播期和地点对南粳46稻米品质及RVA谱的影响

[目的]研究不同播期、地点对南粳46稻米品质及RVA谱的影响。[方法]大田试验于江苏省5个试点进行，每个试点设置7个播期，成熟后测定 RVA谱各相关指标。[结果]随着播期的推迟，南粳46稻米加工品质呈先升后降的变化趋势，外观品质变优，蒸煮食用品质下降；随着地点的南移，南粳46稻米加工品质、外观品质和蒸煮食用品质总体均呈先降后升的变化趋势。不同性状对地点和播期的反应不同，糙米率、粒宽、粒长、长宽比、精米率和整精米率受影响较小，而垩白率和垩白度受影响较大，糊化温度、蛋白质含量、直链淀粉含量、胶稠度和食味值居两者之间。 RVA谱特征值分析表明，崩解值、消减值和起始糊化温度同时受播期和地域环境的影响。峰值黏度、热浆黏度、最终黏度和峰值黏度时间受地域环境的影响较大。随播期的推迟，峰值黏度、热浆黏度、最终黏度、消减值和起始糊化温度呈先降后升的变化趋势，崩解值先升后降，峰值粘度时间变化规律不明显。随纬度的降低，峰值黏度、热浆黏度、崩解值和最终黏度总体上均呈先降后升的变化趋势，消减值和峰值黏度时间降低，起始糊化温度升高。[结论]该研究为南粳46的“优质、高效”生产提供理论依据。

Effects of Different Sowing Dates and Sites on Grain Quality and RVA Profile of Nanjing 46, a Popular Cultivar of Japonica Rice (Oryza sativa L.)

[Objective] This study was performed to determine the effects of sowing dates and sites on grain quality and Rapid Viscosity Analyzer （RVA） profile of Nan-jing 46. [Method] The field experiments were carried out at five sites in Jiangsu Province, and in every site, the seeds were sowing on seven different dates. RVA related indices were measured after harvest. [Result] Along with the delay of sowing date, the mil ing quality of Nanjing 46 increased at first and then reduced, while its appearance quality went up and the cooling and edible quality decreased. With the sowing sites moving southward, the rice mil ing quality, appearance quality, and cooling and edible quality of Nanjing 46 decreased at first and then increased. Grain traits responded variably to the sowing dates and sites. The brown rice rate, grain width, grain length, length/width, mil ed rice rate and head mil ed rice rate were less affected, while the chalky rice rate and chalkiness degree were more af-fected. The gelatinization temperature, protein content, amylose content, gel consis-tency and eating value were in-between. The RVA profile analysis revealed that the breakdown value, setback value and pasting temperature were affected by the sow-ing date and geographical environment. The peak viscosity, hot viscosity, cool vis-cosity and peak time were influenced more by geographical environment. With the delay of the sowing date, peak viscosity, hot viscosity, cool viscosity, setback value and pasting temperature decreased at first and then increased, while the breakdown value changed inversely, and the peak time did not exhibit a regular trend. With the decrease of latitude, the peak viscosity, hot viscosity, breakdown and cool viscosity declined at first and then increased, the setback value and peak time decreased, while the pasting temperature increased. [Conclusion] This study wil provide refer-ences for the effective production of Nanjing 46.