Department of Biology, University of Waterloo, Waterloo, ON, Canada.
Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan.
Methods Mol Biol. 2023;2703:161-171. doi: 10.1007/978-1-0716-3389-2_12.
A brief overview to the Index to Chromosome Numbers in Asteraceae database is provided. The database contains karyological information on Asteraceae and has been repeatedly improved and updated and is now hosted at the National Bioscience Database center. Also, we take the opportunity to revisit the evolution of base chromosome numbers in Asteraceae, emphasizing the phenomena of polyploidy, descending dysploidy, and hybridization, common in the family. Chromosome numbers for species included in one of the most recent phylogenetic treatments of the Asteraceae were obtained from the Index to Chromosome Numbers in Asteraceae database were mapped on to the modified phylogeny diagram, and base chromosome numbers were determined for each branch of the phylogeny. Results for tribal base numbers were the same as those hypothesized in our previous work with additional base numbers added for tribes not previously recognized but supported by newer phylogenetic methods. The Asteraceae show an ancestral base chromosome number of x = 9 and originated in the Antarctica (Gondowanaland) in Cretaceous (80 Mys ago). The x = 9 number has been retained through successive South American lineages of the Barnadesieeae, Gochnatieae, Stiffieae, Wunderlichieae, Astereae, and Senecioneae following northward migration. Northward migration to Africa was accompanied with x = 10 becoming the dominant base chromosome number as the family evolved multiple additional tribes. Northward migration to Australasia with x = 9 was in Astereae and the families Goodeneaseae, Menyanthaceae, and Stylydiaceae. The evolution of the North American Heliantheae alliance began with the appearance of x = 19 which persisted in multiple additional new tribes. Frequent dysploidy decreases, polyploidy and hybridization occurred throughout the history of the family.
简要概述了菊科染色体数目索引数据库。该数据库包含菊科的核型学信息，经过多次改进和更新，现在由国家生物科学数据库中心托管。此外，我们借此机会重新审视了菊科基本染色体数的进化，强调了多倍体、下降的非整倍体和杂交等现象，这些现象在该科中很常见。从菊科最近的系统发育处理之一包含的物种的染色体数目从菊科染色体数目索引数据库中获得，映射到修改后的系统发育图上，并确定了系统发育树每个分支的基本染色体数目。部落基数的结果与我们之前的工作假设相同，在之前未被识别但被更新的系统发育方法支持的部落中增加了额外的基数。菊科的原始基本染色体数为 x = 9，起源于白垩纪（8000 万年前）的南极洲（冈瓦纳大陆）。在向北迁移的过程中，Barnadesieeae、Gochnatieae、Stiffieae、Wunderlichieae、Astereae 和 Senecioneae 等南美连续谱系保留了 x = 9 的数字。随着家族进化出多个额外的部落，x = 10 成为主导的基本染色体数，非洲向北迁移也伴随着这种情况。随着 x = 9 向北迁移到澳大利亚，菊科、Goodeneaseae、Menyanthaceae 和 Stylydiaceae 家族也随之迁移。北美的 Heliantheae 联盟的进化始于 x = 19 的出现，该数字在多个额外的新部落中得以保留。整个家族的历史中，非整倍体减少、多倍体和杂交频繁发生。
