Colored rice is a high-quality and high-added-value rice that has attracted increasing attention in recent years. Therein, the main functional substance in colored rice is anthocyanin, which plays an important role in anti-aging, inhibiting adipocyte accumulation, preventing cancer and treating cancer. However, there are few studies on the effects of shading at different growth periods with various shading intensities on the grain yield and anthocyanin content of colored rice. Field experiments were conducted in Hainan Province in 2020 and 2021, and two inbred rice cultivars, Youxianghongdao (YXHD) and Suixiangheinuo (SXHN), were adopted. Shading treatments were conducted at three different growth periods: shading from the regreening stage to the mid-tillering stage (S1), shading from the mid-tillering stage to the full heading stage (S2), and shading from the full heading stage to the maturity stage (S3). Based on the treatment of these three shading growth stages, three shading intensities were incorporated, including shading 20% (D1), 40% (D2) and 60% (D3) light intensities. No shading during the whole growth stage was used as a control (CK). The results indicated that the grain yield and anthocyanin content of both colored rice varieties were most sensitive to shading treatment during S3 among the three shading periods. The grain yields of both colored rice varieties decreased as the shading intensity increased for the three shading periods. In addition, the grain anthocyanin content of the red rice variety (YXHD) decreased as shading intensity increased under S1 and S2, while under S3, the grain anthocyanin content increased as shading intensity increased. However, for the black rice variety (SXHN), the anthocyanin content in grains showed an opposite trend with the changes in both shading intensity and shading period. Above results suggested that SXHN was more suitable for planting in the rainy season with low light intensity than YXHD based on low grain yield loss, strong shade tolerance and high anthocyanin content. However, it is necessary to explore the effects of light intensity on the anthocyanin synthesis mechanism in the near future.

彩色大米是一种优质、高附加值的大米，近年来受到越来越多的关注。其中，彩色大米中的主要功能物质是花青素，在抗衰老、抑制脂肪细胞堆积、防癌治癌等方面发挥着重要作用。然而，关于不同生长期、不同遮光强度的遮光对有色水稻产量和花青素含量影响的研究较少。2020年和2021年在海南省进行了田间试验，采用了优香红稻（YXHD）和穗香黑糯（SXHN）两个自交水稻品种。在三个不同的生长期进行遮光处理：从回绿期到分蘖中期遮光（S1），从分蘖中期到全抽穗期遮光（S2），以及从完整抽穗期到成熟期（S3）的阴影。基于这三个遮光生长阶段的处理，合并了三种遮光强度，包括遮光20%（D1）、40%（D2）和60%（D3）光强。在整个生长阶段没有阴影用作对照（CK）。结果表明，3个遮光期中，2个有色水稻品种的产量和花青素含量对S3遮光处理最为敏感。三个遮荫期随着遮荫强度的增加，两种有色水稻品种的粮食产量均有所下降。此外，红米品种（YXHD）的籽粒花青素含量在S1和S2下随着遮光强度的增加而降低，而在S3下，籽粒花青素含量随着遮光强度的增加而增加。然而，黑米品种（SXHN）籽粒中花青素含量随遮光强度和遮光期的变化呈相反趋势。以上结果表明，由于粮食产量损失小、耐阴性强、花青素含量高，SXHN比YXHD更适合在光照强度较低的雨季种植。然而，有必要在不久的将来探索光强对花青素合成机制的影响。