[SSR markers linked with early stability in rice]

Area of Science:

• Plant genetics
• Molecular biology
• Agronomy

Context:

• Developing new rice (Oryza sativa L.) varieties with desirable agronomic traits is crucial for global food security.
• Traditional breeding methods can be time-consuming, necessitating research into mechanisms for early stabilization of hybrid lines.

Purpose:

• To investigate the genetic basis of early stabilization observed in specific rice hybrid populations.
• To utilize SSR markers to confirm homozygosity and hybrid origin in uniform rice strains.
• To explore potential genetic mechanisms, such as mutation and somatic meiosis, contributing to rapid trait stabilization.

Summary:

• Crossing nine rice strains with seven cultivars produced 130 hybrids, yielding 32 uniform F2 strains with distinct agronomic traits.
• SSR marker analysis confirmed that the uniform strains were homozygous, while segregating strains exhibited heterozygosity.
• Uniform strains displayed unique marker band frequencies, suggesting gene mutation (linked to ga-1, Rf, ga-8) and subsequent somatic meiosis leading to homozygous embryos and early stabilization.

Impact:

• Provides evidence for a potential mechanism (mutation followed by somatic meiosis) driving rapid stabilization in rice hybrids.
• Identifies specific SSR markers (RM276, RM258, RM248, RM1) associated with uniform strains, aiding marker-assisted selection.
• Offers insights for accelerating rice breeding programs by understanding and potentially manipulating early stabilization processes.