3,759 research outputs found

    First report of early blight caused by Alternaria protenta on potato in Algeria

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    Potato (Solanum tuberosum L.) is one of the most important vegetable crop grown in Algeria. Although less studied than late blight, early blight caused by large-spored Alternaria species including A. solani, and A. grandis is an important foliar disease on these crops under Algerian climatic conditions. Over the past few years, this disease became a major constraint on potato production in Algeria and high incidences of early blight (up to 80 %) were recorded in the north-western parts of Algeria (Bessadat et al., 2016). During years 2012-2014, surveys were carried out and sampling was performed in 12 potato growing regions from East to West and from North to South of Algeria. Two hundred and forty-seven samples with typical early blight symptoms (dark, elongated or circular lesions with concentric rings surrounded by a yellow halo) were collected. Two to three lesions perleaf were excised, surface disinfested for 2 min in 0.1% (v/v) sodium hypochlorite solution and plated on potato dextrose agar medium at 22°C. Twenty-two pure cultures were induced to sporulate by plating on V8 medium and incubating for two weeks under alternating 12 h darkness and 12 h near UV light. Cultural and morphological characteristics of the isolates [color and pigmentation of the culture, shape and size of the conidia (conidial length and width, beak length)] compared with those in the literature (Simmons, 2007) did not clearly differentiate between the large-spored Alternaria species currently reported on potato crops. For identification at the species level, partial regions of the calmodulin (cal) and RNA polymerase second largest subunit (rpb2) genes were amplified using published primer sets (Gannibal et al., 2014; Woudenberg et al., 2014) and sequenced. Maximum likelihood cluster analyses of the resulting nucleotide sequences revealed two isolates (AD82 and AD86 isolated from potato samples collected in the El Oued region) with sequences at the two loci [GenBank accession Nos. KX870505 and KX870506 (cal locus), KX870507 and KX870508 (rpb2 locus)] that shared 100% sequence homology to A. protenta isolate CBS 116696 (KJ718394, JQ646236) and were thus assigned to this species. A. protenta was previously known in Africa only on Helianthus annuus (Simmons, 1986) but isolates from S. tuberosum and S. lycopersicum collected in New Zealand and USA and formerly recognized as A. solani, were recently moved to A. protenta based on phylogeny (Woudenberg et al., 2014). To confirm pathogenicity of the two A. protenta isolates, leaves of susceptible 3-week-old potato plants were inoculated with two 10 µL drops of a 104 conidia/ml suspension. All leaves inoculated with A. protenta showed extending lesions that may reach up 50% of the leaf area at 21 dpi. To our knowledge, we report the first occurrence of A. protenta as pathogen on potato in Algeria.

    Paradigm of tunable clustering using binarization of consensus partition matrices (Bi-CoPaM) for gene discovery

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    Copyright @ 2013 Abu-Jamous et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Clustering analysis has a growing role in the study of co-expressed genes for gene discovery. Conventional binary and fuzzy clustering do not embrace the biological reality that some genes may be irrelevant for a problem and not be assigned to a cluster, while other genes may participate in several biological functions and should simultaneously belong to multiple clusters. Also, these algorithms cannot generate tight clusters that focus on their cores or wide clusters that overlap and contain all possibly relevant genes. In this paper, a new clustering paradigm is proposed. In this paradigm, all three eventualities of a gene being exclusively assigned to a single cluster, being assigned to multiple clusters, and being not assigned to any cluster are possible. These possibilities are realised through the primary novelty of the introduction of tunable binarization techniques. Results from multiple clustering experiments are aggregated to generate one fuzzy consensus partition matrix (CoPaM), which is then binarized to obtain the final binary partitions. This is referred to as Binarization of Consensus Partition Matrices (Bi-CoPaM). The method has been tested with a set of synthetic datasets and a set of five real yeast cell-cycle datasets. The results demonstrate its validity in generating relevant tight, wide, and complementary clusters that can meet requirements of different gene discovery studies.National Institute for Health Researc

    Measurements of the Υ(10860)\Upsilon(10860) and Υ(11020)\Upsilon(11020) resonances via σ(e+eΥ(nS)π+π)\sigma(e^+e^-\rightarrow\Upsilon(n{\rm S})\pi^+\pi^-)

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    We report new measurements of the total cross sections for e+eΥ(nS)π+πe^+e^-\to \Upsilon(n{\rm S})\pi^+\pi^- (nn = 1, 2, 3) and e+ebbˉe^+e^-\to b\bar b from a high-luminosity fine scan of the region s=10.63\sqrt{s} = 10.63-11.0511.05 GeV with the Belle detector. We observe that the Υ(nS)π+π\Upsilon(n{\rm S})\pi^+\pi^- spectra have little or no non-resonant component and extract from them the masses and widths of Υ(10860)\Upsilon(10860) and Υ(11020)\Upsilon(11020) and their relative phase. We find M10860=(10891.1±3.21.7+0.6)M_{10860}=(10891.1\pm3.2^{+0.6}_{-1.7}) MeV/c2c^2 and Γ10860=(53.75.6+7.15.4+1.3)\Gamma_{10860}=(53.7^{+7.1}_{-5.6}\,^{+1.3}_{-5.4}) MeV and report first measurements M11020=(10987.52.5+6.42.1+9.0)M_{11020}=(10987.5^{+6.4}_{-2.5}\,^{+9.0}_{-2.1}) MeV/c2c^2, Γ11020=(6119+920+2)\Gamma_{11020}=(61^{+9}_{-19}\,^{+2}_{-20}) MeV, and ϕ11020ϕ10860=(1.0±0.40.1+1.4)\phi_{\rm 11020}-\phi_{\rm 10860} = (-1.0\pm0.4\,^{+1.4}_{-0.1}) rad.Comment: University of Cincinnati preprint UCHEP-15-01, submitted to Physical Review D - Rapid Communication
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