Construction of Pseudomolecules for the Chinese Chestnut (Castanea mollissima) Genome

• Main Authors: Jinping Wang, Shoule Tian, Xiaoli Sun, Xinchao Cheng, Naibin Duan, Jihan Tao, Guangning Shen
• Format: Article
• Language: English
• Published: Oxford University Press 2020-10-01
• Series: G3: Genes, Genomes, Genetics
• Subjects: chinese chestnut; castanea mollissima blume; genome assembly; single molecular sequencing; high-throughput chromosome conformation capture
• Online Access: http://g3journal.org/lookup/doi/10.1534/g3.120.401532

The Chinese chestnut (Castanea mollissima Bl.) is a woody nut crop with a high ecological value. Although many cultivars have been selected from natural seedlings, elite lines with comprehensive agronomic traits and characters remain rare. To explore genetic resources with aid of whole genome sequence will play important roles in modern breeding programs for chestnut. In this study, we generated a high-quality C. mollissima genome assembly by combining 90× Pacific Biosciences long read and 170× high-throughput chromosome conformation capture data. The assembly was 688.93 Mb in total, with a contig N50 of 2.83 Mb. Most of the assembled sequences (99.75%) were anchored onto 12 chromosomes, and 97.07% of the assemblies were accurately anchored and oriented. A total of 33,638 protein-coding genes were predicted in the C. mollissima genome. Comparative genomic and transcriptomic analyses provided insights into the genes expressed in specific tissues, as well as those associated with burr development in the Chinese chestnut. This highly contiguous assembly of the C. mollissima genome provides a valuable resource for studies aiming at identifying and characterizing agronomical-important traits, and will aid the design of breeding strategies to develop more focused, faster, and predictable improvement programs.