The discovery of maize lines with natural resistance to Aspergillus flavus infection and/or aflatoxin production has aided host resistance in becoming a viable approach for the elimination of aflatoxin contamination of maize. Further breeding involving resistant lines is developing sources of resistance which may be superior to parent lines in both agronomic qualities and resistance. The kernel screening assay (KSA) has played a significant role in identifying new aflatoxin-resistant germplasm and in studying resistance mechanisms. The use of advanced molecular technologies to investigate resistant maize germplasm has produced a growing list of kernel resistance-associated proteins (RAPs), several of which have been subjected to further characterization. The confirmation of breeding markers among RAPs/corresponding genes from this list could facilitate the transfer of aflatoxin-resistance into commercially useful genetic backgrounds without the transfer of unwanted traits. To identify potential breeding markers, research efforts have employed comparative proteomics and microarray analysis to investigate closely-related maize lines that vary in aflatoxin accumulation. RAPs have been further characterized through physiological and biochemical investigations to determine their causal role in resistance and, therefore, their suitability as breeding markers. This includes the use of RNAi gene silencing and plant transformation. The use of information from characterization studies and from QTL mapping studies has facilitated the selection of certain RAPs for field confirmation studies to determine their utility as breeding markers. Results of the above studies are discussed.