Li Zhikang, Zhou Tianyang, Zhu Kuanyu, Wang Weilu, Zhang Weiyang, Zhang Hao, Liu Lijun, Zhang Zujian, Wang Zhiqin, Wang Baoxiang, Xu Dayong, Gu Junfei, Yang Jianchang
Jiangsu Key Laboratory of Crop Genetics and Physiology/Jiangsu Key Laboratory of Crop Cultivation and Physiology, Agricultural College, Yangzhou University, Yangzhou 225009, China.
Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
Plants (Basel). 2023 Sep 12;12(18):3243. doi: 10.3390/plants12183243.
Rice yield and grain quality are highly sensitive to salinity stress. Salt-tolerant/susceptible rice cultivars respond to salinity differently. To explore the variation in grain yield and quality to moderate/severe salinity stress, five rice cultivars differing in degrees of salt tolerance, including three salt-tolerant rice cultivars (Lianjian 5, Lianjian 6, and Lianjian 7) and two salt-susceptible rice cultivars (Wuyunjing 30 and Lianjing 7) were examined. Grain yield was significantly decreased under salinity stress, while the extent of yield loss was lesser in salt-tolerant rice cultivars due to the relatively higher grain filling ratio and grain weight. The milling quality continued to increase with increasing levels. There were genotypic differences in the responses of appearance quality to mild salinity. The appearance quality was first increased and then decreased with increasing levels of salinity stress in salt-tolerant rice but continued to decrease in salt-susceptible rice. Under severe salinity stress, the protein accumulation was increased and the starch content was decreased; the content of short branched-chain of amylopectin was decreased; the crystallinity and stability of the starch were increased, and the gelatinization temperature was increased. These changes resulted in the deterioration of cooking and eating quality of rice under severe salinity-stressed environments. However, salt-tolerant and salt-susceptible rice cultivars responded differently to moderate salinity stress in cooking and eating quality and in the physicochemical properties of the starch. For salt-tolerant rice cultivars, the chain length of amylopectin was decreased, the degrees of order of the starch structure were decreased, and pasting properties and thermal properties were increased significantly, whereas for salt-susceptible rice cultivars, cooking and eating quality was deteriorated under moderate salinity stress. In conclusion, the selection of salt-tolerant rice cultivars can effectively maintain the rice production at a relatively high level while simultaneously enhancing grain quality in moderate salinity-stressed environments. Our results demonstrate specific salinity responses among the rice genotypes and the planting of salt-tolerant rice under moderate soil salinity is a solution to ensure rice production in China.
水稻产量和品质对盐胁迫高度敏感。耐盐/感盐水稻品种对盐胁迫的反应不同。为探究中度/重度盐胁迫下水稻产量和品质的变化，研究了五个耐盐程度不同的水稻品种，包括三个耐盐水稻品种（连粳5号、连粳6号和连粳7号）和两个感盐水稻品种（武运粳30号和连粳7号）。盐胁迫下水稻产量显著降低，而耐盐水稻品种的产量损失程度较小，这是由于其相对较高的灌浆率和粒重。碾米品质随盐胁迫水平的增加持续提高。外观品质对轻度盐胁迫的反应存在基因型差异。耐盐水稻中，外观品质随盐胁迫水平的增加先升高后降低，而感盐水稻中外观品质则持续降低。在重度盐胁迫下，蛋白质积累增加，淀粉含量降低；支链淀粉短支链含量降低；淀粉的结晶度和稳定性增加，糊化温度升高。这些变化导致重度盐胁迫环境下水稻蒸煮食味品质变差。然而，耐盐和感盐水稻品种在蒸煮食味品质和淀粉理化性质方面对中度盐胁迫的反应不同。对于耐盐水稻品种，支链淀粉链长缩短，淀粉结构有序度降低，糊化特性和热特性显著增加，而对于感盐水稻品种，中度盐胁迫下蒸煮食味品质变差。总之，在中度盐胁迫环境下，选择耐盐水稻品种可以有效维持较高的水稻产量水平，同时提高稻米品质。我们的研究结果表明了水稻基因型对盐胁迫的特异性反应，在中度土壤盐渍化条件下种植耐盐水稻是确保中国水稻产量的一种解决方案。
