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1.
The response of recombinant inbred lines (RILs) from a cross of zucchini × scallop (Cucurbita pepo subsp. pepo ‘Murcia MU-CU-16’ × C. pepo subsp. ovifera ‘Scallop UPV-196’) to Meloidogyne incognita and M. javanica was determined after completion of a nematode reproduction cycle in experiments carried out in a growth chamber. The nematode differentiated the C. pepo genotypes at the subspecies level due to lower egg mass production on subspecies pepo than ovifera, and thus subspecies pepo was a poorer host than ovifera. In addition, Murcia MU-CU-16 discriminated M. incognita from M. javanica in terms of egg masses (EM), eggs per gram of root and reproduction factor (Rf), whereas Scallop UPV-196 did so in eggs per gram of root and Rf. The RILs differed in gall formation and EM production depending on the nematode × line combination. Comparisons between nematode isolates resulted in four significant combinations for pathogenic potential (galls/initial population (Pi) × 100), seven for parasitic success (egg masses/Pi × 100), and nine for host efficiency (egg masses/galls per root system × 100) which included all the lines tested against both isolates. Lines that restricted nematode development by at least 90% were considered as having intermediate resistance to M. incognita based on the definition of the International Seed Federation. They included lines 28-1, 35A, 107A, 110-3 and 153-2. All the RILs were susceptible hosts for M. javanica. The information presented here will be helpful for nematode management and also for plant breeders working on pathogen resistance on C. pepo. 相似文献
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Renée S. Arias Scot C. Nelson Anne M. Alvarez 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(2):109-116
The survival of the bacterial pathogen, Xanthomonas campestris pv. campestris (Xcc), was studied in plant debris-infested soil with different matric potentials (0, –10, –30, –50, –100, –200, and –900kPa), and on the phylloplane of crops used for rotation with cabbage. Populations of cellulolytic and proteolytic microorganisms were studied in relation to soil matric potential and Xcc. The survival of Xcc was negatively correlated (r=–0.710; P=0.06) with soil matric potential and with the abundance of cellulolytic microorganisms (P=0.05). In saturated soil, Xcc survived for only 19–28 days, while at –900kPa there was no significant change in the bacterial population within this period. Survival of Xcc on the phylloplane of cabbage (Brassica oleracea var. capitata) (host) was similar to that on mustard and lettuce (48 days), whereas the pathogen was detected for only 9 days on rice. It appears that high matric potentials reduced populations of Xcc in soil, whereas epiphytic survival of this pathogen depended on the plant species. 相似文献
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Pascal Salar Claire Charenton Xavier Foissac Sylvie Malembic-Maher 《European journal of plant pathology / European Foundation for Plant Pathology》2013,135(2):371-381
The multiplication kinetics of the Flavescence dorée phytoplasma in broad bean after inoculation by the experimental vector Euscelidius variegatus was determined. The number of phytoplasma cells, measured by quantitative real-time PCR in the aerial parts of the plants, increased exponentially over the time. After 22 to 30 days post inoculation, when symptoms appeared, bacterial growth reached a stationary phase. Whatever the time following inoculation there were no statistical differences between numbers of phytoplasma cells in plants infected by Map-FD1 (FD-CAM05) and Map-FD2 (FD92 and FD-PEY05) genotype strains. On the contrary, temperature had an influence on Flavescence dorée phytoplasma multiplication which was nearly twice as fast in broad beans incubated at 25 °C than in broad beans incubated at 20 °C. At 25 °C, plants expressed symptoms 1 week earlier. In a context of climate change, the consequences of a global warming on the Flavescence dorée epidemics are discussed. 相似文献
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Radix Suharjo Hiroyuki Sawada Yuichi Takikawa 《Journal of General Plant Pathology》2014,80(3):237-254
