<Emphasis Type="Italic">In vitro</Emphasis> screening of sugarcane to evaluate smut susceptibility

Tissue-cultured plantlets of three sugarcane (Saccharum spp.) cultivars having a known field smut reaction were screened for susceptibility to Ustilago scitaminea H&P Sydow. Plantlets were inoculated with 0.5 l of a suspension of equally mixed quantities of plus and minus mating type sporidia of U. scitaminea at concentrations ranging from 1×10¹ to 1×10⁶ cells. Fungal sori (whips) were produced in cultivar N12 (intermediate) 6weeks following inoculation with 1×10⁵ mixed sporidia and thereafter in cultivar NCo310 (susceptible) but not in cultivar N19 (resistant). Sori bearing teliospores were produced up to 3months following inoculation and incubation at 26°C. No sori were produced at mixed sporidial concentrations lower than 1×10⁵cells. The in vitro soral production in cultivars N19, N12 and NCo310 was 0, 27.5 and 47.5% respectively. Plantlets inoculated with 1×105sporidia of only one mating-type did not produce sori in any of the three cultivars tested. Blind scoring of an unknown sugarcane cultivar by this method corresponded exactly with its field smut rating.     

Development and distribution of the early life stages of the longfin pearleye <Emphasis Type="Italic">Benthalbella linguidens</Emphasis> (Aulopiformes: Scopelarchidae) in the western North Pacific

The early life history and development of the scopelarchid Benthalbella linguidens was studied, based on 203 specimens (from 5.3 to 89.7mm in body length: BL) collected from Kuroshio, Oyashio waters and transition waters of the western North Pacific. The early life stages of B. linguidens are distinguished from those of other species of Benthalbella that inhabit the North Pacific by the characters of 62–64 myomeres in the larval stage and 26–28 anal fin rays in juvenile and transforming specimen. Larvae are elongate; notochord flexion begins at ca. 12mm BL and is completed at ca. 15mm BL. The fin ray complements are established at ca. 40mm BL. The single transforming specimen (89.7mm BL) that has peritoneal pigment was collected from transition waters. All larvae were collected from Kuroshio and transition waters from winter to early summer; however, the size of larvae in Kuroshio waters was apparently smaller than that in transition waters, with ranges of 5.3–32.4mm BL (mean 17.1) and 15.3–35.3mm BL (mean 27.5), respectively. Juveniles were distributed in transition and Oyashio waters and were absent in Kuroshio waters, where adults are commonly distributed. These occurrences of larvae and juveniles in the western North Pacific indicate that B. linguidens spawns in Kuroshio waters in winter and uses transition waters as nursery grounds.     

Larval development and food habits of the marbled parrotfish, <Emphasis Type="Italic">Leptoscarus vaigiensis</Emphasis>, associated with drifting algae

The larval development and food habits of the marbled parrotfish, Leptoscarus vaigiensis (Scaridae) associated with drifting algae were studied. In this study, 628 L. vaigiensis of various developmental stages ranging from postflexion larvae (9.4mm in standard length, SL) to adults (192.0mmSL) were sampled from drifting algae at two fishing ports in Nakagusuku Bay of Okinawa Island. In 3969 fish comprising 65 taxa in 34 families of Teleostei collected with drifting algae, L. vaigiensis occupied 15.8% of samples and occurred generally throughout the whole year. A large number of L. vaigiensis were collected from July to October accompanied by an occurrence of drifting algae composed of Sargassum spp. Larvae and early juveniles ranging from 11.1 to 14.9mmSL appeared sporadically throughout the year, and postflexion larvae 11mmSL occurred from July to November. Their food shifted from planktonic copepods in postflexion larvae and juveniles ranging from 10.0 to 14.9mmSL to seaweed in the juveniles ranging from 15.0 to 24.9mmSL. Furthermore, adults and young over 25mmSL fed almost exclusively on seaweed, with Sargassum spp. constituting the drifting algae. These facts indicate that drifting algae may have a role concerning food and habitat, and may act as a nursery for L. vaigiensis.     

