Abstract

Grain filling of rice is severely reduced under saline-alkaline conditions, resulting in loss of both grain yield and quality. Here we studied the potential improving effect of cytokinins (CKs) on grain filling of rice (Oryza sativa L.) in saline-alkaline paddy fields in the years of 2012 and 2013. The results showed that application of kinetin (KT, a synthetic CK; 10, 50 and 100 μM) to panicles significantly improved grain filling as shown by increase in 1,000-grain weight by 12.53% compared with the mock control treatment. Further, studies using opposite-paired primary rachis branches revealed that KT-application (50 μM) significantly accelerated the grain filling rate in both 2012 and 2013, and also increased the final 1,000-grain weight by 7.74% in 2013. These results demonstrate that CKapplication can significantly improve grain filling, and thus may provide a new approach to increasing grain yield and quality of rice in saline alkaline paddy field.