Hormonal control of the outgrowth of axillary buds in <Emphasis Type="Italic">Alstroemeria</Emphasis> cultured <Emphasis Type="Italic">in vitro</Emphasis>

We study apical dominance in Alstroemeria, a plant with an architecture very different from the model species used in research on apical dominance. The standard explant was a rhizome with a tip and two vertically growing shoots from which the larger part had been excised leaving ca. 1 cm stem. The axillary buds that resumed growth were located at this 1-cm stem just above the rhizome. They were released by removal of the rhizome tip and the shoot tips. Replacement of excised tips by lanolin with indole-3-butyric acid (IBA) restored apical dominance. The auxin transport inhibitors 2,3,5-triiodobenzoic acid (TIBA) and N-1-napthylphthalamic acid (NPA) reduced apical dominance. 6-Benzylaminopurine (BAP) enhanced axillary bud outgrowth but the highest concentrations (> 9 μM) caused fasciation. Thidiazuron (TDZ) did not show improvement relative to BAP. Even though the architecture of Alstroemeria and the model species are very different, their hormonal mechanisms in apical dominance are for the greater part very similar.     

Survey of Helminth Parasites in Populations of <Emphasis Type="Italic">Alouatta palliata mexicana</Emphasis> and <Emphasis Type="Italic">A. pigra</Emphasis> in Continuous and in Fragmented Habitat in Southern Mexico

The 2 howler species that occur in southern Mexico, Alouatta palliata mexicana and Alouatta pigra are endangered, mainly as a result of habitat loss and fragmentation from human activity. Little is known about the gastrointestinal parasite communities affecting their populations, and lack of baseline information for populations of howler species in continuous forest habitats, makes evaluations of gastrointestinal parasite prevalence in populations in fragmented landscapes difficult. We report the results of a one-time broad survey of gastrointestinal parasites in fecal samples of individuals from several demographically stable populations of Alouatta palliata mexicana and A. pigra existing in continuous and/or protected forests. We further report similar data for populations of both species in human-fragmented landscapes. We detected 6 parasites for each howler monkey species, but only 3 of them (Trematode I, Controrchis biliophilus, Trypanoxyuris sp.) were common to both species. While parasitic prevalence in populations of both howler species was, in general, higher in the fragmented habitat than in continuous and/or protected forests. The difference is only marginally significant in Alouatta pigra. Some parasites (Coccidia and Strongylid) only appeared in populations in fragmented landscapes. Preliminary data suggest that adult males tended to have higher parasite prevalence values than those of adult females in both howler species. Parasite prevalence is associated to average group size, but not to population density in Alouatta pigra.     

Occurrence of <Emphasis Type="Italic">Chlamydiaceae</Emphasis> in non-symptomatic free-living raptors in Spain

Few studies have investigated the role of raptors as natural reservoirs of Chlamydiaceae spp. and the preferred anatomical sites where these bacteria can be detected in non-symptomatic wild birds. We investigated the occurrence of Chlamydiaceae in 54 non-symptomatic adult free-living birds belonging to 14 species sampled upon reception in a raptor rehabilitation centre in Spain, and ten juvenile birds from five species born and reared in the centre for subsequent release into the wild. Swabs from conjunctivae, choanae and cloacae were taken to detect Chlamydiaceae DNA by a family-specific polymerase chain reaction (PCR) and a nested genus- and species-specific PCR. Chlamydiaceae DNA was detected in adult raptors belonging to 12 species (85.7%), mainly in conjunctival (40.6%) and, to a lesser extent, choanal (17.2%) swabs, but never in cloacal samples. Neither the genus nor the species of Chlamydiaceae could be confirmed by the nested PCR assay. Our results suggest that most of the raptor species investigated, especially the Common Kestrel (Falco tinnunculus) and Eurasian Griffon Vulture (Gyps fulvus), can be natural reservoirs of Chlamydiaceae spp. in the wild. Failure to identify the organisms at genus and species level might have been due to the poor quality and low concentration of DNA in the samples or to the presence of hitherto unclassified Chlamydiaceae species.     

Recovery of photosynthetic capacity in <Emphasis Type="Italic">Vaccinium vitis</Emphasis>-<Emphasis Type="Italic">idaea</Emphasis> during mild spells in winter

Recent studies suggest that evergreen plants may maintain their photosynthetic capacity through the winter. Since mild winters are predicted to be more frequent in the future, the metabolic activity of plants is also likely to increase. The aim of the present study was to assess how various environmental factors, such as temperature, photoperiod and preceding frost, affect the recovery of photosynthesis during a mild spell in winter. The recovery of photosynthesis was studied in a series of growth chamber experiments where the overwintering of lingonberry (Vaccinium vitis-idaea) was interrupted by an intermittent warm spell of 1 week during different phases of winter. Rapid activation was observed in all the experiments during the first 3–4 days. No obvious effects of the phase of winter or photoperiod on the recovery of photosynthesis were observed, but a severe freezing treatment prior to the warm spell retarded the recovery significantly. Once recovered, however, lingonberry was able to maintain high rates of photosynthesis even at near-freezing temperatures, which prevail in their natural sub-nivean environment. The apparent quantum yield of photosynthesis remained high through the winter for lingonberry. This may prove advantageous for evergreen dwarf shrubs which overwinter in dim environments under snow.     

