Whole‐genome sequencing of allotetraploid bermudagrass reveals the origin of Cynodon and candidate genes for salt tolerance

作者：Huan Wang, Tilin Fang, Xiaoning Li, Xie Yan, Wei Wang, Hu Tao, David Kudrna, Erick Amombo, Yanling Yin, Shugao Fan, Zhiyun Gong, Yicheng Huang, Chunjiao Xia, Jianwei Zhang, Yanqi Wu, Jinmin Fu · 发表于：The Plant Journal · 年份：2024 · DOI：10.1111/tpj.16729 · 被引用次数：26 · 研究领域：Turfgrass Adaptation and Management、Plant Taxonomy and Phylogenetics、Genomics and Phylogenetic Studies

Bermudagrass (Cynodon dactylon) is a globally distributed, extensively used warm-season turf and forage grass with high tolerance to salinity and drought stress in alkaline environments. However, the origin of the species and genetic mechanisms for salinity tolerance in the species are basically unknown. Accordingly, we set out to study evolution divergence events in the Cynodon genome and to identify genes for salinity tolerance. We developed a 604.0 Mb chromosome-level polyploid genome sequence for bermudagrass 'A12359' (n = 18). The C. dactylon genome comprises 2 complete sets of homoeologous chromosomes, each with approximately 30 000 genes, and most genes are conserved as syntenic pairs. Phylogenetic study showed that the initial Cynodon species diverged from Oropetium thomaeum approximately 19.7-25.4 million years ago (Mya), the A and B subgenomes of C. dactylon diverged approximately 6.3-9.1 Mya, and the bermudagrass polyploidization event occurred 1.5 Mya on the African continent. Moreover, we identified 82 candidate genes associated with seven agronomic traits using a genome-wide association study, and three single-nucleotide polymorphisms were strongly associated with three salt resistance genes: RAP2-2, CNG channels, and F14D7.1. These genes may be associated with enhanced bermudagrass salt tolerance. These bermudagrass genomic resources, when integrated, may provide fundamental insights into evolution of diploid and tetraploid genomes and enhance the efficacy of c...