The embryology ofStegnospermataceae,with a discussion on its status,affinities and systematic position

The embryology ofStegnosperma halimifolium andS. watsonii has been studied in detail. The tapetum is of the secretory type and its cells become multinucleate. Simultaneous cytokinesis in the pollen mother cells follows meiosis. The ripe pollen grains are 3-celled. The ovule is crassinucellate, bitegmic and amphitropous, with the micropyle formed by the inner integument alone. The female archesporium is one celled, and the parietal tissue 3–5 layered. The embryo sac development conforms to thePolygonum type. A central strand, 6 or 7 cells thick, differentiates inside the nucellus and extends from the base of the embryo sac to the chalazal region. The endosperm is nuclear. The embryogeny conforms to the Caryophyllad type. The seed coat is formed by the outer epidermis of the outer integument and the inner epidermis of the inner integument. Based on this evidence and other data, the status of the genus as an independent family,Stegnospermataceae (Stegnospermaceae) is confirmed. Apparently, it forms a connecting link betweenPhytolaccaceae andCaryophyllaceae.     

The morphology of styles and stigmas inVicia (Leguminosae), and its systematic implications

The morphology and development of styles and stigmas ofVicia, one of the five genera of tribe Vicieae, were studied by scanning electron microscopy to contribute to a revision of infrageneric classification. Among the 22 species examined, variations were found as to: (1) whether a boundary between stigma and style is V-shaped when viewed from the adaxial side or not; (2) whether stylar hairs sprout on all sides of the style or only on the abaxial side; (3) whether a hairy area of the style connects with the stigma area first at lateral sides or at an adaxial side; (4) whether styles are tapered or bottle-neck-shaped; (5) whether styles are straight or bend abaxially. Based on these variations, five morphological types of styles and stigmas were provided with a diagnostic key. Comparisons with related tribes Cicereae, Coronilleae, Galegeae, Hedysareae, Loteae and Trifolieae as possible outgroups suggested that the V-shaped boundary between stigma and style is a synapomorphy of some species withinVicia, and that a dorsally compressed and abaxially tufted style, which was distributed in separate subgenera and sections sensu Kupicha but is now known to occur together with the V-shaped boundary, has evolved only one time in the genus, rather than more than once as supposed earlier.     

Pollen morphology ofSonchus and related genera,and a general discussion

The pollen morphology of the taxa belonging to the generaAetheorhizaCass.,LaunaeaCass.,ReichardiaRoth andSonchus L. in the Iberian Peninsula has been studied with light and electron microscopy. The pollen is 3(-4)-zonocolporate and echinolophate (without polar lacunae, but in general with prelacunae), with equatorial ridges and 15–20 lacunae: 3–4 poral, 6–8 abporal and 6–8 paraporal. Small to medium size, P × E = 19–36 × 23–42 µm; sometimes two different sizes have been found. Exine 3–9 µm thick and ornamentation microreticulate and echinate. The results clearly show the relationships between genera.Moreno-Socías, E., Mejías, J. A., Díez, M. J., 1994: Morfología polínica deLactuceae (Asteraceae) en la Península Ibérica, I.Lactuca y géneros relacionados. — Acta Bot. Malacitana.19: 103–113.     

Population structure of the sailfin sandfish, Arctoscopus japonicus (Trichodontidae), in the Sea of Japan

