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961.
Nicholas T. Amponsah E. Eirian Jones Hayley J. Ridgway Marlene V. Jaspers 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(3):467-482
This study investigated the prevalence and identity of botryosphaeriaceous dieback pathogens in necrotic grapevines tissues
in New Zealand vineyards, and other woody hosts growing nearby. The presumptive identities of the isolates by conidial and
cultural morphology were confirmed with ITS sequence data as Neofusicoccum australe, N. luteum, N. parvum and Diplodia seriata. They were isolated predominantly from necrotic stems of grapevine and other hosts, but also from leaves, flowers and wood
debris of grapevines. Inoculation with conidia and mycelium of multiple isolates of each species onto excised and attached
green shoots and trunks of five grapevine varieties, Cabernet sauvignon, Chardonnay, Pinot noir, Riesling, and Sauvignon blanc,
showed that all varieties became infected to a similar extent. All species except D. seriata were pathogenic, irrespective of the host source, with N. luteum being the most and D. mutila the least pathogenic (P < 0.05). On trunks, N. parvum caused cankers and the other pathogenic species caused die-back when the inoculated vines became winter-dormant. Conidia
were produced from green shoot lesions and die-back wood, which indicates potential inoculum sources for vineyard infection. 相似文献
962.
Firas Talas Heiko K. Parzies Thomas Miedaner 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(1):39-48
Fusarium head blight (FHB) is one of the most destructive diseases of wheat. Twelve small commercial wheat fields (size 1–3
hectares) were sampled in Germany for Fusarium populations at three spots per field with 10 heads each. PCR assays using generic primers confirmed 338 isolates as F.graminearum sensu stricto (s.s.) (64.9%) out of 521 Fusarium spp. that were further analyzed. Populations of F. graminearum s.s. in Germany contain three types of trichothecenes with a dominancy of 15-acetyldeoxynivalenol chemotype (92%) followed
by 3-acetyldeoxynivalenol chemotype (6.8%) and a few isolates of nivalenol chemotype (1.2%). All these isolates were genotyped
using 19 microsatellite loci. The 12 populations showed a high genetic diversity within the small scale sampling areas resulting
in 300 different haplotypes. Genetic diversity within populations (71.2%) was considerably higher than among populations (28.8%)
as shown by analysis of molecular variance. Gene flow (Nm) between populations ranged from 0.76–3.16. Composition of haplotypes
of one population followed over 2 years changed considerably. No correlation between genetic and geographical distance was
found. In conclusion, populations of F. graminearum s.s. in Germany display a tremendous genetic variation on a local scale with a restricted diversity among populations. 相似文献
963.
Plants defend themselves against microbial invasions by detecting conserved molecules, collectively called pathogen-associated
molecular patterns (PAMPs). PAMPs-triggered basal resistance is the first inducible layer of plant defense. Here we found
that Ralstonia solanacearum strain RS1002 can efficiently grow and cause disease in ecotype Columbia-0 of the model plant Arabidopsis thaliana in a manner dependent on the Hrp type III secretion system (T3SS). The extent of disease symptoms caused by R. solanacearum was reduced in plants pretreated with ΔhrpY mutant deficient in the functional Hrp T3SS. Pretreatment with a boiled extract (BE) from R. solanacearum had a similar inhibitory effect on disease development or bacterial multiplication in both Arabidopsis and several solanaceous plants. Simultaneous inoculations with BE and R. solanacearum did not induce BE-mediated resistance, nor did a BE treatment with proteinases. These results indicate that host plants recognize
an unknown proteinaceous PAMP in the BE to induce disease resistance and that the Hrp T3SS of R. solanacearum can suppress it. From an analysis using Arabidopsis mutants lacking PAMP receptors, the elongation factor Tu of R. solanacearum was shown to partially contribute to BE-mediated basal resistance in Arabidopsis plants. 相似文献
964.
Keisuke Tomioka Yuuri Hirooka Toshirou Nagai Hiroyuki Sawada Takayuki Aoki Toyozo Sato 《Journal of General Plant Pathology》2011,77(4):266-268
Severe blight of potted seedlings of monkshood caused by Plectosporium tabacinum was found in glasshouses in Kagawa Prefecture in southwest Japan in May 2001. Root rot and browning of stem bases were followed
by wilting and yellowing of leaves, then blighting of leaves, flower buds and stems. A fungus was isolated from diseased plants
and confirmed to cause the disease. The new disease was named “Plectosporium blight of monkshood”. 相似文献
965.
Shin-ichi Shimizu Takao Ito Takanori Miyoshi Yasunobu Tachibana Tsutae Ito 《Journal of General Plant Pathology》2011,77(6):326-330
Universal primers to detect Satsuma dwarf virus (SDV), including distantly related strains Citrus mosaic virus (CiMV), Navel orange infectious mottling virus (NIMV), and
Hyuganatsu virus (HV), were tested in a convenient one-step RT-PCR assay. SDV was the most broadly detected using uSDVup/uSDVdo
primers that specifically targeted a nucleotide sequence in the 3′-noncoding region that is conserved in both segmented RNAs
1 and 2 of SDV among the tested primers. Nucleotide sequence analysis confirmed that the amplified RT-PCR products could be
derived from RNAs 1 or 2 of SDV variants, some of which had interesting genetic diversity. 相似文献
966.
