Genetic diversity and geographic differentiation in endangered Ammopiptanthus (Leguminosae) populations in desert regions of northwest China as revealed by ISSR analysis.
OBJECTIVE
The desert legume genus Ammopiptanthus comprises two currently endangered species, A. mongolicus and A. nanus. Genetic variability and genetic differentiation between the two species and within each species were examined.


METHODS
Inter-simple sequence repeat (ISSR) marker data were obtained and analysed with respect to genetic diversity, structure and gene flow.


RESULTS
Despite the morphological similarity between A. mongolicus and A. nanus, the two species are genetically distinct from each other, indicated by 63 % species-specific bands. Low genetic variability was detected for both population level (Shannon indices of diversity Hpop = 0.106, percentage of polymorphic loci P = 18.55 % for A. mongolicus; Hpop = 0.070, P = 12.24 % for A. nanus) and species level (Hsp = 0.1832, P = 39.39 % for A. mongolicus; Hsp = 0.1026, P = 25.89 % for A. nanus). Moderate genetic differentiation was found based on different measures (AMOVA PhiST and Hickory B) in both A. mongolicus (0.3743-0.3744) and A. nanus (0.2162-0.2369).


CONCLUSIONS
The significant genetic difference between the two species might be due to a possible vicariant evolutionary event from a single common ancestor through the fragmentation of their common ancestor's range. Conservation strategies for these two endangered species are proposed.
Ge
Xue-Jun
XJ
South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, P R China. xjge@scbg.ac.cn
Yu
Yan
Y
Yuan
Yong-Ming
YM
Huang
Hong-Wen
HW
Yan
Cheng
C
D000704:Analysis of Variance; D002681:China; D007887:Fabaceae / Q000145:classification / Q000235:genetics*; D005819:Genetic Markers; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D012091:Repetitive Sequences, Nucleic Acid
D005819:Genetic Markers