Forty-one representative Japanese Dickeya spp. (Erwinia chrysanthemi) strains isolated from 24 plants in Japan were investigated using multilocus sequence analysis of recA, dnaX, rpoD, gyrB and 16S rDNA; PCR–RFLP (restriction fragment length polymorphism) of recA, rpoD and gyrB genes; PCR genomic fingerprinting; and biochemical tests. Based on the recA, dnaX, rpoD, gyrB and 16S rDNA sequences and PCR genomic fingerprinting, the strains were essentially divided into six groups (I–VI). Group I corresponded to D. chrysanthemi, group II corresponded to D. dadantii, group III to D. dianthicola and group IV to D. zeae. Meanwhile, group V and group VI could not be assigned to any existing Dickeya species, and they were deduced to be two putative new species. The PCR–RFLP analysis of gyrB, rpoD and recA clearly differentiated the six groups of Dickeya strains. From the results of the biochemical tests, the strains were assigned to biovars 1, 3, 5, 8 and 9; only one strain (SUPP 2525) was not assignable to the existing biovars. We also showed that the PCR–RFLP analysis of rpoD, gyrB and recA can be used as a rapid technique to identify Japanese Dickeya strains. 相似文献
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R. Lebecka 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(3):233-240
Potato and tomato are the two major hosts for Phytophthora infestans causing late blight. The susceptibility of leaves and whole plants of Solanum nigrum, S. villosum, and S. scabrum to infection by P. infestans was tested under laboratory conditions. Out of 39 plants representing 38 different S. nigrum accessions, 16 were highly resistant (seven accessions did not show any symptoms of infection, nine were highly resistant
showing necrotic lesions in the place of infection), and 23 plants of S. nigrum were colonized by, at least, 1 of the 2 isolates of P. infestans (17 accessions were infected with two P. infestans isolates, and 6 accessions showed different reactions depending on the isolate used for inoculation). Three accessions of
S. villosum, and one accession of S. scabrum were tested and did not show any symptoms of infection. The majority of S. nigrum accessions infected by P. infestans in a detached leaf assay were also infected in the whole plant assay. The reaction of field- and greenhouse-grown plants
to inoculation with P. infestans in detached leaf assays was similar, but in some cases leaves from field-grown plants reacted as resistant in comparison
with the leaves from greenhouse-grown plants, which were susceptible. 相似文献
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The asexual fungus Fusarium oxysporum f. sp. cubense (Foc) is the causal agent of fusarium wilt in bananas (Musa spp.). This fungus poses a threat to banana production throughout the world. Here, two Foc genes, fga1 and fga3, were functionally characterized. These genes encode proteins homologous to the G-protein α subunits GPA1 from Saccharomyces cerevisiae and MAGC from Magnaporthe grisea, respectively. The deletion of fga1 leads to a phenotypic defect in colony morphology and reductions in vegetative growth, conidiation and pathogenicity against the banana plant (Musa spp. cv. Brazil), which was not observed for the Δfga3 deletion mutant. Intriguingly, both Δfga1 and Δfga3 deletion mutants showed declines in intracellular cyclic AMP levels and increases in heat resistance, suggesting that FGA1 regulates growth, development, pathogenicity, and heat resistance, whereas FGA3 modulates heat resistance, potentially through the cAMP-dependent protein kinase A pathway. These findings offer insights into the roles of the G-protein α subunits in the development and pathogenicity of the fungus Foc. 相似文献
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Wellington Bressan Jose Edson Fontes Figueiredo 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(3):311-316
Two isolates of Streptomyces spp. DAUFPE 11470 and DAUFPE 14632 were evaluated to determine the antagonist–pathogen inoculum concentration relationship
under greenhouse conditions. Pathogen and antagonist concentration, significantly (P < 0.05) affected development of Fusarium disease in maize with a significant interaction between pathogen and antagonist
concentration. Dose–response relationship also differed significantly (P < 0.05) between the two isolates, but both isolates demonstrated effective control of Fusarium disease, regardless of pathogen
