Varietal improvement is a feasible approach for achieving high yield and superior quality simultaneously in ratoon rice

Abstract

Context

While rice ratooning has been increasingly practiced by farmers recently in China, low and unstable yield of ratoon crop (RC) and poor quality of main crop (MC) have limited the further extension of this technology.

Research question

Variety selection is effective in improving crop yield and quality. However, the traits responsible for achieving high yield and superior quality in both MC and RC of ratoon rice are less studied and remains poorly understood.

Methods

To address this gap, the yield and quality and their related traits of 22 rice varieties, which were widely grown in the major ratoon rice production areas in central China, were studied in field experiments in 2021 and 2022.

Results

Results showed that the yield ranged from 8.22 to 10.82 t ha⁻¹ and from 4.15 to 7.89 t ha⁻¹ across varieties and years in MC and RC, respectively. Varietal differences were also observed in head rice percentage and chalky rice percentage in both MC and RC. Among the tested varieties, three varieties, namely Yongyou4949, Jingliangyou1468, and Shenliangyouyuehesimiao, produced consistently higher yield and head rice percentage, and lower chalky rice percentage than most of the other varieties in both MC and RC. The high spikelets m⁻² determined by spikelets panicle⁻¹ and high biomass production explained the high yield, while low grain weight, grain length and length-width ratio contributed to good milling and appearance quality for the three varieties.

Conclusions

These results suggest that breeding new rice varieties with large panicle size (i.e. spikelets panicle⁻¹⁾ and small grain size (i.e. low grain weight, grain length and length-width ratio) could be an effective approach for achieving high yield and quality simultaneously in both MC and RC of ratoon rice to ensure food security and meet high food quality demand in China.