Quantitative Trait Locus Mapping and Candidate Gene Identification for Fruit Acidity in Chinese Dwarf Cherry (Cerasus...

Area of Science:

• Plant genetics
• Fruit breeding
• Agricultural science

Background:

• Chinese dwarf cherry (Cerasus humilis) is a valuable endemic fruit crop in China.
• Current varieties are often too acidic for fresh consumption, limiting market potential.
• Developing low-acid varieties is crucial for expanding C. humilis utilization.

Purpose of the Study:

• To identify genetic loci associated with fruit titratable acidity in C. humilis.
• To develop high-density genetic maps for C. humilis.
• To discover candidate genes involved in regulating fruit acidity.

Main Methods:

• Restriction site-associated DNA sequencing (RAD-seq) for SNP marker development.
• Construction of a high-density genetic linkage map.
• Quantitative trait locus (QTL) mapping using two years of phenotypic data.

Main Results:

• A high-quality genetic map with 2491 SNP markers across eight linkage groups was constructed.
• Eighteen loci, including 11 major-effect QTLs, were significantly associated with fruit titratable acidity.
• Two candidate genes, including a phosphatase, were identified within QTL intervals, with one showing strong correlation with acidity.

Conclusions:

• This study provides valuable genetic resources for marker-assisted breeding of low-acid C. humilis.
• Findings facilitate the development of consumer-preferred, fresh-eating varieties.
• The research supports the commercial promotion and industrial development of Chinese dwarf cherry.