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.