Iris Japonica Research Articles

The relative importance of sexual reproduction and clonal propagation in rhizomatous herb Iris japonica Thunb. from two habitats of Jinyun Mountain, Southwest China

Reproductive behaviour of clonal plants might change in contrasting habitats. In field and simulated experiments, we studied the relative importance of sexual reproduction and clonal propagation in rhizomatous herb, Iris japonica Thunb. in two forest habitats (BF, bamboo forest and OAFE, open area of forest edge), and effects of population origin (BF vs. OAFE) and environmental effects (shading) on sexual vs. clonal reproduction. In field experiment, the relative importance of reproduction in I. japonica populations was different in two habitats, which showed predominantly sexual reproduction in OAFE and clonal propagation in BF. In simulated experiment, the effect of population origin and light treatment (shading) was significant for reproduction of I. japonica. Clonal propagation was only influenced by population origin, and sexual reproduction was determined both by population origin and light treatment. A trade-off between two reproductive modes exhibited in both experiments. The trade-offs was more obvious in OAFE than in BF because sexual reproduction, resource and inter-specific competition obviously lacked in BF. The results indicated that the selective forces shaping reproduction of I. japonica in contrasting habitats might demonstrate pronounce adaptive population differentiation among forest habitats. Thus, I. japonica populations formed local differentiation by adaptation of reproduction to local heterogeneous forest habitats.

Patterns of ramet population of Iris japonica Thunb. and their effects on herb diversity in different microsites on Jinyun Mountain, China

Spatial patterns of ramet population of Iris japonica Thunb. and their effect on species diversity in the herb layer of 3 microsites (open area of forest edge (OAFE), bamboo forest (BF) and evergreen broad-leaved forest (EBF)) on Jinyun Mountain were studied using spatial pattern, niche and diversity analyses in a combination of population and community methods. The results were as follows: (1) judged by V/m and Morisita index ( I δ ), ramet population of I. japonica in 3 microsites all clumped from scale 0.5 m × 0.5 m to 2 m × 2 m; (2) the pattern scale and pattern intensity both gradually decreased on all scales, and the density of ramet population of I. japonica decreased with the increase in canopy density and the decrease in relative photon flux density (RPFD) and R/FR from OAFE to EBF. In OAFE and BF, widespread I. japonica had significantly negative influence on the dominance of original dominant species and on species diversity in the herb layer ( p < 0.05), while those influences in EBF were extremely weak. The mechanisms that pattern characteristics of ramet population of I. japonica influence herb diversity in 3 microsites were different. In OAFE, strong regeneration niche (above-ground spatial and below-ground root) and trophic niche (nutrient) competition had significantly negative influence on the species diversity of rare herbs and dwarf herbs. In BF, strong regeneration niche (below-ground root) and trophic niche (above-ground for light and below-ground for nutrient) competition had negative effect on the occurrence of rare species and on the survival of other herb species. In EBF, weak niche competition had little effect on the survival of herb species. Intensity of regeneration niche and trophic niche competition between I. japonica and other herb species is the determinant to the mechanism that ramet population of I. japonica influences herb diversity.

A new potyvirus from butterfly flower (Iris japonica Thunb.) in Zhejiang, China

A filamentous virus isolated from Iris japonica with mosaic symptoms was pathogenic to I. japonica and I. bulleyana but not to 12 virus indicator species. Sequencing of the 3'-terminus of the genome showed that it was a potyvirus, most closely related to sunflower mosaic virus (63.2% identical), and phylogenetic analysis also showed a more distant grouping with tobacco etch and Colombian datura viruses. The virus was detected by RT-PCR in symptomatic I. japonica plants from several regions of China. The virus appears to be an isolate of a new species in the genus Potyvirus, tentatively named butterfly flower mosaic virus.

Highly oxygenated isoflavones from Iris japonica

Two new isoflavones, irisjaponins A and B, have been isolated along with seven known isoflavones from the aerial parts of Iris japonica. Their structures have been determined by spectroscopic analyses and comparison of 13C NMR data with those of their congener, as 5,7-dihydroxy-6,2′,3′,4′,5′-pentamethoxyisoflavone and 5,7-dihydroxy-6,2′,3′,4′-tetramethoxyisoflavone.

