Read by QxMD icon Read


Fangfang Guo, Xinglong Chen, Minghong Lu, Li Yang, Shi Wei Wang, Bo Ming Wu
In this study, spatial analyses were conducted at three different scales to better understand the epidemiology of rice blast, a major rice disease caused by Magnaporthe oryzae. At regional scale, across the major rice production regions in China, rice blast incidence was monitored on 101 dates at 193 stations from June 10th to Sep. 10th during 2009-2014, and surveyed in 143 fields in September, 2016; at county scale, 3 surveys were done covering 1-5 counties in 2015-2016; and at field scale, blast was evaluated in 6 fields in 2015-2016...
May 22, 2018: Phytopathology
Clive Bock, Carolyn Young, Katherine Stevenson, Nikki Charlton
Scab (caused by Venturia effusa) is the major disease of pecan in the southeastern U.S.A. There is no information available on the fine scale population genetic diversity, or the occurrence of clonal types at small spatial scales that provides insight into inoculum sources and dispersal mechanisms, and potential opportunity for sexual reproduction. To investigate fine scale genetic diversity, 4 trees (cv. Wichita = populations) were sampled hierarchically: within each tree canopy, 4 approximately evenly spaced terminals (subpopulations) were selected and up to 6 leaflets (sub-subpopulations) were sampled from different compound leaves on each terminal...
May 17, 2018: Phytopathology
Shizhen Wang, Soichiro Asuke, Trinh Thi Phuong Vy, Yoshihiro Inoue, Izumi Chuma, Joe Win, Kenji Kato, Yukio Tosa
The wheat blast fungus (Triticum pathotype of Pyricularia oryzae) first arose in Brazil in 1985 and has recently spread to Asia. Resistance genes against this new pathogen are very rare in common wheat populations. We screened 520 local landraces of common wheat collected worldwide with Br48, a Triticum isolate collected in Brazil, and found a highly resistant, unique accession, GR119. When F2 seedlings derived from a cross between GR119 and Chinese Spring (CS, susceptible control) were inoculated with Br48, resistant and susceptible seedlings segregated in a 15:1 ratio, suggesting that GR119 carries two resistance genes...
May 16, 2018: Phytopathology
Domenico Abate, Rita Milvia De Miccolis Angelini, Caterina Rotolo, Stefania Pollastro, Francesco Faretra
Monilinia fructicola, Monilinia laxa and Monilinia fructigena are the most important pathogens responsible for brown rot disease of stone and pome fruits. Information on their mating system and sexual behaviour is scant. A mating-type specific PCR-based assay was developed and applied to 155 Monilinia isolates from ten countries and ten different host plants. We showed that single isolates carry only one of two opposite idiomorphs at the MAT1 locus consistent with a heterothallic mating system for all three species...
May 16, 2018: Phytopathology
De Peng Yuan, Chong Zhang, Zi Yuan Wang, Li Tian Ya, Xiao Feng Zhu, Yuan Hu Xuan
Rhizoctonia solani causes sheath blight disease in rice; however, the defense mechanism of rice plants against R. solani remains elusive. To analyze the roles of brassinosteroid (BR) and ethylene signaling on rice defense to R. solani, wild-type (WT) rice and several mutants and over-expressing (OX) lines were inoculated with R. solani. Mutants d61-1 and d2 were less susceptible to sheath blight disease, bri1-D was more susceptible, and ravl1 and d61-1/EIL1 Ri5 were similarly susceptible compared to WT. The double mutant ravl1/d61-1 was phenotypically similar to the ravl1 mutant...
May 16, 2018: Phytopathology
Mark E Hilf, Weiqi Luo
'Candidatus Liberibacter asiaticus' is a phloem-colonizing intracellular bacterial pathogen of citrus associated with the disease huanglongbing. A study of patterns of colonization and bacterial population growth in new growth of different citrus types was conducted by pruning infected citron, sweet orange, sour orange, mandarin, citrange and Citrus macrophylla trees to force the growth of axillary and adventitious shoots. The first three leaves on newly emerged shoots were collected at 30, 60 and 90 days to assess colonization and population growth of 'Ca...
May 14, 2018: Phytopathology
Laramy Enders, Trevor Hefley, John Girvin, Robert Whitworth, Charles Smith
Several aphid species transmit barley yellow dwarf, a globally destructive disease caused by viruses that infect cereal grain crops. Data from >400 samples collected across Kansas wheat fields in 2014 and 2015 were used to develop spatio-temporal models predicting the extent to which landcover, temperature and precipitation affect spring aphid vector abundance and presence of individuals carrying Barley yellow dwarf virus (BYDV). The distribution of Rhopalosiphum padi abundance was not correlated with climate or landcover, but Sitobion avenae abundance was positively correlated to fall temperature and negatively correlated to spring temperature and precipitation...
