不同类型玉米籽粒的营养品质及其与籽粒质地的关系

Nutrient Qualities of Kernels in Different Types of Maize and Its Relationship with Kernel Texture

测定普通玉米、爆裂玉米、糯玉米和甜玉米4种类型玉米籽粒不同发育时期的直链淀粉、支链淀粉、总淀粉、可溶性糖和蛋白的含量,分析这些营养物质与角质率的关系。结果表明:灌浆期间4种类型玉米的直链淀粉、支链淀粉和总淀粉含量呈上升趋势,总蛋白含量呈下降趋势,可溶性糖含量变化规律不明显。爆裂玉米的直链淀粉含量始终最高(4.7%～23.1%),甜玉米(1.4%～4.6%)和糯玉米(2.3%～4.9%)的始终较低;甜玉米的支链淀粉含量一直最低(15.7%～35.5%),除授粉10d以外,糯玉米的支链淀粉含量一直最高(65.5%～69.8%);甜玉米总淀粉含量始终最低(17.1%～36.1%)、总蛋白含量(15.2%～26.9%)和授粉30d后的可溶性糖含量最高(14.2%～17.6%)。高蛋白含量可能是爆裂玉米和甜玉米角质率高的原因,糯玉米的角质率低可能与支链淀粉含量高和蛋白积累少有关。

The contents of amylose, amylopectin, total starch, soluble sugar and protein in kernels of normal corn, pop com, waxy corn and sweet corn in different development periods were determined. The relationship between nutrient qualities and the cutin rate were analyzed. The results showed that the contents of amylose, amylopectin and total starch increased during kernel development, protein content decreased and soluble sugar content changed irregularly. Amylose content of pop corn was the highest （4.7%-23.1%） and those of sweet and waxy corn were lowest. Amylopetin content of sweet corn was the lowest （15.7%-35.3%）, and that of waxy corn was the highest （65.5%-69.8%） except for 10 days after pollination. Total starch content of sweet corn was the lowest （17.1%-36.1%）, while soluble sugar content （14.2%-17.6%） in the late period and total protein content （15.2%-26.9%） of sweet corn were the highest. The high cutin rate of pop corn and sweet corn maybe caused by high protein content. The low cutin rate of waxy corn maybe caused by high amylopectin content and low protein content.