Library

Notes: The life-history characteristics and demography of Erythronium japonicum Decne. (Liliaceae) are described here. This is a typical prevernal species of temperate broad-leaved deciduous forests in the Japanese Islands and adjacent Far East regions, and is one of the representative perennials of Arcto-Tertiary origin. It flushes in early to late April (in May at higher elevations) on the deciduous forest floor in the lowlands to lower montane zone in Hokkaido, Honshu, Shikoku and Kyushu. Flowering individuals bear a single but showy large purplish-red flower, blooming downward from the top of the scape. This species is a typical polycarpic perennial and bumblebee-pollinated outbreeder, with pollen/ovule ratios of 4800–6150, although occasional inbreeding is known in the northern populations of Hokkaido. Yellowish-brown seeds, 2–3 mm long, with a tiny elaiosome, are susceptible to ant-dispersal (i.e. myrmecochory). According to our long-term monitoring study that has continued for the past 25 years, since 1979, its mean life expectancy is extremely long (approximately 40 years).

Notes: Extrafloral nectaries formed at the petiole base and periphery of stem nodes of two Fallopia species, Fallopia japonica (= Polygonum cuspidatum) and Fallopia sachalinensis (= Polygonum sachalinense), were examined anatomically, scanning electron microscopy (SEM) observations were made, and the sugar contents of the nectar were analyzed. Ants and other insect species attracted to the extrafloral nectaries were collected and identified, and insect herbivores were observed, collected and identified. Volatile substances were emitted from damaged leaves after insect predation was chemically determined, and a herbivore-induced leaf volatile, (E)-4,8-dimethyl-1,3,7-nonatriene, as a general parasitoid attractant, was emitted 4–6 h after leaf damage. Complex plant–insect interactions in two Fallopia species are discussed in light of the evidence obtained in the present study, and the roles of extrafloral nectaries in combination with chemical signals for defense of insect herbivory are evaluated.

Notes: Coding regions of the rbcL and matK genes of cpDNA and internal transcribed spacers (ITS) of nuclear ribosomal DNA were sequenced to study phylogenetic relationships within and among all four genera of Trilliaceae: Trillium, Paris, Daiswa and Kinugasa. The rbcL gene has evolved much slower than matK and in particular ITS; hence the phylogenetic trees based on the rbcL gene show a much lower resolution than trees based on either matK or ITS. The general topology of phylogenetic trees resulting from separate parsimony analyses of the matK and ITS sequences are relatively congruent, with the exception of the placement of T. pusillum. Both matK and ITS phylogenies reveal that T. rivale diverges at the base of the trees. In both trees, Paris, Daiswa and Kinugasa form a relatively weakly supported group. Within this group, the allo-octaploid Kinugasa japonica is the sister group of Daiswa species. The Paris–Daiswa–Kinugasa group, the major Trillium group, and T. undulatum and T. govanianum showed a loosely related topology, but their affinities are not evident according to these two molecular markers. However, phylogenetic analysis of amino acid sequences derived from matK shows that T. rivale together with clades T. undulatum–T. govanianum, Daiswa–Kinugasa and Paris is basally diverged as a sister group to the remainder of Trillium.

Notes: Abstract Based on demographic genetic differentiations, six isolated small lowland populations and one continuous large montane population of the Siebold's beech forests (Fagus crenata) in Toyama Prefecture, Honshu, Japan, were examined using isozymes as genetic markers. The results of within and among-population genetic variabilities revealed that all six lowland populations, which are fragmented and isolated from each other at present, showed significantly lower percentages of polymorphic loci (P) and lower mean numbers of alleles per locus (A) than the montane population. Fluctuations in allele frequencies were observed in lowland populations. Alleles that were rare in the montane populationshowed unexpectedly higher frequencies in some lowland populations. The mean FST value of the lowland populations (0.116) was significantly higher than that of the montane population in Tateyama (0.005)and several other populations analyzed. All these facts suggest that small isolated Siebold's beech populations remaining on the foothills in the lowlands of Toyama Prefecture have been exposed to climate shifts and strong human disturbances, which result in fragmentation and isolation of local populations. On the other hand, the large continuous montane population on Tateyama maintains a higher genetic variability, with genetic reshuffling within and among subpopulations. Spatial genetic localizations and the resulting changes in the size-class structure in lowland populations were also discussed in relation to the demographic changes.

