Phylogenomic study of Amorphophallus (Alismatales; Araceae): When plastid DNA gene sequences help to resolve the backbone subgeneric delineation

Abstract

Encompassing ca. 200 species distributed in paleotropical Africa and Asia, Amorphophallus is one of the largest genera of Araceae. In spite of the great economic interest in its glucomannan production, only a few studies have attempted to grasp the evolutionary history of this genus. In the current state of knowledge, four main clades, mostly linked to biogeographical delineation, have been identified from phylogenies based on a few genes. However, relationships among and within these clades still remain unclear, due to the rapid radiation that occurred during the early evolutionary history of the genus. Here, we generated genome skimming libraries for 43 specimens from 36 species distributed across the 4 clades, which allowed us to produce a phylogenetic matrix for a set of 71 plastid genes. Our phylogenies confirm the monophyly of these clades but show a new and well‐resolved arrangement among these clades. Our analyses therefore provide a new scenario and timeline for the evolution of the main Amorphophallus clades, consistent with the morphological characteristics of the clades. The inferred scenario is also in agreement with climate dynamics and the onset of long‐distance dispersal by the earliest migratory birds near the Oligocene/Miocene transition around 23 million years ago. Our study provides an up‐to‐date baseline to understand biogeographic and ecological processes that shaped the current diversity and distribution of Amorphophallus, paving the way for larger‐scale phylogenomic studies based on plastid and nuclear genomes.

Patterns and drivers of heat production in the plant genus Amorphophallus

“…Hence, although the monophyly of each of the four subgenera is well supported, their relationship with one another remains inconclusive, a result encountered in most previous studies (Claudel et al., 2017; Sedayu et al., 2010) but resolved and discussed in Pouchon et al. (2022).…”

“…and Claudel (Claudel et al., 2017) and currently encompasses 237 species (Boyce & Croat, 2023). The genus Amorphophallus is widely distributed across the Old World tropics (Africa and Australasia) and is morphologically diverse (Claudel et al., 2017; Hetterscheid & Ittenbach, 1996; Pouchon et al., 2022) (Figure 1).…”

A high trans-zeatin nucleoside concentration in corms may promote the multileaf growth of Amorphophallus muelleri

“…The pearl-bud type of konjac refers to a group of konjacs that can produce pearl-shaped aerial reproductive corms on the leaf surface (at the intersection of leaf veins). This type of konjac is represented by Amorphophallus muelleri, which has the same biogeographic distribution as A. konjac (the current main cultivar in Asia); however, A. muelleri and A. konjac belong to different clades on phylogenetic trees, the Continental Asia I and Continental Asia II clades, respectively (Pouchon et al, 2022).…”

“…Konjac is a common name for a genus of Amorphophallus in the family Araceae. Amorphophallus plants are perennial geophytes that usually consist of an underground corm, which is the main source of glucomannan ( Zhang and Wang, 2010 ; Pouchon et al., 2022 ). Konjac glucomannan (KGM) is a natural polymer polysaccharide with strong water absorption, a high swelling rate and a low caloric value, so it has various beneficial pharmacological effects, including weight loss, antidiabetic and antioxidant properties ( Devaraj et al., 2018 ).…”

“…This type of konjac is represented by Amorphophallus muelleri , which has the same biogeographic distribution as A . konjac (the current main cultivar in Asia); however, A. muelleri and A. konjac belong to different clades on phylogenetic trees, the Continental Asia I and Continental Asia II clades, respectively ( Pouchon et al., 2022 ). A. muelleri has the characteristic of multiple leaves growing sequentially that together feed one corm.…”