Published Papers - NAIKI Akiyo

Molecular Phylogenetic Analyses of Geranium robertianum Populations Recently Found in Japan

NISHIDA SACHIKO, AZUMA HIROSHI, NAIKI AKIYO, OGAWA MAKOTO

Acta phytotaxonomica et geobotanica : APG   62 ( 2 ) 79 - 87   2012.06 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

Heterostyly and the possibility of its breakdown by polyploidization

Akiyo Naiki

PLANT SPECIES BIOLOGY ( WILEY-BLACKWELL )  27 ( 1 ) 3 - 29   2012.01 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Heterostyly is a genetically controlled sexual polymorphism promoting outcrossing by animal pollinators. The occurrence of heterostyly in angiosperms was investigated, and 199 genera in 28 families in 15 orders were recognized as taxa that contain heterostylous species. A correlation between the occurrence of heterostyly and ploidy level was found in some limited groups in Primulaceae and Rubiaceae. In such taxa, individuals with a lower ploidy level tended to have heterostyly and individuals with a higher ploidy level tended to have monomorphic flowers. It appears reasonable that the first step of the breakdown of heterostyly was the recombination of the supergene in a diploid heterostylous plant, and then poyploidization incidentally occurred. Polyploidization itself does not necessarily appear to have direct effects on the breakdown of heterostyly.

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A list of seed plant specimens in Osaka Museum of Natural History 4, Celastraceae. (Japanese with English abstract)

Fujii Shinji, Naiki Akiyo

( Osaka Museum of Natural History )  3 ( 10 ) 143 - 158   2009.12

Type of publication: Research paper (bulletin of university, research institution)

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Population genetic structure, phylogeography, and demographic history of Platycrater arguta (Hydrangeaceae) endemic to East China and South Japan, inferred from chloroplast DNA sequence variation

Qiu Ying-Xiong, Qi Xin-Shuai, Jin Xiao-Feng, Tao Xiao-Yu, Fu Cheng-Xing, Naiki Akiyo, Comes Hans Peter

TAXON   58 ( 4 ) 1226 - 1241   2009.11 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

Pollen morphology of the genus Skimmia (Rutaceae) and its taxonomic implications

Tomoko Fukuda, Akiyo Naiki, Hidetoshi Nagamasu

JOURNAL OF PLANT RESEARCH ( SPRINGER TOKYO )  121 ( 5 ) 463 - 471   2008.09 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Pollen morphology of the genus Skimmia was studied. Of six species of the genus, five species were investigated by light microscopy and scanning electron microscopy. Pollen grains of Skimmia had striate to striate-reticulate sculpture and variable aperture number (3-7), and these characters differed from even the phylogenetically closest relatives such as Dictamnus and Casimiroa which have 3-colporate pollen grains with reticulate exine. In Skimmia laureola, pollen dimorphism is suggested in the aperture number in accordance with the floral system. Pollen grains of Skimmia japonica, a morphologically very variable species, were extensively surveyed covering its whole distribution area. The grains were also striate to striate-reticulate, and the exine sculpture was not different between varieties. However, the aperture number of S. japonica showed a geographical variation ranging from 4 to 6; in Sakhalin, Hokkaido, most part of Honshu and Taiwan, grains with 4-5 apertures were dominant, while in the southern part of Japan, including the Ryukyu Islands and the Izu Islands, those with 5-6 apertures were common.

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Distribution and chromosome number of Damnacanthus indicus (Rubiaceae) in the drainage area of Yamatogawa River system, central Japan (Japanese)

Akiyo NAIKI, Plant Research Group of the Yamatogawa River System (Project Y Osaka Museum of Natural Histoy)

Bulletin of the Osaka Museum of Natural History ( Osaka Museum of Natural History )  62   2008.03 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

Distribution and chromosome number of Damnacanthus indicus (Rubiaceae) in the drainage area of Yamatogawa River system, central Japan (Japanese)

Akiyo NAIKI, Plant Research Group of, the, Yamatogawa River System, Project Y, Osaka Museum of, Natural Histoy

Bulletin of the Osaka Museum of Natural History ( 大阪市立自然史博物館 )  62   2008.03 [ Peer Review Accepted ]

Type of publication: Research paper (bulletin of university, research institution)

