Molecular characterization of <Emphasis Type="Italic">Phoma tracheiphila</Emphasis>, causal agent of Mal secco disease of citrus,in Israel     

David Ezra  Tammy Kroitor  Avraham Sadowsky 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(2):183-191

Mal secco disease of citrus caused by Phoma tracheiphila is a devastating disease in the Mediterranean basin. Susceptible citrus species include lemon, citron, lime and others. Trees attacked by the fungus show characteristic symptoms; the smallest twigs die first, followed by the larger branches. Eventually, the whole tree is killed. The symptoms are clear in the orchards but by the time they are visible the disease is already well established. The need for a sensitive, reliable and rapid diagnostic method for the early identification of the fungus in trees and fruit exists. We have developed a PCR-based method for the identification of P. tracheiphila from plant tissues including fruit. Any such method must take into account the genetic variability in the pathogen population. Molecular methods were used to compare different isolates of P. tracheiphila. This study found no significant differences between different isolates from different citrus species from different parts of Israel.  相似文献   

Cloning of DNA fragments specific to the pathotype and race of <Emphasis Type="Italic">Verticillium dahliae</Emphasis>     

Toshiyuki Usami  Shu Ishigaki  Hiroko Takashina  Yuko Matsubara  Yoshimiki Amemiya 《Journal of General Plant Pathology》2007,73(2):89-95

Japanese isolates of Verticillium dahliae, a causal agent of wilt disease in many plants, are classifiable into pathotypes based on their pathogenicity. Because these pathotypes are morphologically indistinguishable, establishing a rapid identification method is very important for the control of this pathogen in Japan. For cloning DNA fragments that are useful for identification and specific detection of V. dahliae pathotypes, we performed random amplified polymorphic DNA (RAPD) analyses using various isolates. One polymerase chain reaction (PCR) product, E10-U48, was specific to isolates pathogenic to sweet pepper. The other product, B68-TV, was specific to race 1 of isolates pathogenic to tomato. The specificity of these sequences was confirmed by genomic Southern hybridization. Further analyses revealed that the region peripheral to B68-TV obtained from the genomic DNA library includes the sequence specific to all isolates pathogenic to tomato (races 1 and 2). Moreover, sequence tagged site (STS) primers designed from B68-TV and its peripheral region showed race-specific and pathotype-specific amplification in a PCR assay. The probes and primers obtained in this study are likely to be useful tools for the identification and specific detection of pathotypes and races of V. dahliae. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession number AB095266.  相似文献   

Management approach using simple indices of deer density and status of understory vegetation for conserving deciduous hardwood forests on a regional scale     

Yasutaka Kishimoto  Daisuke Fujiki  Hiroshi Sakata 《Journal of Forest Research》2010,15(4):265-273

We investigated the validity and efficiency of a survey using sight per unit effort (SPUE) of sika deer and shrub-layer decline rank (SDR), which is an index of decline in the physical structure of a whole stand caused by sika deer, based on data collected on a broad scale. This survey was to be used to manage a deer population in order to conserve a forest ecosystem. First, we evaluated the spatial and temporal scales of deer density that are most appropriate for predicting decline in the status of understory vegetation. The model with SPUE calculated in a buffer with a radius of 4.5 km using data for the past 4 years was found to be the best. We showed that our knowledge of the relationship between deer density and status of shrub-layer vegetation is improved by identifying the most suitable spatial and temporal scales of SPUE for predicting SDR. Next, we quantified the effects of SPUE and environmental components on SDR in stands. We found that SPUE had the greatest effect on SDR among all explanatory variables. Moreover, the area under the curve (AUC) was large in a model that only used SPUE (AUC = 0.718). This result suggests that the variation in SDR among stands was explained well by SPUE regardless of differences in the forest environment. Furthermore, we identified the effective values of SPUE for preventing shrub-layer vegetation from declining through deer density control. We conclude that a management system based on SPUE and SDR is a simple and valid method for managing deer populations in order to conserve forest ecosystems.  相似文献   

Christos Gallis (ed.): Green care for human therapy,social innovation,rural economy,and education     

Matthew DelSesto 《Agriculture and Human Values》2017,34(1):239-240

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Effects of carbon and nitrogen amendment on soil carbon and nitrogen mineralization in volcanic immature soil in southern Kyushu,Japan     

Ayaka Yamasaki  Ryunosuke Tateno  Hideaki Shibata 《Journal of Forest Research》2011,16(5):414-423

