HPLC fluorometric determination of natural phytoplankton phycocyanin and its usefulness as cyanobacterial biomass in highly eutrophic shallow lake

A method for HPLC determination of phycocyanin in phytoplankton samples using gelchromatography with a fluorescence detector was developed to examine the use of phycocyanin as an index of the appearance and progress of cyanobacterial blooms in highly eutrophic lake. At least two types of phycocyanin with different molecular weights, each spectroscopically different from phycoerythrin and allophycocyanin, were found in natural phytoplankton samples. Changes in phycocyanin concentrations were clearly coupled to changes in chlorophyll-a concentrations during June to October while cyanobacterial blooms were occurring. The chlorophyll-a to phycocyanin relationship was linear at chlorophyll-a concentrations of less than 250 μg L^?1. The relationship between cyanobacterial carbon and phycocyanin concentration was also linear, suggesting that phycocyanin content may be a useful index of cyanobacterial biomass in highly eutrophic lakes where large cyanobacterial blooms occur.     

Determination of organic acids by high-performance liquid chromatography with electrochemical detection during wine brewing

Voltammetric determination of acids by means of the electrochemical reduction of quinone was applied to high-performance liquid chromatography (HPLC) with electrochemical detection (ED) for determining organic acids in fruit wines. A two-channel HPLC-ED system was fabricated by use of an ion-exclusion column and an electrochemical detector with a glassy carbon working electrode. Aqueous solution of 0.1 mM HClO(4) and ethanol containing 2-methyl-1,4-naphthoquinone served as a mobile phase and reagent solution, respectively. Determination of acetic, citric, lactic, malic, succinic, and tartaric acids was made by measuring the peak areas of the flow signals due to the reduction current of quinone caused by the eluted acids. The peak area was found to be linearly related to the acid amount ranging from 0.1 to 40 nmol per 20 microL injection. The present method was characterized by reproducibility with the simple and rapid procedure without derivatization of analytes. The method was shown as an effective means for following acid contents in fruit juices during fermentation with wine yeast.     

Field trials on a live bovine respiratory syncytial virus vaccine in calves.

Field trials were carried out in calves using a live bovine respiratory syncytial (BRS) virus vaccine prepared from the attenuated BRS virus, strain rs-52. Two hundred seventy-five and 353 calves were vaccinated intranasally and intramuscularly, respectively. No undesirable postvaccinal reactions were observed in the vaccinated calves. Of the serum neutralizing (SN) antibody negative calves 89.7% (26/29) and 92.8% (90/97) developed SN antibody 1 month after intranasal and intramuscular vaccination, respectively. Most of the calves having SN antibody titers of 1:1 or 1:2 at the time of vaccination showed a significant increase in SN antibody titer. About 70% and 90% of the calves vaccinated intranasally and intramuscularly, respectively, maintained SN antibody for 6 months after vaccination. In a field trial, a natural BRS virus infection occurred about 5 months after the start of the trial. Ten of the 16 unvaccinated control calves showed respiratory symptoms due to BRS virus infection. On the contrary, all of the 68 vaccinated calves exhibited no symptoms at all, indicating efficacy of the vaccine.     

Stimulatory effect of aluminum on the growth of tea pollen tubes

It is well known that when inorganic elements such as boron (B), calcium, cobalt, and manganese are added to media in combination or alone, they stimulate the germination and/or tube growth of various kinds of pollen (Schmücker 1933; Loo and Hwang 1944; Yamada 1958; Brewbaker and Kwack 1963). Among these elements, the stimulatory effect ofB is the most effective and generally recognized. Aluminum (Al) belongs along with B to Group IIIa in the periodic table, and Fähnrich and Ultlich (1964) reported that Al inhibited the germination and growth of the pollen tube of Petunia hybrida and Antirrhinum majus. However, stimulatory effects of Al on pollen germination or pollen tube growth had not been previously reported.     

Detection of Borna disease virus in a pregnant mare and her fetus

A pregnant mare showing pyrexia, reduced appetite, ataxia and paresis was euthanized and examined for the presence of Borna disease virus (BDV). Her brain, showing multiple neuronal degeneration and necrosis with hemorrhage, and the histologically normal brain of the fetus were both positive for BDV RNA. The BDV nucleotide sequences were identical in the mare and fetus in the second open reading frame (ORF). This is the first report of the possible vertical transmission of BDV in a horse.     

