Abstract

Shading stress after pollination is an important abiotic factor affecting waxy maize starch quality. The objective of the current study is to investigate the effects of shading after pollination on starch physico-chemical properties of waxy maize. The shading experiment was conducted in the field in 2011 and 2012, with a waxy maize variety (Suyunuo5) as the test material. Plants were given shading with black polyethylene nets and the light intensity was reduced by 30%, with plants grown under natural light were taken as control. Shading after pollination decreased the starch granule size and iodine binding capacity, and reduced the peak intensities at 2θ=15º, 17º, 18º and 23º. Pasting viscosities were decreased by shading in both the years. The ΔHgel and Tc were not affected, To and Tp were decreased, while ΔHrest and %R were increased by shading. The results indicated that shading deteriorated the pasting and retrogradation properties through reducing the starch granule size, iodine binding capacity and peak intensities.