A single segment substitution line population for identifying traits relevant to drought tolerance and avoidance

Area of Science:

• Plant genetics and breeding
• Agricultural science
• Crop improvement

Background:

• Developing climate-resilient crops is crucial for global food security.
• Identifying and introgressing genes for drought tolerance is a key breeding objective.
• Chromosome segment substitution lines (CSSLs) are valuable tools for trait introgression.

Purpose of the Study:

• To develop chromosome segment substitution lines (CSSLs) for enhancing drought tolerance in rice.
• To capture quantitative trait loci (QTL) associated with drought avoidance, drought tolerance, and yield under stress.
• To evaluate the performance of CSSLs under irrigated and drought stress conditions.

Main Methods:

• Developed CSSLs using KDML105 as the recurrent parent and DH212 or DH103 as donor parents.
• Utilized a doubled haploid population derived from a cross between japonica (CT9993) and indica (IR62266) accessions.
• Mapped QTL for drought-related traits in the doubled haploid population.
• Phenotyped CSSLs under irrigated and mild drought stress conditions.

Main Results:

• Successfully developed a CSSL population capturing QTL for drought-related traits.
• Identified CSSLs that exhibit improved yield performance under drought stress.
• Demonstrated the successful introgression of beneficial traits from donor parents into the recurrent parent background.

Conclusions:

• The developed CSSL population is a valuable resource for rice breeding programs aiming to enhance drought resilience.
• Introgression of specific chromosome segments can significantly improve yield under drought stress conditions.
• This study provides a foundation for marker-assisted selection and gene pyramiding for drought tolerance in rice.