Cytogeography of the East Asian Tulips (Amana, Liliaceae)

Abstract

Amana Honda (Liliaceae), known as ‘east Asian tulips’, is a spring ephemeral genus endemic to Sino-Japanese Floristic Subregion, mainly distributed in eastern and central China, Japan and the Korean peninsula. Chromosome numbers are reported here for the first time from 89 populations of Amana (representing all seven accepted species, two new species about to be published, and two suspected new species). Three ploidy levels are found in this genus. These are diploid (2n = 2x = 24) and tetraploid (2n = 4x = 48) in the widespread A. edulis, while all the narrow endemics are diploid, except for one population of A. tianmuensis, which is triploid (2n = 3x = 36). The northernmost and southernmost populations of A. edulis are diploid and tetraploid, respectively, while diploids and tetraploids coexist in between, with gradual transition to diploids as the latitude increases. This may indicate polyploids have an advantage in tolerance of environmental stress and are more adaptable to high-temperature environment in subtropical regions than diploids. The species and cytotype distributions in Amana are complex, and these results provide hypotheses about the origins of the genus and the polyploid cytotypes.

Species delimitation in Amana (Liliaceae): transcriptomes battle with evolutionary complexity

“…Polyploidization is the third adaptive strategy and tetraploidy is more common in the widespread A. edulis populations at lower latitudes or altitudes. Contrary to the conclusion that polyploidization increases cold tolerance and environmental adaptability (Husband et al, 2013;Paule et al, 2017), polyploids in A. edulis seem to have better tolerance to high temperature in subtropical regions than diploids, similar to the situation in Solidago canadensis (Cheng et al, 2021;Wu et al, 2022). Generally speaking, A. edulis is the most successful species in this genus.…”

“…Both levels existed in A. edulis , whereas other species are all diploid, except for one population of A. tianmuensis (triploid, 2 n = 3x = 36). With decreasing latitude, A. edulis gradually transitions from diploid to tetraploid populations (Wu et al., 2022).…”

“…Based on Wu's report (Wu et al, 2022), complete chromosomal information was updated for all 12 Amana species that included 11 new samples from Anhui, Henan, Hubei and Hunan provinces in 2022 (Table S9). Root tips (c. 2 mm) were taken to make squashed tablet for chromosome observation.…”

“…Amana is a genus of Liliaceae endemic to East Asia that comprises at least 10 currently recognized species (Honda, 1935;Ohwi, 1965;Shen, 2001;Tan et al, 2007Tan et al, , 2008Han et al, 2014;Wang et al, 2019Wang et al, , 2022Wang et al, , 2023. All of the species are spring ephemerals and inhabit temperate deciduous or subtropical evergreen broadleaved/mixed forests (Li et al, 2017;Wu et al, 2022;Wang et al, 2023). Amana edulis (Miq.)…”

Characteristics and Evolution of Leaf Epidermis in the Genus Amana Honda (Liliaceae)

“…These shifts observed in these epidermal characteristics may be related to their living environment. Amana are spring ephemerals; this is a life strategy in which plants appear quickly in the early spring and complete their life cycle before canopy closure [26]. This rapid growth cycle requires high nutrient accumulation, which requires high photosynthetic efficiency.…”