Diversity and differentiation of <Emphasis Type="Italic">Oryza sativa</Emphasis> and <Emphasis Type="Italic">O. rufipogon</Emphasis> in Indonesia     

Kadapi Muhamad  Kaworu Ebana  Shuichi Fukuoka  Kazutoshi Okuno 《Genetic Resources and Crop Evolution》2017,64(1):41-54

Analysis of the genetic structure of Indonesian Oryza sativa and O. rufipogon using neighbour-joining trees based on single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers revealed that O. sativa in Indonesia is separated from O. rufipogon. Accessions of O. sativa in this study were differentiated into two major groups, indica and tropical japonica, excluding some varieties. SSR and SNP markers revealed the high value of differentiation (F _ST) and genetic distance (D) between indica and tropical japonica and we discovered four loci by SNP markers and one locus by SSR markers that play a role in differentiation between indica and tropical japonica. Interestingly, genetic diversity (H) in O. rufipogon was lower than that in O. sativa, however H in O. rufipogon was the highest and H in tropical japonica was the lowest when O. sativa was divided into two groups. Inbreeding coefficient (Fst) showed evidences that gene flow (Nm) between species and within species might be one of the mechanisms related to the diversification and differentiation of Indonesian rice germplasm by asymmetric pattern between species and within O. sativa as revealed by SSR and SNP markers. In addition, we found evidences on stabilizing selection in Indonesian rice germplasm and they might be the reasons why Indonesian rice germplasm did not differentiate due to source location of landrace. However, we found a weak relation between SSR and SNP markers probably due to highly polymorphic in SSR and the different properties of both markers.  相似文献   

Construction of a system for exploring mitotic homologous recombination in the genome of Pyricularia oryzae     

Takayuki Arazoe  Shuichi Ohsato  Tsutomu Arie  Katsuyoshi Yoneyama  Shigeru Kuwata 《Journal of General Plant Pathology》2013,79(6):422-430

To investigate mitotic homologous recombination (HR) in Pyricularia oryzae, we created an HR detection system. The system consists of two non-functional enhanced yellow fluorescent protein (YFP) and blasticidin S deaminase (BSD) fusion genes (YFP::BSD). If mitotic HR occurs between the two non-functional genes in the genome, restoration of the functional YFP::BSD gene can be expected. The expression of the functional YFP::BSD gene can be detected by both YFP fluorescence and resistance against BS. When the P. oryzae genome was transformed simultaneously with two non-functional genes, all six lines of transformants with both genes had some portion of their hyphae exhibiting YFP fluorescence and BS resistance during growth. Up to ca. 10 % of conidia harvested from the mycelium of each of the six lines had YFP fluorescence, suggesting that HR consistently occurs during mycelium growth. To determine whether and how the HR-mediated phenotypic changes occurred at the DNA level, we analyzed the genomic DNA of BS-resistant mycelia by PCR-RFLP and sequencing and were able to confirm the existence of a restored functional YFP::BSD gene and a non-functional recombinant gene. Collectively, these findings demonstrate that we established a successful HR detection system for P. oryzae, which can be used for other plant pathogens, and that mitotic HR actually occurs in P. oryzae and constitute the first experimental evidence for mitotic HR in a fungus.  相似文献   

Identification of several rice genes regulated by Si nutrition     

Shuichi Watanabe  Emi Shimoi  Naoko Ohkama  Hiroaki Hayashi  Tadakatsu Yoneyama  Junshi Yazaki 《Soil Science and Plant Nutrition》2013,59(8):1273-1276

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Application of the first-order reaction (for) model to modulation by Bradyrhizobium japonicum in the modulation-dilution frequency method and estimation of time of initiation of nodulation     

Susumu Asakawa  Katsuji Watanabe 《Soil Science and Plant Nutrition》2013,59(4):733-736

Abstract

Hattori (1985) proposed a model to simulate the relation between the number of bacterial colonies on agar plates and the incubation time, using the following equation:

where N(t) is the number of colonies observed at time t, and N_∞ λ, and t _r are parameters expressing the expected number of colonies observed at an infinite time, the rate of increase in the number of colonies, and the time of initiation of colony formation, respectively. This model is called the first-order reaction (FOR) model because the Eq. 1 is essentially the same as that of the first-order reaction.  相似文献   

Studies on the nitrification in soil,with special reference to the population of nitrifier     

Shuichi Ishizawa  Tatsuhiko Matsuguchi 《Soil Science and Plant Nutrition》2013,59(6):30-34

A number of papers have been published on nitrification in soil. The problem of the nitrification has become increasingly important because of the appearance of new forms of nitrogenous fertilizers such as ammonium chloride or urea, etc.  相似文献   

A next-generation-sequencing approach to diagnose viral diseases of greenhouse ranunculus     

Hayahi  Saki  Ota  Emi  Kurogi  Shuichi  Matsushita  Yosuke  Kanno  Yoshiaki  Takeshita  Minoru 《Journal of General Plant Pathology》2022,88(2):134-137