May 11, 2018: Phytopathology
Danny Rioux, Martine Blais, Nicholas Nadeau-Thibodeau, Marie Lagacé, Pierre DesRochers, Krystyna Klimaszewska, Louis Bernier
Ophiognomonia clavigignenti-juglandacearum (Oc-j) endangers the survival of butternut (Juglans cinerea) throughout its native range. While screening for disease resistance, we found that artificial inoculations of 48 butternut seedlings with Oc-j induced the expression of external symptoms, but only after a period of dormancy. Before dormancy, compartmentalized tissues such as necrophylactic periderms (NPs) and xylem reaction zones (RZs) contributed to limiting pathogen invasion. Phenols were regularly detected in RZs, often in continuity with NPs during wound closure, and confocal microscopy revealed their presence in parenchyma cells, vessel plugs and cell walls...
May 11, 2018: Phytopathology
Charlotte Poeydebat, Dominique Carval, Philippe Tixier, Marie-Odette Daribo, Luc De Lapeyre De Bellaire
Black leaf streak disease (BLSD), caused by the fungus Mycosphaerella fijiensis, is an important threat to banana production. Although its control relies on costly and unsustainable use of fungicides, ecological regulation of BLSD linked to field-scale plant diversity has received little attention. We monitored banana phytometers in plots in banana-based fields where no fungicides were applied. Within each plot, we measured plant richness in three strata, canopy openness, necrotic leaf removal, Musa abundance and richness...
May 4, 2018: Phytopathology
Tian Tian Cui, Yu Bin, Jian Hong Yan, Peng Ying Mei, Zhong An Li, Chang Yong Zhou, Zhen Song
Yellow vein clearing disease (YVCD) causes significant economic losses in lemon and other species of citrus. Usually, citrus yellow vein clearing virus (CYVCV) is considered to be the causal agent of YVCD. However, mixed infection of CYVCV and Indian citrus ringspot virus (ICRSV) or other pathogens is often detected in citrus plants with YVCD. In this study, we re-examined the causal agent of YVCD to fulfill Koch's postulates. First, the full-length genome of CYVCV isolate AY (CYVCV-AY) was amplified by long-distance RT-PCR from a Eureka lemon [Citrus limon (L) Brum...
May 4, 2018: Phytopathology
Yazmin Rivera, Kurt Zeller, Subodh K Srivastava, Jeremy Sutherland, Marco E Galvez, Mark K Nakhla, Anna Poniatowska, Guido Schnabel, George W Sundin, Gloria Abad
Fungi in the genus Monilinia are known to cause devastating brown rot disease of stone and pome fruits. Here, we report the draft genome assemblies of four important phytopathogenic species: Monilinia fructicola, Monilinia fructigena, Monilinia polystroma, and Monilinia laxa. The draft genome assemblies were 39 Mb (M. fructigena), 42 Mb (M. laxa), 43 Mb (M. fructicola), and 45 Mb (M. polystroma) with as few as 550 contigs (M. laxa). These are the first draft genome resources publicly available for M. laxa, M...
May 3, 2018: Phytopathology
Li-Long Pan, Xi-Yun Cui, Qun-Fang Chen, Xiao-Wei Wang, Shu-Sheng Liu
Cotton leaf curl disease is one of the most significant constraints to the production of cotton. In the past decades our understanding of the begomoviruses (family Geminiviridae) causing the disease has improved, but little is known regarding transmission of these viruses by the different species of whiteflies in the Bemisia tabaci complex. We compared transmission efficiency of cotton leaf curl Multan virus (CLCuMuV), one of the major begomoviruses associated with cotton leaf curl disease, by four whitefly species, of which two are indigenous to Asia and two are invasive worldwide...
May 1, 2018: Phytopathology
Ebrahim Osdaghi, S Mohsen Taghavi, Silvia Calamai, Carola Biancalani, Matteo Cerboneschi, Stefania Tegli, Robert Harveson
A multi-phasic approach was used to decipher the phenotypic features, genetic diversity, and phylogenetic position of 46 Curtobacterium spp. strains isolated from dry beans and other annual crops in Iran and Spain. Pathogenicity tests, resistance to arsenic compounds, plasmid profiling and BOX-PCR were performed on the strains. Multilocus sequence analysis (MLSA) was also performed on five housekeeping genes (i.e. atpD, gyrB, ppk, recA, and rpoB) of all the strains, as well as five pathotype strains of the species...
May 1, 2018: Phytopathology
Takeo Shimizu, Satoko Kanematsu, Hajime Yaegashi
Understanding the molecular mechanisms of pathogenesis is useful in developing effective control methods for fungal diseases. The white root rot fungus Rosellinia necatrix is a soil-borne pathogen that causes serious economic losses in various crops, including fruit trees, worldwide. Here, using next-generation sequencing techniques, we first produced a 44-Mb draft genome sequence of R. necatrix strain W97, an isolate from Japan, in which 12,444 protein-coding genes were predicted. To survey differentially expressed genes (DEGs) associated with the pathogenesis of the fungus, the hypovirulent W97 strain infected with Rosellinia necatrix megabirnavirus 1 (RnMBV1) was used for a comprehensive transcriptome analysis...
