Abstract:To characterize the genetic diversity of present populations of Symplocos laurina, which grow in the montane forests in India, we analyzed the DNA sequences of a nuclear gene. Using the 881 bp sequence of cytosolic Glyceraldehyde-3-phosphate dehydrogenase gene, we detected 24 haplotypes among 195 individuals sampled from 14 populations. Two dominant haplotypes were distributed over the entire range of this species in India and several private haplotypes were found. Low genetic diversity within population, high… Show more
“…However, in contrast to the results of cpDNA sequences, nDNA data revealed relatively high levels of genetic diversity (Hd = 0.773, H T = 0.807), when compared with those of other studies from analyses of the GAPDH gene (Banu et al 2010;Shih et al 2007). These results contrast with our initial expectation that this endangered, uncommon species would have low genetic diversity, but this incongruence between these two markers could be explained by their different effective population size.…”
Section: Genetic Diversity and Population Differentiationcontrasting
The genetic variation and structure of Leucomeris decora, an endangered species in China were investigated. Analyses of three chloroplast DNA (cpDNA) regions (the rpl16 intron, trnQ-5 0 rps16 intergenic spacer and rpl32-trnL intergenic spacer) and one nuclear gene (GAPDH: encoding glyceraldehyde 3-phosphate dehydrogenase) were conducted on 11 L. decora populations. Low levels of cpDNA genetic diversity were found in this species and within populations, with the identification of 2 haplotypes in a total of 2,745 bp, while the level of genetic diversity revealed by the nuclear gene GAPDH was relatively high, indicating that random losses of genetic polymorphisms from populations may have occurred recently. High levels of genetic differentiation among populations for both markers were detected in L. decora, which could be a consequence of the limited gene flow caused by geographic isolation among populations. An analysis of molecular variance revealed at the nuclear locus suggested the presence of geographic structure within the haplotype distribution possibly due to geographical barriers among populations. The haplotype network and mismatch distribution analyses did not detect the signal for a recent population expansion in L. decora. L. decora may persist in situ during climatic oscillations. Based on the genetic diversity and uniqueness of the populations, conservation strategies are discussed for this endangered species.
“…However, in contrast to the results of cpDNA sequences, nDNA data revealed relatively high levels of genetic diversity (Hd = 0.773, H T = 0.807), when compared with those of other studies from analyses of the GAPDH gene (Banu et al 2010;Shih et al 2007). These results contrast with our initial expectation that this endangered, uncommon species would have low genetic diversity, but this incongruence between these two markers could be explained by their different effective population size.…”
Section: Genetic Diversity and Population Differentiationcontrasting
The genetic variation and structure of Leucomeris decora, an endangered species in China were investigated. Analyses of three chloroplast DNA (cpDNA) regions (the rpl16 intron, trnQ-5 0 rps16 intergenic spacer and rpl32-trnL intergenic spacer) and one nuclear gene (GAPDH: encoding glyceraldehyde 3-phosphate dehydrogenase) were conducted on 11 L. decora populations. Low levels of cpDNA genetic diversity were found in this species and within populations, with the identification of 2 haplotypes in a total of 2,745 bp, while the level of genetic diversity revealed by the nuclear gene GAPDH was relatively high, indicating that random losses of genetic polymorphisms from populations may have occurred recently. High levels of genetic differentiation among populations for both markers were detected in L. decora, which could be a consequence of the limited gene flow caused by geographic isolation among populations. An analysis of molecular variance revealed at the nuclear locus suggested the presence of geographic structure within the haplotype distribution possibly due to geographical barriers among populations. The haplotype network and mismatch distribution analyses did not detect the signal for a recent population expansion in L. decora. L. decora may persist in situ during climatic oscillations. Based on the genetic diversity and uniqueness of the populations, conservation strategies are discussed for this endangered species.
“…Like other studies, the Quaternary glaciation also had a significant effect on L. tongolensis . The presence of two dominant haplotypes in two specific regions (Jinshajiang and Yalongjiang) implies that the populations in these regions might have originated from two different sources of refugia (Banu et al, 2010). Because only the high‐elevational regions were disjunctly covered by ice sheets during the glacial stages and the glacier of each mountain system did not connect (Shi et al, 1998; Shi et al, 1999; Xu et al, 2005; Wang & Ge, 2006), L. tongolensis could have survived between the two sides of Shaluli Mountain where it was ice‐free.…”
In this research, we aimed to study the genetic variation and phylogeographic pattern of Ligularia tongolensis, a perennial herb endemic to the Hengduan Mountains region of China. We sequenced two chloroplast DNA (cpDNA) intergenic spacers (trnQ‐5′rps16, trnL‐rpl32) in 140 individuals from 14 populations of three groups (Jinshajiang vs. Yalongjiang vs. Wumeng) within this species range. High levels of haplotype diversity (Hd = 0.814) and total genetic diversity (Ht = 0.862) were detected at the species level, based on a total of 12 haplotypes identified. Low levels of intrapopulation diversity (Hs = 0.349), high levels of genetic divergence (Gst = 0.595, Nst = 0.614, Fst = 0.597), and the absence of isolation by distance tests were also found in L. tongolensis. Furthermore, H2 and H5, the dominant haplotypes that located at internal nodes and deviated from extinct ancestral haplotype in the network, were found to be shared between Jinshajiang and Yalongjiang groups. These results indicate that past fragmentation may be the important factor responsible for the present phylogeographical pattern of L. tongolensis. Meanwhile, the locations occupied by each group might have served as independent refugia for L. tongolensis during the Quaternary glaciation. Unimodal mismatch distribution and star‐like genealogies indicated this species underwent past demographic expansion events, with expansion ages of 274 ka BP.
“…1).Depending on age of the plants, more than 99% of the available plants were sampled from each population and are from natural populations.After collection, the tissues were stored at -80 ºC until DNA extraction. Total genomic DNA was isolated from 100 mg tissue of each plant using amodified Cetyl-trimethylammonium bromide (CTAB) method (Banu et al, 2010). The DNA was suspended in 100 µl of Tris-EDTA buffer and stored at 4 ºC.…”
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