Karyotypic analysis of Skimmia japonica (Rutaceae) and related species

Tomoko Fukuda, Akiyo Naiki, Hidetoshi Nagamasu

JOURNAL OF PLANT RESEARCH ( SPRINGER TOKYO )  120 ( 1 ) 113 - 121   2007.01 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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A karyotypic analysis of three species of Skimmia (Rutaceae) in East Asia was performed that examined 88 individuals from 53 localities. Chromosome numbers of S. japonica, S. reevesiana and S. arisanensis were 2n=30, 31, 32 (=30+0-2B), 2n=60 and 2n=60, respectively. The chromosome number of S. arisanensis was reported for the first time. All species had a large chromosome pair or quartet (the first pair or quartet) with a median - submedian centromere in the karyotype. In S. japonica the arm ratio of this first pair was considerably variable and showed a geographical pattern. In the northern half of the distribution range, Sakhalin, Hokkaido, Honshu, Shikoku and part of Kyushu, the arm ratio was 1-1.2, while in the southern half, part of Kyushu, Ryukyu and Taiwan, the arm ratio was very variable and ranged from 1.2 to 2.4. In S. japonica the first pair was sometimes rather heteromorphic; however, the heteromorphism was not related to sex of the plant.

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Mating system, seed production and population genetic structure of Ophiorrhiza japonica (Rubiaceae) in Iriomote Island, Japan

NAKAGAWA Masato, NAIKI Akiyo, TAKASO Tokushiro

Journal of plant research   119   2006.12 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

Phylogeny and breakdown of distyly correlated with polyploidization in Damnacanthus (Rubiaceae).

Naiki, A, H. Nagamasu

XVII International Botanical Congress － Abstract: 439     2005.07 [ Peer Review Accepted ]

Type of publication: Research paper (other science council materials etc.)

Morphological variation in leaf domatia enables coexistence of antagonistic mites in Cinnamomum camphora

S Nishida, A Naiki, T Nishida

CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE ( NATL RESEARCH COUNCIL CANADA )  83 ( 1 ) 93 - 101   2005.01 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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We examined variation in Cinnamomum camphora (L.) J. Presl (Lauraceae) leaf domatium morphology with respect to domatium inhabitants in the tree's natural habitats. Canonical discriminant analysis revealed that domatium morphology could be classified into four different types: pouch type, domatia with a narrow (about 0.06 mm) pubescent opening; pubescent pit type, domatia with a wider (about 0.21 mm) pubescent opening; glabrous pit type, domatia similar to the pubescent pit type but with a glabrous opening; and dish type, domatia with a wide (about 0.26 mm) glabrous opening. These four domatium types were found in different positions on a leaf, and domatia with narrower openings tended to occur in or near the position between the midrib and basal secondary veins. The four domatium types were associated, respectively, with herbivorous Eriophyidae mites and herbivorous or fungivorous Tarsonemidae mites; with carnivorous Stigmaeidae mites; with Stigmaeidae mites and egg shells or excuviae of carnivorous Phytoseiidae mites; and with egg shells or excuviae of Phytoseiidae mites. These results suggest that different mites use different domatia, even on the same C. camphora leaf. This conclusion may explain the different results in previous reports about domatium fauna. It suggests that ecological interactions within the plant-herbivore-carnivore system are complicated.

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Correlation between distyly and ploidy level in Damnacanthus (Rubiaceae).

Naiki A, Nagamasu H

American journal of botany ( American Journal of Botany )  91 ( 5 ) 664 - 671   2004.05 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Somatic chromosomes were observed in 661 individuals of 14 taxa, nine species and five varieties, of Damnacanthus (Rubiaceae). Chromosome numbers are reported for the first time for 13 taxa. Diploid (2n = 22) and tetraploid (2n = 44) counts were obtained. Distyly is reported for the first time for four species, D. angustifolius, D. henryi, D. labordei, and D. officinarum. A strong correlation exists between chromosome number and occurrence of distyly. Regardless of taxa in Damnacanthus, distylous populations are diploid, and monomorphic populations are tetraploid. Flowers of the monomorphic populations observed have a long style and short stamens with few exceptions. Polyploidization may have caused the breakdown of distylous to monomorphic flowers. In D. indicus, leaves from the tetraploid populations tend to be larger than those from the diploid populations. Populations of tetraploid D. indicus were distributed in more northern areas than those of the diploid. Three types of sympatric distribution were found for the varieties of D. indicus in Japan: diploid and tetraploid, two diploids, and two tetraploids. Based on the present chromosome number study, the taxonomy of the varieties of D. indicus should be revised.