Introgression of unique characteristics of floral initiation under 24 hour day-length of Fragaria chiloensis ‘CHI-24-1’ into F. × ananassa

A unique flower initiation of the wild Junebearing strawberry strain ‘CHI-24-1’ in Fragaria chiloensis occurs under 24 h DL and high temperature conditions. To introduce the floral initiation characteristics of ‘CHI-24-1’ into cultivated strawberries of F. × ananassa, a cross pollination was conducted between ‘CHI-24-1’ and the Japanese short-day type strawberry cultivar ‘Nyoho’. The floral initiation of ‘CHI-24-1’ was induced in both parent and daughter plants linked with runners under a 24 h DL and 23/20 ^∘C, but not 8 and 16 h DLs at the same temperatures. Of the 21 F1 hybrids grown under the 24 h DL, 12 showed flower truss production in the parent and/or daughter plants linked with runners. Among 64 F1 hybrids, 26 exposed to 8, 16 and 24 h DLs for 30 days produced no flower trusses. However, 32, one and five F1 hybrids produced flower trusses under the 24 h DL alone, 8 h DL alone and both the 8 and 24 h DLs, respectively. The results of the experiments indicated that none of the F1 hybrids were day-neutral plants, but approximately 60% had the characteristics of floral initiation under 24 h DL, which was inherited from the pollen parent of ‘CHI-24-1’. The importance of the unique floral initiation characteristics under 24 h DL with high temperature for strawberry breeding was discussed.     

Potential impacts of non‐native channel catfish on commercially important species in a Japanese lake,as inferred from long‐term monitoring data

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Aneuploid strawberry (2n = 8x + 2 = 58) was developed from homozygous unreduced gamete (8x) produced by second division restitution in pollen

Unreduced gamete formation is significant in the evolutionary development of complex polyploidy series found in wild strawberry, genus Fragaria (Rosaceae). Also, it is important for genetics and breeding in strawberry plants to elucidate the mechanism of unreduced gamete formation. The objective of this study was to search for ploidy anomalies resulting from artificial diploid × octoploid crosses, and examine the mechanism through which these unreduced gametes were produced. Five everbearing cultivars of Fragaria vesca L. diploid (2n = 2x = 14) were crossed with pollen from six June-bearing cultivars of Fragaria × ananassa Duch., octoploid (2n = 8x = 56). A total of 3000 mature seeds, 100 from each of the 30 parental combinations were sown at 23 °C/20 °C (day/night) under artificial lighting with a 16 h day. The seedlings were transplanted to pots and grown in a greenhouse. Reproductive and morphological observations, flow cytometry analyses, chromosome counts and DNA analyses using CAPS markers were performed to identify the genetic background of the offspring. Most of the seed (79%) did not germinate or died soon after germination. Of the seedlings produced, 7% seemed to be pure F. vesca based on morphological characteristics, flow cytometry analyses and chromosome counts; 14% were pentaploids (2n = 5x = 35), 0.1% were hexaploids (2n = 6x = 42), and 0.03% (one individual) was aneuploid (2n = 8x + 2 = 58). Electrophoresis banding patterns obtained by CAPS marker analysis were heterozygotic in the 8x pollen parent but homozygotic in the aneuploid progeny. Judging from the chromosome counts and the CAPS marker analysis, the aneuploid was the result of a homozygous unreduced pollen grain (8x) crossed with an incomplete chromosome compliment from the egg. Because of the homozygosity, the unreduced male gamete must have been derived from second division restitution (SDR) in the octoploid pollen parent.     

Improvement of staining method for observation of mitotic chromosomes in octoploid strawberry plants

An important strategy to conduct intentional breeding of octoploid strawberry plants is to recognize the functions of every chromosome. To do so, a methodology must be developed to distinguish chromosomes one by one. We reported the possibility of distinguishing chromosomes using light microscopy when somatic cells of octoploid strawberry plants were stained using ordinary methods with lacto-propionic orcein (LPO). However, karyotype analysis of octoploid strawberry plants required clearer chromosome images. This study obtained clearer chromosome images of octoploid Fragaria × ananassa and F. chiloensis plants. Three staining methods were examined: 60% acetic acid (AA) alone, 1.5% LPO alone, and two-step treatments with 60% AA and 1.5% LPO. Collected root tips of the plants were placed in 2 mM 8-hydroxyquinoline solution for 1 h and were subsequently stored at 4 °C for 15 h. The samples were then fixed in a 3:1 absolute alcohol: glacial acetic acid solution for 40 min, followed by mixture with 1N HCl solutions at room temperature for 2 h and then at 60 °C for 10 min. For separate staining using 60% AA and 1.5% LPO, the root tip was expelled on the glass slide with a drop of each solution for a few minutes to stain the chromosomes. For the two-step staining method, the samples stained with 60% AA were frozen at −80 °C for at least 5 min. The cover slip was removed using a razor blade. Subsequently, the specimens were air-dried and stained with the 1.5% LPO for 3 min. Digital images of chromosomes were obtained using light microscopy. Samples of the two-step staining method produced the clearest chromosome images in both F. × ananassa and F. chiloensis. Furthermore, the greatest color difference between the chromosomes and the cytoplasm was obtained from images of the two-step staining method among the three staining methods. These results demonstrate that the two-step staining method is useful for chromosome counting and karyotype analysis in strawberry plants.