Zhang Yue, Zhou Shujun, Chen Yu, Zhang Pengchong, Zhang Yongchun, Cai Junhuo, Nie Zixuan, Zhang Lu
Jiangxi Provincial Key Laboratory of Subtropical Forest Resources Cultivation, 2011 Collaboration Innovation Center of Jiangxi Typical Trees Cultivation and Utilization, Jiangxi Agricultural University, Nanchang, Jiangxi, 330045, China.
Institute of Landscape Science and Technology, Nanchang Landscaping Service Center, Nanchang, 330000, China.
BMC Plant Biol. 2025 Jan 21;25(1):78. doi: 10.1186/s12870-025-06112-w.
Frequent interspecific hybridization, unclear genetic backgrounds, and ambiguous evolutionary relationships within the genus Lycoris pose significant challenges to the identification and classification of hybrids, thereby impacting the application and development of Lycoris. This study utilizes karyotype structure, genome size, and fluorescent in situ hybridization (FISH) technology to explore the chromosomal evolution and hybrid identification of Lycoris employing three approaches at the cytogenetic level.
The findings indicate that species with a smaller basic chromosome number exhibit less asymmetry than those with a larger basic chromosome number, suggesting that species with different basic chromosome numbers may have followed different evolutionary pathways. Lycoris aurea has a more symmetrical karyotype, which may be the plesiomorphic state, reflecting an evolutionary transition from symmetry to asymmetry in Lycoris chromosomes. Systematic clustering of 18 Lycoris species is consistent with chromosomal karyotype classification, primarily dividing into two groups: species with M + T + A type an M + T type as one group, and A type as another group. The average nuclear genome size (C-value) of the Lycoris genus is 22.99 Gb, with the smallest genome being that of L. wulingensis (17.10 Gb) and the largest being L. squamigera (33.06 Gb). Chromosome length is positively correlated with the C-value, and the haploid genome size (Cx-value) decreases with an increase in basic chromosome number (x). The FISH technique can quickly identify and authenticate artificial hybrids, thus inferring the parentage of natural hybrids.
The study reveals the genetic background and interspecific relationships of 18 Lycoris species, identifies the authenticity of artificial Lycoris hybrids, and infers the possible parentage of natural hybrids, offering technical insights for the identification, classification, and genomic projects of Lycoris.
石蒜属内频繁的种间杂交、不清楚的遗传背景以及模糊的进化关系给杂种的鉴定和分类带来了重大挑战，从而影响了石蒜属的应用和发展。本研究利用核型结构、基因组大小和荧光原位杂交（FISH）技术，在细胞遗传学水平上采用三种方法探索石蒜属的染色体进化和杂种鉴定。
研究结果表明，基本染色体数较少的物种比基本染色体数较多的物种表现出更低的不对称性，这表明不同基本染色体数的物种可能遵循了不同的进化途径。忽地笑具有更对称的核型，这可能是原始状态，反映了石蒜属染色体从对称到不对称的进化转变。18种石蒜属植物的系统聚类与染色体核型分类一致，主要分为两组：具有M+T+A类型和M+T类型的物种为一组，A类型为另一组。石蒜属的平均核基因组大小（C值）为22.99 Gb，最小的基因组是武陵石蒜（17.10 Gb），最大的是换锦花（33.06 Gb）。染色体长度与C值呈正相关，单倍体基因组大小（Cx值）随着基本染色体数（x）的增加而减小。FISH技术可以快速鉴定和验证人工杂种，从而推断天然杂种的亲本来源。
该研究揭示了18种石蒜属植物的遗传背景和种间关系，鉴定了人工石蒜杂种的真实性，并推断了天然杂种可能的亲本来源，为石蒜属的鉴定、分类和基因组计划提供了技术见解。
