Genetic diversity of six Amorphophallus species in Southwest China based on cpDNA sequences

Abstract

Investigating mechanisms underlying genetic variation and differentiation of wild resources is critical for the utilization and improvement of crop germplasms. Amorphophallus species is an important economic crop in Southwest China for its glucomannan production. However, the wild populations of this genus are declining due to human activities. To investigate the genetic diversity and phylogenetic relationship of representative Amorphophallus species in Southwest China, the phylogenetic relationships between species were reconducted by using three chloroplast DNA (cpDNA) fragments and analyzing genetic diversity of six Amorphophallus species. The results were as follows: (1) The genetic diversity of wild Amorphophallus populations was generally low with an average haplotype diversity (Hd) of 0.428. In addition, nearly half of the total populations had only one haplotype. The haplotype diversity of each species varied from 0.704 to 0.983. (2) The genetic differentiation between each pair of six species was relatively high, and the genetic differentiation coefficient (FST) values ranged from 0.481 to 0.967. (3) The phylogenetic analysis suggested that 27 selected Amorphophallus species should be mainly divided into three clades Africa clade, Southeast Asia clade, and East Asian continent clade. A. paeoniifolius belonged to the Southeast Asia clade. The East Asian continent A clade included A. konjac and A. krausei, and East Asian continent B clade was comprised of A. kiusianus, A. yunnanensis and A. tonkinensis. Geographic isolation and human disturbance could have caused the low genetic diversity in wild populations of Amorphophallus. The divergence of the East Asian continent clade may be driven by the rapid radiation and ecological adaptation in species of this clade. These findings provide theoretical guidance for the conservation, sustainable utilization and breeding of Amorphophallus species in Southwest China.

Keywords

• southwest china
• amorphophallus
• genetic diversity
• phylogeny
• species conservation