Soil N mineralization is affected by microbial biomass and respiration, which are limited by available C and N. To examine the relationship between C and N for soil microbial dynamics and N dynamics, we conducted long-term laboratory incubation (150 days) after C and N amendment and measured changes in C and N mineralization, microbial biomass C, and dissolved C and N throughout the incubation period. The study soil was volcanic immature soil from the southern part of Japan, which contains lower C and N compared with other Japanese forest soils. Despite this, the area is covered by well-developed natural and plantation forests. Carbon amendment resulted in an increase in both microbial biomass and respiration, and net N mineralization decreased, probably due to increasing microbial immobilization. In contrast, N amendment resulted in a decrease in microbial respiration and an increase in net N mineralization, possibly due to decreased immobilization by microbes. Amendment of both C and N simultaneously did not affect microbial biomass and respiration, although net N mineralization was slightly increased. The results suggested that inhibitory effect on microbial respiration by N amendment should be reduced if carbon availability is higher. Thus, soil available C may limit microbial biomass and respiration in this volcanic immature soil. Even in immature soil where C and N substrate is low, soil C, such as plant root exudates and materials from above- and belowground dead organisms, might help to maintain microbial activity and N mineralization in this study site.  相似文献   

Laura T. Raynolds,Douglas Murray,and John Wilkinson (eds.): Fair Trade: The Challenges of Transforming Globalization     

Daniel Jaffee 《Agriculture and Human Values》2008,25(3):455-456

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R. N. Gibson (ed), Flatfishes: Biology and Exploitation     

Albert K. Imsland 《Aquaculture International》2008,16(4):373-374

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Erratum to: Classification and characteristic of maturity groups of Chinese landraces of soybean [<Emphasis Type="Italic">Glycine max</Emphasis> (L.) Merr.]     

Wang Yuesheng  Gai Junyi  Zhang Mengchen  Wang Jian  Chang Ruzhen 《Genetic Resources and Crop Evolution》2007,54(7):1633-1633

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NrDNA internal transcribed spacer revealed molecular diversity in strains of red seaweed <Emphasis Type="Italic">Porphyra yezoensis</Emphasis> and genetic insights for commercial breeding     

ZiMin Hu  FuLi Liu  ZhanRu Shao  JianTing Yao  DeLin Duan 《Genetic Resources and Crop Evolution》2010,57(5):791-799

Unraveling the cryptic genetic diversity and selective breeding network in various Porphyra strains is of significance for conservation and utilization of economically important nori crops, for both current and future needs. Here, we used nuclear ribosomal spacer (ITS1) region to investigate the genetic variation and intra-specific relatedness of 59 Porphyra yezoensis Ueda specimens worldwide using phylogenetic and parsimony genealogical approaches. 23 nrDNA ITS1 genotypes were revealed and clustering analysis grouped them into two distinct clades. High genetic diversity was detected in wild P. yezoensis strains from Miyagi and Hokkaido Prefectures in Japan, while the cultivated strains from China and South Korea exhibited relatively higher genetic diversity likewise, which provided crucial genetic insights for future commercial breeding of P. yezoensis on a global scale. In addition, phylogenetic study has revealed the genetic relationship of strains with unknown parentage to those with known parentage, and also ITS1 sequence pattern could be correlated with the geographic origin of P. yezoensis specimens. All these pedigree information generated from this research can be used to select parents for inter-specific or intra-specific selective breeding and cross breeding to maximize the preservation of stock resource and sustainable development of nori industry.  相似文献   

Protein extraction from rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) root for two-dimensional electrophresis     

Xiaoliang Xiang  Shuju Ning  Xia Jiang  Xiaogui Gong  Renlei Zhu  Lanfang Zhu  Daozhi Wei 《Frontiers of Agriculture in China》2010,4(4):416-421

An efficient protein extraction method for two-dimensional gel electrophoresis (2-DE) from plant samples is usually challenging due to the low protein content and high level of interfering compounds. Proteomic analyses of rice (Oryza sativa L.) roots are limited by the lack of an efficient protein extraction method. To establish an effective protocol of protein extraction suitable for 2-DE analysis in rice roots, we evaluated three protein extraction methods (trichloroacetic acid [TCA]/acetone, Mg/NP-40/TCA, and tris-base/acetone). Our results showed that the Mg/NP-40/TCA extraction method had the highest protein yield and is the best resolution of protein separation among the three methods. The TCA/acetone method exhibited clear protein profiles and detected more protein spots with the highest intensity in the region of high Mr (above 45 kDa) than the other methods. However, this method was unable to detect proteins with low-Mr (less than 24.0 kDa). The Tris-base/acetone method showed the poorest resolution of protein separation. Our results suggest that the Mg/NP-40/TCA method was the most effective among the three methods and may provide enhanced proteomic information for rice and other crop roots.  相似文献