concentration. The isolate DAUFPE 11470 provided the most effective control. The lowest value for disease incidence occurred
at low pathogen (103 chlamydospore g−1 soil) and high antagonist concentration (106 cfu ml−1) for both isolates. The disease incidence for control plants ranged from 19% to 76%. However, in relation to control the
lowest disease reduction occurred at low pathogen (103 chlamydospore g−1 soil) and high antagonist concentrations (106 cfu ml−1). These reductions were 10.6% and 13% for DAUFPE 14632 and DAUFPE 11470, respectively. The highest disease reductions, in
relation to control plants, occurred at high pathogen (106 chlamydospore g−1 soil) and antagonist (106 cfu ml−1) concentrations for both isolates. These values were 55% and 62.2% for DAUFPE 14632 and DAUFPE 11470, respectively. The chlamydospore
germination of Fusarium moniliforme was affected by glucose addition, antagonist isolates and type of inoculum. The lowest chlamydospore germination was observed
with bacterial suspensions of the isolates, for all glucose additions. The results suggested that both Streptomyces spp. isolates were effective at different doses as biocontrol agents against F. moniliforme. Also, there was evidence for at least two mechanisms of biocontrol and that apparently, both isolates showed the same mechanisms
of biocontrol action related to production of bioactive compounds and competition for carbon. Further studies will be developed
to improve the level and effectiveness of control by these isolates. 相似文献
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Journal of Plant Diseases and Protection - The term ‘girth scab’ describes a chronic disease of sugar beet roots (Beta vulgaris ssp. vulgaris) for which the causes still remain unclear.... 相似文献
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Charlotte Thrane Arne Tronsmo Dan Funck Jensen 《European journal of plant pathology / European Foundation for Plant Pathology》1997,103(4):331-344
There were indications that endo-1,3--glucanase (1,3-(1,3;1,4)--D-Glucan 3(4)-glucanohydrolase (EC 3.2.1.6)) and cellulase (1,4-(1,3;1,4)--D-Glucan 4-glucanohydrolase (EC 3.2.1.4)) activity of Trichoderma harzianum Rifai isolate T3 were induced in sphagnum peat moss cultivations and dual culture experiments by the presence of Pythium ultimum. Further, P. ultimum stimulated the germination of Trichoderma conidia. Endo-1,3--glucanase and cellulase were purified from T. harzianum isolate T3, known to control Pythium damping-off of cucumber seedlings. The enzymes were purified from the culture filtrate of the fungus by gel filtration and isoelectric focusing. The purified endo-1,3--glucanase was a small protein with a molecular mass of 17 kilodaltons and a pI of 5.0. Two cellulases were purified to homogeneity and had molecular masses of 40 and 45 kilodaltons respectively, and pI's of 6.4 and 7.6 respectively. Germination of encysted zoospores and elongation of germ tubes of a plant pathogenic Pythium isolate were inhibited by low concentrations of the purified enzymes. A strong synergistic effect was observed on the inhibition of cyst germination by a combination of the endo-1,3--glucanase and the fungicide Fongarid. Finally, a time-course study of colonization of the rhizosphere of cucumber seedlings showed that the active fungal mycelial biomass of a GUS-transformant of T. harzianum isolate T3 increased over four weeks. Trichoderma appeared to colonize healthy roots only superficially, whereas the mucilage of the root hairs and of distal parts of wounded areas or broken parts of the roots, were extensively colonized. 相似文献
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Vasić Tanja Jevremović Darko Krnjaja Vesna Živković Sanja Trkulja Vojislav 《植物病害和植物保护杂志》2021,128(5):1357-1361
Journal of Plant Diseases and Protection - In autumn 2018, daffodil (narcissus) plants with basal bulb rot were noticed in a plantation in locality Jasika, Serbia. Morphological characterization... 相似文献
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Journal of Plant Diseases and Protection - A Triticum durum — T. monococcum amphiploid (AABBAmAm) was synthesized by chromosome doubling of sterile triploid hybrids obtained between the two... 相似文献
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棉花烂铃不仅直接为害棉铃降低产量而且还损害棉花的品质。由于烂铃是由真菌、细菌和棉铃虫之类的害虫所致的复合病害,因此单一或混合使用杀真菌剂和杀细菌剂对于减轻烂铃的发生不可能是无济于事的。尽 相似文献