<Emphasis Type="Italic">Uncisudis posteropelvis</Emphasis>, a new species of barracudina (Aulopiformes: Paralepididae) from the western North Pacific Ocean

Six specimens (2 flexion larvae: 9.5–10.4mm in notochord length; 4 postflexion larvae: 12.3–18.2mm in standard length) collected from the western North Pacific are tentatively ascribed to the genus Uncisudis of the tribe Lestidiini of the subfamily Paralepidinae (Paralepididae) in sharing remarkably elongate and filamentous pelvic fin rays, their tips reaching the origin of the anal fin. They are described as Uncisudis posteropelvis sp. nov. in uniquely having the insertion of pelvic fins closer to the origin of anal fin than to the posterior end of dorsal fin base among lestidiine species. Addition to this character, the new species has remarkably elongate and filamentous dorsal fin rays, the short distance between anus and origin of anal fin (4.2–6.1% of standard length, SL), the posteriorly located pelvic fins (prepelvic length 69.4–71.5% SL), dorsal fin rays 10, anal fin rays 28–29, myomeres 41–42+38–40=80–81 (vertebrae 38+41=79), and peritoneal pigment spots 11–12. The occurrence of larvae differing in pigment pattern from the present new species suggests another undescribed species of Uncisudis in the western South Pacific.     

Summer forage biomass and the importance of litterfall for a high-density sika deer population

The biomass of summer forage and their contributions were surveyed to show that litterfall supported a high-density population of sika deer (Cervus nippon Temminck) in summer on Nakanoshima Island, Toya Lake, Japan. In July 1974, the grassland had the highest productivity among understory vegetations (228±55kgha^–1: mean±SE). In deciduous forests, palatable plants occupied only 0.1% of the biomass of 0.872±0.366kgha^–1, and deciduous leaves within the reach of deer (=220cm at height) produced 0.208±0.070kgha^–1. However, litterfall during this period had the highest productivity, 28.7± 5.3kgha^–1. The deer consumed litterfall (75.6% in dry weight), short grasses (17.2%), deciduous forest understory (4.1%), deciduous leaves within the reach of deer (3.0%) and conifer plantation under story (0.1%). It is suggested that the high-density deer population would be maintained by litterfall through the year instead of browsing in deciduous forests, which has been overlooked.     

Light utilization and competition between Echinacea purpurea, Panicum virgatum and Ratibida pinnata under greenhouse and field conditions

Competitive interactions were compared under field and greenhouse conditions for three representative tallgrass prairie species, Echinacea purpurea, Panicum virgatum and Ratibida pinnata. These were planted in monoculture and in mixtures of two species using a replacement series design with groups of four or eight plants. Competition was determined from shoot dry weight data collected during 120days in the greenhouse and after 415days in the field. Yields declined with increased density of a single species in the greenhouse from 40days onward and in the field. Relative yields were up to 100% higher in mixtures than in monocultures for all species early on in the greenhouse experiment. Later in the experiment and in the field relative yields of E.purpurea decreased in the presence of P.virgatum and R.pinnata, whereas relative yields of these two species increased in the presence of E.purpurea. There were correlations in relative yield between the field and the greenhouse experiment at 80 and 120days. In the greenhouse P.virgatum maintained higher net assimilation rates than the other species. Relative growth rates of all species were higher in monoculture and in mixtures up to 40days, after which they declined, especially for E.purpurea in mixtures. In the field, higher light intensities occurred in pure stands of E.purpurea than in mixed stands with other species. The order of competitive ability that was apparent from these field and greenhouse studies, P.virgatum=R.pinnata>E.purpurea, could be partially explained by photosynthetic rates in relation to canopy light interception.     

