Lycium is the only member of tribe Lycieae (Solanoideae, Solanaceae), and it has a cosmopolitan distribution with its greatest diversity in southern South America, southern Africa, and southwestern North America. To date, there has been no attempt to synthesize and evaluate the significance of the available cytogenetical data from a phylogenetic perspective, which is the objective of this study. Firstly, new data on 27 taxa from all its range of distribution (FISH in all of them, banding in 23, Feulgen technique in 14) were provided to fill gaps in the information. The chromosome numbers of L. australe, L. humile, and L. repens were recorded for the first time. Species showed x = 12 with different ploidy levels (mostly diploid or tetraploid), small chromosomes, and symmetrical karyotypes. Lycium fremontii and L. repens were outstanding for having the highest numbers reported for the genus: 10x and 11x, respectively. North American species showed comparatively longer chromosomes. Secondly, cytogenetical traits were mapped on a phylogenetic tree, using character mapping and ancestral states reconstruction, to understand the dynamics of the evolutionary changes. The main cytotaxonomical features were included: chromosome number, presence of polyploidy, total length of the haploid chromosome set, mean chromosome length, karyotype formula, A₁ and A₂ asymmetry indices, percentage of heterochromatin, number of CMA⁺/DAPI⁻ NORs bands, and number and position of 5S and 18S‐5.8S‐26S sites. The mean chromosome length, total haploid chromosome length, number of 18S‐5.8S‐26S loci, number of CMA⁺/DAPI⁻ NORs bands underwent comparatively few transitions compared with the ploidy level and number of 5S loci. The mapping of the characters on the phylogenetic tree showed that the most probable ancestral chromosome number was 2n = 24 with several independent polyploidization events and one pair of each rDNA locus. The most likely ancestral condition for the genus would be: diploid, with small chromosomes, scarce heterochromatin, asynteny of rDNA loci, and one pair of both 18S‐5.8S‐26S and 5S loci.

中文翻译：

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大都会属枸杞（茄科）的染色体进化

枸杞是枸杞科（茄科，茄科）的唯一成员，它具有国际化的分布，在南美南部，南部非洲和西北西南地区具有最大的多样性。迄今为止，还没有尝试从系统发育的角度综合和评估可用细胞遗传学数据的重要性，这是本研究的目的。首先，提供了来自其所有分布范围的27个分类单元的新数据（全部中的FISH，23条中的带，14中的Feulgen技术），以填补信息中的空白。首次记录了澳大利亚乳杆菌（L. australe），人类乳杆菌（L. humile）和白杨乳杆菌（L. repens）的染色体数。物种显示x =12种具有不同的倍性水平（主要是二倍体或四倍体），小的染色体和对称的核型。fremontii枸杞和L. repens因其属报道的最高数量而杰出：分别为10 x和11 x。北美物种显示出相对较长的染色体。其次，通过特征映射和祖先状态重建将细胞遗传学特征映射到系统树上，以了解进化变化的动态。主要的细胞分类学特征包括：染色体数目，多倍性的存在，单倍体染色体组的总长度，平均染色体长度，核型公式，A ₁和A ₂不对称指数，异染色质百分比，CMA ⁺ / DAPI ^- NOR谱带数量以及5S和18S-5.8S-26S位点的数量和位置。平均染色体长度，总单倍体染色体长度，18S-5.8S-26S位点数量，CMA ⁺ / DAPI ^- NORs条带数量与五倍体水平和5S位点数量相比，发生的转变相对较少。系统发育树上这些字符的映射表明，最可能的祖先染色体数为2 n =24个，有多个独立的多倍体化事件，每个rDNA位点有一对。该属最可能的祖先条件是：二倍体，染色体小，异染色质稀少，rDNA基因座无序，以及一对18S-5.8S-26S和5S基因座。