» Articles » PMID: 36909446

A Chromosome-level Genome Assembly of an Early Matured Aromatic Rice Variety Qigeng10 to Accelerate Rice Breeding for High Grain Quality in Northeast China

Overview
Journal Front Plant Sci
Date 2023 Mar 13
PMID 36909446
Authors
Affiliations
Soon will be listed here.
Abstract

Early-matured aromatic rice from the Northeast is the most popular rice commodity in the Chinese market. The Qigeng10 (QG10) was one of the varieties with the largest planting area in this region in recent years. It was an early-matured rice variety with a lot of superior traits such as semi-dwarf, lodging resistance, long grain, aromatic and good quality. Therefore, a high-quality assembly of Qigeng10 genome is critical and useful for japonica research and breeding. In this study, we produced a high-precision QG10 chromosome-level genome by using a combination of Nanopore and Hi-C platforms. Finally, we assembled the QG10 genome into 77 contigs with an N50 length of 11.80 Mb in 27 scaffolds with an N50 length of 30.55 Mb. The assembled genome size was 378.31Mb with 65 contigs and constituted approximately 99.59% of the 12 chromosomes. We identified a total of 1,080,819 SNPs and 682,392 InDels between QG10 and Nipponbare. We also annotated 57,599 genes by the Ab initio method, homology-based technique, and RNA-seq. Based on the assembled genome sequence, we detected the sequence variation in a total of 63 cloned genes involved in grain yield, grain size, disease tolerance, lodging resistance, fragrance, and many other important traits. Finally, we identified five elite alleles ( , , , , and ) controlling long grain size, four elite alleles ( , , , and ) controlling cold tolerance, three non-functional alleles ( , , and ) for early heading, two resistant alleles ( and ) for rice blast, a resistant allele for rice stripe virus, an allele for higher nitrate absorption activity, an elite allele for stronger culms, and the typical aromatic gene for fragrance in QG10. These results not only help us to better elucidate the genetic mechanisms underlying excellent agronomic traits in QG10 but also have wide-ranging implications for genomics-assisted breeding in early-matured fragrant rice.

References
1.
Du H, Yu Y, Ma Y, Gao Q, Cao Y, Chen Z . Sequencing and de novo assembly of a near complete indica rice genome. Nat Commun. 2017; 8:15324. PMC: 5418594. DOI: 10.1038/ncomms15324. View

2.
Liu X, Lin F, Wang L, Pan Q . The in silico map-based cloning of Pi36, a rice coiled-coil nucleotide-binding site leucine-rich repeat gene that confers race-specific resistance to the blast fungus. Genetics. 2007; 176(4):2541-9. PMC: 1950653. DOI: 10.1534/genetics.107.075465. View

3.
Li Y, Fan C, Xing Y, Jiang Y, Luo L, Sun L . Natural variation in GS5 plays an important role in regulating grain size and yield in rice. Nat Genet. 2011; 43(12):1266-9. DOI: 10.1038/ng.977. View

4.
Doi K, Izawa T, Fuse T, Yamanouchi U, Kubo T, Shimatani Z . Ehd1, a B-type response regulator in rice, confers short-day promotion of flowering and controls FT-like gene expression independently of Hd1. Genes Dev. 2004; 18(8):926-36. PMC: 395851. DOI: 10.1101/gad.1189604. View

5.
Lu R, Liu J, Wang X, Song Z, Ji X, Li N . Chromosome-Level Genome Assembly of a Fragrant Rice Cultivar 'Changxianggeng 1813' Provides Insights into Genomic Variations between Fragrant and Non-Fragrant Rice. Int J Mol Sci. 2022; 23(17). PMC: 9456513. DOI: 10.3390/ijms23179705. View