Genetic diversity and geographic differentiation in Tacca chantrieri (Taccaceae): An autonomous selfing plant with showy floral display

Laboratory for Plant Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650204, China.
Annals of Botany (Impact Factor: 3.65). 09/2006; 98(2):449-57. DOI: 10.1093/aob/mcl123
Source: PubMed


Despite considerable investment in elaborate floral displays, Tacca chantrieri populations are predominantly selfing. It is hypothesized that this species might possess considerable spatial or temporal variation in outcrossing rates among populations. To test this hypothesis, genetic variability and genetic differentiation within and among T. chantrieri populations were investigated to find out if they are in agreement with expectations based on a predominantly inbred mating system.
Genetic diversity was quantified using inter-simple sequence repeats (ISSR) in 303 individuals from 13 populations taken from known locations of T. chantrieri in China, and from one population in Thailand.
Of the 113 primers screened, 24 produced highly reproducible ISSR bands. Using these primers, 160 discernible DNA fragments were generated, of which 145 (90.62 %) were polymorphic. This indicated considerable genetic variation at the species level. However, there were relatively low levels of polymorphism at population levels, with percentages of polymorphic bands (PPB) ranging from 8.75 % to 55 %. A high level of genetic differentiation among populations was detected based on different measures (Nei's genetic diversity analysis: G(ST) = 0.5835; AMOVA analysis: F(ST) = 0.6989). Furthermore, based on levels of genetic differentiation, the 14 populations clustered into two distinct groups separated by the Tanaka Line.
High levels of differentiation among populations and low levels of diversity within populations at large spatial scales are consistent with earlier small-scale studies of mating patterns detected by allozymes which showed that T. chantrieri populations are predominantly selfing. However, it appears that T. chantrieri has a mixed-mating system in which self-fertilization predominates, but there is occasional outcrossing. Significant genetic differences between the two distinct regions might be attributed to vicariance along the Tanaka Line. Finally, possible mechanisms of geographic patterns based on genetic differentiation of T. chantrieri are discussed.