Ryo Kubota Mark A. Schell Gabriel D. Peckham Joanne Rue Anne M. Alvarez Caitilyn Allen Daniel M. Jenkins 《Journal of General Plant Pathology》2011,77(3):182-193
New rapid diagnostic methods are urgently needed to discriminate the quarantine pathogen Ralstonia solanacearum (Rs) race 3 biovar 2 (R3B2) from other populations of Rs that lack the adaptation to cause bacterial wilt disease in temperate
regions. We used an in silico bioinformatic approach to identify several genome sequences potentially specific to R3B2 strains. Primer sets were designed
to PCR-amplify sequences in these regions, and four sets were ultimately shown to be >99% accurate for detection of R3B2 strains.
On the basis of these results, several primers were designed to enable development of a loop-mediated isothermal amplification
assay that was rapid, technologically simple, and essentially 100% accurate for identification of R3B2 when applied to a comprehensive
collection of geographically diverse Rs strains. We fortuitously found that a sequence in one of the “R3B2-specific” regions
has ~90% identity to a sequence present in strains of the blood disease bacterium (BDB), a member of the Rs species complex
that infects banana. Alignments of these sequences allowed design of a second PCR primer set that proved 100% accurate for
identification of BDB strains when tested on the 22 BDB strains available to us. These results demonstrate the power of in silico genomic subtraction for rapid identification of population-specific DNA sequences and for the development of simple, reliable
detection methods for Rs subpopulations. 相似文献
967.
Syed Jawad Ahmad Shah Shaukat Hussain Musharaf Ahmad Farhatullah Iftikhar Ali Muhammad Ibrahim 《Journal of General Plant Pathology》2011,77(3):174-177
Fifty wheat varieties along with Jupateco-73 and Morocco were studied for the expression of leaf tip necrosis (LTN), a trait
linked with the durable rust resistance gene pair Lr34/Yr18. LTN was frequent (i.e., ≥6) in nine replications of a field experiment over 3 years in 17 genotypes, and the varieties were
considered positive for LTN. In molecular analyses of these varieties, having relative severity values up to 78 for yellow
rust and 45 for leaf rust, the 150-bp Lr34/Yr18-linked allele was consistently amplified. Expression of LTN in six of nine replications is an appropriate threshold for predicting
the presence of Lr34/Yr18 gene pair, and genotypes can be selected using this trait. 相似文献
968.
Jun Ohnishi Toshio Kitamura Fumihiro Terami Ken-ichiro Honda 《Journal of General Plant Pathology》2011,77(1):54-59
The ability of the whitefly Bemisia tabaci to transmit two strains of Tomato yellow leaf curl virus, the Israel and Mild strains, was studied after serial transfers of individual whiteflies that were viruliferous for both
strains to tomato plants. After single whiteflies had successive acquisition feedings first on a single plant infected with
one strain and then on a plant infected with the other strain, the single whiteflies later transmitted intermittently one,
the other, or both strains to the test plants during serial transfers at 1-day intervals. Because both strains were found
in the head, abdomen, and legs dissected from whiteflies during the retention period after the two successive acquisition
feedings, both strains apparently circulate from midgut cells to salivary glands through the hemolymph. 相似文献
969.
Shinpei Banno Hidenari Saito Hiroshi Sakai Toshihiko Urushibara Kentaro Ikeda Takeshi Kabe Isao Kemmochi Makoto Fujimura 《Journal of General Plant Pathology》2011,77(5):282-291
Verticillium longisporum and V. dahliae, causal agents of Verticillium wilt, are spreading through the cabbage fields of Gunma Prefecture. Using the V. longisporum-specific intron within the 18S rDNA and differences between ITS 5.8S rDNA sequences in Japanese isolates of V. longisporum and V. dahliae, we developed three quantitative nested real-time (QNRT) PCR assays. The QNRT-PCR quantification of V. longisporum or V. dahliae in cabbage field soil was consistent with the severity of Verticillium wilt disease in those fields. In field trials of resistant
cultivar YR Ranpo grown for three seasons in soil infested with the pathogen, disease severity and pathogen density in the
soil were significantly reduced in a field moderately contaminated by V. dahliae, but only slightly reduced in a highly contaminated field. These results suggest that continuous cultivation of a resistant
cultivar is an effective way to reduce the pathogen population. QNRT-PCR assays provide a powerful analytical tool to evaluate
the soil population dynamics of V. longisporum and V. dahliae for disease management. 相似文献
970.
Here Fusarium oxysporum was killed in exudates obtained from soil biologically disinfested with ethanol, indicating that physical interaction with
soil microorganisms was not essential. Because acetic acid was confirmed to accumulated during the treatment, we evaluated
the effect of acetic acid amendment against the pathogen in plastic containers. A drop in the soil redox potential seemed
to be correlated with the fungicidal efficacy of acetic acid. Under reductive soil conditions, metal ions such as Mn2+ and Fe2+ formed, and the pathogen was effectively suppressed in Mn2+ and Fe2+ solution. Therefore, Fe2+ and Mn2+ may be the agents that induce suppression of the pathogen during biological soil disinfestation. 相似文献