糯玉米不同采收期子粒降水及糊化特性研究

Grain Dehydration and Gelatinization Characteristics of Waxy Maize at Different Harvesting Time

以京科糯2000等6个糯玉米品种和待审品种黑糯101为研究材料,设置授粉后17、20、23、26和29d 5个采收期,研究不同采收期糯玉米子粒含水量及糊化特性的变化,为糯玉米适期收获和淀粉糊化特性调控提供参考。结果表明:参试玉米材料子粒平均含水量在品种和采收期间存在显著差异,其中京科糯2000和京科糯2000E在适采期内子粒降水速率显著低于其他品种。糊化特征值在材料和采收期间存在显著差异。随采收期推迟,参试材料淀粉的峰值黏度、终值黏度、崩解值和回复值呈先升高后降低的趋势。京科糯2000、京科糯2000E、京科糯2000K、黑糯101、渝糯7号的峰值黏度、终值黏度和崩解值在授粉后20d达到峰值,天紫23和先达糯001在授粉后23d达到峰值。京科糯2000K平均回复值(252)最低,黑糯101平均回复值(343)最高。以糊化特征值做系统聚类分析,可将参试糯玉米品种分为三类,第1类京科糯2000和京科糯2000K为峰值黏度和崩解值高、黏度特性最好、回复值较低的品种;第2类京科糯2000E为峰值黏度和崩解值相对较高的糯玉米品种;第3类黑糯101、天紫23、先达糯001、渝糯7号为峰值黏度和崩解值较低,黏度特性较差和回复值较高的糯玉米品种。由此可见,子粒含水量和淀粉黏度指标在参试糯玉米品种和采收期间存在显著差异。京科糯2000在5个采收期内子粒降水速率最慢且黏度特性最好,回复值较低,品质优良。

In order to study the change of grain dehydration and gelatinization characteristics of waxy maize at different harvesting time,7 days after potlination(DAP),DAP 20,DAP 23,DAP 26 and DAP 29,seven waxy maize varieties such as Jingkenuo 2000 were used as materials,which are the main waxy maize varieties in China.The results showed:There were significant differences in grain moisture content among varieties and harvesting time.The grain dehydration rates of Jingkenuo 2000,Jingkenuo 2000 E were significantly lower than those of other varieties in the suitable harvesting time.There were significant differences in gelatinization characteristics among varieties and harvesting time.With the postponement of harvest,the peak viscosity,final viscosity,breakdown value and setback value of starch showed the trend of "increased first and then decreased".The peak viscosity,final viscosity and breakdown value of Jingkenuo 2000,Jingkenuo 2000 E,Jingkenuo 2000 K,Heinuo 101 and Yunuo 7 reached the peak values at 20 d after pollination,but Tianzi 23 and Xiandanuo 001 at 23 d after pollination.Setback value of Jingkenuo2000 K(252) was the lowest,while Heinuo 101 was the highest(343).The starch gelatinization characteristics of Jingkenuo 2000 and Jingkenuo 2000 K had the highest peak viscosity,breakdown value and the lowest setback value,so they belonged to the best viscosity characteristic;Heinuo 101,Tianzi 23,Xiandanuo 001 and Yunuo 7 had lower peak viscosity,breakdown value and the lowest peak viscosity.Therefore,there were significant differences in grain moisture content and starch viscosity among waxy maize varieties and harvesting time.Jingkenuo 2000 had the slowest precipitation rate and the best viscosity characteristics in five harvesting time,with low setback and good quality.