Notes: Abstract Variability in life history traits and phenology of field populations of Cardamine flexuosa and C. fallax was investigated. C. flexuosa is an annual that typically grows all year around and occurs as a weed in cultivated fields such as paddy fields, crop gardens and orchards. C. fallax is a typical winter-green annual that mainly grows along the roadside on foothills. Differences in growth form of both species corresponded to variations in habitat conditions. Plants of paddy field populations of C. flexuosa normally possess many basal branches, while those of orchard populations of C. flexuosa typically have an erect growth form with few basal branches. C. fallax also possesses a typical erect growth form. Other life history traits (e.g., individual plant biomass and reproductive traits) of both species were highly variable both within and between populations. In C. flexuosa, seasonal differences were also found in flowering and fruiting performance. Synchronous flowering of all plants was observed in spring populations, while partial flowering occurred in summer-autumn populations. Differences in the size class structure of plants in the autumn appeared to be caused by different cultivation schedules for crop plants in the fields. C. fallax, in contrast, possesses a rather fixed seasonal growth cycle as a typical winter-green annual with a synchronized flowering in spring.

Notes: Abstract Fifteen Asiatic and four North American taxa of the genus Disporum (Liliaceae-Polygonateae) were karyologically examined. The chromosome numbers and karyotypes of D. multiflorum (2n= 14), D. sessile var. sessile f. minus (2n= 16), D. sessile var. micranthum (2n= 16), and D. taipingense (2n= 16) were determined for the first time. Thirteen additional chromosome counts and karyotype analyses were made for the following 11 Asiatic Disporum taxa (Section Disporum): D. calcaratum (2n= 14 and 16-a new count), D. cantoniense (2n= 14 and 16), D. kawakamii (2n= 16), D. longistylum (2n= 16), D. lutescens (2n= 16), D. sessile var. sessile f. sessile (2n= 16), D. shimadai (2n= 14), D. smilacinum var. smilacinum (2n= 16), D. smilacinum var. ramosum (2n= 16), D. uniflorum (2n= 16), and D. viridescens (2n= 16 + 1B-a new count).The karyotypes of four North American taxa (Section Prosartes) were reported for the first time, although the same chromosome counts had been previously known for each taxon: D. hookeri (2n= 18), D. lanuginosum (2n= 18), D. maculatum (2n= 12), and D. smithii (2n= 16). D. maculatum possesses a very characteristic satellite on the long arm of the fifth subterminal chromosome; the karyotype of D. smithii (x= 8) is also characterized by possessing a minute satellite on the short arm of the fifth pair and also by a secondary constriction on the short arm of the sixth pair.One of the most noteworthy findings made in the present study is that the species of Section Disporum and Section Prosartes possess conspicuously distinct cytological features in the size of resting nuclei and cells, interphase chromosomes, and mitotic prophase and metaphase chromosomes. The plants of Section Disporum have distinctly larger resting nuclei and cells than those of Section Prosartes; Section Disporum possesses a typical homogeneously diffused type (= densely diffuse type according to Tanaka, 1977) of interphase chromosomes, while Section Prosartes has a prochromosome type; the condensation pattern of their prophase chromosomes is of a continuous type in Section Disporum, while a proximal type occurs in Section Prosartes; Section Disporum possesses distinctly larger sized metaphase chromosomes, as compared with Section Prosartes. All of these karyological differences described above strongly support D. Don's original concept (1839, 1841) of treating Disporum and Prosartes as two separate genera.

Notes: Abstract Volatile substances emitted from the flowers of eight Magnolia taxa (M. sieboldii ssp. japonica, M. praecocissima var. praecocissima and var. borealis, M. tomentosa, M. salicifolia, M. obovata, M. denudata, and M. grandiflora) and one Michelia species (M. compressa) (Magnoliaceae) were examined and identified using GC-MS. Volatile substances of these Magnolia and Michelia species consist primarily of monoterpenoids and sesquiterpenoids produced by the mevalonate pathway, acetogenins by the acetate-malonate pathway, and phenyl-propanoids by the shikimate pathway. These Magnolia and Michelia species all possessed various combinations of volatile monoterpenoids, acetogenins, and phenylpropanoids, except for Magnolia obovata, which emitted primarily sesquiterpenoids. Free amino acids in pollen of 12 Magnolia and one Liriodendron species were also analyzed, and their value as food sources for pollinators evaluated.Pollinators visiting the flowers of five Magnolia species were collected in their native sites and identified. Their behaviors and roles as pollinating agents were assessed.