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21.
Sharifah Rahmah Keitaro Kato Shinji Yamamoto Kenji Takii Osamu Murata Shigeharu Senoo 《Aquaculture Research》2014,45(12):2000-2009
Manipulation of stocking densities (10, 20, 30, 40 and 50 larvae L?1), each with or without the presence of shelter was conducted to determine the effects on survival, cannibalism and growth performances of larval bagrid catfish Mystus nemurus (Valenciennes 1840) from 2 to 14 days after hatching. This study revealed that stocking density significantly affected survival, cannibalism, total length, feed intake, specific growth rate and final weight of bagrid catfish larvae. Significantly higher survival was observed at moderate stocking density of more than 20 but less than 50 larvae L?1. Survival was significantly low beyond this threshold and was the lowest at 10 larvae L?1, coincides with the highest cannibalism. Total length, feed intake, specific growth rate and final weight were significantly higher at 10 larvae L?1. Shelter significantly improved total length and feed intake. No significant effects of stocking density and shelter were observed on the apparent feed conversion ratio and coefficient of variation. There was also no significant interaction between stocking density and shelter in all parameters. This study suggests that bagrid catfish larvae could be cultured at more than 20 but less than 50 larvae L?1 with the availability of shelter for optimal larviculture condition. 相似文献
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M. J. Telebanco-Yanoria R. Ohsawa S. Senoo N. Kobayashi Y. Fukuta 《Plant Breeding》2008,127(4):355-363
A wide variation in resistance to blast disease caused by Magnaporthe grisea (Hebert) Barr. ( Rossman et al. 1992 ) was found using 922 rice ( Oryza sativa L.) varieties collected mainly from Asia. These were classified into six varietal groups, termed clusters A–F, according to Ward's hierarchical cluster analysis, based on the reaction pattern to 20 standard differential blast isolates from the Philippines. The most susceptible two clusters, B and C, dominated in varieties from the Far East (Japan). Varieties from East Asia and Southeast Asia occurred less frequently in B and C clusters than those of Japan, and more frequently in E and F clusters, which were the most resistant of the cluster groups. Varieties from South Asia showed the widest variation, occurring in all clusters but less frequently in cluster B. The cluster B varieties dominated in Japan and showed a high frequency of isozyme type VI, corresponding to Japonica type. In contrast, the frequency of cluster B was low in the groups with isozyme types I, II, III and V, which dominated in South Asia. Isozyme type I corresponds to Indica type varieties. The distribution of resistance corresponded to the geographical distribution of rice varieties and might be related to differentiation into Indica and Japonica types. These findings will provide useful information for understanding the variation in blast resistance at the global level. 相似文献
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Nan?Gao Weishou?ShenEmail author Estefania?Camargo Yutaka?Shiratori Tomoyasu?Nishizawa Kazuo?Isobe Xinhua?He Keishi?Senoo 《Biology and Fertility of Soils》2017,53(8):885-898
The only known sink for nitrous oxide (N2O) is biochemical reduction to dinitrogen (N2) by N2O reductase (N2OR). We hypothesized that the application of N2O-reducing denitrifier-inoculated organic fertilizer could enhance soil N2O consumption while the disruption of nosZ genes could result in inactivation of N2O consumption. To test such hypotheses, a denitrifier-inoculated granular organic fertilizer was applied to both soil microcosms and fields. Of 41 denitrifier strains, 38 generated 30N2 in the end products of denitrification (30N2 and 46N2O) after the addition of Na15NO3 in culture condition, indicating their high N2O reductase activities. Of these 41 strains, 18 were screened in soil microcosms after their inoculation into the organic fertilizer, most of which were affiliated with Azospirillum and Herbaspirillum. These 18 strains were nutritionally starved to improve their survival in soil, and 14 starved and/or non-starved strains significantly decreased N2O emissions in soil microcosms. However, the N2O emission had not been decreased in soil microcosms after inoculating with a nosZ gene-disruptive strain, suggesting that N2O reductase activity might be essential for N2O consumption. Although the decrease of N2O was not significant at field scales, the application of organic fertilizer inoculated with Azospirillum sp. TSH100 and Herbaspirillum sp. UKPF54 had decreased the N2O emissions by 36.7% in Fluvisol and 23.4% in Andosol in 2014, but by 21.6% in Andosol in 2015 (H. sp. UKPF54 only). These results suggest that the application of N2O-reducing denitrifier-inoculated organic fertilizer may enhance N2O consumption or decrease N2O emissions in agricultural soils. 相似文献
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Rie Gappa-Adachi Kazutaka Yano Shigeharu Takeuchi Yasuaki Morita Seiji Uematsu 《Journal of General Plant Pathology》2012,78(1):39-42
In 2004, a damping-off symptom was found on southern star, Oxypetalum caeruleum, in Kochi Prefecture, Japan. Two Phytophthora strains with different colony patterns on potato dextrose agar were isolated, and their pathogenicity was confirmed by inoculation
