Body-length frequency and spatial segregation of the North Pacific spiny dogfish <Emphasis Type="Italic">Squalus suckleyi</Emphasis> in Tsugaru Strait,northern Japan

The present study elucidated the length structure and habitat segregation of North Pacific spiny dogfish (SPD) Squalus suckleyi in the Tsugaru Strait of northern Japan. Length–frequency distributions using kernel density estimation were determined for SPD captured by the bottom longline fishery landed at Minmaya from 1999 to 2011 and at Ohma from 2007 to 2011. Length–frequency distributions significantly differed between landings at the two ports; SPD at Minmaya were on average larger (65–85 cm precaudal length: PCL) than at Ohma (55–75 cm PCL). This difference is evidence of the length-based spatial segregation of the SPD. The seasonal landing pattern of the SPD was also different between the two ports. The SPD landed at Minmaya were largest during February–June and SPD < 75 cm PCL were caught at Ohma throughout the year. This different landing pattern was related to seasonal differences in bottom-layer water temperatures between the two fishing grounds. Females were thought to be dominant at Minmaya, whereas males dominated in most of the catches at Ohma. These results suggest spatial patterns of sexual segregation for this species in the Tsugaru Strait and require elucidation of the SPD stock condition at Minmaya and Ohma.     

Enhanced local recruitment of glass eel <Emphasis Type="Italic">Anguilla japonica</Emphasis> in Oyodo River,Miyazaki and offshore environmental conditions in 2002

To examine the environmental factors controlling the inshore recruitment dynamics of Anguilla japonica in the Oyodo River, Miyazaki Prefecture, Kyushu, glass eel samplings were carried out using fyke nets during winter (November–March) of 1994–2014. The peak CPUEs (catch per unit effort) were observed between November and February, but differed from year to year. The yearly CPUE was extremely high in 2002, when the sea surface temperature (SST) in the offshore area of the Oyodo River was the lowest in winter of all the sampling years. The negative SST anomaly of less than ? 0.5 °C was sustained in the offshore area during the recruitment season in 2002, which was caused by two combined factors; low air temperature and the Kuroshio path. The oceanographic data showed that the dominant path of the Kuroshio was displaced eastward at 31°N in 2002, which was different from the average Kuroshio path. The eastward displacement of the Kuroshio induced a cyclonic mesoscale eddy in the offshore area of the Oyodo River, resulting in the entrainment of the cold seawater into coastal waters from deep water. The oceanographic condition in relation to the continuous low SST could be favorable for local recruitment of glass eels.     

Development of a technique to estimate the horizontal distribution of lit fishing vessels in the East China Sea using satellite luminescence

Fisheries Science - The East China Sea is a semi-enclosed sea, surrounded by Japan, China, South Korea and Taiwan, and is continuously influenced by lit fishing vessels overexploiting fishery...     

Feeding habits of mesopelagic fish <Emphasis Type="Italic">Lampanyctus jordani</Emphasis> (Family: Myctophidae) over the continental slope off Tohoku area,northern Japan

ABSTRACT:   The feeding habits of Lampanyctus jordani , an abundant mesopelagic fish in the subarctic North Pacific, was examined based on the stomach contents of 721 specimens collected over the continental slope off the Tohoku area, Pacific coast of northern Japan during April and October from 1996 to 1998. The prey items comprised mainly crustaceans such as copepods, amphipods, euphausiids and decapods. Euphausiids were the most important items in the diet both during April and October. During April, when the annual maximum of zooplankton biomass occurred and the Oyashio Intrusion Current prevailed, L. jordani fed intensively and consumed a high proportion of Euphausia pacifica . These seasonal variations also influenced the feeding intensity and dietary diversity. Feeding intensity, measured by the stomach contents index, was higher during April than October, reflecting the higher biomass of zooplankton in the Tohoku area during spring. The dietary diversity of L. jordani was lower during April than October, indicating that L. jordani shifted to a wider variety of prey when the availability of E. pacifica was limited.     

Breeding and brewing quality of the Canadian malting barley variety ‘CDC Goldstar’ lacking lipoxygenase-1

Various types of malt quality profiles have been investigated to benefit the North American brewing industry. Herein, we report the development and brewing quality of the hulled, two-row malting barley (Hordeum vulgare L.) variety ‘CDC Goldstar’ lacking lipoxygenase-1 (LOX-1-less). This new variety offers a novel malt type for the improvement of beer flavor stability. The agronomic performance of ‘CDC Goldstar’ was tested in the Western Cooperative Two Row Barley Registration Trials during 2013–2014. In addition to high lodging tolerance, the new variety showed 6% higher yield than the current leading variety ‘CDC Copeland’. The malt quality of ‘CDC Goldstar’ showed higher diastatic power and lower wort β-glucan content than ‘CDC Copeland’ and controllable proteolytic modification (soluble nitrogen and Kolbach Index). Pilot- (100 L) and commercial-scale (5,000 L) brewing trials were conducted using ‘CDC PlatinumStar’, another LOX-1-less variety with a low enzymatic profile, as the control variety. Absence of the LOX-1 trait from ‘CDC Goldstar’ maintained trans-2-nonenal levels in aged beers as low as those in other LOX-1-less varieties without affecting major beer parameters, such as ester and aldehyde content or foam stability. The newly developed ‘CDC Goldstar’ malting barley provides added value for the beer industry and consumers.     