Recombinant Components of the EcoRII Restriction–Modification System: Restriction Endonuclease Can Interact with DNA · RNA Duplexes

To obtain recombinant restriction endonuclease (R) and methylase (M) of the EcoRII restriction–modification system, bacterial strains overproducing their functional hexahistidine derivatives were constructed. Active full-length R·EcoRII was produced only in cells that also expressed M·EcoRII from a multicopy plasmid. Recombinant R·EcoRII bound with hybrid DNA·RNA duplexes.     

Flexibility on the karyotype evolution in bitterlings (Pisces, Cyprinidae)

In bitterlings (Acheilognathinae) C- and Ag-banding karyotypes of 6 species-subspecies collected in China and South Korea were analyzed. The chromosomal constitution of 2n=46 (4SM+42ST) in Rhodeus atremius fangi was quite different from that of 2n=48 (8M+20SM+20ST) in other species-subspecies in Rhodeus. It was concluded from the analysis of banded chromosomes that the increase in number of ST during the karyotype change from 2n=48 to 2n=46 was achieved by a series of pericentric inversions from 24 M-SM to 24 ST, and the decrease in the diploid number was caused by an additional tandem fusion of 4 ST chromosomes, forming a new ST pair in the 2n=46 karyotype. The karyotype of Tanakia koreensis, T. signifer, and Acheilognathus macropterus is 2n=48 (8M+20SM+20ST), 2n=48 (8M+20SM+14–16ST+4–6 A), 2n=44 (14M+16SM+14ST), respectively. In R. ocellatus ocellatus, T. koreensis, T. signifer and A. macropterus, karyotype changes from 2n=48 to 2n=44 due to centric fusion and inversion have also been estimated. It was suggested that C-banding heterochromatin was greatly concerned with the karyotype evolution in bitterlings.     

Different impacts of two species of aphid-attending ants with different aggressiveness on the number of emerging adults of the aphid’s primary parasitoid and hyperparasitoids

The impacts of two species of ants (Lasius niger and Pristomyrmex pungens) attending the cotton aphid (Aphis gossypii) on the number of emerging adults of the aphids primary parasitoid (Lysiphlebus japonicus) and hyperparasitoids were assessed experimentally at a no-pesticide mandarin grove. L.japonicus females were observed foraging frequently in aphid colonies attended by either ant species, with more females in P.pungens-attended than in L.niger-attended colonies, but rarely in aphid colonies where ants were artificially excluded. Females were less often attacked by P.pungens workers than by L.niger workers, so that they stayed longer and oviposited into more aphids in P.pungens-attended than in L.niger-attended colonies. Attendance by each ant species reduced predator numbers in aphid colonies, compared to colonies where ants were absent, although P.pungens was slightly less effective in repelling predators. Therefore, both ant species incidentally protected parasitized aphids from predators. Consequently, L.japonicus-mummies were abundant in colonies attended by either ant species, with more mummies in P.pungens-attended colonies, and were scarce in ant-excluded colonies. The hyperparasitism and predation on L.japonicus larvae within mummies occurred more frequently in P.pungens-attended than in L.niger-attended colonies, but mummy predation rate was only 20% in the former. As a result, the number of emerging L.japonicus adults did not differ significantly between aphid colonies attended by the two ant species, but significantly more hyperparasitoids emerged in colonies attended by the relatively less aggressive P.pungens than in colonies attended by L.niger.     

Synaptonemal Complex Analysis in Oocytes and Spermatocytes of Threespine Stickleback Gasterosteus Aculeatus (Teleostei, Gasterosteidae)

A surface-spreading synaptonemal complex (SC) technique was employed to analyze spermatocytes and oocytes of stickleback, Gasterosteus aculeatus, in order to visualize the process of chromosome synapsis. The mean SC length was 150±18m in three males and 143±12m in one female analyzed. A representative SC karyotype with 21bivalents was also presented. Each SC had lateral elements of equal length. No bivalent displaying the atypical synaptic behaviour which is often associated with heteromorphic sex chromosomes was observed neither in males nor in the female analyzed.     

