Optimization of genetic transformation system of potato and introduction of maize starch branching enzyme gene SBEⅡb into potato Effects of nitrogen top-dressing on starch gelatinization and retrogradation properties of spring and autumn waxy maize at the jointing stage Study on porous maize starch preparation and powdering coix seed oil Starch Physicochemical Characteristics and Granule Size Distribution at Apical, Middle and Basal Ear Positions in Normal, Sweet, and Waxy Maize Starch Granule Size Distribution and Thermal Properties in Eight Waxy Maize Cultivars Grown in Spring and Autumn