Effect of abscisic acid and proline on <Emphasis Type="Italic">in vitro</Emphasis> flowering in <Emphasis Type="Italic">Vigna aconitifolia</Emphasis>

An experiment was taken up to find out possibilities of manipulating the in vitro flowering in moth bean. Abscisic acid (ABA) and proline both alone and in combination influenced days to flower induction, number of flowers per plant, number of pods per plant and seeds per pod. Frequency of flowering plants approached 100 % at 1 and 3 μM ABA and 800 μM proline. The range of flowering period (3 to 23.6 d) has also been influenced by various treatments.     

National surveillance of <Emphasis Type="Italic">Salmonella enterica</Emphasis> in food-producing animals in Japan

A total of 518 fecal samples collected from 183 apparently healthy cattle, 180 pigs and 155 broilers throughout Japan in 1999 were examined to determine the prevalence and antimicrobial susceptibility of Salmonella. The isolation rates were 36.1% in broilers, 2.8% in pigs and 0.5% in cattle. S. enterica Infantis was the most frequent isolate, found in 22.6% of broiler fecal samples. Higher resistance rates were observed against oxytetracycline (82.0%), dihydrostreptomycin (77.9%), kanamycin (41.0%) and trimethoprim (35.2%). Resistance rates to ampicillin, ceftiofur, bicozamycin, chloramphenicol and nalidixic acid were <10%. CTX-M-2 β-lactamase producing S. enterica Senftenberg was found in the isolates obtained from one broiler fecal sample. This is the first report of cephalosporin-resistant Salmonella directly isolated from food animal in Japan.     

Yield‐biodiversity trade‐off in patchy fields of Miscanthus × giganteus

Increasing crop productivity to meet rising demands for food and energy, but doing so in an environmentally sustainable manner, is one of the greatest challenges for agriculture to date. In Ireland, Miscanthus × giganteus has the potential to become a major feedstock for bioenergy production, but the economic feasibility of its cultivation depends on high yields. Miscanthus fields can have a large number of gaps in crop cover, adversely impacting yield and hence economic viability. Predominantly positive effects of Miscanthus on biodiversity reported from previous research might be attributable to high crop patchiness, particularly during the establishment phase. The aim of this research was to assess crop patchiness on a field scale and to analyse the relationship between Miscanthus yield and species richness and abundance of selected taxa of farmland wildlife. For 14 Miscanthus fields at the end of their establishment phase (4–5 years after planting), which had been planted either on improved grassland (MG) or tilled arable land (MT), we determined patchiness of the crop cover, percentage light penetration (LP) to the lower canopy, Miscanthus shoot density and height, vascular plants and epigeic arthropods. Plant species richness and noncrop vegetation cover in Miscanthus fields increased with increasing patchiness, due to higher levels of LP to the lower canopy. The species richness of ground beetles and the activity density of spiders followed the increase in vegetation cover. Plant species richness and activity density of spiders on both MT and MG fields, as well as vegetation cover and activity density of ground beetles on MG fields, were negatively associated with Miscanthus yield. In conclusion, positive effects of Miscanthus on biodiversity can diminish with increasing productivity. This matter needs to be considered when assessing the relative ecological impacts of developing biomass crops in comparison with other land use.     

Change in compactness of inclusion bodies of recombinant β-galactosidase expressed in the <Emphasis Type="Italic">araBAD</Emphasis> promoter system of <Emphasis Type="Italic">Escherichia coli</Emphasis>

We investigated the relevance of the relationship between the compactness of β-galactosidase inclusion bodies (β-gal IBs) and their enhanced enzymatic activity with or without the addition of D-fucose (inducer analog) or methyl α-D-glucopyranoside (α-MG, catabolite repressor) after induction in the araBAD promoter system of Escherichia coli. Experiments conducted to evaluate the solubilization of β-gal IBs in guanidine hydrochloride as well as their trypsin degradation and temperature stability revealed that β-gal IBs expressed in response to the addition of D-fucose or α-MG had a looser structure. Additionally, β-gal IBs expressed when D-fucose or α-MG was added were more quickly solubilized in guanidine hydrochloride or degraded by trypsin-treatment than those produced when these compounds were not added. Moreover, the activity of β-gal IBs expressed when D-fucose or α-MG were added was less stable at various temperatures. Consequently, we deduced that the looser structure of β-gal IBs resulted in enhanced enzymatic activity of β-gal IBs upon addition of D-fucose or α-MG after induction.     