We analyzed patterns of genetic diversity in the sailfin sandfish (Arctoscopus japonicus), focusing on population subdivisions within the Sea of Japan. We observed 270 specimens from nine sampling sites in 1999–2000, i.e., seven sites in the Sea of Japan and two sites from the Pacific coast of Hokkaido. An additional site (30 specimens) was sampled from eastern Korea in the spawning season of 2004 for comparison. Forty haplotypes, compiled into three haplogroups (A–C), were detected based on the comparison of a 400-bp sequence of the anterior part of the mitochondrial control region. In accordance with previous hypotheses from morphological and molecular analyses, genetic discontinuity between the Sea of Japan and the Pacific coast of Hokkaido was conspicuous. Within the Sea of Japan, eight sampling sites were not genetically uniform, and most of the variations among sites were detected between eastern Korea [the “eastern Korea” (EK) population: distributed from the Korean Peninsula to Mishima, Yamaguchi Prefecture] and the other sites along the coast of Japan [the “western Japan” (WJ) population: from Oki Islands to western Hokkaido] (Φ _CT  = 0.096, P = 0.0183). The WJ population, having lower genetic variability, showed significant departure from neutrality, indicating influences through a recent population expansion. The period of the expansion can be estimated to have begun on the order of 10⁴ years ago. We consider that the present Japan Sea populations have been formed through the invasion of a small ancestral stock to the Sea of Japan and its population expansion during the last glacial period or later. On the other hand, we failed to detect distinct evidence of a population expansion in the EK population. Haplogroup C, detected in a high frequency in this population, was estimated to have mixed with haplogroup A after rapid differentiations of the latter. Therefore, the EK population, strongly influenced by such a mixture, might possess haplogroup C in a higher frequency and a different haplotype composition from the WJ population.     

The syndrome of sea cucumber (Apostichopus japonicus) infected by virus and bacteria

A outbreak of disease with symptoms of evisceration and skin ulteration led to mass mortality in sea cucumber Apostichopus japonicus cultivated in indoor ponds near the Dalian coast from December 2004 to April 2005. Spherical virus particles with a diameter of 75–200 nm were found in the cytoplasm of cells in the water-system, the alimentary canal and in the respiratory trees of the diseased and dying sea cucumber individuals by electron microscopic observation of ultrathin sections. Examination by negative stained samples revealed that all the diseased sea cucumbers were infected by the virus, while the healthly ones cultivated outside the contagious area were not. Two bacterial strains were also isolated from the diseased animals. When exposed to a medium containing the virus particles, regardless of whether the bacterial suspension was added, healthy sea cucumbers exhibited identical disease symptoms as the ones in the indoor ponds, and had a mortality of 90%–100%. However, when exposed to a medium in which there was only one of the two bacterial strains, 30%–80% of the sea cucumbers were infected and nearly 20% died. Negative staining showed that the viral particles were detected only in the bodies of the tested animals that were exposed to the viral medium. Histopathologically, the diseased sea cucumbers are characterized by karyopycnosis, and disintegration of the endoplasmic reticula and mitochondria in the epithelial cells in the water-system, the respiratory tree and the alimentary canal. Fundation items: Supported by commonweal program of State Oceanic Administration of China (200705007), Science and Technology Project of Liaoning Province (2004203001) and Science and Technology Project of Dlian (2004 BINS030).     

Osteological development of the lumpfish,inimicus japonicus (pisces: Synanceiidae)

The osteological development of the synanceiidInimicus japonicus, was described on the basis of five larvae and four juveniles (4.2–10.1 mm BL) reared in the laboratory, and two wild adult specimens. All bones, except for the basisphenoid, were formed in all larvae and juveniles, but fusions between the uppermost actinost and scapula, upper caudal plate and urostyle, and third preural centrum and hemal spine were not completed by 10.1 mm BL. Following comparison with the adult condition, a rod-like ossified bone without a tooth plate on the upper branchial arch of larvae and juveniles was considered homologous with the second pharyngobranchial. The number of epurals and length of the neural spine on the second preural centrum varied (unrelated to growth) and it is inferred thatJ. japonicus shows intraspecific variations in these bones.     

