Cytotaxonomy of Allium (Amaryllidaceae) subgenera Cyathophora and Amerallium sect. Bromatorrhiza

Abstract

In the present study, we examined the karyotype data of subg. Cyathophora and sect. Bromatorrhiza, to determine some disputed karyotypes (e.g., A. spicatum and A. fasciculatum), and further to estimate the karyotype evolution along their phylogenetic frameworks. Our results revealed a fairly stable basic chromosome number (x = 8) in subg. Cyathophora, and we therefore revised x = 8 as the basic chromosome number of A. spicatum, rather than x = 10 mostly due to misidentifications concerning A. fasciculatum. The karyotype asymmetry analyses for subg. Cyathophora indicated that, the karyotype evolution for diploid species showing a high karyotype similarity was mainly due to intrachromosomal changes, while the interchromosomal changes were linked to the evolution of tetraploid populations. However, indeed different dysploid basic chromosome numbers (x = 7, 10, 11) and greatly different karyotype patterns occurred in sect. Bromatorrhiza, corresponding to the subsections revealed by molecular evidence. The combined evidence suggested that species with x = 11 compose a segmental allotriploid complex. It was also indicated that karyotype pattern of polyploids usually is closely related with their diploid progenitors.

Comparative Analysis of the Complete Chloroplast Genomes in Allium Subgenus Cyathophora (Amaryllidaceae): Phylogenetic Relationship and Adaptive Evolution

“…farreri, and A. spicatum, while A. kingdonii and A. trifurcatum did not belong to this group. Micromorphological and cytological features supported that the subgenus Cyathophora is a monophyly and contains five species [5,6]. Among species of the subgenus Cyathophora, A. spicatum grows in the droughty western QTP with the extremely abnormal spicate inflorescence [3], while A. cyathophorum and A. cyathophorum var.…”

Comparative Analysis of the Complete Chloroplast Genomes in Allium Section Bromatorrhiza Species (Amaryllidaceae): Phylogenetic Relationship and Adaptive Evolution

“…Bromatorrhiza species while in A. trifurcatum , A. cyathophorum , and A. cyathophorum var. farreri , x = 8 [ 20 , 21 , 22 , 23 , 24 ]. Meanwhile, A. cyathophorum var.…”

Evolutionary origin of a tetraploid Allium species on the Qinghai–Tibet Plateau

“…Cyathophora , and those between A. cyathophorum and the other three diploid species. Given the tetraploid state (2 n = 4 x = 32) of A. tetraploideum (Li et al, 2017), we expected the phylotranscriptomics of subg. Cyathophora (Rabier et al, 2014) to provide evidence for the genomic heterogeneity of A. tetraploideum .…”

“…It occurs at altitudes ranging from 3100 and 3700 m on the eastern Qinghai–Tibet Plateau (QTP) (Figure 1a,b) (Li et al, 2019), a region with numerous endemic species (Liang et al, 2018). Two closely related diploid species (2 n = 2 x = 16), Allium cyathophorum and A. farreri , occur to the southwest and northeast respectively, with little or no range overlap (Figure 1b), while two other diploids, Allium mairei (this also has tetraploid lineages; Li et al, 2017) and A. spicatum , occur farther south and west, respectively (Figure 1a). These five species constitute a well‐supported clade, known as Allium subg.…”