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Seyed Mahyar Mirmajlessi Inmaculada Larena Marika Mänd Evelin Loit 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2016,66(7):619-629
Verticillium dahliae Kleb, the cause of Verticillium wilt disease, is a destructive pathogen that leads to severe yield losses in strawberry fields and thus considerable economic damages. Although rapid identification and detection methods are becoming available more, pathogen quantification remains one of the main challenges in the disease management. In this study, a real-time polymerase chain reaction (rtPCR) assay was developed to quantitatively assess V. dahliae abundance directly from affected roots and soil collected from different areas in Estonia. A specific primer pair based on the ribosomal DNA (rDNA) internally transcribed spacer was designed for SYBR Green-based assay. Strawberry plant and soil samples were randomly collected from different areas in Estonia and analyzed for V. dahliae by soil plating technique and rtPCR assay. The assay was specific for V. dahliae so that the minimum detection limit was 0.93?pg?µl?1 of pathogen DNA and the lowest amount of V. dahliae detected in soil was 10.48?pg?µl?1 of target DNA corresponding to one microsclerotia per gram of soil. This technique allowed rapid detection and quantification of the pathogen DNA at the picogram level in soils and even in symptomless plants, facilitating the screening of the pathogen in diverse areas. This is the first study about the rtPCR technique being used successfully to assess populations of V. dahliae with high specificity and sensitivity in Estonia strawberry fields. Results of this research can be useful for growers and agricultural organizations to improve available disease management strategies against Verticillium wilt. 相似文献
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S. M. Mirmajlessi M. Bahram M. Mänd N. Najdabbasi S. Mansouripour E. Loit 《Eurasian Soil Science》2018,51(6):682-691
Soil fungal pathogens are the most common cause of diseases in commercial strawberry crops worldwide. Since simultaneous infections by different pathogens can severely damage the crop, understanding the associated fungal communities can be helpful to mitigate crop loss. Herein, we used Illumina metabarcoding to assess the structure of fungal communities in five strawberry production areas in Estonia. Our analysis revealed 990 to 1430 operational taxonomic units (OTUs) per soil sample (pools of eight soil samples per production area). Based on our analyses, Ascomycota (55.5%) and Basidiomycota (25.0%) were the most OTUs-rich. Amongst the 24 most abundant OTUs, Geomyces, Rhodotorula, Verticillium and Microdochium were the most abundant genera, which were found across nearly all the soil samples. The OTUs were also clustered into three distinct groups, corresponding to different functional guilds of fungi. In addition, Fusarium solani, V. dahliae, Rhizoctonia solani and Colletotrichum truncatum were enormously abundant in the fields with disease symptoms, whereas arbuscular mycorrhizal fungi especially Rhizophagus irregularis were considerably more abundant in the fields with healthy plants. These findings provide support that mycorrhizal fungi may play an important role in suppressing pathogens. Our study for the first time shows the usefulness of Illumina technology in surveying the communities of soil fungi in strawberry fields effectively, which may improve available disease management strategies against strawberry diseases. 相似文献
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Eve Runno-Paurson Kaire Loit Merili Hansen Berit Tein Ingrid H. Williams Marika Mänd 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(5):422-432
In recent years, potato early blight [Alternaria solani (Ellis & G. Martin) L.R. Jones, A lternaria alternata (Fr.) Keissl.] has occurred with increasing frequency in European potato fields, including those in northern regions. In our study, early blight was evaluated during the two years 2010–2011 on potato plants in a conventional farming experiment. Both growing seasons were very favourable for early blight development and evaluation. Our study indicates that, despite chemical treatments, potato early blight is a great problem for potato growers in conventional farming systems in the North-East region in years when temperatures are higher than average. In 2011, early blight damage was particularly high on the untreated (N0P0K0) treatment plots where severity increased abruptly from an initial 2% to 91%, and killed the potato haulms within five weeks. In 2010, the most severely infected plants were also recorded on the untreated (N0P0K0) plots, where 70% of foliage was destroyed by the end of the growing season. Results showed that a more efficient chemical strategy is needed against this disease on susceptible cultivars. Breeding and growing more resistant cultivars of potato is considered the most efficient, cost effective and environmentally friendly control method for sustainable cultivation in conventional growing systems. As an increase in the frequency of warmer summers is predicted, greater problems from this pathogen are to be expected in Northern Europe. 相似文献