Early development of the self-fertilizing mangrove killifish <Emphasis Type="Italic">Rivulus marmoratus</Emphasis> reared in the laboratory

The mangrove killifish Rivulus marmoratus was reared at 25°±1°C and 17ppt salinity from 0 to 100 days after hatching (DAH), and its early development was described by examining growth and morphometric parameters, meristic characters (vertebral and fin-ray counts), bone-cartilage development, and pigmentation. Growth was isometric for preanal length, head length, snout length, body depth, pectoral-fin length, dorsal-fin length, anal-fin length, and caudal-peduncle depth. Negative allometric growth was observed in eye diameter and gape size. Meristic counts (mean±SD) for vertebrae (34.2±0.4) and dorsal- (8.6±0.5), anal- (11.4±0.5), and caudal-fin rays (30.2±0.8) were complete at 0 DAH (n=5), whereas pectoral-fin rays and pelvic-fin rays were complete by 30 DAH (14.5±0.4, n=5) and 60 DAH (4.2±0.8, n=5). Full ossification of meristic elements proceeded in the following sequence: vertebrae (by 30 DAH), caudal-, dorsal-, and anal-fin rays (by 60 DAH), pectoral-fin rays (between 60 DAH and 100 DAH), and pelvic-fin rays (by 100 DAH). Both morphological characters and meristic counts indicate that this species can be considered to be a juvenile after 9.8mm in standard length (20 DAH).     

Effects of sex and age of a dioecious tree, <Emphasis Type="Italic">Forchhammeria pallida</Emphasis> (Capparaceae) on the performance of its primary herbivore, <Emphasis Type="Italic">Murgantia varicolor</Emphasis> (Hemiptera: Pentatomidae)

The effects of sex and age of a dioecious tree, Forchhammeria pallida, on the survival and development of a Mexican harlequin bug, Murgantia varicolor, were examined. In the laboratory, bugs reared on fruits or fruits and leaves developed rapidly and had a high rate of survivorship, whereas bugs reared on leaves alone developed slowly after the second instar and died by the fifth instar. Murgantia varicolor showed a preference for leaves from juvenile plants over leaves from mature plants, and bugs reared on leaves from juvenile plants survived significantly longer than those reared on leaves from mature plants. Murgantia varicolor showed no preference for feeding on leaves of mature male versus mature female plants. In the field, M.varicolor occurred on male, female and juvenile plants. Although nymphs were less common on male than female F.pallida, their presence in substantial numbers shows that M.varicolor oviposits on both male and female plants. However, adult M.varicolor were rare on male plants. This result is supported by the inability of nymphs to complete their development on vegetative parts of F.pallida in the laboratory. These observations suggest that dioecy in F.pallida may be disruptive to populations of M.varicolor.     

Enhancement of photorespiration in immobilized <Emphasis Type="Italic">Chlamydomonas reinhardtii</Emphasis> cells

Immobilization of Chlamydomonas reinhardtii in alginate increases its photorespiration rate. In the immobilized cells, the photorespiratory enzyme, phosphoglycolate phosphatase, was 75% higher than in freely suspended cells. Thus, the immobilized cells produced glycolate at twice the rate than in freely suspended cells when treated with aminooxyacetate (a transaminase inhibitor). With immobilized cells in a batch reactor, 270mol glycolatemg^–1 Chl was produced after 12h.Revisions requested 27 October 2004; Revisions received 13 December 2004     

Defective remethylation of homocysteine is related to decreased synthesis of coenzymes B2 in thyroidectomized rats

