Unraveling the evolutionary complexity of Lycoris: Insights into chromosomal variation, genome size, and phylogenetic relationships

作者：Xiaochun Shu, Ruisen Lu, J. S. Heslop‐Harrison, Trude Schwarzacher, Zhong Wang, Yalong Qin, Ning Wang, Fengjiao Zhang · 发表于：Acta Botanica Yunnanica · 年份：2025 · DOI：10.1016/j.pld.2025.06.010 · 被引用次数：7 · 研究领域：Chemical synthesis and alkaloids、Botanical Research and Chemistry、Plant and animal studies

Hybridization and polyploidy are key drivers of species diversity and genome variation in Lycoris , but their cytological and evolutionary consequences remain poorly understood. Here, we investigated chromosome numbers and genome sizes in 64 accessions representing the morphological diversity across the genus. Chromosome numbers ranged from 12 to 33, with seven accessions newly identified, including L. chunxiaoensis (2 n = 33), two putative L. guangxiensis (2 n = 19), and five natural hybrids (2 n = 16, 18, 29, 33). Genome sizes varied from 18.03 Gb ( L. wulingensis ) to 32.62 Gb ( L. caldwellii ). Although no significant correlation was found between genome size and chromosome number across all accessions, a strong correlation within ploidy-level groups (i.e., diploid or aneuploid) suggested roles for post-polyploid diploidization, aneuploidy, and dysploidy in speciation. Phylogenetic analyses based on chloroplast genomes and nuclear DNA sequences revealed significant discordance, indicating a complex reticulate evolution and historical hybridization, which may complicate morphological classification. Chromosome number aligned more closely with morphological groups, underscoring the necessity of integrating cytological, molecular, and morphological data for accurate taxonomy, particularly in large-genome taxa. Based on this evidence, we propose a putative speciation pathway involving multiple hybridization and polyploidization events, with allopolyploidy playing a predominan...