TEA5K: a high-resolution and liquid-phase multiple-SNP array for molecular breeding in tea plant

Area of Science:

• Plant genetics
• Genomics
• Molecular breeding

Background:

• High-throughput genotyping is crucial for plant molecular breeding and genetic research.
• Liquid-phase array genotyping uses nanomagnetic beads and biotinylated probes for target DNA capture.
• Existing methods need novel tools for comprehensive tea plant genetic analysis.

Purpose of the Study:

• Develop a novel liquid-phase genotyping array for tea plants.
• Enable cultivar identification, genetic map construction, and QTL analysis.
• Analyze population structure and phylogenetic relationships in tea germplasm.

Main Methods:

• Developed the TEA5K mSNP array with 5,781 liquid-phase probes using the Genotyping by Target Sequencing (GBTS) system.
• Genotyped 231 tea cultivars and 519 tea germplasm accessions.
• Constructed a high-density genetic map and performed population structure and phylogenetic analyses.

Main Results:

• TEA5K mSNP array accurately distinguished tea cultivars with high intra- and low inter-cultivar similarity.
• A high-density genetic map (3,274 markers, 2,225.19 cM) was constructed, facilitating QTL identification for amino acids and the albino-leaf trait.
• Population structure analysis revealed three main groups (wild, landraces, modern cultivars) with lower diversity in modern cultivars and limited gene flow from wild relatives, indicating an improvement bottleneck.

Conclusions:

• The TEA5K mSNP array is a versatile, cost-effective genotyping tool for tea plant research and breeding.
• It provides a robust platform for genome-wide analysis, aiding in the identification of key QTLs.
• The array offers valuable insights for enhancing genetic diversity and agronomic traits in tea cultivars.