High-frequency<Emphasis Type="Italic">in vitro</Emphasis> flowering in six species of<Emphasis Type="Italic">ceropegia</Emphasis>

High-frequencyin vitro flowering is reported here fromin vitro regenerated shoots ofin vitro-raised seedlings of rare and endemicCeropegia lawii, Ceropegia maccannii, Ceropegia oculata, andCeropegia sahyadrica, as well as the widely distributedCeropegia bulbosa var.bulbosa andCeropegia hirsuta. In our first set of experiments, the MS medium contained 87 mM sucrose and was supplemented with varying concentrations of BAP (4.4 to 26.6 μM). For the second set of trials, varying concentrations of sucrose (87 to 233 mM) were tested in MS media containing a constant 4.4 p.M BAP. Sub-cultured apical as well as axillary buds flowered with similar frequencies after 30 d of incubation. For all six species, the highest percentage of flowering shoots was obtained with either 26.6 μM BAP or 175 mM sucrose. Although smaller in size, theirin vitro flowers were morphologically comparable within wVo-derived flowers. Variations among species were noted for the number of flower buds per shoot and the percentage of flower formation. Because all six species showed similar responses in both experiments, we can suggest that this protocol is applicable across the wide range ofCeropegia species.     

The development of embryos in <Emphasis Type="Italic">Brassica rapa</Emphasis> L. in microgravity

In this work we present the results of the comparative cytoembryological research on embryos of an identified age that were produced in microgravity and in the ground laboratory control. A considerable similarity was found between the rate of embryo development and degree of their differentiation in both variants. Abnormalities in the process of embryo formation and acceleration in development of the endosperm were revealed at the early stages of embryogenesis in microgravity.     

<Emphasis Type="Italic">Fopius arisanus</Emphasis> oviposition in four <Emphasis Type="Italic">Anastrepha</Emphasis> fruit fly species of economic importance in Mexico

We studied the oviposition performance of Fopius arisanus (Sonan) (Hymenoptera: Braconidae) attacking eggs of four fruit flies of the genus Anastrepha Schiner (Diptera: Tephritidae) under laboratory conditions. The complete process of oviposition on an individual egg of Anastrepha ludens (Loew) lasts in average 85.4 ± 2.9 s, including a tremor (25.8 ± 1.03 s) observed in the middle of this process related to the egg’s descent. The average parasitism of A. ludens egg was 60.9 ± 7.5%, with only 1.2% of superparasitized eggs. During individual acts of oviposition, we noted that F. arisanus possesses a highly flexible ovipositor that curves easily as it searches for additional suitable eggs, which may be of particular benefit when a female finds large clutches of eggs. The individual oviposition of F. arisanus in host fruits attacked by Anastrepha spp. varies with the egg clutch size of each fruit fly species: A. serpentina laid the biggest egg clutches (21.3 ± 1.4), followed by A. ludens (14.2 ± 0.9), and A. striata (1.0 ± 0.0) (=A. obliqua). The time spent by F. arisanus in individual ovipositions was parallel to these findings, reinforcing the idea that F. arisanus attacks several eggs in each individual insertion of its ovipositor. Neither formal oviposition acts, nor adult emergences of F. arisanus were registered in A. obliqua. We discuss the potential of F. arisanus as natural enemy of fruit flies of the genus Anastrepha, and explore the eventual developing of its mass rearing. Handling Editor: Torsten Meiners.     

Identification and transcriptional analysis of genes involved in <Emphasis Type="Italic">Bacillus cereus</Emphasis>-induced systemic resistance in <Emphasis Type="Italic">Lilium</Emphasis>

Bacillus cereus C1L was demonstrated to induce systemic resistance in Lilium formosanum against leaf blight caused by Botrytis elliptica. Suppression subtractive hybridization library of L. formosanum triggered by B. cereus C1L were screened and 3 differentially expressed genes were identified. Based on sequence analysis, these genes encoding putative glycine-rich protein, metallothionein-like protein, and PsbR protein of photosystem 2, were designated LfGRP1, LfMT1, and LfPsbR, respectively. The results of Northern blot analysis showed that expressions of LfGRP1, LfMT1 and LfPsbR increased in response to B. elliptica infection. On the other hand, expression of LfMT1 increased but expressions of LfGRP1 and LfPsbR decreased when the rhizosphere of L. formosanum was drenched with suspension of B. cereus C1L with or without subsequent challenge with B. elliptica on lily leaves. Similar expression profiles of homologues of LfGRP1, LfMT1, and LfPsbR (named LsGRP1, LsMT1, and LsPsbR, respectively) were presented in Lilium oriental hybrid Star Gazer. In addition, application of the photosynthetic inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, on the leaves reduced disease severity and expressions of LsGRP1 and LsPsbR just as that in response to B. cereus C1L treatment.