摘要
The aim of the present study is to investigate the difference between ITS sequences ofArtemisia halodendron Turcz. from differ- ent habitat gradients in Horqin Sandy Land, with Artemisia depauperata Krasch. selected as the outgroup. Results indicate that the total length ofA. halodendron ITS is 696 bp, the lengths of unaligned ITS-1 and ITS-2 sequences varied from 253 to 256 bp and 264 to 269 bp, respectively, and GC content of ITS-1 and ITS-2 sequences ranged from 54.02% to 54.77% and 56.75% to 58.64%, respectively. This indicates a high difference of length and composition of sequences in ITS-1 than ITS-2. The genetic identity between ITS sequences ofA. halodendron from nine populations ranged from 85.7% to 99.7% which indicates some genetic dif- ferentiation between sequences. In the maximum parsimony （MP） tree, most ITS sequences from A. halodendron show two major clades： Clade I and Clade II, with Clade II older than Clade I. The order is subp4→ subpl → subp2 → subp3→ subp8 → subp6 → subp7 → subp9 → subp5, and corresponding habitat order is： inter-dune lowlands → semi-mobile dune → mobile dune →semi-fixed dune -→fixed dune. This indicates a close relation between the evolutionary processes ofA. halodendron and deserti- fication forming processes and ecological restoration processes of Horqin Sandy Land.
The aim of the present study is to investigate the difference between ITS sequences ofArtemisia halodendron Turcz. from differ- ent habitat gradients in Horqin Sandy Land, with Artemisia depauperata Krasch. selected as the outgroup. Results indicate that the total length ofA. halodendron ITS is 696 bp, the lengths of unaligned ITS-1 and ITS-2 sequences varied from 253 to 256 bp and 264 to 269 bp, respectively, and GC content of ITS-1 and ITS-2 sequences ranged from 54.02% to 54.77% and 56.75% to 58.64%, respectively. This indicates a high difference of length and composition of sequences in ITS-1 than ITS-2. The genetic identity between ITS sequences ofA. halodendron from nine populations ranged from 85.7% to 99.7% which indicates some genetic dif- ferentiation between sequences. In the maximum parsimony （MP） tree, most ITS sequences from A. halodendron show two major clades： Clade I and Clade II, with Clade II older than Clade I. The order is subp4→ subpl → subp2 → subp3→ subp8 → subp6 → subp7 → subp9 → subp5, and corresponding habitat order is： inter-dune lowlands → semi-mobile dune → mobile dune →semi-fixed dune -→fixed dune. This indicates a close relation between the evolutionary processes ofA. halodendron and deserti- fication forming processes and ecological restoration processes of Horqin Sandy Land.
基金
financially supported by research projects 41201561, 2011BAC07B02, Y351151001, 41071185 and 31170413
