The Study About The Starch Development Of Sweet Corn And Ordinary Corn

The amyloplasts'development and enrichment of maize endosperm play an important role in the yield and quality of maize production. In ordinary corn, amyloplasts grow well, the grain is plump, while in sweet corn, amyloplasts grow unwell, grain is shrunken. In this research, sweet corn (Zea mays var. rugosa L.) the King-Sweet-688, ordinary hybrid corn (Zea mays L.) Yedan-13 was studied. Respiratory rate was detected by infra-red carbon dioxide analyzer determination of; TTC, I2-KI, Evans Blue staining were used to analyze metabolic activates, starch and dead cells; the sugar and starch contents were measured by dual-wavelength spectrophotometric determination and anthrone-sulfuric acid method. And the development of aleurone layer and endosperm transfer cells were studied by using resin embedding and cutting section, which combined optical microscopy with electron microscopy.The main results were shown as follows:1. Amyloplast of maize endosperm development shows a clear temporal and spatial specificity. Ordinary maize first accumulates starch near aleurone layer, and the grains enrich well, the immature starch granules show a ball shape, and the ripe granules polygonal. The nearer to eh aleurone layer, the better starch granules grow.2. Sweet corn and ordinary corn shows no significant differences in the growth trend in the early stage of development; while in the latter part, starch content showed significantly lower than that of ordinary corn starch, and starch enriched deficiently, ball shaped.3. Ordinary corn grains enriched starch well; develop into a continuous whole, relatively hard, while sweet corn produces shrunken and crisp grains. However, the sugar content of sweet corn was much higher than ordinary corn.4. In both ordinary maize and sweet corn, a central endosperm cavity is formed.