Fusariosis in rubber tree: pathogenic,morphological, and molecular characterization of the causal agent

Fusariosis, one of the phytosanitary problems found in rubber producing areas in the northwest of the state of São Paulo, is a disease that affects the bark of the adult plants, affecting the exploitation of latex. The typical symptoms appear as cracks in the bark that expand from the rootstock towards the tapping panel, causing a drying of the latex flux in the injured region, impeding latex tapping. Due to the recent incidence of this disease in rubber plantations, the goal of this study was to characterize the Fusarium associated with symptomatic rubber tissue in three different locations in the state of São Paulo. In order to identify Fusarium species, pathogenicity, morphological, cultural and molecular studies were carried out. A total of 51 isolates were obtained and separated into three groups based on macroconidium morphology, presence or absence of sporodochia, types of chlamydospores, formation of phialides and conidiogenesis of microconidia and mesoconidia, mycelial growth rate and coloring of the colonies. These groups were corroborated using DNA sequence information for five different genetic loci, and were subsequently recognized as Fusarium oxysporum, F. incarnatum and F. decemcellulare. Our results further showed that all 51 of the Fusarium isolates recovered were pathogenic to rubber tree seedlings of RRIM 600 standard clone. This study also reports for the presence of F. oxysporum and F. incarnatum in rubber plantations in the state of São Paulo and in Brazil.

     

Use of S1 nuclease in deep sequencing for detection of double-stranded RNA viruses

Metagenomic approach using next-generation DNA sequencing has facilitated the detection of many pathogenic viruses from fecal samples. However, in many cases, majority of the detected sequences originate from the host genome and bacterial flora in the gut. Here, to improve efficiency of the detection of double-stranded (ds) RNA viruses from samples, we evaluated the applicability of S1 nuclease on deep sequencing. Treating total RNA with S1 nuclease resulted in 1.5–28.4- and 10.1–208.9-fold increases in sequence reads of group A rotavirus in fecal and viral culture samples, respectively. Moreover, increasing coverage of mapping to reference sequences allowed for sufficient genotyping using analytical software. These results suggest that library construction using S1 nuclease is useful for deep sequencing in the detection of dsRNA viruses.     

WIPPER: an accurate and efficient field phenotyping platform for large-scale applications

More accurate, rapid, and easy phenotyping tools are required to match the recent advances in high-throughput genotyping for accelerating breeding and genetic analysis. The conventional data recording in field notebooks and then inputting data to computers for further analysis is inefficient, time-consuming, laborious, and prone to human error. Here, we report WIPPER (for Wireless Plant Phenotyper), a new phenotyping platform that combines field phenotyping and data recording with the aid of Bluetooth communication, thus saving time and labor not only for field data recoding but also for inputting data to computers. Additionally, it eliminates the risk of human error associated with phenotyping and inputting data. We applied WIPPER to 100 individuals of a rice recombinant inbred line (RIL) for measuring leaf width and relative chlorophyll content (SPAD value), and were able to record an accurate data in a significantly reduced time compared with the conventional method of data collection. We are currently using WIPPER for routine management of rice germplasm including recording and documenting information on phenotypic data, seeds, and DNA for their accelerated utilization in crop breeding.     

Hybrid plant of Phaseolus vulgaris L. and P. lunatus L. obtained by means of embryo rescue and confirmed by restriction endonuclease analysis of rDNA

Summary Hybridizations between three lines of the common bean (Phaseolus vulgaris L.) and two lines of the lima bean (P. lunatus L.) were attempted in order to transfer characters from the lima bean to the common bean. A total of 115 interspecific hybrid embryos were rescued and cultured, and 7 plantlets were eventually transferred to soil. The most compatible cross was Edogawa XPI164891, which had a high proportion of expanded ovules, and from which we obtained one mature interspecific hybrid. In general, morphological characters of the hybrid were intermediate between the parents, and the chromosome number of the hybrid was 2n=22 the same as that of both parents. The hybrid nature of the progeny plant was confirmed by restriction endonuclease analysis of rDNA. Species specific fragments were detected when total DNA was digested by BamHI, and BamHI-digested total DNA of the hybrid contained all fragments from both parents. Selves and backcrosses were attempted, but no progeny were obtained. The only hybrid obtained was completely sterile and meiosis highly irregular.     

False positive responses of Campylobacter jejuni when using the chemical-in-plug chemotaxis assay

Campylobacter jejuni reportedly exhibits chemotactic behavior towards fucose, several amino acids and organic acids, mucin and bile. The chemotaxis of C. jejuni has mainly been studied using the chemical-in-plug chemotaxis assay. In this study, a nonchemotactic mutant (cheY mutant) and nonmotile mutant (flhA mutant) were constructed and used as negative controls in an assay. Apparent zones of accumulation around test plugs containing several amino acids and organic acids were observed with both of the mutants. Our results suggest that positive responses of C. jejuni in the chemical-in-plug assay are not always indicative of chemotaxis.