Cao XianMei, Sun HuiYan, Wang ChunGe, Ren XiaoJia, Liu HongFei, Zhang ZuJian
Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics, Ministry of Education of China, Agricultural College of Yangzhou University, Yangzhou, China.
J Sci Food Agric. 2018 Apr;98(6):2332-2340. doi: 10.1002/jsfa.8723. Epub 2017 Dec 13.
With the rapid development of modern agriculture, high-quality rice production and consumption has become the current urgent demand for the development of rice production. In this paper, the effects of late-stage nitrogen fertilizer application on rice quality were studied under the same genetic background. Wx near-isogenic lines were used as test materials to study the starch composition, amylopectin structure and cooking quality of rice.
Results showed that rice amylose content and gel consistency significantly differed when different Wx genes were tranformed into waxy rice. The law of apparent amylose content in rice is Wx > Wx > Wx > wx at the same nitrogen level, while the trend of gel consistency was opposite to that of apparent amylose content, presenting obvious characteristics of Indica and Japonica varieties. As the amount of fertilizer application increased, apparent amylose content increased, gel consistency decreased, breakdown and peak viscosities dropped and setback viscosity and peak time increased. Moreover, the cooking quality of rice significantly decreased with the use of nitrogen fertilizer, especially under low-level nitrogen fertilizer application. Amylopectin structure varied significantly in different genotypes of the Wx gene, and the degree of branching was as follows: wx > Wx > Wx > Wx . This result indicated that the closer to Indica rice, the fewer short chains of amylopectin. Starch crystallinity and swelling potential were negatively correlated with amylose content but significantly positively correlated with amylopectin branching degree, decreasing with the increase of late-stage nitrogen fertilization.
Late-stage nitrogen fertilization reduced the cooking quality of rice by increasing amylose content and reducing amylopectin branching degree, which decreased starch crystallinity and aggravated pasting properties. Obviously, controlling late nitrogen application is essential to optimize rice quality. © 2017 Society of Chemical Industry.
随着现代农业的快速发展，优质水稻生产与消费已成为当前水稻生产发展的迫切需求。本文在相同遗传背景下研究了后期施氮对稻米品质的影响。以Wx近等基因系为试验材料，研究了水稻淀粉组成、支链淀粉结构及蒸煮品质。
结果表明，不同Wx基因导入糯稻后，稻米直链淀粉含量和胶稠度存在显著差异。在相同施氮水平下，水稻表观直链淀粉含量规律为Wx＞Wx＞Wx＞wx，而胶稠度变化趋势与表观直链淀粉含量相反，呈现明显的籼粳品种特征。随着施肥量增加，表观直链淀粉含量增加，胶稠度降低，崩解值和峰值黏度下降，回生值和峰值时间增加。此外，施氮显著降低了稻米蒸煮品质，尤其是在低施氮水平下。不同基因型Wx基因的支链淀粉结构差异显著，分支程度顺序为：wx＞Wx＞Wx＞Wx。这一结果表明，越接近籼稻，支链淀粉短链越少。淀粉结晶度和膨胀势与直链淀粉含量呈负相关，但与支链淀粉分支程度呈显著正相关，随着后期施氮量增加而降低。
后期施氮通过增加直链淀粉含量和降低支链淀粉分支程度降低了稻米蒸煮品质，进而降低了淀粉结晶度并加剧了糊化特性。显然，控制后期施氮对优化稻米品质至关重要。© 2017化学工业协会。
