Mitigating rice chalkiness while ensuring grain quality and seed vigor

Zhao, Dongsheng; Sreenivasulu, Nese; Liu, Qiaoquan

Mitigating rice chalkiness while ensuring grain quality and seed vigor

Autores

Zhao, Dongsheng

Sreenivasulu, Nese

Liu, Qiaoquan

Editor

Elsevier

Descripción

As the third-most-produced crop globally, rice (Oryza sativa) is predominantly cultivated and consumed in Asia. Rice chalkiness typically arises from incomplete endosperm development, in which loosely packed starch and protein granules form air spaces that scatter light, thereby producing a white, opaque region (Figure 1). Based on its position within the grain, chalkiness is classified as white core, white belly, or white back. Endosperm development in rice is described as grain filling, a process involving the accumulation of starch, proteins, and other nutrients, with starch constituting the major component. The physiological basis of chalkiness is often linked to insufficient nutrient accumulation, reflecting an imbalance in the source– sink relationship (Liu et al., 2022; Zhou et al., 2025). Chalkiness is a complex trait primarily governed by genetic factors. Several genes with natural allelic variation, such as Chalk9, Chalk5, and WCR1, have been cloned to date (Zhao et al., 2022). In addition, environmental factors can influence chalkiness formation, for example through QT12, a quality thermotolerant gene, under high-temperature stress (Li et al., 2025), or OsNLP3 in response to nitrogen availability (Sun et al., 2024).