Effects of 15-day continuously shading treatment after flowering on grain yield, quality and aroma of aromatic rice

Objective To investigate the effects of 15-day continuously shading treatment after flowering on yield, quality and major aromatic compound 2-acetyl-1-pyrroline (2-AP).

Method Two conventional aromatic rice cultivars of Yuxiangyouzhan and Nongxiang18 were treated by 15-day continuously shading after flowering and natural light in the field. The yield, quality, 2-acetyl-1-pyrroline content and other indexes of aromatic rice were measured.

Result and conclusion The results showed that compared with natural light, the 15-day continuously shading treatment after flowering significantly increased the contents of 2-acetyl-1-pyrroline and protein in grains, and significantly decreased 1000-grain mass, seed setting rate and yield as well as head rice rate. Therefore, low-light stress plays a positive role in the aroma enhancement of aromatic rice but leads to a yield reduction. The effects of shading on other grain quality traits are different due to different varieties.