甜玉米不同采收期籽粒品质性状研究

为研究不同采收期甜玉米品质性状的变化,以7个国内生产主推甜玉米品种为研究材料,设置授粉后15、18、21、24、27、30天共计6个采收期,动态监测甜玉米籽粒含水率、果皮厚度和糖组分等指标。结果表明：（1）参试甜玉米品种的籽粒含水率在授粉后15~30天呈下降趋势,其籽粒含水率变幅为80.09%~68.76%。不同甜玉米品种间籽粒含水率的平均下降速率各异。‘京科甜608’、‘京科甜533’和‘中农大甜413’籽粒含水率下降速率相对缓慢。（2）参试甜玉米品种果皮厚度随授粉后天数增加呈先升高后降低的单峰变化趋势,峰值出现在授粉后21天左右。不同品种间籽粒平均果皮厚度以‘京科甜608’和‘米哥’最低,为78.40 μm;‘中农大甜413’最高,为91.63 μm。（3）参试甜玉米品种籽粒中葡萄糖和果糖含量在授粉后15~30天呈降低趋势,‘京科甜533’、‘京科甜183’、‘京科甜608’葡萄糖和果糖含量在授粉后15~24天相对较高。蔗糖和山梨醇含量随授粉后天数增加呈先升高后降低趋势,在授粉后21~30天,蔗糖含量以‘京科甜158’和‘米哥’含量相对较高。籽粒发育初期（授粉后21天之前）,籽粒中以果糖和葡萄糖为主,之后蔗糖逐渐增加。不同品种间,‘京科甜533’、‘京科甜183’、‘中农大甜413’和‘京科甜608’籽粒中总糖含量均高于‘米哥’,其籽粒中糖组分主要以果糖和葡萄糖等还原性糖为主,而蔗糖含量相对较低。

Changes of Grain Quality Characters of Sweet Maize at Different Harvesting Periods

Seven main sweet maize varieties in China were used as research materials, and six harvesting periods were set up at 15, 18, 21, 24, 27 and 30 d after pollination to study the effect of different harvesting periods on the quality traits of sweet maize. The water content, pericarp thickness and sugar composition in sweet corn were monitored dynamically. The results showed that: (1) grain moisture content of the tested sweet maize varieties decreased at 15-30 d after pollination, the change ranging from 80.09% to 68.76%; the grain water content of ‘Jingketian 608’, ‘Jingketian 533’ and ‘Zhongnongdatian 413’ decreased slowly; (2) the pericarp thickness of sweet maize varieties increased first and then decreased with the time after pollination, and the peak appeared about 21 days after pollination; the average pericarp thickness of ‘Zhongnongdatian 413’ was the highest among the tested varieties, 91.63 μm, and that of ‘Jingketian 608’ and ‘Mige’ were the lowest, 78.40 μm; (3) the content of glucose and fructose in the grains decreased at 15-30 d after pollination, the content of glucose and fructose of ‘Jingketian 533’, ‘Jingketian 183’ and ‘Jingketian 608’ were relatively high at 15-24 d after pollination; the sucrose and sorbitol content increased first and then decreased with the time after the pollination, the sucrose content of ‘Jingketian 158’ and ‘Mige’ were relatively high among different varieties at 21-30 d after pollination. At the grain early development stage (before 21 days after pollination), fructose and glucose were the main sugars in grains, and then sucrose gradually increased. Among different varieties, the total sugar content of ‘Jingketian 533’, ‘Jingketian 183’, ‘Zhongnongdatian 413’ and ‘Jingketian 608’ were higher than that of ‘Mige’. The main sugar components were fructose and glucose, while the sucrose content was relatively low.