Effect of salinity stress on rice yield and grain quality: A meta-analysis

Salinity is one of the major abiotic stresses limiting the improvement in rice grain yield. The present study aimed to perform the meta-analysis and dose-response analysis using data collected from 58 studies to understand the responses of grain yield and grain quality traits to salinity stress. The results revealed that salinity stress reduced the grain yield (-64.52 %, 95 % confidence interval:-66.49 % to-62.44 %), primarily due to the decrease in the seed set rate, effective panicle number, and grain number per panicle. The effect of salinity initiated in the reproductive stage was more significant than that started in the seedling stage. In addition, alkaline salts had a higher impact on the grain yield compared with neutral salts. Salinity decreased the head rice rate and increased the chalky rice rate, adversely affecting the grain quality. However, salinity exhibited no significant effect on the length-to-width ratio, brown rice, and total milled rice. These results suggested that improving the effective panicle number and seed set rate is crucial for breeding salinity-tolerant rice cultivars. In addition, the grain quality should be considered while developing new rice cultivars for saline soil.

Automated summary

Salinity is a major abiotic stress that limits rice grain yield. Meta-analysis and dose-response analysis of 58 studies were conducted to examine the response of grain yield and quality traits to salinity stress. The results showed that salinity stress significantly reduced grain yield, primarily due to a decrease in seed set rate, effective panicle number, and grain number per panicle. Salinity stress during the reproductive stage had a greater impact than during the seedling stage. Alkaline salts had a stronger effect on grain yield compared to neutral salts. Salinity negatively affected grain quality by decreasing head rice rate and increasing chalky rice rate, while having no significant effect on length-to-width ratio, brown rice, and total milled rice. These findings highlight the importance of improving effective panicle number and seed set rate for breeding salinity-tolerant rice cultivars, as well as considering grain quality in developing new rice cultivars for saline soil.