皖南地区同域分布的两种蛙类景观遗传学比较研究

In this project, we evaluate the relative influence of landscape or environmental factors at different spatial scales on the genetic variation and its spatial distribution of two co-distributed frog species (Oderrana tormota and Hylarana latouchii) with distinct ecological and breeding habits in southern Anhui province using the theories and methods of landscape genetics. We first use three different molecular markers (mtDNA cyt b gene, microsatellite loci and MHC II class B loci) to investigate the level of genetic variation and its spatial distribution within and among populations. Then, we correlate the observed population genetic structure to different landscape or environmental characters at two different but explicitly spatial scales, i.e., at the scale of major rivers with straight line distance larger than 50 km between local populations and at the fine scale with straight line distance less than 2 km. Based on these analyses, we aim to answer the following questions, 1) what are the levels of genetic diversity and the patterns of population genetic structure for both species; 2) How do landscape features and its changes at different spatial scales shape the patterns of population genetic structure and gene flow for both species ? Furthermore, through comparing the similarities and differences in the patterns of landscape genetic structure between the two co-distributed species, we want to determine whether there is any difference in the effects of the same landscape pattern on the genetic structure of different frog species, and which dispersal strategies the two co-distributed frogs will select to response to the same landscape process in the study area? Results of the current project, on one hand, will provide scientific basis for the protection plan to be designed for the concave-eared frog, a rare species endemic to China, and other frogs inhabit in the same area, and possibly frogs in areas with similar landscape features. Additionally, the results will provide valuable evidences for insight into species-specific dispersal pattern in fragmented landscape pattern.

本项目研究皖南地区破碎化景观格局中两种生态和繁殖习性不同的蛙类（凹耳臭蛙和阔褶水蛙）种群遗传结构和基因流模式。利用景观遗传学的理论和方法，基于3种不同的分子标记（mtDNA cyt b基因序列、微卫星和MHC II类B基因位点）检测各斑块种群的遗传变异以及种群间的遗传结构，定量分析不同空间尺度上（水系间和水系内）的景观或环境特征与种群遗传结构之间的相关性。阐明这两种蛙类的遗传多样性水平、种群遗传结构模式及其形成原因；揭示不同空间尺度上影响这两种蛙类扩散的景观或环境因子；通过比较同域分布的两种蛙类遗传结构和基因流模式，探讨相同景观格局对不同物种的遗传效应是否存在差异，以及不同蛙类在扩散行为上对相同景观格局的特异性响应策略。研究结果将为我国特有的珍稀蛙类- - 凹耳臭蛙，以及与皖南景观相近地区蛙类的保护（设计斑块种群间的连通廊道）提供科学依据；为探讨破碎化景观格局中物种特异性扩散模式提供实验证据。

本项目研究皖南地区破碎化景观格局中3种不同蛙类（凹耳臭蛙、武夷湍蛙和花臭蛙）种群遗传变异、种群间遗传分化和基因流模式。利用景观遗传学的理论和方法，主要基于mtDNA cyt b 基因序列与微卫星变异检测各斑块种群的遗传变异、种群历史、种群间的遗传分化程度，分析不同空间尺度上（水系间和水系内）的景观因素与种群遗传分化之间的关系。阐明了这3种蛙类的遗传多样性水平、种群遗传分化模式及其形成原因；通过比较同域分布的3种蛙类遗传分化和基因流模式，揭示由于生态习性、扩散能力以及种群历史的差异，导致皖南同域分布的3种蛙类种群间遗传分化模式迥然不同。陆地景观格局中的植被完整性和水系的连通性是凹耳臭蛙种群间基因流的关键因素。研究结果将为我国特有的珍稀蛙类——凹耳臭蛙，以及与皖南景观相近地区蛙类的保护（设计斑块种群间的连通廊道）提供科学依据；为探讨破碎化景观格局中物种特异性扩散模式提供实验证据。