Comparative studies on the reproductive systems ofMazus japonicus andM. miquelii (Scrophulariaceae)

Mazus japonicus is predominantly self-pollinated,M. miquelii mostly cross-pollinated, with a low degree of self-incompatibility. Correlated differences effect structure, development and seismonasty of the stigma, spatial relationships of stigma and anthers, and pollinator visits.M. japonicus produces numerous and light,M. miquelii fewer and heavier seeds. Growth experiments under different temperature regimes demonstrate thatM. japonicus dies after flowering and fruiting, and behaves as an annual, whileM. miquelii has additional asexual propagation and is clearly perennial.M. japonicus grows in somewhat drier and more disturbed habitats thanM. miquelii.     

Taxonomic review of East Asian <Emphasis Type=Italic>Pleuronichthys</Emphasis> (Pleuronectiformes: Pleuronectidae), with description of a new species

A review of East Asian frog flounders, genus Pleuronichthys (family Pleuronectidae), recognized Pleuronichthys japonicus sp. nov. and P. cornutus (Temminck and Schlegel 1846). Pleuronichthys japonicus sp. nov. is characterized by small, dark, rounded spots or marbled markings on the ocular side of the body, rounded cycloid scales somewhat irregularly arranged, usually 12 abdominal vertebrae, 67–80 (modally 75) dorsal-fin rays, 48–59 (modally 55) anal-fin rays, and a short branch of the supratemporal lateral line usually present on both sides. Pleuronichthys cornutus is characterized by densely distributed small, dark, irregular spots on the ocular side of the body, elongate cycloid scales somewhat regularly arranged, usually 13 abdominal vertebrae, 72–88 (modally 77) dorsal-fin rays, 52–65 (modally 58) anal-fin rays, and a branch of the supratemporal lateral line usually absent on both sides. Whereas P. cornutus is distributed from Miyagi Prefecture (Tohoku District) southward along the Pacific coast of Japan to the Bungo Channel, from Akita Prefecture (Tohoku District) southward along the Sea of Japan coast through the Tsushima Strait to the East China Sea, Yellow and Bohai Seas, the Taiwan Strait, and northern Chinese coast of the South China Sea, P. japonicus is distributed from southern Hokkaido southward along the Sea of Japan and Pacific coasts of Japan to the southern East China Sea. Geographic variations were found in caudal vertebrae and anal-fin ray counts, and caudal-peduncle depth in P. cornutus, and in ocular side body coloration, body depth, and head length in P. japonicus. Pleuronichthys lighti Wu 1929 was regarded as a junior synonym of P. cornutus.     

Amylostereum laevigatum associated with the Japanese horntail,Urocerus japonicus

The fungus associated with the Japanese horntail,Urocerus japonicus, in Kochi, Kagawa and Ehime Prefectures was studied. Cultures isolated from the mycangia of 113 adult females of the horntail showed the same cultural characteristics. Four of basidiocarps found on felled logs ofCryptomeria japonica were identifieds asAmylostereum laevigatum based on morphological characteristics. This was the first record ofA. laevigatum from Japan. The cultures isolated from the basidiocarps had the same cultural characteristics as those from the mycangia ofU. japonicus. One mycangial isolate produced basidiocarps on artificially inoculated stem segments ofCr. japonica after a 6-mo incubation and was identified asA. laevigatum. One isolate from the basidiocarps ofA. laevigatum and one from the mycangium ofU. japonicus were artificially inoculated into five trees each ofChamaecyparis obtusa andCr. japonica. The wood of all inoculated trees showed discoloration, with no difference in shape and pattern of discoloration between the two isolates. The inoculated fungi were reisolated from the areas of discoloration in the inoculated trees.     

Isolation and Characterization of Twenty Microsatellite Loci in Japanese Sea Cucumber (Stichopus japonicus)

Twenty microsatellite markers were first developed from the Japanese sea cucumber Stichopus japonicus using an enrichment protocol. Of the 20 microsatellite loci, 19 loci were polymorphic in the population examined. At these polymorphic loci, the number of alleles per locus varied from 2 to 15, and the observed heterozygosities ranged from 0.03 to 0.97, which is considerably higher than those previously found for allozymes. The high variability of the microsatellite markers identified in this study will make them excellent tools for genetic analyses of S. japonicus.     

