大熊貓是我國(guó)特有珍稀瀕危動(dòng)物,，被譽(yù)為“活化石”、“和平使者”和“外交使節(jié)”,。由于受天然屏障（如大江大河）,、棲息地破碎化和大型工程建設(shè)的影響，其野生種群被分割成20多個(gè)小種群,，特別是相嶺山系被分割得最為嚴(yán)重,。
中科院動(dòng)物研究所魏輔文研究員領(lǐng)導(dǎo)的研究組近年來(lái)一直致力于“棲息地破碎化將如何影響大熊貓孤立小種群的遺傳結(jié)構(gòu)及種群生存力”的研究，他們采用非損傷性遺傳方法,，發(fā)現(xiàn)小相嶺大熊貓孤立小種群曾發(fā)生過(guò)嚴(yán)重的崩潰,，種群數(shù)量從清康乾盛世開(kāi)始劇烈下降，這與清朝時(shí)期的政策激勵(lì)人口數(shù)量劇增所導(dǎo)致的土地開(kāi)墾,、森林砍伐加劇致使大熊貓棲息地嚴(yán)重喪失密切相關(guān)（Conservation Biology,，2010）。
他們進(jìn)一步對(duì)大,、小相嶺地區(qū)大熊貓的種群歷史與空間遺傳結(jié)構(gòu)進(jìn)行了分析,，發(fā)現(xiàn)大渡河阻隔了大熊貓種群間的基因流，導(dǎo)致小相嶺和大相嶺為不同的遺傳基因簇,；而近現(xiàn)代公路（108國(guó)道）限制了道路兩側(cè)大熊貓種群間的基因流,。
大熊貓為具有較強(qiáng)擴(kuò)散能力的大型食肉目動(dòng)物，傳統(tǒng)觀點(diǎn)認(rèn)為河流和公路可能不會(huì)對(duì)其擴(kuò)散構(gòu)成障礙,。但本研究卻表明,，大渡河是影響大熊貓擴(kuò)散的天然屏障，而108國(guó)道是為近期物理障礙,，揭示大江大河與公路是塑造大熊貓種群空間遺傳格局的重要因素,。結(jié)合大熊貓個(gè)體的空間遺傳分布與生境適宜度等信息，該研究還確定了兩條最佳廊道建設(shè)區(qū)域,，相關(guān)建議已被相關(guān)管理部門(mén)采納,，這將為大、小相嶺地區(qū)大熊貓小種群的長(zhǎng)期存活提供有力保障,。該研究成果于近期在線(xiàn)發(fā)表于分子生態(tài)學(xué)主流期刊Molecular Ecology,。（生物谷Bioon.com）
生物谷推薦原文出處：
Molecular Ecology, doi: 10.1111/j.1365-294X.2011.04999.x.
Significant genetic boundaries and spatial dynamics of giant pandas occupying fragmented habitat across southwest China
LIFENG ZHU1, SHANNING ZHANG2, XIAODONG GU3, FUWEN WEI1
Keywords:conservation;genetic boundaries;giant pandas;habitat fragmentation;spatial dynamics
Abstract
Understanding population history and genetic structure are key drivers of ecological research. Here, we studied two highly fragmented and isolated populations (Xiaoxiangling and Daxiangling) of giant pandas (Ailuropoda melanoleuca) at the extreme southwestern edge of their distribution. This area also contains the Dadu River, national road 108 and various human infrastructure and development, providing an ideal region in which we can identify the effects of different barriers on animal movements. We used partial mitochondrial control region (mtDNA) and nine microsatellite loci (nuclear DNA) data derived from 192 faecal and one blood sample collected from the wild. We found 136 genotypes corresponding to 53 unique multilocus genotypes and eight unique control region haplotypes (653 bp). Significant genetic boundaries correlated spatially with the Dadu River (K = 2). We estimate that a major divergence took place between these populations 26 000 years bp, at around the similar time the rock surface of valley bottom formed in Dadu River. The national road has resulted in further recent population differentiation (Pairwise FS on mtDNA and nuclear DNA) so that in effect, four smaller sub-populations now exist. Promisingly, we identified two possible first-generation migrants and their migration paths, and recommended the immediate construction of a number of corridors. Fortunately, the Chinese government has accepted our advice and is now planning corridor construction.
