文献类型： 外文期刊

作者： Hu, Qun ¹ ; Liu, Qiuyuan ¹ ; Jiang, Weiqin ¹ ; Qiu, Shi ³ ; Wei, Haiyan ¹ ; Zhang, Hongcheng ¹ ; Liu, Guodong ¹ ; Xing, Z ¹ ;

作者机构： 1.Yangzhou Univ, Jiangsu Key Lab Crop Genet & Physiol, Jiangsu Coinnovat Ctr Modern Prod Technol Grain C, Agr Coll, Yangzhou 225009, Jiangsu, Peoples R China

2.Xinyang Agr & Forestry Univ, Agr Coll, Xinyang, Peoples R China

3.Jiangsu Acad Agr Sci, Inst Crop Germplasm & Biotechnol, Prov Key Lab Agrobiol, Nanjing, Peoples R China

关键词： application timing; japonica rice starch; mid‐ stage nitrogen; morphological structure; physicochemical properties

期刊名称：JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE （ 影响因子：3.638； 五年影响因子：3.802 ）

ISSN： 0022-5142

年卷期：

页码：

收录情况： SCI

摘要： BACKGROUND Nitrogen management of crops, especially when mid-stage nitrogen is applied, is a key factor affecting the yield and grain quality of rice (Oryza sativa). Here, the timing of mid-stage nitrogen application was evaluated for its effect on rice grain quality by assessing the morphological structure and physicochemical properties of starch from two japonica rice cultivars growing in fields (Nangeng 9108 and Nangeng 5055). RESULTS The experiment was arranged in a split-plot design, with the two rice cultivars as the main plot factor and three timings of mid-stage nitrogen application as the within-plot factor. Briefly, three applications were made: at the emergence of the top-sixth-leaf (ahead), the top-fourth-leaf (normal), and the top-second-leaf (delayed) of the main stem. Delaying mid-stage nitrogen application caused the starch granule surface to become uneven and significantly reduced its particle size, whereas it increased the polished rice rate, chalkiness degree, and protein content. Furthermore, the apparent amylose content decreased with a delay in mid-stage nitrogen application, thereby resulting in higher relative crystallinity, swelling power, water solubility, gelatinization enthalpy, and low retrogradation. Finally, we also found that delaying this nitrogen application lowered the characteristic values of rice flour viscosities, leading to cooking quality deterioration. CONCLUSION These results therefore suggest that delaying mid-stage nitrogen application enhances the processing and nutritional qualities of japonica rice but evidently has an adverse effect upon its appearance and cooking qualities. (c) 2020 Society of Chemical Industry