Greater Propensity to Photosynthesize Enables Superior Grain Quality of <i>Indica–japonica</i> Hybrid Rice under Shading
Cheng Shang,
Matthew Tom Harrison,
Jun Deng,
Jiayu Ye,
Xuefen Zhong,
Chunhu Wang,
Xiaohai Tian,
Liying Huang,
Ke Liu,
Yunbo Zhang
Affiliations
Cheng Shang
MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River/College of Agriculture, Yangtze University, Jingzhou 434000, China
Matthew Tom Harrison
Tasmanian Institute of Agriculture, University of Tasmania, Newnham Drive, Launceston, TAS 7248, Australia
Jun Deng
MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River/College of Agriculture, Yangtze University, Jingzhou 434000, China
Jiayu Ye
MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River/College of Agriculture, Yangtze University, Jingzhou 434000, China
Xuefen Zhong
Agricultural and Rural Bureau of Duodao District, Jingmen 448000, China
Chunhu Wang
MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River/College of Agriculture, Yangtze University, Jingzhou 434000, China
Xiaohai Tian
MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River/College of Agriculture, Yangtze University, Jingzhou 434000, China
Liying Huang
MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River/College of Agriculture, Yangtze University, Jingzhou 434000, China
Ke Liu
MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River/College of Agriculture, Yangtze University, Jingzhou 434000, China
Yunbo Zhang
MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River/College of Agriculture, Yangtze University, Jingzhou 434000, China
Indica–japonica hybrid rice (I–JR) typically has greater grain yield than that of Indica hybrid rice (IR) under prolific shading, but it is not known how shading impacts on physiological characteristics underpinning grain quality. Here, we conducted a two-year field experiment in the mid-reaches of the Yangtze River region using I–JR (genotypes Yongyou 1540 and Yongyou 538) and IR (genotypes Y-liangyou 900 and Quanyouhuazhan). We found that shading reduced grain appearance and quality, particularly milling and heading rates, and chalkiness. Shading disrupted carbon and nitrogen metabolism, impacting traits influencing the human perception of the taste of the grain, such that amylose decreased by 5.9% (I–JR) and 12.9% (IR); grain protein significantly increased, with lesser effects in I–JR than IR under shading. Shading also reduced peak, hot, and final viscosities, and breakdown value. I–JR had improved rice quality compared with that of IR due to the greater propensity of the former to photosynthesize under shading, leading to the improved functioning of carbon and nitrogen metabolism.
