Mansonia altissima is an important West African timber tree species. For the purpose of examining the effect of human impact on its genetic diversity, genetic diversity and spatial genetic structure of the species und...Mansonia altissima is an important West African timber tree species. For the purpose of examining the effect of human impact on its genetic diversity, genetic diversity and spatial genetic structure of the species under different regimes of human impact were investigated in the Akure Forest Reserve, Nigeria, using 504 amplified fragment length polymorphism （AFLP） markers. The results indicate a very low genetic diversity in M. altissima within the forest reserve （He = 0.045; PPL = 16.75%; Br = 1.162）. The highest genetic diversity was observed in the primary forest （H e= 0.062; PPL - 21.00%; Br = 1.204）, with the lowest genetic diversity in the isolated forest patch （He = 0.032; PPL = 9.00%; B r= 1.089）. A significant and pronounced spatial genetic structure was found in the logged forest and in the isolated forest patch. In contrast, the primary forest exhibited very weak spatial genetic structuring. As expected, no spatial genetic structure was found in the planted stands of M. altissima. From a conservation point of view, our results suggest that genetic diversity ofM. altissima is at risk in the forest reserve. The scale of human impact in the study area could pose a serious threat to the maintenance of genetic diversity of the species. These results would offer practical applications in the conservation of other tropical tree species.展开更多
Transferability of five nuclear microsatellite markers (Jc-16, Jc-31, Jc-32, Jc-35 and Jc-37) that were originally developed for J. communis was tested to J. procera. Jc-31 & Jc-37 showed successful amplifications...Transferability of five nuclear microsatellite markers (Jc-16, Jc-31, Jc-32, Jc-35 and Jc-37) that were originally developed for J. communis was tested to J. procera. Jc-31 & Jc-37 showed successful amplifications and polymorphism in J. procera. Jc-35 which had been reported as polymorphic in J. communis was monomorphic in J. procera while the primer pair for Jc-32 failed to record any amplification. The remaining one primer pair (Jc-16) showed double loci ampli-fication in both J. procera and the control J. communis suggesting further examination of the primer pair and its binding sites. Genetic variation of six Ethiopian J. procera populations: Chilimo, Goba, Menagesha-Suba, Wef-Washa, Yabelo and Ziquala was assessed based on the two polymorphic loci (Jc-31 & Jc-37) in 20 - 24 individuals of each population. From these two loci, a total of 41 alleles could be retrieved. Two populations that are located south east of the Great Rift Valley together harboured 75% of private alleles signifying their deviant geo-ecological zones and suggesting special consideration for conservation. Chilimo, which is at the western margin of Juniper habitat in Ethiopian central highlands scored the highest fixation (FIS = 0.584) entailing lower immigrant genes and hence higher inbreeding. The AMOVA revealed that 97% of the variation resided within the?population while still among population variation was significant展开更多
基金the DAAD (German academic exchange service) for providing funds to support collection of samples in Nigeria
文摘Mansonia altissima is an important West African timber tree species. For the purpose of examining the effect of human impact on its genetic diversity, genetic diversity and spatial genetic structure of the species under different regimes of human impact were investigated in the Akure Forest Reserve, Nigeria, using 504 amplified fragment length polymorphism （AFLP） markers. The results indicate a very low genetic diversity in M. altissima within the forest reserve （He = 0.045; PPL = 16.75%; Br = 1.162）. The highest genetic diversity was observed in the primary forest （H e= 0.062; PPL - 21.00%; Br = 1.204）, with the lowest genetic diversity in the isolated forest patch （He = 0.032; PPL = 9.00%; B r= 1.089）. A significant and pronounced spatial genetic structure was found in the logged forest and in the isolated forest patch. In contrast, the primary forest exhibited very weak spatial genetic structuring. As expected, no spatial genetic structure was found in the planted stands of M. altissima. From a conservation point of view, our results suggest that genetic diversity ofM. altissima is at risk in the forest reserve. The scale of human impact in the study area could pose a serious threat to the maintenance of genetic diversity of the species. These results would offer practical applications in the conservation of other tropical tree species.
基金The German Academic Exchange Service(DAAD)is appreciated for financial support to the first author
文摘Transferability of five nuclear microsatellite markers (Jc-16, Jc-31, Jc-32, Jc-35 and Jc-37) that were originally developed for J. communis was tested to J. procera. Jc-31 & Jc-37 showed successful amplifications and polymorphism in J. procera. Jc-35 which had been reported as polymorphic in J. communis was monomorphic in J. procera while the primer pair for Jc-32 failed to record any amplification. The remaining one primer pair (Jc-16) showed double loci ampli-fication in both J. procera and the control J. communis suggesting further examination of the primer pair and its binding sites. Genetic variation of six Ethiopian J. procera populations: Chilimo, Goba, Menagesha-Suba, Wef-Washa, Yabelo and Ziquala was assessed based on the two polymorphic loci (Jc-31 & Jc-37) in 20 - 24 individuals of each population. From these two loci, a total of 41 alleles could be retrieved. Two populations that are located south east of the Great Rift Valley together harboured 75% of private alleles signifying their deviant geo-ecological zones and suggesting special consideration for conservation. Chilimo, which is at the western margin of Juniper habitat in Ethiopian central highlands scored the highest fixation (FIS = 0.584) entailing lower immigrant genes and hence higher inbreeding. The AMOVA revealed that 97% of the variation resided within the?population while still among population variation was significant