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Unusual flowering shoots in Damnacanthus (Rubiaceae)

Naiki, A, H. Nagamasu

Acta Phytotaxonomica et Geobotanica ( 日本植物分類学会 )  55 ( 2 ) 129 - 132   2004 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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The spine of Damnacanthus has been interpreted as a metamorphosed leaf or a lateral branch. There is a hypothesis that a pair of spines is modified inflorescence by the observation in which vegetative and reproductive branching units are comparable to each other. Our observations of various transitional forms between the spines and the pedicels in Damnacanthus agree with the hypothesis.

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アリドオシ属(アカネ科)の分類学的および二型花柱性に関する研究(学位論文紹介)

内貴 章世

分類 ( 日本植物分類学会 )  4 ( 1 ) 91 - 94   2004 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Correlation between distyly and ploidy level in Demnacnathus (Rubiaceae)

NAIKI A

Am J Bot   91   664 - 671   2004 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Correlation between distyly and ploidy level in Damnacanthus (Rubiaceae)

NAIKI A

Am J Bot   91   664 - 671   2004 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Distyly and pollen dimorphism in Damnacanthus (Rubiaceae)

A Naiki, H Nagamasu

JOURNAL OF PLANT RESEARCH ( SPRINGER-VERLAG TOKYO )  116 ( 2 ) 105 - 113   2003.04 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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We document distyly in Damnacanthus (Rubiaceae) and investigate pollen morphology in the genus. Within nine taxa in Japan (four species, four varieties and one form), five show distyly. Non-distylous taxa of Damnacanthus always have a long style and short stamens. We examined the pollen morphology of all taxa of Damnacanthus in Japan. The pollen grains of Damnacanthus are 3- to 5-orthocolporate or sometimes loxocolporate. Polymorphic pollen is sometimes observed even within a single flower. Pollen dimorphism is associated with distyly; pollen grains from short-styled (thrum) flowers are significantly larger than those from long-styled (pin) flowers, and the muri are smooth in pin flowers whereas the pollen grains of thrum flowers have minute granules on the top and/or on the sides. In non-distylous taxa, in which the style is longer than stamens, the muri are always provided with minute granules. Interestingly, the pollen grains with granules in the non-distylous taxa contrast with the pollen of the distylous taxa, because granulate pollen grains are found only in thrum flowers. Although Damnacanthus is a stenopalynous genus, the number of colpi is useful for delimiting taxa. Based on palynological characters, we conclude that Damnacanthus should be revised.

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Carex jubozanensis (Cyperaceae), a new species from Japan

Oda, J, A. Tanaka, A. Naiki, H. Nagamasu

Acta Phytotaxonomica et Geobotanica ( 日本植物分類学会 )  54 ( 2 ) 127 - 135   2003 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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Carex (sect. Rhomboidales) jubozanensis J. Oda & A. Tanaka is described as a new species from the western and central Honshu, Japan. This new species is characterized and clearly distinguished from its allies in the sect. Rhomboidales by the actively stoloniferous habit and the emarginate scales of both staminate and pistillate flowers. The micromorphology of achene surface is also different from that of its allies.

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Pollination system and evolution of dioecy from distyly in Mussaenda parviflora (Rubiaceae)

Akiyo Naiki, Makoto Kato

Plant Species Biology ( Plant Species Biology )  14 ( 3 ) 217 - 227   1999.12 [ Peer Review Accepted ]

Type of publication: Research paper (scientific journal)

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The floral morphology arid reproductive ecology of a scandent shrub species, Mussaenda parviflora Miq. (Rubiaceae), were studied on Iriomote and Amami Ohshima Islands, Japan. The morphological study demonstrated that M. parviflora was gynodioecious. Crossing experiments, however, revealed that if was functionally dioecious. The flowers were visited mainly by butterflies in the daytime and mainly by crepuscular hawkmoths in the evening. Dioecy in this species is thought to have evolved from distyly. Dioecy of this species, which is pollinated by long-tongued Lepidoptera, is unusual as the evolution of dioecy from distyly in plants with long corolla tubes is thought to have been triggered by a pollinator shift from long- to short-tongued insects. In this species, however, two floral morphological features may have caused the evolution. The first feature is the presence of many upward-facing hairs covering the inner Surface of the upper part of the corolla tube these hairs appear to have impeded pollen flow from long- to short-styled flowers. The second feature is the overlap in anther height between the two types of flowers, which may have reduced seed set by clogging stigma with incompatible pollen grains. Accordingly, male sterility in long-styled plants may have evolved.

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