Study of iridaceae plants with the capability to induce differentiation of HL-60 promyelocytic leukemia cells

Thirteen species of Iridaceae plants were studied with the capability to induce HL-60 promyelocytic leukemia cells into macrophages. The neutrophil stimulating activity in these plants was also examined by measuring superoxide production. Both activities are known to be possessed by tumor promoters such as 12-O-tetradecanoylphorbol-13-acetate (TPA). Dried parts of Iridaceae plants were extracted with methanol. Then, each extract was added to a culture medium of HL-60 cells and cultured for two days. A morphological change of the cells from suspended to adherent state, which was reported to occur in the process of differentiation, was observed. Nine species, most of which belong to the Iris genus, had the activity to cause cell adhesion. Each of the cell adhesion-positive extract was applied to a silica gel column and eluted with chloroform, ethyl acetate and methanol in order. The activity was recovered only in the ethyl acetate eluate in all the cases. Those partially purified fractions also activated superoxide generation of neutrophils. When ethyl acetate fractions of Iris tectorum and Iris japonica were analyzed by HPLC, three active peaks different from TPA and teleocidins in UV spectra were detected. From these results, it was suggested that several plants of Iridaceae may contain TPA-type and yet structurally-different tumor promoters.

Iridals from Belamcanda chinensis and Iris japonica

Three new iridals were isolated, along with two known compounds; (+)-6 R,10 S,11 S,14 S,26 R)-26-hydroxy-15-methylidenespiroirid-16-enal and iso-iridogermanal, from the rhizomes and roots of Belamcanda chinensis and Iris japonica. The new iridals were determined to be 28-acetoxy-14,15-dihydro-26-hydroxy-19-methylidenespiroirida-15,17-dienal (belamcandal), its deacetyl derivative and 16- O-acetyl iso-iridogermanal. Their fatty acid esters were also isolated. Belamcandal stimulates throat membrane.

Damage to Medic Pastures By Skylarks in North-Western Iraq

An investigation was made on the growth indices of Iris japonica growing on the yellow soil and Karst soil within a subtropical evergreen broad-leaved forest and in the forest gaps, aimed to approach the clonal plasticity of I. japonica in heterogeneous habitats. The results showed that the ramet height and diameter and the rhizome diameter of I. japonica were significantly higher in yellow soil habitat than in Karst soil habitat, while the individual density was in adverse. Light had significant effects on rhizome diameter, but soil condition had lesser effects under the same light environment. Within the forest of Karst soil habitat, the bud number and flower number of I. japonica were zero, possibly due to the double pressure from soil quality and light environment for the balance between resources uptake and energy assignment and for the sustaining of growth. In a certain extent, I. japonica in yellow soil habitat tended to K strategy via decreasing the individual number for improving competition to adapt environment, while I. japonica in Karst soil habitat tended to r strategy via increasing individual number for sustaining competition capability.

Studies on constituents of Iris genus plants. VI. The constituents of the rhizoma of Iris florentina L. and the constituents of the petals of Iris japonica Thunb (author's transl)

Studies on constituents of Iris genus plants. VI. The constituents of the rhizoma of Iris florentina L. and the constituents of the petals of Iris japonica Thunb (author's transl)

