title: Differences in Viscosity of Superior and Inferior Spikelets of Japonica Rice with Various Percentages of Apparent Amylose Content.
abstract: Viscosity, a crucial characteristic for rice palatability, is affected by endosperm characters. We compared correlations between differences in viscosity of japonica rice with various palatability and endosperm characters. Changes in apparent amylose and protein contents (AAC% and PC%, respectively) and amylopectin side-chain distribution and the relationship of these traits with palatability were investigated in superior and inferior spikelets of good cultivars with low amylose content from Hokkaido and common cultivars from northeastern Japan, using rapid visco analyzer characteristics and rice-grain microstructures. Significant differences occurred in PC%, AAC%, breakdown, setback, peak time, and pasting temperature of different cultivars and grain positions. Amylopectin components showed remarkable differences in grain surfaces, surface layers, and section structure between the grain varieties. Hokkaido cultivars showed better viscosity than northeastern cultivars, particularly initial stage grains. Correlation analysis indicated viscosity was mainly AAC%-dependent, whereas differences in endosperm characteristics between spikelet positions were mainly due to grain-filling temperature.
authors.affiliation: Rice Research Institute of Shenyang Agricultural University, Key Laboratory of Northern Japonica Rice Genetics and Breeding, Ministry of Education and Liaoning Province, Key Laboratory of Northeast Rice Biology and Genetics and Breeding, Ministry of Agriculture , Shenyang, China 110866.
authors.forename: Zhao-Hui
authors.identifier: http://orcid.org/0000-0002-5750-4555
authors.initials: ZH
authors.lastname: Ma
authors.affiliation: Rice Research Institute of Shenyang Agricultural University, Key Laboratory of Northern Japonica Rice Genetics and Breeding, Ministry of Education and Liaoning Province, Key Laboratory of Northeast Rice Biology and Genetics and Breeding, Ministry of Agriculture , Shenyang, China 110866.
authors.forename: Hai-Tao
authors.initials: HT
authors.lastname: Cheng
authors.affiliation: The College of Agriculture, Ibaraki University Ami , Inashiki, Ibaraki 300-0393, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nitta
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo , 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Naohiro
authors.initials: N
authors.lastname: Aoki
authors.affiliation: Rice Research Institute of Shenyang Agricultural University, Key Laboratory of Northern Japonica Rice Genetics and Breeding, Ministry of Education and Liaoning Province, Key Laboratory of Northeast Rice Biology and Genetics and Breeding, Ministry of Agriculture , Shenyang, China 110866.
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Rice Research Institute of Shenyang Agricultural University, Key Laboratory of Northern Japonica Rice Genetics and Breeding, Ministry of Education and Liaoning Province, Key Laboratory of Northeast Rice Biology and Genetics and Breeding, Ministry of Agriculture , Shenyang, China 110866.
authors.forename: Heng-Xue
authors.initials: HX
authors.lastname: Chen
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo , 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Ryu
authors.initials: R
authors.lastname: Ohsugi
authors.affiliation: Rice Research Institute of Shenyang Agricultural University, Key Laboratory of Northern Japonica Rice Genetics and Breeding, Ministry of Education and Liaoning Province, Key Laboratory of Northeast Rice Biology and Genetics and Breeding, Ministry of Agriculture , Shenyang, China 110866.
authors.forename: Wen-Yan
authors.initials: WY
authors.lastname: Lyu
mesh_terms: D000688:Amylose / Q000737:chemistry*; D007564:Japan; D012275:Oryza / Q000737:chemistry* / Q000145:classification; D011208:Powders / Q000032:analysis; D012639:Seeds / Q000737:chemistry; D013696:Temperature; D014783:Viscosity
chemical_list: D011208:Powders; D000688:Amylose
keywords: filling grain; grain position; japonica rice; low AAC percent; viscosity