Epibiotic bacteria associated with microcrustaceans in the overlying water of paddy fields     

Misako Taniguchi  Koki Toyota  Makoto Kimura 《Soil Science and Plant Nutrition》2013,59(3):633-641

The surface of micro crustaceans collected from the overlying water of a submerged paddy soil was observed in detail by scanning electron microscopy. Epibiotic bacteria were less diverse compared to free-living bacteria in the overlying water. Specific bacteria appeared to preferentially colonize certain parts of microcrustaceans. The epibiotic bacteria, the sites they colonized and their density depended on the kinds of microcrustaceans (Moina macrocopa, Cyclopidae, Cypretta sp., and Tanycypris sp.). These results suggested the presence of significant associations in the overlying water between specific groups of bacteria and microcrustaceans.  相似文献   

Effects of successive soil freeze-thaw cycles on soil microbial biomass and organic matter decomposition potential of soils     

Yosuke Yanai  Koki Toyota  Masanori Okazaki 《Soil Science and Plant Nutrition》2013,59(6):821-829

Abstract

Effects of soil freeze-thaw cycles on soil microbial biomass were examined using 8 soil samples collected from various locations, including 4 arable land sites and 2 forest sites in temperate regions and 2 arable land sites in tropical regions. The amounts of soil microbial biomass C and N, determined by the chloroform fumigation and extraction method, significantly decreased by 6 to 40% following four successive soil freeze-thaw cycles (- 13 and 4°C at 12 h-intervals) compared with the unfrozen control (kept at 4°C during the same period of time as that of the freeze-thaw cycles). In other words, it was suggested that 60 to 94% of the soil microorganisms might survive following the successive freeze-thaw cycles. Canonical correlation analysis revealed a significantly positive correlation between the rate of microbial survival and organic matter content of soil (r = 0.948*). Correlation analysis showed that the microbial survival rate was also positively correlated with the pore-space whose size ranged from 9.5 to 6.0 μm (capillary-equivalent-diameter; r = 0.995**), pH(KCI) values (r = 0.925**), EC values (r = 0.855*), and pH (H₂O) values (r = 0.778*), respectively. These results suggested that the soil physicochemical properties regulating the amount of unfrozen water in soil may affect the rate of microbial survival following the soil freeze-thaw cycles. The potential of organic matter decomposition of the soils was examined to estimate the effects of the soil freeze-thaw cycles on the soil processes associated with the soil microbial communities. The soil freeze-thaw cycles led to significant 6% increase in chitin decomposition and 7% decrease in rice straw decomposition (p < 0.05), suggesting that the partial sterilization associated with the soil freeze-thaw cycles might disturb the soil microbial functions.  相似文献   

Identification of novel genetic markers and evaluation of genetic structure in a population of Japanese crested ibis     

Kanako Tsubono  Yukio Taniguchi  Hirokazu Matsuda  Takahisa Yamada  Toshie Sugiyama  Kosuke Homma  Yoshinori Kaneko  Satoshi Yamagishi  Hiroaki Iwaisaki 《Animal Science Journal》2014,85(4):356-364

Japanese population of the Japanese crested ibis Nipponia nippon was founded by five individuals gifted from the People's Republic of China. In order to exactly evaluate genetic structure, we first performed development of novel genetic makers using 89 microsatellite primer pairs of related species for cross‐amplification. Of these, only three primer pairs were useful for the genetic markers. Additionally, we sequenced allelic PCR products of these three markers together with 10 markers previously identified. Most markers showed typical microsatellite repeat units, but two markers were not simple microsatellites. Moreover, over half of the markers did not have the same repeat units as those of the original species. These results suggested that development of novel genetic markers in this population by cross‐amplification is not efficient, partly because of low genetic diversity. Furthermore, the cluster analysis by STRUCTURE program using 17 markers showed that the five founders were divided into two clusters. However, the genetic relationships among the founders indicated by the clustering seemed to be questionable, because the analysis relied largely on a small number of triallelic markers, in spite of the addition of the three useful markers. Therefore, more efficient methods for identifying large numbers of single nucleotide polymorphisms are desirable.  相似文献   

Effects of Freshness and Heating Temperature on the Discoloration of Squid Meat Products     

Hideto Fukushima  Koki Yamada  Toshimichi Maeda  Ritsuko Wada  Masahiro Matsumiya 《Journal Of Aquatic Food Product Technology》2020,29(7):671-680

