Effects of salinity stress on starch morphology, composition and thermal properties during grain development in triticale

Abstract

He, J.-F., Goyal, R., Laroche, A., Zhao, M.-L. and Lu, Z.-X. 2013. Effects of salinity stress on starch morphology, composition and thermal properties during grain development in triticale. Can. J. Plant Sci. 93: 765–771. Triticale is a man-made cereal crop developed from a cross between wheat and rye. It has excellent agronomic traits for starch production on arid and semi-arid lands. This study investigated the effects of salinity stress on the alterations of starch morphology, composition and physicochemical properties during triticale grain development. Three triticale varieties (AC Certa, AC Ultima and Blue Alta) were treated with three levels of NaCl solutions (50, 100 and 200 mM), termed low salinity stress (LSS), moderate salinity stress (MSS) and high salinity stress (HSS), respectively. Reduction in seed weight and starch content were observed under salinity stress; the values decreased by 9–42% under MSS and 18–51% under HSS. MSS and HSS favored an increase of amylose synthesis and accumulation in triticale starch. Triticale starch synthesized under salinity stress showed a decreased population of small granules and an increased ratio on A-type to B-type granules. MSS and HSS decreased the peak temperature and increased the starch enthalpy, and an inverse relationship between salinity stress and a range of starch gelatinization temperature was also observed. This is the first report demonstrating that starch morphology, composition and thermal properties in triticale grains can be significantly affected by salinity stress.