Title page for etd-0724115-101740


[Back to Results | New Search]

URN etd-0724115-101740
Author Chia-ying Chung
Author's Email Address No Public.
Statistics This thesis had been viewed 5526 times. Download 0 times.
Department Biological Sciences
Year 2014
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Genetic diversity, genetic divergence and phylogeographical patterns in Calocedrus based on microsatellites
Date of Defense 2015-07-23
Page Count 86
Keyword
  • genetic diversity
  • genetic differentiation
  • microsatellite
  • phylogeographical
  • Calocedrus
  • Abstract The genus Calocedrus is Eastern Asian – North American disjunctive distribution. Calocedrus formosana (Florin) Florin is restricted to Taiwan, Calocedrus macrolepis Kurz, and C. rupestris Aver., T.H. Nguyên & K.L. Phan are scattered throughout southwestern of China to northern of Indochina and Hainan Island, and Calocedrus decurrens Florin is native to western North America. According to fossil records, Calocedrus had been widespread in the Northern Hemisphere. In this study, we examined phylogeographical patterns, genetic diversity and genetic divergence in this genus based on 20 microsatellite markers. These 20 polymorphic microsatellite loci were used to evaluate genetic diversity among 627 samples from 27 populations of four taxa in Calocedrus, including 10 populations from C. formosana 265 individuals, 14 populations from C. macrolepis 314 individuals, 2 populations from C. rupestris 33 individuals, and 15 individuals from C. decurrens. Genetic diversity indices for 4 species based on 20 polymorphic loci, including the number of alleles (Na), the number of effective alleles (Ne) and the observed and expected heterozygosity (Ho and He), were estimated. The 4 species genetic diversity indices mean value range are: Na: from 3.65 to 8.05, Ne: from 2.04 to 2.66, Ho: from 0.14 to 0.26, He: from 0.48 to 0.54. In 10 C. formosana populations, genetic diversity indices mean value range are: Na: from 3.65 to 8.05, Na: from 2.35 to 4.4, Ne: from 1.76 to2.17, Ho: from 0.13 to 0.19, He: from 0.36 to 0.49. In 14 C. macrolepis populations, genetic diversity indices mean value range are: Na: from 4.25 to 2.45, Ne: from 1.83 to 2.39, Ho: from 0.18 to 0.35, He: from 0.36 to 0.53. AMOVA showed 78.12% genetic variation accumulated within population and high levels of genetic differentiation (FST =0.22). In C. formosana, C. macrolepis and C. rupestris AMOVA showed 61% and 48.72% genetic variation accumulated in among individuals within populations and with individuals and low levele of genetic differentiation (FST=0.07&0.094). The results of PCoA showed high genetic divergence among species except between C. macrolepis and C. rupestris, also significant genetic divergence among populations in C. formosana and C. macrolepis. In STRUCTURE analysis at K=2 and K=3 significant genetic clustering for four Calocedrus species might caused by Neogene, Paleogene and Quaternary climatic oscillations. In IMa result, the ancestral effective population size (21 million) is greater than C. formosana and C. macrolepis (385 and 7048). This result indicated these two species retreated to refugia caused by Quaternary climatic oscillations. The migration rate from C. formosana to C. macrolepis (M12)was 1.08×10-3and migration rate from C. macrolepis to C. formosana (M21) was 2.55×10-5. This result indicated species migration path from island to mainland at Eastern Asian. In STRUCTURE result no significant geographical barrier caused by gene flow in C. formosana populations. In C. macrolepis populations, the population geographical differentiation and caused by long distance dispersal or species retreat to multipule refuges. For C. formosana conservation suggestions was the seed production stand should be maintained and established. In addition, the species molecular identification system was needed to avoid confusion between the seedeing of C. formosana and C. macrolepis during reforestation.
    Advisory Committee
  • Ho-Yih Liu - chair
  • Kuo-Hsiang Hung - co-chair
  • Yu-Chung Chiang - advisor
  • Files
  • etd-0724115-101740.pdf
  • Indicate in-campus at 99 year and off-campus access at 99 year.
    Date of Submission 2015-08-24

    [Back to Results | New Search]


    Browse | Search All Available ETDs

    If you have more questions or technical problems, please contact eThesys