ABSTRACT

Squid processed products such as dried-seasoned squid turn brown during storage, causing a change in quality. The main cause of this browning is melanoidin produced by the Maillard reaction. In this study, four types of squid were processed at different heating temperatures between 50 and 90°C and examined for suppression of the production of D-ribose, the main component of melanoidin. Furthermore, the color change of the squid meat with each heat treatment during storage of 32 days at 30°C was investigated. Bigfin reef squid and cuttlefish with a relatively high freshness decreased D-ribose generation as the heating temperature increased, and the browning during storage also decreased accordingly. In contrast, Humboldt squid with a low freshness did not generate new D-ribose at any heating temperature during storage. Nevertheless, the browning was reduced as the heating temperature increased. It is thought that the Maillard reaction was also reduced by the heat denaturation of muscular proteins. These results suggest that browning due to the Maillard reaction of squid meat is greatly affected by initial freshness and heating temperature.  相似文献   

Anaerobic orbital abscess/cellulitis in a Yorkshire Terrier dog     

Homma K  Schoster JV 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2000,62(10):1105-1107

A retrobulbar abscess/cellulitis occurred in a Yorkshire Terrier dog. The clinical signs were exophthalmos, prolapsed nictitating membrane and purulent ocular discharge. Ultrasonography showed a marked soft tissue swelling of the retrobulbar tissues as well as echogenic parallel lines between the globe and the medial orbital rim. Surgical exploration of the orbit was performed and no foreign body was found. The pterygopalatine fossa was incised and therapeutic retrobulbar drainage attempted. A drain was placed to encourage ventral drainage of the abscess. Anaerobic cultures revealed heavy growth of gram negative rods (prevotella bivia and prevotella buccae were isolated). Recovery was successful but subsequent treatment for keratoconjunctivitis sicca was necessary. A full recovery of tear production occurred after several weeks.  相似文献   

Effects of butyrate supplementation in antibiotic‐free milk replacer and starter on growth performance in suckling calves          下载免费PDF全文

Sanggun Roh  Nobuhiro Kimura  Kazushi Sakamoto  Koki Nishihara  Keiichi Suzuki  Kazuo Katoh 《Animal Science Journal》2018,89(10):1486-1491

The aim of this study was to evaluate butyrate supplementation of antibiotic‐free milk replacer and starter on growth performance in male Holstein calves. Twenty‐nine calves were divided into two groups. Group C (n = 13) was fed antibiotic‐free milk replacer without supplementation, and Group B (n = 16) was fed antibiotic‐free milk replacer supplemented with butyrate (1.6 % DM of Gustor BP70^®). Starter in Group B contained 0.3 % DM of Gustor BP70^®. The intake of milk replacer was lower in group B than in C (p = 0.07 for the treatment x week interaction). Body weight (BW) and heart girth (HG) in group B was higher than in C during the experimental period (p = 0.07 and 0.01 for the treatment × week interaction, respectively). The duration of the weaning period in group B was shorter than in group C (p = 0.02). β‐hydroxybutyrate (BHBA) was higher in group B than in C (p = 0.04). Insulin like growth factor‐1 (IGF‐1) concentrations tended to be higher in group B than in C (p = 0.07 for treatment × week interaction). Our results show that butyrate supplementation in antibiotic‐free milk replacer and starter exerted positive effects on growth performance in suckling calves.  相似文献   

Differences in flowering phenology and seed production of four morning glory (Ipomoea) species in Japan     

Hidenori Asami  Gen Ishioka  Masaaki Tachibana  Koki Homma 《Weed Biology and Management》2023,23(1):14-22

