施氮量对机插粳型超级稻主要米质性状及淀粉RVA谱特征的影响

研究氮肥对粳型超级稻主要米质性状及淀粉RVA谱特征的影响,为超级稻米质调优和氮肥合理施用提供依据。以粳型超级稻常规品种南粳44和杂交品种常优1号为材料,在机械插秧条件下,研究施氮量(0、90、180、270、360kg/hm~2)对粳型超级稻主要米质性状及淀粉粘滞谱(RVA谱)特征的影响。结果表明:施氮量对2个品种的稻米加工品质、营养品质、蒸煮食味品质及淀粉RVA谱3个曲线峰值的影响达到显著或极显著水平,对淀粉RVA谱其他特征参数的影响因不同品种而异;常优1号的外观品质指标(垩白粒率和垩白度)对氮肥施用量的反应较南粳44表现敏感,增加施氮量使杂交粳稻外观品质变差。随施氮量的增加,2个品种的糙米率、精米率、整精米、精米蛋白质含量呈增加趋势,而稻米的直链淀粉含量、食味值和淀粉RVA谱曲线峰值(峰值黏度、热浆黏度和冷胶黏度)呈现下降趋势。研究表明增施氮肥在提高粳型超级稻加工和营养品质的同时,降低了稻米食味品质,并使稻米淀粉粘性变劣。

Effects of Nitrogen Application Rate on Rice Quality and Starch RVA Profile Parameters ofMechanical Transplanting Super Japonica Rice

Using conventional Japonica rice cultivar Nanjing 44 and hybrid Japonica rice combination Changyou 1,the effects of nitrogen（N） application rate（0,90,180,270,360 kg/hm^2） on rice quality and starch RVA profile parameters of super Japonica rice were investigated under manual transplanting rice cultivation pattern.The results showed that rice milling quality,nutritional quality,cooking and taste quality,three peak starch RVA profile parameters（peak viscosity,hot viscosity,cool viscosity） of super Japonica rice measured in this study were significantly influenced by N application rate treatments,and the other starch RVA profile parameters differed between two super Japonica rice cultivars.Compared with Nanjing 44,rice appearance quality of Changyou 1 was more sensitive to N treatments;increasing N application rate would increase chalkiness rice rate and chalkiness degree of Changyou 1.Both Nanjing 44 and Changyou 1 showed the same trend that,with raising N application rate,brown rice rate,milled rice rate,head rice rate and rice protein content increased,while rice amylase content,taste value,peak viscosity,hot viscosity,cool viscosity of rice starch decreased.These results indicated that increasing N application rate would result in increment of milling quality and nutritional quality of rice,while rice taste quality and starch viscosity decreased.