Developing Climate-Resilient, Direct-Seeded, Adapted Multiple-Stress-Tolerant Rice Applying Genomics-Assisted...

Area of Science:

• Agricultural Science
• Plant Breeding
• Genetics

Background:

• Increasing water and labor scarcity necessitates the development of dry direct-seeded rice varieties.
• Conventional and genomics-assisted breeding programs were employed to address this need.

Purpose of the Study:

• To develop high-yielding, direct-seeded adapted rice varieties.
• Utilize biparental and multiparental crosses with extensive parent numbers (6 in conventional, 12 in GAB).
• Employ rigorous selection strategies including phenotypic and marker-assisted selection.

Main Methods:

• Conventional breeding involved biparental and multiparental crosses with single plant selection from F2 generation.
• Genomics-assisted breeding (GAB) utilized quantitative trait locus (QTL)/gene-based/linked markers alongside phenotypic selection.
• Selection focused on tracking desirable alleles of targeted QTL/genes.

Main Results:

• Multiparent lines in conventional breeding showed higher yields than biparental lines.
• GAB lines from multiparent crosses significantly outperformed conventional multiparent lines.
• Eleven GAB lines carried 7-11 QTL/genes, and eight conventional lines showed substantial grain-yield improvements.

Conclusions:

• Genomics-assisted breeding offers a significant advantage in developing high-yielding direct-seeded rice.
• The developed lines represent valuable genetic resources for future rice breeding programs.
• These lines can be released as varieties or parental lines for direct-seeded cultivation.