ONT
For ultra-long ONT sequencing, high-molecular weight DNA was extracted using the CTAB method. After quality inspection by NanoDrop One spectrophotometer (NanoDrop Technologies, Wilmington, DE) and Qubit 3.0 Fluorometer (Life Technologies, Carlsbad, CA, USA), we used SQK-ULK001 kit to  prepare a standard library. Sequencing was performed on a PromethION sequencer (Oxford Nanopore Technologies, Oxford, UK).