Maize (Zea mays L.) yield and aflatoxin accumulation responses to exogenous glycinebetaine application

Document Type: Research Paper

Authors

Department of Plant and Soil Sciences, Mississippi State University, Box 9555, Mississippi State, MS 39762, USA.

Abstract

Exogenously applied glycinebetaine (GB) accumulates at high levels in maize
(Zea mays L.). Under water deficit and high temperature conditions GB application
produces yield benefits. These sub-optimum conditions often result in high levels
of aflatoxin accumulation which reduces grain quality. A 3-year (2008, 2009 and
2010) field experiment was conducted to determine the effects of GB on maize
yield and aflatoxin accumulation. Weekly and alternate weekly GB application
increased plant biomass by 10 and 13%, respectively. Net photosynthesis increased
by 6% with GB application; however, stomatal conductance, transpiration rate and
electron transport rate were not significantly affected. Grain yield increased by 6
and 13% with GB applied alternate weekly and weekly, respectively, over control
plots averaged over years. GB application resulted in a trend of reduced aflatoxin
accumulation in inoculated ears compared with non-inoculated controls in 2009
and 2010; however, inherent field and sampling variation did not allow us to
conclude statistically any advantage attributable to GB application. We can
conclude that GB did not significantly reduce aflatoxin production in the
inoculated treatments.
Keywords: Maize; Glycinebetaine; Photosynthesis; Growth; Aflatoxin accumulation.