The spread of morning glory (Ipomoea spp.) in soybean fields in Japan has severely decreased soybean yield. Yet, current control measures do not control the proliferation of Ipomoea spp. As little is known about the flowering period and seed production among the different invading Ipomoea spp., it is challenging to create targeted control measures based on ecological characteristics. This study aimed to reveal the characteristics of the flowering phenology and seed production of four morning glory species, namely, Ipomoea coccinea L. (red morning glory), Ipomoea lacunosa L. (pitted morning glory), Ipomoea hederacea L. Jacq. var. integriuscula A. Gray (entireleaf morning glory), and Ipomoea triloba L. (three-lobe morning glory). Between 2017 and 2019, the four selected study species were grown under similar conditions of soil quality, irrigation, and environmental influences and their flowering phenology and seed data were recorded. The flowering period ranged from 36 to 40 days, and the initial flowering of I. triloba was approximately 2 weeks later than the others. I. coccinea had the highest flowering number and seed production, followed by I. lacunosa, I. triloba, and I. hederacea var. integriuscula. The fruit setting rate of I. triloba decreased later in the reproductive stage but tended to increase as the daily mean temperature increased on each flowering day. Thus, we report that the flowering phenology and seed production differed greatly among the Ipomoea spp. These findings can provide crucial insights into designing targeted species-specific control measures against the spread of Ipomoea spp. in Japan.  相似文献   

Estrous cycle based on blood progesterone profiles and changes in vulvar appearance of Malayan tapirs (Tapirus indicus)     

Kusuda S  Ikoma M  Morikaku K  Koizumi J  Kawaguchi Y  Kobayashi K  Matsui K  Nakamura A  Hashikawa H  Kobayashi K  Ueda M  Kaneko M  Akikawa T  Shibagaki S  Doi O 《The Journal of reproduction and development》2007,53(6):1283-1289

The progesterone (P(4)) profiles and macroscopic vulvar changes of female Malayan tapirs were investigated in order to understand their fundamental reproductive physiology and to search for visual indicators of estrus. Blood was collected once or twice a week from seven female Malayan tapirs kept at four zoos. Serum or plasma P(4) concentrations were determined by radioimmunoassay. The P(4) concentrations changed cyclically throughout the years, and a total of 56 cycles was confirmed in the seven females. The length of the estrous cycle based on the P(4) profiles was 43.6+/-2.0 days; however, this mean includes great variation in length, from 21 to 84 days. Mucous discharge from the vulva and vulvar swelling were seen when the P(4) concentrations were low before the beginning of a rise in most cases. In conclusion, captive female Malayan tapirs have variations of approximately 1 to 3 months in estrous cycle length, and visual changes in the vulva are helpful in estimating estrus in female Malayan tapirs.  相似文献   

Effects of erect panicle genotype and environment interactions on rice yield and yield components          下载免费PDF全文

WANG Yuan-zheng  Olusegun IDOWU  WANG Yun  HOMMA Koki  NAKAZAKI Tetsuya  ZHENG Wen-jing  XU Zheng-jin  SHIRAIWA Tatsuhiko 《农业科学学报》2023,22(3):716-726

The dense and erect panicle (EP) genotype conferred by DEP1 has been widely used in the breeding of high-yield Chinese japonica rice varieties.  However, the breeding value of the EP genotype has rarely been determined at the plant population level.  Therefore, the effects of the interaction of EP genotype and the environment at different locations and times on rice yield and its various components were investigated in this study.  Two sets of near-isogenic lines (NILs) of EP and non-EP (NEP) genotypes with Liaojing 5 (LG5) and Akitakomachi (AKI) backgrounds were grown in the field in 2016 and 2017 in Shenyang, China, and Kyoto, Japan.  In 2018, these sets were grown only in Kyoto, Japan.  The average yields of the EP and NEP genotypes were 6.67 and 6.13 t ha⁻¹ for the AKI background, and 6.66 and 6.58 t ha⁻¹ for the LG5 background, respectively.  The EP genotype positively affected panicle number (PN) and grain number per square meter (GNPM), mostly resulting in a positive effect on harvest index (HI).  In contrast, the EP genotype exerted a negative effect on thousand-grain weight (KGW).  The ratio of the performance of the EP genotype relative to the NEP genotype in terms of yield and total biomass correlated positively with mean daily solar radiation during a 40-day period around heading.  These results indicate that the effectiveness of the EP genotype depends on the availability of solar radiation, and the effect of this genotype is consistently positive for sink formation, conditional in terms of source capacity, and positive in a high-radiation environment.  相似文献   

Effects of water saving irrigation and rice variety on greenhouse gas emissions and water use efficiency in a paddy field fertilized with anaerobically digested pig slurry     

Khin Thawda Win  Ryoko Nonaka  Aye Thida Win  Yu Sasada  Koki Toyota  Takashi Motobayashi 《Paddy and Water Environment》2015,13(1):51-60

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