XianMei Cao1, HuiYan Sun1, ChunGe Wang1, XiaoJia Ren1, HongFei Liu1, ZuJian Zhang1. 1. 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.
Abstract
BACKGROUND: 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: 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 Wxa > Wxin > Wxb > 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 > Wxb > Wxin > Wxa . 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. CONCLUSION: 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.
BACKGROUND: 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: Results showed that riceamylose content and gel consistency significantly differed when different Wx genes were tranformed into waxy rice. The law of apparent amylose content in rice is Wxa > Wxin > Wxb > 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 > Wxb > Wxin > Wxa . 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. CONCLUSION: 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.
Authors: Izhar Ali; Anas Iqbal; Saif Ullah; Ihsan Muhammad; Pengli Yuan; Quan Zhao; Mei Yang; Hua Zhang; Min Huang; He Liang; Minghua Gu; Ligeng Jiang Journal: Foods Date: 2022-02-22