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61.
Silicon(Si) is known as a beneficial nutrient in the cultivation of rice, playing a key role in photosynthesis enhancement, lodging resistance and tolerance to various environmental stress. The present study aimed to examine available Si content in both lowland soils(n = 29) and neighboring upland soils(n = 21) collected from Benin and Nigeria and to evaluate the validity of the assessment results through a pot experiment. Our results revealed that the acetate-buffer method predicted Si concentration in rice straw at the harvest stage(R~2 = 0.68, P < 0.01) better than the anaerobic-incubation method(R2 = 0.31, P > 0.05), and 76% of the uplands and 38% of the lowlands were deficient(< 50 mg/kg) in acetate-buffer soluble Si. These findings suggest that the Si-deficiency soils prevail across the study area, making rice plants starved for Si and prone to environmental stress. 相似文献
62.
Establishment of a new cell line susceptible to Cyprinid herpesvirus 3 (CyHV‐3) and possible latency of CyHV‐3 by temperature shift in the cells
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M Imajoh H Fujioka K Furusawa K Tamura K Yamasaki S Kurihara J Yamane K Kawai S Oshima 《Journal of fish diseases》2015,38(6):507-514
A new cell line named CCF‐K104 predominantly consisting of fibroblastic cells showed optimal growth at temperatures from 25 °C to 30 °C. Serial morphological changes in the cells induced by Cyprinid herpesvirus 3 (CyHV‐3) included cytoplasmic vacuolar formation, cell rounding and detachment. Mature virions were purified from CyHV‐3‐infected CCF‐K104 cells by sucrose gradient ultracentrifugation and had a typical herpesvirus structure on electron microscopy. Infectious CyHV‐3 was produced stably in CCF‐K104 cells over 30 viral passages. Our findings showed that CCF‐K104 is a useful cell line for isolation and productive replication of CyHV‐3. A temperature shift from 25 °C to 15 °C or 35 °C did not allow serial morphological changes as observed at 25 °C for 14 days. Under the same conditions, real‐time PCR showed that CyHV‐3 was present with low viral DNA loads, suggesting that CyHV‐3 may establish latent infection in CCF‐K104 cells. Amplification of the left and right terminal repeat sequences of the CyHV‐3 genome arranged in a head‐to‐tail manner was detected by nested PCR following an upshift in temperature from 25 °C to 35 °C. The PCR results suggested that the circular genome may represent a latent form of CyHV‐3. 相似文献
63.
Soil-borne Rhizoctonia fungi cause serious diseases in several plant species. For the classification of these fungi, the number of nuclei in a hyphal cell and the anastomosis reaction are important criteria. Although Rhizoctonia spp. has a wide host range, the causal agents have been reported to be selective for host plant families or species and lead to severe disease. Reports of new diseases, particularly in new host plants, and severe damage in agricultural fields incurred by subdivided or newly found groups of Ceratobasidium and Waitea circinata (a varied teleomorph of Rhizoctonia) have been increasing in recent years. The food production environment is altering because of climate change, introduction of potential new host plants, and heavy use of chemicals that reduce microbial diversity. These changes favor the occurrence of new diseases incurred by undefined anastomosis groups (AGs) or subgroups of Rhizoctonia spp. On the basis of the phylogenetic relationships of AGs and subgroups in Rhizoctonia spp., molecular markers for discriminating the groups of the Rhizoctonia species complex have been developed. The application of genetic markers, in the form of microsatellites or simple sequence repeats (SSR), has become increasingly important in fungal genetics. The analyses of population genetics for Rhizoctonia spp. using SSR markers elucidated the modes of sexual and asexual reproduction, phylogeographical distributions, and global migrations associated with adaptation to agroecosystems. 相似文献
64.
