Homogenized Phylogeographic Structure across the Indo-Burma Ranges of a Large Monoecious Fig, Ficus altissima Blume

Jian-Feng Huang,Yan-Qiong Peng,Clive T Darwell

doi:10.3390/d13120654

Abstract

As well as bountiful natural resources, the Indo-Burma biodiversity hotspot features high rates of habitat destruction and fragmentation due to increasing human activity; however, most of the Indo-Burma species are poorly studied. The exploration of plants closely associated with human activity will further assist us to understand our influence in the context of the ongoing extinction events in the Anthropocene. This study, based on widely and intensively sampled F. altissima across Indo-Burma and the adjacent south China ranges, using both the chloroplast psbA-trnH spacer and sixteen newly developed nuclear microsatellite markers (nSSRs), aims to explore its spatial genetic structure. The results indicated low chloroplast haplotype diversity and a moderate level of nuclear genetic diversity. Although limited seed flow was revealed by psbA-trnH, no discernible phylogeographic structure was shown due to the low resolution of cpDNA markers and dominance of an ancestral haplotype. From the nSSRs data set, phylogeographic structure was homogenized, most likely due to extensive pollen flow mediated by pollinating fig wasps. Additionally, human cultivation and human-mediated transplanting further confounded the analyses of population structure. No geographic barriers are evident across the large study range, with F. altissima constituting a single population, and extensive human cultivation is likely to have had beneficial consequences for protecting the genetic diversity of F. altissima.

Highlights

As one of the 34 identified global biodiversity hotspots [1], Indo-Burma, coveringBurma, Thailand, Laos, Cambodia, and Vietnam, as well as parts of southern China, northeast India, and Bangladesh, harbours great diversity in both plants and animals
The endemic species’ ecological and evolutionary trajectories were strongly influenced by plate tectonics, climatic oscillations, river system dynamics, sea level fluctuations, shifting coastlines, and human activity [2,3,4,5]
Our results showed relatively high genetic diversity in many populations sampled from Dai villages (e.g., Nah, Che, Chi) and disturbed urban areas (e.g., Mas, Rui, Don, Pin)

Summary

Introduction

As one of the 34 identified global biodiversity hotspots [1], Indo-Burma, coveringBurma, Thailand, Laos, Cambodia, and Vietnam, as well as parts of southern China, northeast India, and Bangladesh, harbours great diversity in both plants and animals. As one of the 34 identified global biodiversity hotspots [1], Indo-Burma, covering. The biodiversity of the Indo-Burma region is severely threatened by factors such as human population growth, deforestation and habitat conversion, resource exploitation, pollution, and global warming [6,7,8]. Our knowledge about the underlying genomic structures (e.g., population structure, phylogeography, cryptic diversity) among Indo-Burma flora and fauna is extremely poor, mainly due to political instability and lack of infrastructure during long periods of the 20th century in many parts of this region [9,10]. The conditions that prevented the researchers from entering large parts of Indo-Burma to explore the biodiversity have been improved along with the general development in this region.

Objectives

Methods

Findings

Discussion

Conclusion