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ABSTRACT: Eight microsatellite loci for the perennial herb Farfugium japonicum, including the rheophytic variety luchuense endemic to riparian areas of the Ryukyu Islands, Japan, were isolated and characterised. The number of alleles ranged from
5 to 14. The expected (H
E) and observed (H
O) heterozygosities were 0.344–0.885 and 0.121–0.754, respectively, from 69 individuals in one population. Six loci exhibited
significantly fewer heterozygotes than expected under Hardy–Weinberg equilibrium (P<0.05). The primers amplifying microsatellite sequences in F. japonicum may provide a population genetics tool useful in the establishment of a conservation strategy.
Conservation Genetics 04/2012; 10(4):1093-1095. · 1.61 Impact Factor
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ABSTRACT: Farfugium (Asteraceae) is a small genus that contains the two species F. japonicum and F. hiberniflorum and is distributed along a long archipelago in east Asia. The common taxon, F. japonicum, includes three varieties associated with a wide range of habitats, including forest understorey (sciophytes), coastal crag (heliophytes) and riverbed (rheophytes). Leaf shape is an important taxonomic character within this genus and is associated with the habitat.
Twenty populations that included all Farfugium taxa were collected throughout its range. Leaf morphology was measured to determine differences amongst the taxa. Phylogenetic analyses based on sequences of the internal transcribed spacer of nuclear rDNA and four plastid DNA regions (matK, trnL-trnF, trnH-psbA and rpl20-rps12) were conducted separately.
Leaf morphology was significantly different amongst taxa, but morphological variations were partly explained by adaptation to certain environmental conditions that each population inhabited. Molecular phylogenies for the nDNA internal transcribed spacer and cpDNA were consistent in classifying F. hiberniflorum and the Taiwanese var. formosanum, whilst suggesting polyphyletic origins for the rheophyte, sciophyte and heliophyte taxa. All samples from the southern Ryukyus (Japan) and Taiwan clustered into a monophyletic group, which corroborates the land configuration theory involving Quaternary land-bridge formation and subsequent fragmentation into islands. The incongruence between the two DNA datasets may imply traces of introgressive hybridization and/or incomplete lineage sorting.
The occurrence of rheophyte, sciophyte and heliophyte plants within Farfugium may be attributable to their isolation on islands and subsequent adaptation to the riparian, coastal crag and forest understorey environments, following their migration over the Quaternary land-bridge formation along their distribution range. Nearly identical DNA sequences coupled with highly divergent morphologies amongst these taxa suggest that diversification was rapid.
Annals of Botany 09/2010; 106(3):467-82. · 4.03 Impact Factor
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ABSTRACT: In conifers, which have non-saccate Cupressaceae-type pollen, the pollen must land on a pollination drop or be picked up by the pollination drop from the surface of the cone near the ovule before it can be taken into the ovule. After contact with the drop, the pollen intine absorbs moisture from the drop, expands and the exine is shed. In this study the significance of the shedding of the exine is interpreted from experiments in which simulated pollination drops and micropyles were used to determine the movement of pollen and other particles in suspension. The non-expanded pollen, which can be observed upon contact with the pollination drop, sheds the exine, which then functions as a non-elastic particle, while the pollen from which the exine was shed swells and functions as an elastic particle because it is enclosed by the flexible intine. Non-elastic particles are not easily transferred through narrow passages (the micropyle and micropylar canal) and tend to plug these passages. However, elastic particles, such as the swollen pollen, are easily transferred along narrow passages even when non-elastic particles are present. The simulated experiments demonstrate that exine shedding is an important feature in getting pollen through the narrow micropyle and micropylar canal to the nucellus of the ovule.
Journal of Plant Research 02/2008; 121(1):83-5. · 1.75 Impact Factor
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ABSTRACT: We investigated the anatomical and physiological characteristics of stenophyllous leaves of a rheophyte, Farfugium japonicum var. luchuence, and sun and shade leaves of a non-rheophyte, F. japonicum, comparing three different populations from coastal, forest floor, and riparian habitats. Light adaptation resulted in smaller leaves, and riparian adaptation resulted in narrower leaves (stenophylly). The light-saturated rate of photosynthesis (P (max)) per unit leaf area corresponded to the light availability of the habitat. Irrespective of leaf size, the P (max) per unit leaf mass was similar for sun and shade leaves. However, the P (max) per mass of stenophyllous leaves was significantly lower than that of sun and shade leaves. This was because the number and size of mesophyll cells were greater than that required for intercellular CO(2) diffusion, which resulted in a larger leaf mass per unit leaf area. Higher cell density increases contact between mesophyll cells and enhances leaf toughness. Stenophyllous leaves of the rheophyte are frequently exposed to a strong water flow when the water level rises, suggesting a mechanical constraint caused by physical stress.
