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1.
The relative parasitic fitness of isolates of Pyricularia oryzae with different sensitivities to isoprothiolane (di-isopropyl 1,3-dithiolan-2-ylidenemalonate) and IBP (S-benzyl O, O-di-isopropyl phosphorothioate) was studied in the absence of fungicides. Four field isolates (S-1,S-2,MR-1 and MR-2) and two in-vitro mutants (Rvt-1 and Rvt-2) were used for disease epidemics. S-l and S-2 were wild types; MR-1 and MR-2 were sensitive to isoprothiolane and moderately resistant to IBP, and Rvt-1 and Rvt-2 were resistant to both fungicides. Twelve epidemics were made by inoculating rice seedlings with mixed conidial suspensions of two isolates or mutants. The value of relative parasitic fitness (W = 0-1.0) was calculated for each isolate and epidemic. S-l and S-2 were stronger (W = 1.0) than MR-2, Rvt-1 and Rvt-2; but weaker (W = 0.75, 0.73, respectively) than MR-1. MR-1 was strongest among all isolates and mutants used. MR-2 was slightly weaker (W = 0.9-1.0) than S-l and S-2, but stronger than Rvt-1 and Rvt-2. Rvt-1 and Rvt-2 had smaller values of W, ranging from 0.25-0.58, in the epidemics with each field isolate. These results suggest that the proportions of in-vitro mutants do not increase unless intensive selection pressure is given, and would be expected to decrease rapidly after the selection pressure is removed. Isolates moderately resistant to IBP, such as MR-1 and MR-2, however, had high values of W, suggesting that they would increase or would not decrease rapidly in the absence of selection pressure. These results may well explain why isolates highly resistant to isoprothiolane and IBP have seldom been found, and why a large number of isolates moderately resistant to IBP but sensitive to isoprothiolane have been observed in the field. 相似文献
2.
Fujimoto Kiyoshi Miyagi Toyohiko Kikuchi Takao Kawana Toshio 《Mangroves and Salt Marshes》1996,1(1):47-57
Mangrove habitats on Kosrae are divided into three types, i.e., an estuary or delta type, a backmarsh or lagoon type and a coral reef or tidal-flat type. Most of the mangrove forests of Kosrae have been developed during the last 2000 years by accumulating mangrove peat with the gradual sea-level rise of 1 to 2 mm/yr except the landward part of the estuary or delta type. On the other hand, during the period of rapid sea-level rise of about 10 mm/yr between 4100 and 3700 yr B.P., the mangrove forests ceased peat accumulation and retreated landward. Until 3500 yr B.P., mangrove forests were distributed only in narrow bands in the inlets. Therefore, the critical rate of mangrove peat accretion with sea-level rise is estimated at more than 2 mm/yr and less than 10 mm/yr. If the anticipated sea-level rise exceeds this critical rate, all of the mangrove forests of Kosrae will retreat landward and reduce rapidly. 相似文献
3.
ABSTRACT: A quantitatively major collagen was isolated from the pepsin-solubilized collagen preparation of the mantle by differential salt precipitation and phosphocellulose column chromatography, and its constituent α components (α1 and α2) were purified by phosphocellulose column chromatography. The subunits were demonstrated to be genetically distinct from each other by peptide mapping and amino acid analysis. The amino acid composition calculated from those of the α1 and α2 components in 2 : 1 ratio coincided well with that of the major collagen from the mantle. These results suggest that the major collagen in the mantle of the oyster may have a heterotrimer structure (α1)2 α2. 相似文献
4.
5.
J Miyagi K Tsuhako T Kinjo T Iwamasa Y Kamada T Kinju Y Koyanagi 《Veterinary pathology》1999,36(5):452-456
A 37-year-old female orangutan died at the zoological garden. Autopsy examination demonstrated severe coxsackievirus B4 myocarditis immunohistochemically as a cause of the death. Apoptosis of the cardiac muscle cells was observed using the TdT-mediated dUTP-biotin nick endo labeling method and was considered to play a role in the myocarditis. Congestion of the liver and both lungs due to cardiac failure was also observed. Coxsackievirus infection is found frequently in the Okinawan human population. The present orangutan's infection might have come from visitors who were allowed to go near the orangutan. Malignant tumors, severe suppurative infections, and intestinal parasite infections were not observed. Epstein-Barr virus DNA was detected in lymph nodes, but there was no Burkitt's lymphoma. 相似文献
6.
The inhibitory effect of isoprothiolane(diisopropyl 1,3-dithiolan-2-ylidenemalonate), a fungicide for rice blast control, on the metabolism of dibutyl N-methyl-N-phenylphosphoramidate (BPA) by 20 isolates of Pyricularia oryzae was examined in relation to sensitivity of the isolates to the reference fungicide IBP(S-benzyl diisopropylphosphorothiolate). The isolates were divided into five groups based on the modes of BPA metabolism and the inhibition of BPA metabolism by isoprothiolane. Every isolate in groups I and II, which was either a field isolate or a stock culture, decomposed BPA rapidly and produced both hydroxylated and N-demethylated BPA as metabolites. BPA decomposition by these isolates was strongly inhibited by isoprothiolane, resulting in the decreased production of both metabolites in group I and of the hydroxylated metabolite in group II. These isolates were almost equally sensitive to isoprothiolane. Isolates in groups III, IV, and V were all obtained from selection of the fungus mutants found growing on media containing isoprothiolane. Isolates in group III, derived by plating large numbers of conidia, did not decompose BPA to any extent. Mutants of groups IV and V were obtained from fast-growing sectors on agar containing isoprothiolane. Both these groups decomposed BPA, but isolates belonging to group IV produced copious amount of N-demethylated BPA whereas isolates in group V did not. BPA metabolism by these in vitro mutants in groups III, IV, and V was not inhibited by isoprothiolane. Thus, the inhibitory effect of isoprothiolane on BPA metabolism was correlated with sensitivity of an isolate to isoprothiolane. The inhibitory effect of IBP on BPA metabolism was not always correlated with the sensitivity of an isolate to IBP. 相似文献
7.