Summary. We investigated the influence of hypothyroidism on homocysteine metabolism in rats, focusing on a hypothetical deficient synthesis of FAD by riboflavin kinases. Animals were allocated in control group (n=7), thyroidectomized rats (n=6), rats with diet deficient in vitamin B2, B9, B12, choline and methionine (n=7), thyroidectomized rats with deficient diet (n=9). Homocysteine was decreased in operated rats (2.6±1.01 vs. 4.05±1.0mol/L, P=0.02) and increased in deficient diet rats (29.56±4.52 vs. 4.05±1.0mol/L, P=0.001), when compared to control group. Erythrocyte-Glutathione-Reductase-Activation-Coefficient (index of FAD deficiency) was increased in thyroidectomized or deficient diet rats (P=0.004 for both). Methylenetetrahydrofolate-reductase and methionine-synthase activities were decreased in thyroidectomized rats but not in those subjected to deficient diet. Cystathionine--synthase was increased only in operated rats. Taken together, these results showed a defective re-methylation in surgical hypothyroidism, which was due in part to a defective synthesis of vitamin B2 coenzymes. This defective pathway was overcompensated by the increased Cystathionine--synthase activity.     

Relation between trace element levels in plasma and myocardium during coxsackievirus B3 myocarditis in the mouse

During most infections the plasma levels of trace elements change, but it is not clear if this reflects changes in the infected tissues. Coxsackievirus B3 (CB3) infection may result in viral replication, subsequent inflammation and changed trace element levels in the myocardium. In the present study, the trace element levels in the plasma and heart of adult male A/J mice were determined during the pre-inflammatory stage (day 4) of CB3 myocarditis for the following trace elements: aluminium (Al), arsenic (As), calcium (Ca), cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), selenium (Se), silver (Ag), vanadium (V) and zinc (Zn). The severity of the infection was assessed through clinical signs of disease and trace element levels were measured through inductively-coupled plasma mass-spectrometry (ICP-MS). In the heart, the levels decreased for V (59%; p<0.01), Co (38%; p<0.01), Al (81%; p< 0.01), As (66%; p<0.01) and Se (16%; p<0.01). Increased levels were detected for Mn (13%; p<0.05), Fe (48%; p<0.01), Cu (34%; p<0.01) and Ag (46%; p< 0.01). In the plasma, decreases were detected in the level of Zn (32%; p<0.05), whereas increases were seen in Mn (362%; p<0.05), Fe (272%; p<0.01), Co (71%; p<0.05), Cu (25%; n.s.) and Mg (43%; p<0.01) levels. A correlation was found between the levels in plasma and myocardium for Co (r _s=–0.636; p<0.05), Fe (r _s=0.764; p<0.05), Mn (r _s=0.682; p<0.05) and Mg (r _s=–0.791; p<0.05). Thus, determination of some of these trace elements in the plasma may be useful to indicate target tissue involvement in the early pre- inflammatory stage of an infectious disease. Some of these elements are important nutrients for the immune system, while others may be associated with the development of disease complications, such as cardiac arrhythmias.     

Larvae of <Emphasis Type="Italic">Arnoglossus elongatus</Emphasis> (Pleuronectiformes: Bothidae) from northwestern Australia

Eleven postflexion larvae (9.1–23.9mm standard length: SL) of a bothid, Arnoglossus elongatus, from northwestern Australian waters were described. These specimens were characterized by vertebral numbers of 11–12+32–34=43–45, slender body, remarkably elongated second dorsal fin ray, and presence of melanophores on and slightly above midlateral line of body, plus on dorsal wall of abdominal cavity and air bladder (specimens >12.6mm SL), proximally on caudal fin rays (>16.5mm SL), and on pterygiophore zones of dorsal fin and anal fin (>23.8mm SL).     

Conservation status of parrot populations in an Atlantic rainforest area of southeastern Brazil

A census of four species of syntopic parrots was carried out using distance sampling methods on São Sebastião island, SE Brazil. Most of the 33593 ha island is covered by mature and secondary Atlantic rainforest. Almost 80% of these forests are within the Ilhabela Park. Although the species counted have marked differences in size and weight, density (individuals/km²) and estimated population size in 23500 ha of well-preserved forests were similar: Amazona farinosa (13.82±5.94; 3247±1395), Pionus maximiliani (15.79±7.04; 3712±1654), Brotogeris tirica (15.05±4.87; 3537±1143) and Pyrrhura frontalis (13.06±5.53; 3068±1298). Encounter rates of Forpus crassirostris and Pionopsitta pileata were very low, which suggests that there is only a small population of these species on the island. The São Sebastião forests still support healthy populations of parrots. Although woodpecker population estimates on the island are large enough to provide nesting sites for parrots, competition for holes with other secondary cavity nesters such as toucans, flycatchers and tytiras, and the selective cutting of dead trees for canoe construction, which is a common practice on the island, may limit hole availability for parrots.     