Protein requirement of the prawn Marsupenaeus japonicus estimated by a factorial method

The protein requirement to give maximum body protein retention in the prawn Marsupenaeus japonicus was assessed by determining both daily protein needed for maintenance (M) and daily body protein increment (G) when the juvenile prawn was maintained on a diet containing high quality protein. The body protein increment was obtained by determining carcass nitrogen increment when the prawn was fed on casein-based diets. The protein required for maintenance was estimated by regressing weight gains of the prawn on the diets containing graded levels of casein. True daily increase or retention of body protein in the prawn corresponded to the sum of G and M, and it was 3.2 g protein per kg body weight per day. The dietary protein requirement of juvenile M. japonicus for maximum body protein retention was suggested to be about 10 g per kg body weight per day providing that the prawn was fed the casein-based diet containing 50% crude protein (net protein utilization = 32) at the feeding level of 2%.     

Cranial morphology of the golden monkey (Rhinopithecus) and douc langur (Pygathrix nemaeus)

Because they have been less studied than most other non-human primates (partly due to the difficulties in accessing their habitat) the origins and phylogenetic relationships ofR. roxellana andR. bieti are controversial. These controversies may be clarified to some degree by adding information on the cranium. To this end, ten cranial dimensions analysed morphometrically here provide data about cranial differences among species of the genusRhinopithecus, and between species ofRhinopithecus andPygathrix nemaeus. Though more similar to each other than to any others in the same genus, the results show a significant separation betweenR. roxellana andR. bieti to the degree that they may be regarded as two different species. This confirms the conclusions of prior studies of external features, qualitative morphological characteristics and biochemical evidence (Yeet al, 1987; Zhang and Ryder, 1995; Jablonski, 1998; Penget al., 1988). The differences between these two species are mainly size-related, being highly correlated with cranial length. Other differences, probably non-size related shape differences, however, are highly correlated with cranial width. Sexual dimorphism plays a part in these findings. In relation to the other species, however, the results show that the Vietnam golden monkey (R. avunculus) has closer craniometric relationships with the douc langur (Pygathrix nemaeus) rather than with the three Chinese golden monkey species. Of these, the Gouzhou species (R. brelichi) shares more similarity withR. avunculus and is more separate fromRhinopithecus roxellana and R. bieti. The smaller differentiation between the two latter species could be due to their more recent separation following the dramatic elevation of Qinghai-Tibetan Plateau after the Middle Pleistocene.     

Growth and nitrogen fixation in Lotus japonicus and Medicago truncatula under NaCl stress: nodule carbon metabolism

Lotus japonicus and Medicago truncatula model legumes, which form determined and indeterminate nodules, respectively, provide a convenient system to study plant-Rhizobium interaction and to establish differences between the two types of nodules under salt stress conditions. We examined the effects of 25 and 50mM NaCl doses on growth and nitrogen fixation parameters, as well as carbohydrate content and carbon metabolism of M. truncatula and L. japonicus nodules. The leghemoglobin (Lb) content and nitrogen fixation rate (NFR) were approximately 10.0 and 2.0 times higher, respectively, in nodules of L. japonicus when compared with M. truncatula. Plant growth parameters and nitrogenase activity decreased with NaCl treatments in both legumes. Sucrose was the predominant sugar quantified in nodules of both legumes, showing a decrease in concentration in response to salt stress. The content of trehalose was low (less than 2.5% of total soluble sugars (TSS)) to act as an osmolyte in nodules, despite its concentration being increased under saline conditions. Nodule enzyme activities of trehalose-6-phosphate synthase (TPS) and trehalase (TRE) decreased with salinity. L. japonicus nodule carbon metabolism proved to be less sensitive to salinity than in M. truncatula, as enzymatic activities responsible for the carbon supply to the bacteroids to fuel nitrogen fixation, such as sucrose synthase (SS), alkaline invertase (AI), malate dehydrogenase (MDH) and phosphoenolpyruvate carboxylase (PEPC), were less affected by salt than the corresponding activities in barrel medics. However, nitrogenase activity was only inhibited by salinity in L. japonicus nodules.     