of southern star plants and their reisolation from symptomatic plants. Both fungi were identified as Phytophthora palmivora based on morphology, physiology, and sequence analysis of the internal transcribed spacers of nuclear ribosomal DNA. This
is the first report of Phytophthora blight of southern star in the world. 相似文献
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Megumi Kuroiwa Keisuke Koba Kazuo Isobe Ryunosuke Tateno Asami Nakanishi Yoshiyuki Inagaki Hiroto Toda Shigeto Otsuka Keishi Senoo Yuichi Suwa Muneoki Yoh Rieko Urakawa Hideaki Shibata 《Journal of Forest Research》2011,16(5):363-373
Measurements of gross NH 4 + and NO 3 ? production in forest soils were conducted using the 15N pool dilution method. Mineral topsoils (0?C10?cm depth) were collected from four forests from northern to southern Japan with a natural climate gradient to elucidate the mechanisms regulating gross nitrification rates in forest soils. Additionally, we attempted to evaluate the relative importance of heterotrophic nitrification in gross total nitrification using acetylene as a specific inhibitor of autotrophic nitrification. Distinct differences were found among sites in the gross rates of NH 4 + production (3.1?C11.4?mg?N?kg?1?day?1) and gross total nitrification (0.0?C6.1?mg?N?kg?1?day?1). The rates of gross heterotrophic nitrification were low in this study, indicating that heterotrophic nitrification is of minor importance in most forest mineral topsoils in Japan. Significant relations were found between gross autotrophic nitrification and gross NH 4 + production, soil N, and soil C concentrations, but none was found between gross autotrophic nitrification and soil pH. We determined the critical value of the gross NH 4 + production rates for gross autotrophic nitrification under which no gross autotrophic nitrification occurred, as well as the critical soil C/N ratio above which gross autotrophic nitrification ceased. Results show that tight coupling of production and consumption of NH 4 + prevents autotrophic nitrifiers from utilizing NH 4 + as long as NH 4 + availability is low. 相似文献
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Gardner MJ Bishop R Shah T de Villiers EP Carlton JM Hall N Ren Q Paulsen IT Pain A Berriman M Wilson RJ Sato S Ralph SA Mann DJ Xiong Z Shallom SJ Weidman J Jiang L Lynn J Weaver B Shoaibi A Domingo AR Wasawo D Crabtree J Wortman JR Haas B Angiuoli SV Creasy TH Lu C Suh B Silva JC Utterback TR Feldblyum TV Pertea M Allen J Nierman WC Taracha EL Salzberg SL White OR Fitzhugh HA Morzaria S Venter JC Fraser CM Nene V 《Science (New York, N.Y.)》2005,309(5731):134-137
We report the genome sequence of Theileria parva, an apicomplexan pathogen causing economic losses to smallholder farmers in Africa. The parasite chromosomes exhibit limited conservation of gene synteny with Plasmodium falciparum, and its plastid-like genome represents the first example where all apicoplast genes are encoded on one DNA strand. We tentatively identify proteins that facilitate parasite segregation during host cell cytokinesis and contribute to persistent infection of transformed host cells. Several biosynthetic pathways are incomplete or absent, suggesting substantial metabolic dependence on the host cell. One protein family that may generate parasite antigenic diversity is not telomere-associated. 相似文献
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Pathipan Sutigoolabud Keishi Senoo Somchai Ongprasert Makoto Hisamatsu 《Soil Science and Plant Nutrition》2013,59(2):293-296
Potassium chlorate is widely used as an active substance for flower induction in longan plantations for off-season production of fruits in northern Thailand. Contamination of groundwater with residual chlorate in soil is a cause for concern because of its toxicity to human health. Based on the assumption that potassium chlorate might adversely affect chlorate-reducing soil microorganisms due to its disinfecting nature, the effect of repeated applications of chlorate on chlorate decomposition in soil was examined in a laboratory study. In the longan plantation field soil which had received an annual application of potassium chlorate for three years, chlorate decomposition was slower than that in the soil without application. The suppression of chlorate decomposition was confirmed in the soil to which potassium chlorate was applied repeatedly in the laboratory. However, even in such soils that had received multiple applications of potassium chlorate, chlorate decomposition was remarkably enhanced by soil amendment with glucose or sucrose. Sugar amendment seemed to be an effective way of cleaning-up the residual chlorate in longan plantation field soils. 相似文献
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Abstract Extract We succeeded in isolating a γ-HCH (γ-1,2,3,4,5,6-hexachlorocyclohexane)-decomposing aerobic bacterium from an upland field where γ-HCH had been repeatedly applied for more than 10 years. The bacterium was identified as Pseudomonas paucimobilis (Oyaizu and Komagata, 1983; Senoo and Wada 1989; Wada et al. 1989). We assumed that P. paucimobilis was able to thrive in the upland field by acquiring the γ-HCH-decomposing ability (Tu 1975, 1976) based on the following mechanism: 相似文献