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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 #185349
Title: EFFECTS OF XENIA ON EXPRESSION OF RESISTANCE TO ASPERGILLUS FLAVUS INFECTION AND AFLATOXIN ACCUMULATION IN MAIZE INBREDS

Author
item Gardner, Hilma
item Williams, William
item Windham, Gary

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2006
Publication Date: 9/1/2006
Citation: Gardner, H.D., Williams, W.P., Windham, G.L. 2006. Effects of Xenia on Aspergillus flavus infection and aflatoxin accumulation in maize inbreds. Crop Science. 46:2151-2154.

Interpretive Summary: Aflatoxin is a toxin produced by the fungus Aspergillus flavus. Contamination of corn with aflatoxin reduces its value and makes it unfit for human food. Aflatoxin contamination is a serious problem for corn produced in the South. Growing corn with genetic resistance to fungal infection and aflatoxin production is generally considered the best way to cope with the problem. The objectives of this study were to evaluate eight maize lines in terms of their resistance to A. flavus infection and aflatoxin contamination and to determine the importance of the maternal versus the paternal line’s influence on toxin production. Grain harvested from Mp313E, Tx601, and SC229 plants in 2003 and Mo18W and SC212M plants in 2004 performed differently in terms of A. flavus infection depending upon the pollen used to pollinate the plant; however, aflatoxin accumulation was not affected by pollen type. Further analysis showed that A. flavus infection and aflatoxin contamination were not affected by the male parent. Rather, the female parent appeared to have a more influential role in A. flavus infection and toxin accumulation in the grain. These results suggest that reliable evaluation of A. flavus infection and aflatoxin contamination can be gained from experiments in the field that do not have strict pollination controls, but it is possible that the pollen parent may still influence to some degree the fungal and toxin resistance of maize grain.

Technical Abstract: Aspergillus flavus infection and aflatoxin contamination pose an economic threat to maize (Zea mays L.) producers of the United States. Efforts to identify germplasm resistant to A. flavus infection and aflatoxin accumulation have raised questions regarding the role of xenia, the paternal effect, in resistance of maize grain. The objectives of this study were to evaluate eight inbred lines in terms of their resistance to A. flavus infection and aflatoxin contamination and to determine the importance of the maternal and nonmaternal (xenia) influence. Resistant and susceptible maize lines were hand-pollinated as would be done to produce seed for a diallel cross. The ears were inoculated 14 d after pollination with A. flavus spores. Grain from each single cross was plated to determine the extent of A. flavus infection, and the aflatoxin content was measured. Grain harvested from maternal inbreds Mp313E, Tx601, and SC229 in 2003 and Mo18W and SC212M in 2004 performed significantly differently in terms of A. flavus infection depending upon the grain’s paternal genotype; however, aflatoxin accumulation was not affected by xenia in these genotypes. Analyses performed using DIALLEL-SAS showed no significant nonmaternal effects affected A. flavus infection and aflatoxin contamination. Maternal effects appeared to have a more influential role in A. flavus infection and toxin accumulation. These results suggest that reliable evaluation of A. flavus infection and aflatoxin contamination can be gained from open-pollinated field experiments; however, the effect of the paternal parent on fungal and toxin resistance of maize grain should not be discounted.