Developmental behavior of gene expression for brown rice thickness under different environments

Area of Science:

• Plant genetics
• Agricultural science
• Developmental biology

Background:

• Brown rice thickness (BRT) is a crucial quality trait in rice (Oryza sativa L.).
• Understanding the genetic basis of BRT, including genotype x environment (GE) interactions, is vital for breeding programs.
• Dynamic changes in genetic effects across different developmental stages require investigation.

Purpose of the Study:

• To investigate the dynamic changes of genetic effects on brown rice thickness (BRT).
• To analyze main effects and genotype x environment (GE) interaction effects on BRT across different environments.
• To understand the genetic control of BRT at various filling stages using developmental genetic models.

Main Methods:

• Utilized developmental genetic models for analysis.
• Employed a factorial design with seven cytoplasmic male sterile indica rice lines and five restoring lines.
• Produced and analyzed F(1) and F(2) grains across two environments (years).

Main Results:

• Genetic effects, especially GE interactions involving endosperm, cytoplasm, and maternal genes, significantly impact BRT.
• BRT is controlled by net genetic effects expressed during early (1-7 days) and late (15-21 days) filling stages.
• Net GE interaction effects were most crucial at early filling and mature stages; additive and cytoplasm main effects were also significant.

Conclusions:

• Genotype x environment interactions play a critical role in determining brown rice thickness.
• Additive and cytoplasm main effects, along with their interactions, are valuable for selecting BRT in breeding.
• Parents V20 and Xieqingzao show potential for improving BRT in progenies.