Shiaki Takagi Lanlan Bai Tomomitsu Ozeki Hikaru Miyagi Kengo Kuroda Shunji Hayashi Hiroshi Yoneyama Tasuke Ando Emiko Isogai 《Animal Science Journal》2014,85(3):342-346
The cathelicidin family is one of the several families of antimicrobial peptides (AMPs). A bovine myeloid antimicrobial peptide (BMAP‐28) belongs to this family. Recently, the emergence of drug‐resistant bacteria such as methicillin‐resistant Staphylococcus aureus (MRSA) has become a big problem. AMPs are expected to be leading compounds of new antibiotics against drug‐resistant bacteria. In this study, we focused on the activity of BMAP‐28 against bacterial cell surfaces. First, we observed morphological change of MRSA caused by BMAP‐28 using a scanning probe microscope. We also studied activities of BMAP‐28 against adherence of S. aureus to fibronectin, collagen type I, collagen type IV. We confirmed whether BMAP‐28 can bind to lipoteichoic acid (LTA) of S. aureus. BMAP‐28 was indicated as damaging the cell surface of MRSA. In a particular range of concentrations, BMAP‐28 promoted adherence of S. aureus against fibronectin and collagens. It was revealed that BMAP‐28 and LTA of S. aureus bound with each other. Our study showed the potential of BMAP‐28 which can damage MRSA and interact with LTA of S. aureus but promote its adherence in some concentrations. This study provides new points of which to take notice when we use AMPs as medicines. 相似文献
8.
Takahiro Tezuka Keisuke Waki Kazutoshi Yashiro Maki Kuzuya Tomoko Ishikawa Yasumasa Takatsu Makoto Miyagi 《Euphytica》2009,168(2):177-188
Resistance to Fusarium oxysporum f.sp. melonis race 2 is conferred by a single dominant gene, Fom-1 in melon. Here, we identified DNA markers tightly linked to Fom-1 that could be used for marker assisted selection in breeding programs. First, we developed 125 F2 plants derived from the cross between melon lines P11 (fom-1fom-1) and MR-1 (Fom-1Fom-1). Using the F2 population, we constructed a linkage map including 14 SSR markers which had not been mapped previously. Fom-1 was confirmed to be allocated to linkage group 7. Then, we identified four AFLP markers using bulked segregant analysis.
The AFLP marker TAG/GCC-470 was completely linked to Fom-1 and other three markers were mapped near Fom-1. TAG/GCC-470 and TCG/GGT-400 were respectively converted to STS and CAPS markers. Usefulness of DNA markers was confirmed
in the analysis with several melon cultivars and lines. 相似文献
9.
LI Cun-dong BAI Zhi-ying Ye G Miyagi M Chapman S Reader S M LIU Chun-ji 《中国农业科学(英文版)》2011,10(2):159-165
Rapid expansion of leaves of early-stage plants in wheat produced by chromosomal control of characteristics related to rapid expansion of the first six leaves of wheat were investigated using a set of single chromosome substitution lines under two different temperature regimes(TRs).Results from this study indicated that several chromosomes could be responsible for each of the four characteristics studied(including leaf width,leaf length,leaf elongation rate and leaf appearance index)and that different chromosomes may be responsible for the same characteristics at different TRs.Only a small number of substitutions that showed the most significant effects on leaf length were found among those that showed the most significant effects on leaf width,providing further evidence that these two characteristics are likely controlled by different sets of genes.Substitutions 4B,4D,and 5A are among those that were repeatedly detected to having significant effects on different leaf characteristics at the lower-TR and genes residing on these three chromosomes could be homologous.This possibility and its implication are discussed. 相似文献
10.
Merkel S McNamara AK Kubo A Speziale S Miyagi L Meng Y Duffy TS Wenk HR 《Science (New York, N.Y.)》2007,316(5832):1729-1732
Polycrystalline (Mg(0.9),Fe(0.1))SiO3 post-perovskite was plastically deformed in the diamond anvil cell between 145 and 157 gigapascals. The lattice-preferred orientations obtained in the sample suggest that slip on planes near (100) and (110) dominate plastic deformation under these conditions. Assuming similar behavior at lower mantle conditions, we simulated plastic strains and the contribution of post-perovskite to anisotropy in the D' region at the Earth core-mantle boundary using numerical convection and viscoplastic polycrystal plasticity models. We find a significant depth dependence of the anisotropy that only develops near and beyond the turning point of a downwelling slab. Our calculated anisotropies are strongly dependent on the choice of elastic moduli and remain hard to reconcile with seismic observations. 相似文献