Functional expression of keratinase (kerA) gene from Bacillus licheniformis in Pichia pastoris

A 1.2 kb DNA fragment coding for the pro-peptide and mature keratinase from Bacillus licheniformis PWD-1 (kerA) was cloned into vectors pPICZA and pGAPZA for extracellular expression in the methylotrophic yeast, Pichia pastoris. Recombinant keratinase was secreted by the pPICZA-kerA transformants 24 h after methanol induction of shake-flask cultures, and reached a final yield of 124 mg l^–1 (285 U ml^–1) 144 h after the induction. The recombinant keratinase was glycosylated ( 39 kDa), and was optimal between pH 8.5–9.5 and between 55°C –60°C using azokeratin as substrate. The enzyme degraded bovine serum albumin, collagen, and soy protein concentrate. In conclusion, P. pastoris can be used as an efficient host to express keratinase for nutritional and environmental applications.     

Effects of population size on genetic diversity and seed production in the rare <Emphasis Type="Italic">Dictamnus albus</Emphasis>(Rutaceae) in central Germany

It is widely assumed that population size significantly affects the dynamics of plant populations. Smaller populations are threatened by genetic drift and inbreeding depression, both of which may result in a decrease of genetic variation and a resulting negative impact on plant fitness. In our study we analysed the patterns of random amplified polymorphic DNA (RAPD) variation among 10 Dictamnus albuspopulations of varying size. The aim was to examine local differentiation in relation to spatial isolation resulting from limited population size and geographical distancing between populations. Significant correlations were noted between population size and both percentage of polymorphic loci (P <0.01) and genetic diversity (P<0.01). The matrix correlation between genetic and geographical distances revealed that geographical differentiation was reflected in the RAPD profile (Mantel test: r²=0.34, P<0.001). We found the highest level of molecular variance of RAPD patterns among individuals within the populations (72.6%), whereas among-population variation accounted for only 21.6% of variation. These results were highly significant in that they indicated a restricted population differentiation, as would be expected from outcrossing species. An additional analysis of seed production showed that there was significant variation among populations in terms of mean seed number per flower and mean seed mass per population which could be attributed to differences in population size as well as levels of genetic variation.     

Carbon dynamics and budget in a <Emphasis Type="Italic">Miscanthus sinensis</Emphasis> grassland in Japan

We investigated the carbon dynamics and budget in a grassland of Miscanthus sinensis, which is widely distributed in Japan, over a 2-year period (2000–2001). Plant biomass began to increase from May and peaked in September, then decreased towards the end of the growing season (October). Soil respiration rates also exhibited seasonal fluctuations that reflected seasonal changes in soil temperature and root respiration. The contribution of root respiration to total soil respiration was 22–41% in spring and summer, but increased to 52–53% in September. To determine the net ecosystem production (carbon budget), we estimated annual net primary production, soil respiration, and root respiration. Net primary production was 1207 and 1140gCm^–2 in 2000 and 2001, respectively. Annual soil respiration was 1387gCm^–2 in 2000 and 1408gCm^–2 in 2001; root respiration was 649 and 695gCm^–2 in 2000 and 2001, respectively. Moreover, some of the carbon fixed as net production (457–459gCm^–2) is removed by mowing in autumn in this grassland. Therefore, the annual carbon budget was estimated to be –56gCm^–2 in 2000 and – 100gCm^–2 in 2001. These results suggest that the Miscanthus sinensis grassland in Japan can act as a source of CO₂.