二三のアヤメ属植物における単面葉の背腹構造

In all Iris species with unifacial leaves the rhizome lies in the soil horizontally and is distinctly dorsiventral. In most of them, the foliage shoots with equitant and isobilateral leaves which stand erect, both leaf surfaces being exposed equally to light and gravity. However, some species, for instance, Iris gracilipes A. Gray, Iris tectorum Maxim., etc. have plagiotropic shoots which do not show any anatomical unequality of the surfaces of their leaves.In the species described in the present report a structural dorsiventrality was found. In ris formosana the seedling has, except for the first 1 or 2, dorsiventral leaves. The dorsiventrality can be inverted by changing their direction in relation to gravity, as in Iris japonica. In Iris uniflora and Iris Rossii the seedling is not dorsiventral but the lateral shoots are distinctly so. Once established, this dorsiventrality cannot be inverted by changing the direction in respect to external factors. The growing point seems to be determined dorsiventrally and it gives rise to leaves with unequal surfaces. In this case also gravity seems to have the determining rôle. In the mode of induction Iris Wilsoni and Iris Bulleyana seem to belong to the stable type.It is noteworthy that all the above species are members of Asiatic flora. They Cbelong to the section Apogon except Iris japonica and Iris formosana, which are representatives of the section Evansia. The taxonomic or systematic significance of leaf dorsiventrality cannot be evaluated until more Iris species are thoroughly examined. In literature the indications are that many have leaves with unequal surfaces.* The causal sequence of aitiogenous induction of dorsiventral differentiation of the leaves is yet obscure. The unequal distribution of food materials and some determining hormones may probably be the factors which cause the unequal differentiation, as can be assumed from the eccentric growth in the thickness of the inclined trunks or lateral branches in many plants (14, 15). For the materials used in the present study we are indebted to Dr. M. Reed, Brooklyn Botanic Garden, U.S.A., Dr. Yu, Ching-jang, Dr. Shoichi Tanaka, Mr. Ryuhon Saito and Mr. Taketo Mizoguchi. We wish to express to all the above mentioned persons our sincere thanks for kindly supplying the rare plant materials.

しやがノ芽胞及ビ胚嚢形成, 特ニ其不稔ニ就イテ

1. In Iris japonica, an allotriploid plant, 13.2% of the ovules had each an embryo sac with normal structure, in 39.2% the embryo sac showed. incomplete development, and 32.2% had abnormal, embryo sacs (Table 2), therefore at least 86.8% of ovules were sterile.2. 63.4% of the pollen grains were found to be viable (Table 3).3. There were observed some ovules having two or three megaspore mother cells (Table 1). These mother cells were situated either side by side or end to end in the nucellus. The processes of the development of the embryo sac suggest that they are probably unable to develop into twin or polyembryo.

しやがノ稀ナル朔ノ形成及ビ其不稔トノ關係ニ就イテ

しやがノ稀ナル朔ノ形成及ビ其不稔トノ關係ニ就イテ

Karyological Studies on &lt;i&gt;Iris japonica&lt;/i&gt; Thunb. and Its Allies

1. Iris japonica Thunb. (Japanese name “Syaga”) is an allotriploid (2n=54), but neither autotriploid nor hypertriploid. It contains 2 different karyotypes; the chromosome constitution may be described as AAB.2. I. japonica has been probably derived from a hybrid between 2 species which had different karyotypes, probably A and B, and one set (A) of the parent chromosomes was doubled. It might have originated partly in its present habitat and survived there, while the parent species have become extinct.3. A Chinese species allied to I. japonica is a diploid plant having 36 somatic chromosomes. Its karyotype (C) is different from A and B. Neither this species nor SIMONET's I. japonica is to be considered as the direct parent of our I. japonica Thunb.4. I. formosana Ohi is also a diploid plant having 28 somatic chromosomes. Not only its karyotype (D) but also the number of the chromosomes are different from those of other species. This type may be intimately related to the ancestral type of other species. The absence of terminal-constriction chromosomes in this karyotype and their presence in other species suggests that the increase of the chromosome number in the latter is mostly due to the fragmentation of the chromosomes which occurred at the attachment constriction.5. I. japonica and its allied species show an aneuploid series, 2n=28, 34, 36, and an allotriploid 2n=54. They all show different karyotypes.6. Aneuploidy may appear occasionally in any plant, but in that which propagates by seeds only, the aberrant chromosomes will be easily eliminated through meiosis. Therefore the survival of the aneuploid series in nature is probably due to the capability of vegetative propagation in these plants.

あやめ屬植物ノ細胞學的研究 (豫報)

The diploid number of chromosomes of several species of Iris have been determined as follows: Iris Kaempferi var. hortensis 24, I. Kaempferi var. spontanea 24, I. sibirica var. orientaris 28, I. laevigata 32, I. gracilipes 36, I. florentina 48, I. japonica 54. Among these species, Iris japonica and I. florentina form trivalent chromosomes in the prophase of the heterotypic nuclear division in their pollen-mother-cells. Therefore their chromosomes must be considered as triploid. It is a remarkable fact that all the individuals of a distinct species have triploid chromosomes.