评估增加二氧化碳对稻米品质的影响正成为全球关注的问题。然而,调整源库比是否会影响稻米品质对CO2浓度升高的响应尚不清楚。在2016-2018年,我们使用在环境和升高的CO2水平(eCO2,增加200ppm)下生长的流行粳稻品种进行了自由空气CO2富集实验。在抽穗阶段通过切叶(LC)降低源库比,为了研究eCO2和LC及其相互作用对大米加工的影响,外观,营养,和饮食质量。平均3年,eCO2显著降低糙米百分比(-0.5%),碾米百分比(-2.1%),和水稻百分比(-4.2%),但增加了白垩粒率(22.3%)和白垩度(26.3%)。很明显,eCO2增加了峰值粘度(+2.9%)和最小粘度(+3.8%),但减少了粉末大米的挫折(-96.1%),增加了外观(+4.5%),米饭的粘性(+3.5%)和平衡度(+4.8%),同时降低硬度(-6.7%),导致更好的适口性(+4.0%)。Further,eCO2显著降低了蛋白质的浓度,Ca,S,铜分别为5.3、4.7、2.2和9.6%,分别,但钾浓度增加了3.9%。不同粒位(糙米和精米)的营养品质对eCO2的响应趋势相同。与对照治疗相比,LC显着增加白垩粒百分比,白垩度,蛋白质浓度,矿质元素含量(B和Mn除外),和植酸浓度。我们的结果表明,eCO2降低了大米加工的适用性,外观,和营养质量,但提高了饮食质量。稻米品质在不同年份之间差异很大;然而,每年二氧化碳都很少,LC的CO2,或CO2通过谷物位置相互作用被检测到,表明eCO2对稻米品质的影响随生长季节变化不大,源-汇比率的降低或不同的晶粒位置。
Evaluating the impact of increasing CO2 on rice quality is becoming a global concern. However, whether adjusting the source-sink ratio will affect the response of rice grain quality to elevated CO2 concentrations remains unknown. In 2016-2018, we conducted a free-air CO2 enrichment experiment using a popular japonica cultivar grown at ambient and elevated CO2 levels (eCO2, increased by 200 ppm), reducing the source-sink ratio via cutting leaves (LC) at the heading stage, to investigate the effects of eCO2 and LC and their interactions on rice processing, appearance, nutrition, and eating quality. Averaged across 3 years, eCO2 significantly decreased brown rice percentage (-0.5%), milled rice percentage (-2.1%), and head rice percentage (-4.2%) but increased chalky grain percentage (+ 22.3%) and chalkiness degree (+ 26.3%). Markedly, eCO2 increased peak viscosity (+ 2.9%) and minimum viscosity (+ 3.8%) but decreased setback (-96.1%) of powder rice and increased the appearance (+ 4.5%), stickiness (+ 3.5%) and balance degree (+ 4.8%) of cooked rice, while decreasing the hardness (-6.7%), resulting in better palatability (+ 4.0%). Further, eCO2 significantly decreased the concentrations of protein, Ca, S, and Cu by 5.3, 4.7, 2.2, and 9.6%, respectively, but increased K concentration by 3.9%. Responses of nutritional quality in different grain positions (brown and milled rice) to eCO2 showed the same trend. Compared with control treatment, LC significantly increased chalky grain percentage, chalkiness degree, protein concentration, mineral element levels (except for B and Mn), and phytic acid concentration. Our results indicate that eCO2 reduced rice processing suitability, appearance, and nutritional quality but improved the eating quality. Rice quality varied significantly among years; however, few CO2 by year, CO2 by LC, or CO2 by grain position interactions were detected, indicating that the effects of eCO2 on rice quality varied little with the growing seasons, the decrease in the source-sink ratios or the different grain positions.