Genomics and genetic improvement in main bast fiber crops: advances and perspectives

Abstract

With the development of sequencing technology, main bast fiber crops (jute, kenaf, ramie, flax, and hemp) have completed genome sequencing from 2011 to 2020, which marks that the science of bast fiber crops has entered the era of genome. Firstly, this paper reviews the genome sequencing of bast fiber crops. Secondly, the important gene identification of bast fiber crops is also reported. Based on reference genome and transcriptome sequencing, a large number of candidate genes related to fiber development and response to abiotic stress have been detected, corresponding to the species characteristics of bast fiber and the adversity agriculture of "not competing with food". Meanwhile, candidate genes for specific bast fiber crops have also been identified, such as male fertility in kenaf, seed oil content in flax, cannabinoid related candidate genes. Thirdly, the completion of bast fiber crop genome sequencing provides the possibility of omics-based genetic improvement, which will facilitate to study the formation of bast fiber and evolution mechanisms of bast fiber crop germplasms and systematically analyze the molecular basis for the formation of agronomic traits such as fiber yield, fiber quality, disease resistance, and stress tolerance. Also, it will facilitate to establish a high-throughput genotype-phenotype database, mine excellent gene resources, and create new germplasm. Moreover, it will facilitate to establish efficient rapid breeding technology systems by the innovation and combination of molecular marker-assisted selection, genome selection, transgenic technology and so on. To meet the market demand particularly bast fiber crop-related industries and adapt to the production model of bast fiber crops, we should breed new bast fiber crop varieties with high yield, high efficiency, stress resistance, disease resistance, suitable for light simplification and mechanization cultivation, high quality, and special purpose. Although the important information of gene resources and loci has been obtained from the reference genomes, there are still a series of challenges that how to utilize the existing resources efficiently for genetic improvement of bast fiber crops, such as stable and efficient genetic transformation system, construction of gene editing system, and genome selection breeding.