Download full-text


Available from: De-Zhu Li,
  • Source
    • "Forrest et al. (2004) explained the strong differentiation found among European populations of Spiranthes romanzoffiana (Orchidaceae) (ΦST = 0.892) as resulting from the lack of gene flow between the evaluated populations, combined with different reproductive strategies across populations (autogamy, vegetative reproduction and crossing). Other works with autogamous species (Nybon and Bartish 2000; Xiao et al. 2006; Zhang et al. 2006; Voss et al. 2012; Aguayo et al. 2013 "
    [Show abstract] [Hide abstract]
    ABSTRACT: Despite the fact that invasive species are of great evolutionary interest because of their success in colonizing and spreading into new areas, the factors underlying this success often remain obscure. In this sense, studies on population genetics and phylogenetic relationships of invasive species could offer insights into mechanisms of invasions. Originally from Africa, the terrestrial orchid Oeceoclades maculata, considered an invasive plant, is the only species of the genus throughout the Americas. Considering the lack of information on population genetics of this species, the aim of this study was to evaluate the genetic diversity and structure of Brazilian populations of O. maculata. We used 13 ISSR primers to assess the genetic diversity of 152 individuals of O. maculata distributed in five sampled sites from three Brazilian states (São Paulo, Mato Grosso and Paraná). Low diversity was found within samples, with estimates of the Shannon index (H) ranging from 0.0094 to 0.1054 and estimates of Nei's gene diversity (He) ranging from 0.0054 to 0.0668. However, when evaluated together, the sampling locations showed substantially higher diversity estimates (H=0.3869, He=0.2556), and most of the genetic diversity was found among populations (ΦST=0.933). Both clustering and principal coordinate analysis (PCoA) indicate the existence of five distinct groups, corresponding to the sampled localities, and which were also recovered in the Bayesian analysis. A substructure was observed in one of the localities, suggesting a lack of gene flow even between very small distances. The patterns of genetic structure found in this study may be understood considering the interaction of several probable reproductive strategies with its history of colonization involving possible genetic drift, selective pressures and multiple introductions. Published by Oxford University Press on behalf of the Annals of Botany Company.
    AoB PLANTS 07/2015; 7. DOI:10.1093/aobpla/plv077 · 2.27 Impact Factor
  • Source
    • "Using inter simple sequence repeat (ISSR) markers, we previously demonstrated that there is a strong genetic differentiation in T. chantrieri across eastern and western parts of the Tanaka line (Zhang et al., 2006), but the divergent time and the factors that resulted in the genetic differentiation of T. chantrieri between the two lineages were unclear. Here, we utilize chloroplast DNA variation of T. chantrieri distributed in tropical regions to elucidate phylogeographic patterns and demography of this species and then explore the possible causes that can explain the phylogeographic patterns of distribution in T. chantrieri. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The geological and climatic oscillations influenced the geographic distribution and demography of most present-day species, but few studies have investigated evolutionary history of species adapted to the tropical regions of Southeast Asia. Here, using sequence datasets obtained from three chloroplast DNA fragments (trnH-psbA, trnS-trnG, and trnL-F) from 320 individuals belonging to 24 natural populations, we investigated the phylogeographical history of Tacca chantrieri, which inhabits Southeast Asian tropical forests. Although relatively high level of differentiation among the populations were observed, mismatch distribution and neutrality tests showed no evidence of recent demographic population expansion. Phylogenetic inference exhibited two identified population groups showing a disjunctive distribution of dominant haplotypes. The split in cpDNA was largely consistent with the Tanaka line and Red River geographically. Molecular clock estimations revealed that the two lineages diverged during Pleistocene approximately 1.16 Ma. Therefore, the disjunct distribution of T.chantrieri could be explained by both the vicariance caused by Red River as well as ecological barriers caused by the different monsoon climates (Southwest monsoon vs. Southeast monsoon) that developed during the Pleistocene. The Tanaka line can be considered as a climatically driven barrier that influenced present-day plant dispersal.
    Biochemical Systematics and Ecology 11/2014; 58:139-148. DOI:10.1016/j.bse.2014.11.011 · 0.97 Impact Factor
  • Source
    • "ISSR is a technique that overcomes most of these limitations [5,7]. This technology has been used to DNA fingerprint a wide range of crops [5,7,8–10] and to understand ploidy complex and the geographic origin of some plant species [11,12–16]. DNA profiling techniques that have been successfully used in assessing relatedness of Cynodon accessions includes DNA amplification fingerprinting (DAF) [17], RAPD [18,19], AFLP [20,21], ISSR [22], SSR [23] and chloroplast specific simple sequence repeat length polymorphism (CpSSRLP) [20]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Bermudagrass (Cynodon spp.) is a major turfgrass for home lawns, public parks, golf courses and sport fields and is known to have originated in the Middle East. Morphological and physiological characteristics are not sufficient to differentiate some bermudagrass genotypes because the differences between them are often subtle and subjected to environmental influences. In this study, twenty seven bermudagrass accessions and introductions, mostly from different parts of Iran, were assayed by inter-simple sequence repeat (ISSR) markers to differentiate and explore their genetic relationships. Fourteen ISSR primers amplified 389 fragments of which 313 (80.5%) were polymorphic. The average polymorphism information content (PIC) was 0.328, which shows that the majority of primers are informative. Cluster analysis using the un-weighted paired group method with arithmetic average (UPGMA) method and Jaccard's similarity coefficient (r = 0.828) grouped the accessions into six main clusters according to some degree to geographical origin, their chromosome number and some morphological characteristics. It can be concluded that there exists a wide genetic base of bermudograss in Iran and that ISSR markers are effective in determining genetic diversity and relationships among them.
    International Journal of Molecular Sciences 01/2012; 13(1):383-92. DOI:10.3390/ijms13010383 · 2.86 Impact Factor
Show more