Bosheng Li from the Institute of Advanced Agricultural Sciences of Peking University in China presented at London Calling 2024. The session’s title was “Plant T2T genome assembly using ultra-long and adaptive nanopore sequencing.” They spoke about the importance of ultra-long reads. These reads produce N50 length >100 kb. These are crucial in the assembly of plant genomes. Li and the team improved DNA extraction. The key, Li said, was to obtain high-quality nuclei. Younger tissues seemed to produce longer DNA fragments after their extraction system. Improvements in library preparation were made to sequence wheat. Most reads were above 100 kb in length! In the case of ultra-long reads in pepper sequencing, four flow cells were used. These helped assemble this genome. Other sequencing technologies were used as well. Li explained that they obtained a 5 Mb read in one case! Adaptive sampling was used to fill in gaps in sequence read depth. Adaptive sampling read coverage was used in Arabidopsis thaliana sequencing and assembly. Adaptive sampling and long-reads were needed to fill in the gaps.
