Multiple Variant Calling Pipelines in Wheat Whole Exome Sequencing.

Area of Science:

• Genomics
• Bioinformatics
• Plant Science

Background:

• The hexaploid wheat genome (Triticum aestivum) is complex, yet advancements in reference genomes facilitate understanding trait variation.
• Variant calling in polyploids like wheat presents challenges in tool selection and false-positive filtering compared to diploids.

Purpose of the Study:

• To evaluate the performance of different variant calling pipelines using whole exome sequencing (WES) data in 48 wheat cultivars.
• To determine the impact of various computational methods on variant identification accuracy and reproducibility in polyploid wheat.

Main Methods:

• Whole exome sequencing (WES) was performed on 48 diverse wheat cultivars.
• Multiple variant calling pipelines were assessed using their default settings for read alignment and variant identification.
• Performance metrics including sensitivity and precision were analyzed for raw and filtered SNP calls.

Main Results:

• All assessed variant calling pipelines necessitated post-calling filtering to remove false positives.
• The best-performing pipelines demonstrated high consensus in called SNPs after filtering, indicating reliable results.
• Detailed comparisons revealed varying levels of sensitivity and precision across pipelines for both raw and filtered data.

Conclusions:

• Filtering is essential for accurate and reproducible variant calling in hexaploid wheat whole exome sequencing data.
• The study provides a comparative analysis to guide the selection of optimal variant calling strategies for polyploid wheat genomics.
• Understanding pipeline performance is crucial for leveraging genomic variation in wheat breeding and research.