Genomic-Assisted Marker Development Suitable for CsCvy-1 Selection in Cucumber Breeding

Area of Science:

• Plant Pathology
• Molecular Genetics
• Agricultural Science

Background:

• Cucumber is a vital crop susceptible to Cucumber Vein Yellowing Virus (CVYV), causing significant economic losses globally.
• CVYV is transmitted by whiteflies and poses challenges for cucumber cultivation, necessitating resistant varieties.
• Existing resistance sources for CVYV in cucumber are limited, and associated molecular markers are scarce, hindering breeding efforts.

Purpose of the Study:

• To develop novel, marker-assisted selection (MAS)-friendly Kompetitive Allele Specific PCR (KASP) markers for the CsCvy-1 gene in cucumber.
• To fine-map the genomic region associated with CVYV resistance in cucumber.
• To provide valuable SNP data for accelerating the breeding of CVYV-resistant cucumber lines.

Main Methods:

• Utilized genomics and bulked segregant analysis (BSA) on an F2 mapping population and commercial lines.
• Generated single-nucleotide polymorphism (SNP)-based markers through variant analysis for mapping and genotyping.
• Fine-mapped the target genomic region using newly developed markers, narrowing it down to 101 kb.

Main Results:

• Successfully developed MAS-friendly KASP markers for efficient selection of the CsCvy-1 resistance locus.
• Fine-mapped the resistance region to a 101 kb interval containing eight genes.
• Generated comprehensive SNP data for the identified interval, facilitating marker-assisted breeding.

Conclusions:

• The developed KASP markers are effective for selecting CsCvy-1 in cucumber breeding programs.
• The fine-mapped genomic region and SNP data provide a foundation for identifying candidate genes and cloning the resistance gene.
• This research contributes to developing cucumber varieties with improved resistance to CVYV, enhancing crop security.