西南地区 6 种魔芋属植物基于 cpDNA 序列的遗传多样性研究

Investigating mechanisms underlying genetic variation and differentiation of wild resources is critical for the utilization and improvement of crop germplasms. Amorphophallus 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, three chloroplast DNA fragments were amplified and used to conduct population genetic and phylogenetic studies. 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 FST values ranged from 0.481 to 0.967. (3) The phylogenetic inference suggested that 27 selected Amorphophallus species should be divided into three clades. A. paeoniifolius belonged to the Southeast Asia clade. The continental Asia A clade included A. konjac and A. krausei, and continental Asia 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 continental Asia clade may be driven by the rapid radiation and ecological adaptation in species of this clade. These findings provide theoretical guidance for the conservation, utilization and breeding of Amorphophallus species in Southwest China.