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ARS Home » Southeast Area » Stoneville, Mississippi » Crop Genetics Research » Research » Publications at this Location » Publication #332793
Title: Grain chemical composition as affected by genetic backgrounds and toxigenic Aspergillus flavus inoculation in corn hybrids

Author
item Bellaloui, Nacer
item Abbas, Hamed
item Bruns, Herbert
item Mengistu, Alemu

Submitted to: Atlas Journal of Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/6/2016
Publication Date: 10/15/2016
Citation: Bellaloui, N., Abbas, H.K., Bruns, H.A., Mengistu, A. 2016. Grain chemical composition as affected by genetic backgrounds and toxigenic Aspergillus flavus inoculation in corn hybrids. Atlas Journal of Plant Biology. 66-76. doi:10.5147/ajpb.2016.0158.

Interpretive Summary: Mycotoxins are toxins produced by fungi commonly found in corn and known to cause health issues to human and animals. Therefore, the control of these toxins and their effects on grain quality and mineral nutrition is critical. Recently, scientists discovered what is called stacked-gene corn hybrids (corn varieties released with multiple insect resistance genes and herbicide resistance genes). In the current research, ARS scientists at Delta States Research Center, Stoneville, MS, USA, investigated the possible nutritional advantage of stacked-gene corn hybrids over round-up ready resistant (RR) and non-GMO (conventional) corn under inoculated and non-inoculated soils with the toxigenic fungus Aspergillus flavus. The relationship between corn grain inoculated with fungus toxin and grain nutrients (protein, oil, fatty acids, sugars, and amino acids) corn hybrids, especially in stacked-gene hybrids is very limited. Therefore, the grain nutritional status of stacked-gene hybrids, RR, and non-GMO was evaluated. The experiment was conducted in two locations (clay and sandy soils) in 2011 in irrigated field. The results showed that stacked-gene hybrids had no observable nutritional advantage over RR or non-GMO as all hybrid classes (stacked-gene, RR, or non-GMO) accumulated adequate nutrients in their grains; this effect may be due to adequate concentrations of nutrients in the soil. Higher levels of grain protein and sugars, oleic acid, total amino acids, and some minerals were observed under inoculated conditions in clay and sandy soils indicated a possible role of these biochemical compounds as stress indicators under inoculated conditions. Levels of grain nutrients in clay soil were higher than those in sandy soils; nutritient differences may be due to sandy soil possibly suffering drier conditions, especially inoculated soil, reducing nutrient absorption and mobility of nutrients to the grain. This research increased our knowledge of the relationship between grain nutritional qualities and fungal toxins in corn hybrids, especially stacked-gene hybrid. Further research is needed by conducting a multi-year experiment under different conditions (irrigated and non-irrigated), with severe level of inoculation, and with bigger number of hybrids from each hybrid class.

Technical Abstract: Mycotoxins are secondary metabolites commonly found in corn and known to cause health issues to human and animals. The relationship between corn grain inoculated with mycotoxins and grain nutrients (protein, oil, fatty acids, sugars, and amino acids) corn hybrids, especially stacked-gene hybrids is very limited. The objective of this research was to investigate the nutritional advantage of stacked-gene hybrids (Stgene) over non-GMO or glyphosate-resistant corn (RR). The experiment was conducted in two locations (clay and sandy soils) in 2011, irrigated, and inoculated with toxigenic Aspergillus flavus using four hybrids of stacked-gene, four of RR, and two non-GMO (conventional). Non-inoculated plots were used as control. The results showed that stacked-gene hybrids had no observable nutritional advantage over RR or non-GMO as all hybrid classes accumulated adequate nutrients in their grains; this effect may be due to adequate concentrations of nutrients in the soil. Higher levels of grain protein, carbohydrates (glucose, reducing sugars, and starch), oleic acid, total amino acids, and some minerals were observed under inoculated conditions in clay and sandy soils indicated a possible osmotic adjustment role of these compounds as stress indicators and osmoprotectants under inoculated conditions. Levels of grain nutrients in clay soil were higher than those in sandy soils; nutrient differences may be due to sandy soil possibly suffering drier conditions, especially inoculated soil, reducing nutrient uptake and mobility to the grain. Since the experiment was conducted only under irrigated conditions with a limited number of hybrids, no recommendations can be made. Further research is needed by conducting a multi-year experiment under different conditions (irrigated and non-irrigated), with severe level of infection, and with bigger number of hybrids from each hybrid class.