Neoschumannia (includingSwynnertonia), a primitive genus of theAsclepiadaceae-Stapelieae

A comparison of the West AfricanNeoschumannia Schltr. and the East AfricanSwynnertonia S. Moore reveals that the two monotypic genera must be united.Swynnertonia is sunk into synonymy ofNeoschumannia and the new combinationNeoschumannia cardinea (S. Moore)Meve is made for the East African species.Neoschumannia is shown to belong to the tribeStapelieae. The taxon exhibits a very unusual character combination: the growth form of a woody liana is combined with a tripartite corona unique within theAsclepiadaceae. The morphology of the corona suggests a position ofNeoschumannia close to the base of theStapelieae —Ceropegiinae alliance.     

The effect of crossing distances and population subdivision on floral morphology inScleranthus annuus (Caryophyllaceae), a selfing annual

I used a discontinuous population ofScleranthus annuus (Caryophyllaceae) to study the effect of crossing distances on flower morphology of the progeny. Four types of progeny were produced by artificial selfing, crossing with pollen-donors from the same patch in the population, crossing with pollen from donors from other patches in the population and inter-population crosses. The size of gynoecium parts and 12 sepal characters in this petal-lacking species were significantly influenced by the type of cross and the patch in the population from where the seed-parents originated. All comparisons of progeny types except selfed vs progeny produced by within-patch crosses were significantly separated from each other, while all four seed-parent patches used were significantly separated in a multidimensional space.     

Seedling morphology ofLespedeza (Leguminosae)

Seedling morphology was studied in 22 species ofLespedeza, of which six belong to subgenusMacroles-pedeza and 16 to subgenusLespedeza. Two seedling types were recognized: 1) those with opposite leaves at the first node; 2) those having the first and subsequent leaves alternate. The two types are distinguished in the number of leaf primordia in the plumule of the seed: the opposite type has two leaf primordia, but the alternate type has only one primordium. Most species exhibited one of the two types, but rarely both types were observed in several species. In species having two types, one type always far outnumbers the other. The opposite type was common in Asian species, while the alternate type was common in North American ones. Because seedlings are of the opposite type inKummerowia which is the most closely related genus withLespdeza, the alternate type is considered to be apomorphic inLespedeza. The apomorphic seedling morphology is, there-fore, dominantly occurred in North American species ofLespedeza. This fact may be an evidence which suggests a monophyletic origin for North American species from an Asian ancesfor.     

Gap-detecting mechanism in the seed germination ofMallotus japonicus (Thunb.) Muell. Arg., a common pioneer tree of secondary succession in temperate Japan

Germination responses ofMallotus japonicus (Thumb). Muell. Arg. seeds to temperature revealed a gap-detecting mechanism in the seed germination of the species. Among various constant and alternating temperatures examined in the range from 12–40°C, only very limited temperature regimes were found to be favourable for seed germination, specifically, alternating temperatures between 18–32°C and 28–40°C. A single several-hour higher-temperature (32–40°C) treatment could also induce the germination of seeds which had been imbibed for several days at a constant temperature in the range of 20–26°C, suggesting that there is a process requiring higher temperature among the overal germination processes. Seeds located at or near the surface of denuded soil would have a good chance of experiencing such a temperature change when several rainy days are followed by fine weather, while seeds beneath close vegetation would not. On the other hand, the pressence or absence of light or a simulated ‘canopy ligh’ had little effect on the germination. Therefore, it was concluded that the seeds ofM. japonicus have a ‘gapdetecting mechanism’ in the form of a higher-temperature requirement of a certain process involved in the overall germination processes.