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Jéssica Figueiredo Rezende Monik Evelin Leite Douglas Willian Nogueira Danilo Gustavo Nogueira Alex Antonio da Silva Wilson Roberto Maluf 《Plant Breeding》2020,139(1):65-72
Pvr4 locus, commonly associated with a co-dominant CAPS marker, confers monogenic dominant resistance to potyvirus complex in Capsicum spp. Aiming to investigate whether the resistance found in resistant genotypes not bearing Pvr4 marker is due to allelism in the Pvr4 locus, or due to a new locus of the pvr series, segregation analyses of an F2 population obtained from a cross between two pepper lines “Myr-29-10” (P1) (resistant to PepYMV, showing a single band of 444 bp, Pvr4/Pvr4) and “PIM-025” (P2) (resistant to PepYMV, showing a single band of 458 bp, Pvr4+/Pvr4+) were performed. According to the results, there is strong evidence that the locus controlling PepYMV resistance in PIM-025 (P2) is not Pvr4. These results provide evidence that those resistant genotypes, bearing a susceptible band pattern in the Pvr4 locus (458 bp, Pvr4+/Pvr4+), carry a different gene from those described in the literature up to the present time. 相似文献
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A soil map at the scale 1:10,000 serves as a major important document for land owners and local governments, which allows them to use soil information in their daily activity. The intensity of exploitation of soil maps will increase when the very map and its legend are supplemented, within colored and indexed polygons, with information about soil texture and reaction by layers, but also about the thickness and characterization of the epipedon, quality indices for soil assessment, classes of stoniness, and prevalent fractions of stones, erosion risk, etc. Special maps of agronomical status, with a list of proper measures for improvement of soils and their associations, should form a regular component of large‐scale mapping. As decrease in arable land and increase in the forest area are common trends in land use, these maps and general soil data should serve as the fundamental source of information for decision making concerning land use. Data indicating the suitability of any soil for any crop should be entered in a database. Application of GIS on any level of national economy, digitization of a large‐scale soil database and making it accessible to land users would allow to expand the amount of available information for each soil map polygon. 相似文献
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The occurrence of race-specific resistance genes to the stem canker fungus, Leptosphaeria maculans, was analysed in 453 accessions of B. napus, mainly originating from the Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK) GeneBank. Major resistance genes
Rlm1, Rlm2, Rlm4 and the putative RlmBBA gene were investigated using genetically improved strains of the fungus harbouring as few corresponding avirulence genes
as possible. In addition, a screening with fully virulent isolates was used to uncover novel resistance sources. Major resistance
genes were rarer in frequency and diversity in spring-type cultivars compared to winter types. In the former, 65.7% of the
accessions were fully susceptible to all isolates, whereas only 12.2% of the winter types were devoid of at least one R gene.
In spring cultivars, the most common R gene, Rlm4 was found in 26.6% of accessions, whereas the other R genes were rare. In winter cultivars, the most common R genes were
Rlm2 (more than 45.9–54.0% of the accessions) and Rlm4 (26.4–27.7% of the genotypes). In winter types however, the improvement of the quality of oils, through the generation of
single- and double-low genotypes improved the homogeneity of the cvs, whereas it impoverished R gene diversity, including
the loss of complete resistance that was harboured by 18.4% of the less advanced accessions, and a reduction in the ratio
of accessions harbouring Rlm1. Correlation between the R gene(s) present in the accessions and their field resistance is discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Susana B. Rosas Germn Avanzini Evelin Carlier Carolina Pasluosta Nicols Pastor Marisa Rovera 《Soil biology & biochemistry》2009,41(9):1802-1806
Wheat (Triticum aestivum L.), rice (Oryza sativa) and maize (Zea mays L.) are the most important cereals worldwide. However, in the last few years, soil has been submitted to both use and handling pressures due to the increase in agricultural practices, which are leading to its degradation. The use of plant growth-promoting rhizobacteria (PGPR) as inoculants constitutes a biological alternative for sustainable production. Pseudomonas aurantiaca SR1 was formulated as an inoculant in order to evaluate its growth promotion effect in the field when applied on maize and wheat seeds at the sowing time. P and N fertilization treatments were also included in the assays. P. aurantiaca SR1 colonized the root system of both crops and it persisted at appropriate population densities. It also showed a significant plant growth-promoting effect that was reflected in the yield. Another relevant finding was that both crops, when inoculated with P. aurantiaca SR1, presented higher yields with fertilization doses lower than those conventionally applied. This indicated its potential use as a reasonable alternative for crop production, with a minimization of the ecological impact. 相似文献