摘 要：松乳菇Lactarius deliciosus是一種對松樹的生長具有重大意義的外生菌根真菌，具有很高的經(jīng)濟(jì)價值,，因無法人工培育，過度的人工采摘造成產(chǎn)地生態(tài)的嚴(yán)重破壞,。比較中國南方3個省9個不同地區(qū)的68個松乳菇的rDNA ITS區(qū)堿基序列的差異,，以期研究各不同群體的ITS單倍體型多樣性，不同地區(qū)群體之間的遺傳關(guān)系,，以及遺傳分化與地理隔離的關(guān)系,。遺傳分析發(fā)現(xiàn)，得到的68個松乳菇樣品的ITS序列可認(rèn)定為7種單倍體型,，這些單倍體型聚集為2個不同的系統(tǒng)進(jìn)化群體,，表現(xiàn)出兩種不同的系統(tǒng)進(jìn)化方向。7種單倍體型中,，兩個主要的單倍體型（Haplotype3和Haplotype6）分別含有34和26個樣品,，且基本上每個樣品采集地都有分布。AMOVA測試中,，觀察到的總的單倍體型變異頻率主要體現(xiàn)在不同地理種群的個體內(nèi)（84%）,。剩下的16%屬于不同地理種群間的變異，PhiPT的顯著性分析結(jié)果p＜0.01,。Mantel測試顯示地理距離與遺傳差異FST值沒有顯著的線性關(guān)系（p=0.32）,。研究結(jié)果說明松乳菇自然種群間有一定程度的基因漂流發(fā)生。群體遺傳分析還發(fā)現(xiàn)在松乳菇自然種群中存在顯著遺傳分化,，但遺傳分化程度與地理距離沒有顯著的線性關(guān)系,。
關(guān)鍵詞：外生菌根真菌，遺傳多樣性,，遺傳分化,，基因漂移
Mycosystema
Genetic diversity of Lactarius deliciosus from South China
GUO Liang LIU Jun-Ang ZHOU Guo-Ying LI He
Abstract: Lactarius deliciosus is an ectomycorrhizal mushroom that forms symbiotic associations with species of Pinus and plays an important ecological role in natural forest ecosystems in many parts of the world. It is also an economically important gourmet mushroom. Because no artificial cultivation is available, natural populations of this species are under increasing threats, primarily from habitat disturbance and destruction. We analyzed 68 samples of L. deliciosus from South China using ITS sequences. By comparing the difference of ITS sequences, the haplotype diversity within each population, the relationships among local populations, the relationship between the level of genetic differentiation and geographical separation, and the contributions of local and regional geographical separations to the overall ITS haplotype variation were analysed. Our genetic analysis identified a total of 7 ITS haplotypes and these haplotypes were clustered into two distinct phylogenetic groups, and revealed two different phylogenetic directions. Among the 7 ITS haplotypes, the two major haplotypes (Haplotype3 and Haplotype6) contained 34 and 26 specimens respectively, and distributed in all of the 9 sites. AMOVA test showed that there was significant genetic differentiation at both among local populations (－16%) and within local populations (－84%) levels, and p<0.01 for PhiPT. The Mantel test identified that the extent of genetic differentiation was statistically insignificant correlated with geographical distance (p=0.32). Our study revealed significant genetic divergence within L. deliciosus and detectable gene flow among geographical populations of this ectomycorrhizal mushroom, but the extent of genetic differentiation were insignificant correlated with geographical distance.
Key words: ectomycorrhizal fungi, genetic diversity, genetic divergence, gene flow（生物谷Bioon.com）
