of speciman and literatures, the distribution and of populations T. fortunei were probed. T. fortunei distributed mainly in Yunnan, Guangxi, Guangdong, Hunan, Hubei, Zhejiang, Sichuan, Fujian, Guizhou, Shanxi, Jiangxi and Gansu.The popultion size of T. fortunei are small, number of young tree small and the age struction inconsequence. The distribution of genus Trachycarpus were analysised and its origin been discussed.
Genomic DNA was isolated from leaf samples using the improved hexadecyl- Cetyl Trimethyl Ammonium Bromide (CTAB) method. Inter-Simple Sequence Repeat (ISSR) is a good molecular marker for revealing genetic diversity. Reaction system differed with difference species, so optimization of ISSR-PCR reaction is very important. The study discussed mainly the factors impacting the banding patterns of PCR. To optimize the reactions, several parameters were tested, including the concentration of DNA template, MgCl2, dNTP, primer and Taqpolymerase with different annealing temperature.
In this study Inter-simple sequence repeat (ISSR) method revealed genetic diversity of 200 individuals among 12 natural populations from three province Yunnan, Guangxi and Hunan and one cultivated population from Shenzhen FairyLake Botany Garden. Twelve of 100 ISSR primers can amplify clear bands, and produced 107 loci, 102 of which is polymorphic, the percentage of polymorphic loci is 95.33%. The band size ranged from 300 to 1900bp, with an average of 8.9 bands per primer with an average 无忧论文 【http://www.uklunwen.com】of 8.5 bands per primer. The indices of genetic diversity and gene variation were computed by the POPGENE in this study. The value of total gene diversity (HT) is 0.3234, gene diversity within population (HS) is 0.1982. The value of (GST) is 0.3827. The gene variation remains mainly within population. Nei’s gene diversity h = 0.3218, Shannon’s information index I = 0.4843.
The dendrogram based on Nei's genetic distance by the UPGMA method. The genetic distance between populations is between 0.06 and 0.27, the shortest genetic distance is 0.06 between GHS6 and GHP7. The second shortest genetic distance is 0.09 between DWS1 and DWS2, between DWS2 and DWS3 and between DYX4 and DFG5. The longest genetic distance is 0.27 between DWS1 and GHS6, between DHS6 and XAR10. The second longest genetic distance is 0.26 between DWS1 and GHP7.
The 13 populations formed four groups according to the dendrogram. The first group is population DYX4, DFG5, GHS6 and GHP7; the second group is population XAR10, XYY11, XZJ12 and YFL13; the third group is GJX8 and GNOP9; the forth group is population DWS1, DWS2 and DWS3. Populations in Wenshan (DWS1, DWS2 and DWS3) showed a closer genetic relationship, Population GHS6 and GHP7, XAR10 and XYY11 and XZJ12 have a closer genetic relationship. Their genetic distance accord with geographic range. The cultivated population YFL13 and population XZJ12 has a closer genetic relationship.
The rank of the percentages of polymorphic sites of 13 populations was: |
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