Development and Application of KASP Markers for Candidate Glucosinolate Biosynthesis Genes in Broccoli

Area of Science:

• Plant genetics
• Agricultural science
• Biochemistry

Background:

• Broccoli (Brassica oleracea) contains glucosinolates (GSLs), vital for plant defense and human health.
• Optimizing aliphatic GSL composition is a key breeding goal, but effective molecular markers are scarce.

Purpose of the Study:

• To develop and validate candidate gene-based kompetitive allele-specific PCR (KASP) markers for marker-assisted selection (MAS) of GSLs in broccoli.
• To identify robust markers for major aliphatic GSLs, specifically targeting AOP2 and GSL-OH.

Main Methods:

• Developed KASP markers from 19 GSL biosynthesis genes, focusing on AOP2 and GSL-OH.
• Evaluated marker-trait associations in natural and F2 broccoli populations.
• Utilized ROC analysis and GLM/MLM frameworks for validation.

Main Results:

• Marker S101 (AOP2) demonstrated consistent genotype-dependent effects on GNA and PRO content across populations.
• S101 showed strong classification performance for high- and low-GSL genotypes.
• Other markers (S074, S035) exhibited population-dependent associations.

Conclusions:

• Candidate gene-based KASP markers, particularly S101, hold significant potential for marker-assisted selection to enhance broccoli's aliphatic GSL profile.
• This approach can accelerate breeding programs for improved GSL content in broccoli.