April 24, 2018: Phytopathology
Marco Aurélio Siqueira Gama, Rosa Ramos Mariano, Wilson José Silva Júnior, Antônio Roberto Gomes Farias, Maria Angélica Guimarães Barbosa, Marisa A S V Ferreira, César Raimundo Lima Costa Júnior, Liliana A Santos, Elineide B Souza
Grapevine bacterial canker, which is caused by Xanthomonas campestris pv. viticola, is one of the most important grapevine diseases in the northeastern region of Brazil. This disease causes severe damage and represents a high potential risk to the development of Brazilian viticulture. In turn, pigmented isolates pathogenic to cashew plant, making cashew fruit unfit for sale, also have been detected in Northeastern Brazil. Given that the taxonomic position of these bacteria is unclear, the multilocus sequence analysis (MLSA) technique, average nucleotide identity (ANI) values and tetranucleotide frequency correlation coefficients (TETRA) were used to analyze their phylogenetic relationship in relation to other Xanthomonas species...
April 24, 2018: Phytopathology
Paul W Tooley, Marsha Browning
We examined the impact of relative humidity (RH) on Phytophthora ramorum sporangia production on Rhododendron 'Cunningham's White'. When diseased plants were maintained under continuous moisture in a mist tent, sporangia were collected from some plants for 22 weeks. More than 3,000 sporangia/leaf/week were collected over the first 3 weeks but levels declined to <100 sporangia/leaf/week after 7 weeks. We also examined the impact of drying on P. ramorum sporangia production. Diseased, detached leaves were maintained in humidity chambers (100, 96...
April 17, 2018: Phytopathology
Murir Mawassi, Orit Dror, Moshe Bar-Joseph, Alon Piasetzky, Jennifer Sjölund, Naama Levitzky, Nofar Shoshana, Ludmila Meslenin, Sabrina Haviv, Carmel Porat, Leron Katsir, Svetlana Kontsedalov, Murad Ghanim, Einat Zelinge-Reichert, Yvonne M Arnsdorf, Abed A Gera, Ofir Bahar
Carrot yellows disease has been associated for many years with the Gram-positive, insect-vectored bacteria, Candidatus Phytoplasma and Spiroplasma citri. However, reports in the last decade link carrot yellows symptoms also with a different, Gram-negative, insect-vectored bacterium - 'Ca. Liberibacter solanacearum'. Our study shows that to date 'Ca. L. solanacearum' is tightly associated with carrot yellows symptoms across Israel. The genetic variant found in Israel is most similar to haplotype ,D found around the Mediterranean basin...
April 17, 2018: Phytopathology
Xinglong Chen, Yulin Jia, Melissa H Jia, Shannon Pinson, Xueyan Wang, Bo Ming Wu
Major blast resistance (R) genes confer resistance in a gene-for-gene manner. However, little information is available on interactions between R genes. In this study, interactions between two rice blast R genes, Pi-ta and Pi-b, and other minor blast resistance quantitative trait loci (QTL) were investigated in a recombinant inbred line (RIL) population comprising of 243 RILs from a 'Cybonnet' (CYBT)×'Saber' (SB) cross. CYBT has the R gene Pi-ta and SB has Pi-b. Ten differential isolates of four Magnaporthe oryzae races (IB-1, IB-17, IB-49, and IE-1K) were used to evaluate disease reactions of the 243 RILs under greenhouse conditions...
April 16, 2018: Phytopathology
Paul Esker, Denis Anthony Shah, Carl A Bradley, Shawn P Conley, Pierce A Paul, Alison Robertson
Foliar fungicide use in hybrid maize in the United States was rare before 2000. The decade from 2000 to 2010 saw foliar fungicides increasingly applied to maize in the absence of appreciable disease pressure, a practice seemingly at odds with integrated pest management philosophy. Yet, it is commonly believed that growers do not employ management strategies unless there are perceived benefits. Maize (corn) growers (CGs) and certified crop advisors (CCAs) across four Midwestern states (Iowa, Illinois, Ohio and Wisconsin) were surveyed to better understand their practices, values and perceptions concerning the use of foliar fungicides during 2005 to 2009...
April 16, 2018: Phytopathology
Kamrun Nahar, Claudia Goyer, Bernie J Zebarth, David L Burton, Sean Whitney
Potato cultivars vary in their tolerance to common scab (CS), however how they affect CS-causing Streptomyces spp. populations over time is poorly understood. This study investigated the effects of potato cultivar on pathogenic Streptomyces spp. abundance, measured using quantitative PCR, in three spatial locations in a CS-infested field: 1) soil close to the plant (SCP); 2) rhizosphere (RS); and 3) geocaulosphere (GS) soils. Two tolerant (Gold Rush, Hindenburg) and two susceptible cultivars (Green Mountain, Agria) were tested...
April 16, 2018: Phytopathology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"