A high-quality genome of basic citrus species was built up by using a haploid pummelo.The genome was sequenced and assembled by a combination strategy using both short-read(lllumina)and single molecule sequencing data(PacBio long reads).This genome constitutes a valuable source of basic citrus after the recently published genomes of secondary citrus such as sweet orange(Xu et al.2013)and Clementine(Wu et al.2014).Annotation of the genome was performed by strand-specific RNA-Seq reads of leaf,flower,embryo,seed and fruit tissues.All the genome sequence,annotation files and raw data will be deposited from our website http://citrus.hzau.edu.cn/orange/.Recently,we collected a dozen of spontaneous mutant of pummelo(Citrus grandis)from the field,one of which showed distinct phenotype in the fruit pulp,a red-fleshed mutant.The mutant accumulates massive lycopene,and the biosynthetic genes are all functional and the sequences are identical to those from the wild type.A strategy combined genome and bioinformatics to identify the mutant locus was applied and succeeded.The genomic locus was further validated by Sanger-sequencing.This approach provides a fast,convenient,time-saving way to identify mutation locus without the genetic population data.