Journal of General Plant Pathology - Viruses that infect Ranunculus asiaticus L., a globally important greenhouse ornamental, have consistently caused serious damage in Japan. We coupled...  相似文献   

Genome editing of Nf1, Pten,and Trp53 in neonatal mice induces glioblastomas positive for oligodendrocyte lineage transcription factor 2     

Hiromi Yamamoto  Keisuke Yamamura  Haruka Nagasaki  Takamasa Suzuki  Fumiko Ninomiya  Kenji Matsubara  Naomoto Harada  Shuichi Ohkubo 《Journal of toxicologic pathology》2021,34(4):359

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Formation of the density profile and its effects on the properties of fiberboard   总被引：1，自引：1，他引：0  

Ee Ding Wong  Min Zhang  Guangping Han  Shuichi Kawai  Qian Wang 《Journal of Wood Science》2000,46(3):202-209

Two main types of fiberboards were produced using lauan (Shorea spp.) fibers with an isocyanate resin as the binder; fiberboard with a flat, homogeneous (homoprofile), and typical U-shaped (conventional) density profile along the board thickness. The processing parameters included manipulation of mat moisture content distribution, press closing speed, and hot pressing method. The results are summarized as follows: (1) A larger variation was observed in the peak density (PD) and core density (CD) of fiberboards at 0.5g/cm³ mean density (MD) level than in those at 0.7 g/cm³. Generally, PD showed a greater variation than CD, irrespective of MD level. (2) Boards produced using two-step hot pressing recorded substantially higher PD with reduced CD. (3) Multiple regression analysis showed that CD and PD could be calculated based on the other profile defining factors, and a rough estimation for peak distance and gradient factor was possible. (4) Based on static bending, conventional fiberboard had a higher modulus of rupture (MOR) than the homo-profile board but a similar modulus of elasticity (MOE). (5) At 0.5 g/cm³ the MOR and dynamic MOE of fiberboard increased by up to 67% and 62%, respectively, when the PD increased from 0.5 to 1.07 g/cm³. Similarly, an increase of PD from 0.7 to 1.1 g/cm³ resulted in corresponding increases of 55% and 34% in the MOR and dynamic MOE of 0.7 g/cm³ boards. (6) The internal bond strength and screw withdrawal resistance were almost entirely dependent on the CD and MD, respectively. (7) Homo-profile fiberboards registered higher thickness swelling and water absorption than conventional fiberboards throughout the dry/wet conditioning cycle.  相似文献   

Involvement of granulin in estrogen-induced neurogenesis in the adult rat hippocampus     

Chiba S  Suzuki M  Yamanouchi K  Nishihara M 《The Journal of reproduction and development》2007,53(2):297-307

Recent studies have demonstrated the presence of neurogenesis in the adult mammalian hippocampus, and it has been suggested that estrogen and various growth factors influence the processes of adult neurogenesis. The present study assessed cell proliferation in the dentate gyrus and the mRNA expression levels of granulin, insulin-like growth factor-I (IGF-I), and brain-derived neurotrophic factor (BDNF) in the hippocampus 4 h after treatment with estradiol benzoate (EB) in 3- and 12-month old ovariectomized rats. At 3 months of age, mRNA expression of granulin precursor and cell proliferation were increased by EB treatment, although the mRNA expressions of IGF-I and BDNF remained unchanged. At 12 months of age, however, neither mRNA expression of the three genes nor cell proliferation in the dentate gyrus were affected by EB treatment. In addition, 17beta-estradiol enhanced the proliferation of neural progenitor cells derived from hippocampal tissue of 3-month-old female rats in vitro; this was inhibited by neutralization of granulin with specific antibody. These results suggest that estrogen induces granulin gene expression in the hippocampus and that the product of this gene is involved in the mitogenic effects of estrogen in the dentate gyrus, although the responses to estrogen decline with age.  相似文献   

Chemical structural elucidation of total lignins in woods I: fractionation of the lignin in residual wood meal after extraction of milled wood lignin     

Shuichi Hirosawa  Rui Katahira  Fumiaki Nakatsubo 《Journal of Wood Science》2002,48(1):46-50

Residual wood meal after extraction of milled wood lignin (WMEM) ofEucalyptus globulus was extracted with alkali and LiCl/N,N-Dimethylacetamide (DMAc). These agents dissolve mainly hemicellulose and cellulose, respectively. The extractability of WMEM in alkali solutions was influenced by the degree of swelling of the cellulose. Under good swelling conditions, considerable amounts of cellulose and lignin were extracted with the hemicellulose. Maximum extractability was about 60% of the WMEM under optimum conditions (3 M or 5 M LiOH or 3M NaOH solution). Some portion of cellulose was extracted with LiCl/DMAc at room temperature. Thus, lignin inE. globulus WMEM was divided into three fractions: hemicellulose-lignin fraction, cellulose-lignin fraction, and insoluble-lignin fraction.Part of this work was presented at the 49th annual meeting of the Japan Wood Research Society, Tokyo, April 1999; and at the 50th annual meeting of the Japan Wood Research Society, Kyoto, April 2000  相似文献