Journal of Plant Research 12/2006; 119(6):645-56. · 1.75 Impact Factor
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ABSTRACT: We investigated the phylogenetic relationships within the genus Cardiandra based on plastid DNA sequences. The phylogenetic tree showed that Cardiandra populations from the Ryukyu Islands (Japan) and Taiwan were monophyletic (Ryukyu-Taiwan clade), whereas taxa from China and mainland Japan were sisters to this clade. The divergence time between the Ryukyu-Taiwan clade and the other species was estimated to be 0.082 MYA, i.e., the late Pleistocene. The infrageneric and/or infraspecific differentiation of Cardiandra is estimated to have depended largely on allopatric differentiation caused by the presence or division of the past landbridge of the Ryukyu Islands, which connected mainland Japan to the Asian Continent during the Quaternary.
Journal of Plant Research 08/2006; 119(4):401-5. · 1.75 Impact Factor
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ABSTRACT: The flowers of mangrove plants are pollinated by a variety of pollinators including birds, bats, and insects. This study analyzed the floral scent chemistry of mangroves on Iriomote Island (located near Taiwan) including Bruguiera gymnorrhiza (L.) Lamk. (Rhizophoraceae), Kandelia candel (L.) Druce (Rhizophoraceae), Rhizophora stylosa Griff. (Rhizophoraceae), Sonneratia alba J. Smith (Sonneratiaceae), Nypa fruticans (Thunb.) Wurmb. (Palmae), Lumnitzera racemosa Willd. (Combretaceae), Avicennia marina (Forsk.) Vierh. (Avicenniaceae or Verbenaceae), and Pemphis acidula Forst. (Lythraceae). A total of 61 chemicals (fatty acid derivatives, terpenoids, carotenoid derivatives, benzenoids, nitrogen-containing compounds, 13 unknown chemicals) were detected in the floral scents of the various species. The species displayed a distinct chemical profile ranging from only two chemicals in the floral scent of Kandelia candel to more than 25 chemicals in the floral scent of Nypa fruticans. All of the identified chemicals have been found in the floral scents of other angiosperms. The chemical profile of some species can be correlated with their floral morphology and pollinators.
Journal of Plant Research 03/2002; 115(1117):47-53. · 1.75 Impact Factor
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ABSTRACT: InLarix pollen captured by the ovule and rested at the distal end of the micropylar canal is transferred upward to the nucellus before
it develops a pollen tube. This upward movement occurs after the canal is filled with secreted fluid, despite the fact that
the pollen sinks in the fluid. We examined the mechanism of the movement based on the morphology of the canal and its simulation
using pipettes. When a water column moves upward in a waxed pipette, suspended particles also move upward carried by the meniscus.
InL. x eurolepis the inner surface of the integument lining the micropylar canal is coated by a cuticle layer. This layer is further coated
by an integumentary membrane before the fluid is secreted. This membrane, however, becomes distorted or disappears during
fluid secretion. The exposed cuticle and the degenerated hydrophilic nucellar apex may facilitate the movement of the meniscus
toward the nucellus as in the simulated pipette. Pollen is interpreted to move by being carried by the meniscus when the fluid
recedes.
Journal of Plant Research 04/1997; 110(2):259-264. · 1.75 Impact Factor
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ABSTRACT: The seed coat surface morphology of Celtidaceae and Ulmaceae (Urticales) indicates a significant evolutionary diversity.Celtis, Chaetachme andPteroceltis (Celtidaceae) have a unique sculpturing with many crateriform holes; such holes occasionally sparsely occur in seeds ofAphananthe, Gironniera (Celtidaceae) andPlanera (Ulmaceae), but not in those of the nine remaining genera of the two families. The perforated seed coat further occurs in
at least some genera of all other urticalean families. A pattern of its occurrence in families and genera suggest that the
perforation represents a common archaic feature of all Urticales, rather than a feature derived many times independently within
the order. The seed coat of Celtidaceae and Ulmaceae seems to have lately lost the holes probably by a neotenic evolution:
one or more times within Celtidaceae, and one time in an ancestral line leading to all Ulmaceae. The derived reticulate seed
coat surface sculpturing, which is shared byGironniera (Celtidaceae) and some Ulmaceae, is probably the result of parallel evolution. On the basis of evidence from seed coat morphology
and other sources, close relationships ofLozanella, Parasponia andTrema within Celtidaceae, as well as variously distinct positions ofAmpelocera, Aphananthe andGironniera, are also discussed.
Journal of Plant Research 04/1990; 103(1):25-41. · 1.75 Impact Factor
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ABSTRACT: Our understanding of pollination in conifers has advanced rapidly in recent years, but it still lags behind our knowledge of this process in angiosperms. In part this is because conifers are not considered to be high priority crops and, unlike many cultivated flowers, conifer seed cones are generally neither large nor colorful. The use of genetics to improve tree growth has primarily been through selection and asexual propagation rather than breeding, and because incompatibility is not thought to occur in conifer pollination systems, concern about pollination has primarily been with regard to seed production. Here we examine the ancestral wind-pollination mechanism in conifers and discuss how the process may have evolved to improve pollination success.
Trends in Plant Science.
