Late-stage vigor contributes to high grain yield in high-quality hybrid rice

Abstract

Improving grain quality is critical to the development of hybrid rice. In recent years, multiple hybrid rice cultivars with superior grain quality have been developed in China through dedicated breeding efforts. However, limited information is available on yield performance and yield formation characteristics of these high-quality hybrid rice cultivars. In this study, field experiments were conducted to compare yield attributes between a recently developed indica hybrid rice with superior grain quality (Jingliangyou 1468, JLY1468) and a relatively older indica hybrid rice cultivar with high yield potential (Liangyoupeijiu, LYPJ). Results showed that grain yield was 13–17% higher in JLY1468 than in LYPJ. The higher grain yield of JLY1468 than of LYPJ was mainly attributable to a higher spikelet filling percentage, which was closely related to a higher harvest index resulting from a higher crop growth rate during the post-heading period. The results of this study suggest that late-stage vigor may be a vital trait for the development of indica hybrid rice cultivars with both high quality and high yield.