Haruo Yamaguchi Yuko Tanimoto Takamichi Yoshimatsu Shinya Sato Tomohiro Nishimura Keita Uehara Masao Adachi 《Fisheries Science》2012,78(5):993-1000
Blooms of toxic dinoflagellates of the genus Ostreopsis, which is known as a producer of palytoxin (PTX) analogs, may pose a threat to human health in tropical, subtropical, and temperate regions around the world. In the present study, we established a suitable culture method for Ostreopsis spp. isolated from Japanese coastal waters and characterized their growth potential using the method to discuss their bloom dynamics. Each clonal strain of Ostreopsis cf. ovata, Ostreopsis sp.?1, Ostreopsis sp.?5, and Ostreopsis sp.?6 was incubated in 25?×?150?mm test tubes with a flat bottom containing various kinds of medium. Since Ostreopsis spp. strains grew well in IMK and/or f/2 media, we selected these media for cultivation of all the Ostreopsis spp. isolates. Growth rates of O. cf. ovata (0.834?divisions/day), Ostreopsis sp.?1 (0.619?divisions/day), and Ostreopsis sp.?6 (1.04?divisions/day) that produce PTX analogs significantly differed (p?<?0.05) respectively and are clearly higher than those of other reported epiphytic dinoflagellate Gambierdiscus toxicus, Prorocentrum lima, and Coolia monotis cultures, which suggest that these species have ecological advantages to predominate through the algal succession in Japanese coastal waters, resulting in a potential risk to human health in this region. 相似文献
65.
Yohei Koide Leodegario A. Ebron Hiroshi KatoHiroshi Tsunematsu Mary Jeanie Telebanco-YanoriaNobuya Kobayashi Masao YokooSachio Maruyama Tokio ImbeYoshimichi Fukuta 《Field Crops Research》2011,123(1):19-27
A set of near-isogenic lines for blast resistance genes was developed by using an Indica-type elite rice variety, IR49830-7-1-2-2, suitable for the rainfed lowland conditions in the tropics, as a genetic background. Initially, we revealed that IR49830-7-1-2-2 harbors five blast resistance genes - Pia, Pib, Pik-s, Pita, and Pi11(t) - by using a differential system involving 19 selected standard blast isolates from the Philippines. Based on this result, we developed nine near-isogenic lines (NILs) targeting eight resistance genes - Pik, Pi7(t), Pi3, Pi5, Pita-2, Piz-5, Pish, and Pi9 - by recurrent backcrossing. The introgression of each resistance gene in the NILs was confirmed by reaction patterns to the blast isolates, allelism tests, and DNA marker analysis. In addition, a genome-wide DNA marker survey revealed that most of the chromosome regions in each NIL were of the IR49830-7-1-2-2 type. The agricultural characteristics of most of the developed NILs were almost the same as those of IR49830-7-1-2-2. Moreover, with one exception, they showed submergence tolerance similar to IR49830-7-1-2-2. The developed NILs could be used as a multiline variety suitable for the rainfed lowland in the tropics. 相似文献
66.
67.
Naoya Yamaguchi Takashi Sayama Hiroyuki Yamazaki Tomoaki Miyoshi Masao Ishimoto Hideyuki Funatsuki 《Breeding Science》2014,64(4):300-308
Lodging tolerance (LT) is an important trait for high yield and combine-harvesting efficiency in soybean [Glycine max (L.) Merr.]. Many previous studies have investigated quantitative trait loci (QTLs) for lodging score (LS) in soybean. Most of the investigated QTLs were located in the proximal region of maturity or growth habit loci. The aim of this study was to identify genetic factors for LT not associated with maturity or growth habit. QTL analysis was performed using a recombinant inbred line (RIL) population derived from a cross between ‘Toyoharuka’ (TH), a lodging-tolerant cultivar, and ‘Toyomusume’ (TM). The genotypes of TH and TM were estimated as both e1e2E3E4 and dt1. The average LS over 4 years was used for QTL analysis, identifying a major and stable QTL, qLS19-1, on chromosome 19. The LS of the near-isogenic line (NIL) with the TH allele at Sat_099, the nearest marker to qLS19-1, was significantly lower than the NIL with the TM allele at that position. The TH allele at Sat_099 rarely had a negative influence on seed yield or other agronomic traits in both NILs and the TM-backcrossed lines. Our results suggest that marker-assisted selection for qLS19-1 is effective for improving LT in breeding programs. 相似文献
68.
Katsuhiro Tokugawa Dan Aoki Ryutaro Asai Yasuyuki Matsushita Masao Ishiguro Yasufumi Noda Kazuhiko Fukushima 《Journal of Wood Science》2017,63(3):281-287
In order to understand the kraft pulp decolouring mechanism on using a nonionic detergent, the pulp washing process and the resulting pulp handsheets were investigated by examining the brightness, kappa number, thioacidolysis product yield, and dewatering efficiency in the pressing sheet making process. The pulp decolouring could be attributed to a decrease in the lignin content and an improvement in the dewatering efficiency. Furthermore, the detergent distribution in the aqueous pulp suspension obtained during the pulp washing process was visualised using cryo-time-of-flight secondary ion mass spectrometry/scanning electron microscopy (cryo-TOF-SIMS/SEM). The detergent was clearly observed at the transverse surface of the pulp fibre cell wall and was also detected in the lumen of the fibres, suggesting the permeation of the detergent into the pulp fibre cell wall. Based on these results, the pulp decolouring mechanism can be proposed as follows: the detergent permeates into the pulp fibre cell wall and promotes the solution-exchange between the inside and the outside parts of the fibre cell wall, finally washing away the chromophoric substances such as lignin and its degradation products owing to the enhanced dewatering efficiency. 相似文献
69.
In this article, we report on an estimation method for Young’s modulus that entails measuring only the stress wave propagation
velocity of timber built into structures such as wooden buildings. Methods of estimating Young’s modulus that use the stress
wave propagation velocity and characteristic frequency of timber in conjunction with timber density have long been used. In
this article, we propose a method of easily and accurately estimating Young’s modulus from the stress wave propagation velocity
without knowing the timber density. This method is based on a database of wood strength performance and density accumulated
from a variety of research data and the method estimates Young’s modulus by a simulation method. We compared the Young’s moduli
estimated by this method with those obtained by the bending test and by the measurement of the stress wave propagation velocity
and density, and found similar results. This coincidence suggests that the method of estimating Young’s modulus presented
in this article is valid. For example, the method is effective for convenient evaluation on site when determining whether
a wooden building’s structural components should be reused or replaced when repairing or remodeling a building. 相似文献
70.
M. Parvez Rana Sharif Ahmed Mukul M. Shawkat Islam Sohel Mohammad Shaheed Hossain Chowdhury Sayma Akhter M. Qumruzzaman Chowdhury Masao Koike 《Small-Scale Forestry》2010,9(1):41-51
An exploratory survey was carried out to assess economics and employment generation of the trade of bamboo and bamboo-based
secondary products in the eastern Bangladesh, to obtain reliable information about their status, socio-economic significance,
production and marketing. The study was undertaken over 30 bamboo-based enterprises in a suburban market of eastern Bangladesh,
to investigate regional product details, economic profitability and employment opportunities. The sample entrepreneurs, corresponding
to about 25% of the bamboo enterprise population were interviewed using a semi-structured questionnaire. About 202 full and
part-time workers were employed in the factories, under categories of artisan (who manufactured secondary products). The average number of worker’s in the large, medium and small factories were 9 (artisan
40%), 6.45 (artisan 35%) and 5 (artisan 25%) respectively. The study revealed that there was always a satisfied demand of
skilled artisans. Most of the workers were relatively newly employed (not more than 5 years). The daily wage rate varied between
70 and 130 Tk. ($US 1 equals approximately 70 Bangladeshi Taka (Tk.), as at December 2008). Bambusa balcooa was the most utilized species (39.96%) in terms of monetary value. The price of a single B. balcooa culm in the local market was Tk. 160–210. Nine sizes of articles under seven bamboo categories were identified, these being
bera (36″ × 120″ and 72″ × 96″), bookshelf (36″ × 24″), chaluni (12″ × 12″), chatai (48″ × 60″ and 36″ × 48″), jhuri, rickshaw hood and tukri. Net average profit per article was the highest for rickshaw hoods (Tk. 400 at the retailer stage). The total expected annual
income for an enterprises from all articles types sold was estimated to be Tk. 85,800. Three distinct marketing channels were
identified for selling bamboo and value-added secondary products. The study also generated policy implications for effective
management of bamboo-based enterprises. 相似文献