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H. D. Frinking R. Verweij 《European journal of plant pathology / European Foundation for Plant Pathology》1989,95(1):63-72
Colonization of rose by powdery mildew (Sphaerotheca pannosa) is described in terms of mycelium growth, conidiophore production and sporulation in time. The data used are gathered during different years, put together and treated by means of graphic models. Colonies could be separated into fast and slow growing colonies. Colonies initiated on leaves of increasing age showed a decreasing growth rate. Production of conidiophores and conidia started on the same day, and the relative activity of conidiophore production reached its maximum 6 days after the end of the latency period, followed 1 day later by the maximum activity of conidium production. Both conidiophore and conidium production continued for a long time at a low level. The effect of leaf age on conidiophore production found expression in differences in production rate during the first days of colony development and in final production levels. Observations on naturally infected leaves in an outdoor experiment showed a rapid decrease of sporulation on leaves of 10 days and older. Highest percentages of sporulating leaf area were observed on leaves between 7 and 10 days old. 相似文献
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Miroslav Švec Marta Miklovičová 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(6):537-544
In 1993–1996, the virulence of regional populations of the wheat powdery mildew pathogen (Erysiphe graminis DC f. sp. tritici Marchal) from the Czech Republic, Austria, Hungary and Slovakia against 13 resistance genes was investigated. The populations differed mainly at the regional level. Populations from the Czech Republic, mainly from the western regions, showed higher values of virulence against the Pm4b gene. Lower frequency of virulence against Pm4b was found in Austria, and the lowest value was observed in Hungary. The differences in frequencies of virulence against Pm4a and Pm4b showed a similar geographic pattern across the four countries: a continuous decline from west to east and from north to south. Virulence against Pm2 decreased in all countries considered; virulence to pm5, Pm6, Pm8 and Mli was high throughout. Genes and gene combinations that can ensure a relatively effective biological protection against this pathogen across Central Europe at present are Pm3b, Pm2+Mld and Pm1+2+9. Czech and Slovak populations were the most complex: virulence complexity reached a maximum in Slovakia in 1994. A similar evolution, though less significant, was observed in the Czech Republic. Data on complexity of isolates suggest that Central European populations of wheat powdery mildew tend to reach an intermediate level representing the optimal number of virulence genes. This process is probably a consequence of stabilizing selection. 相似文献
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Rola El Amil Sajid Ali Bochra Bahri Marc Leconte Claude de Vallavieille-Pope Kumarse Nazari 《Plant pathology》2020,69(4):618-630
Yellow rust is the major wheat disease in central West Asia and North Africa. Recently, severe epidemics have occurred, with major yield losses in 2010–2011 in Lebanon and Syria. We conducted an extensive field survey, with a collection of 273 samples of Puccinia striiformis f. sp. tritici, to explore the origin of these epidemics. All samples were genotyped with 20 microsatellite markers, and 54 isolates were pathotyped. The population was dominated by the PstS2 lineage, which has spread worldwide since 2000 and displays considerable pathotype diversity (10 pathotypes). The 22 multilocus genotypes (MLGs) detected corresponded to variants of the clonal lineage PstS2, but they differed from the common PstS2 genotype found in the worldwide study conducted between 1981 and 2010. No strong differentiation was observed between Lebanon and Syria. The dominant MLG in Syria was common to both countries. Nine MLGs were found exclusively in the Syrian population and four were restricted to the Lebanese population, including the dominant MLG in Lebanon. The predominant MLG-11 was found in nine pathotypes, at high frequency. The dominant pathotype in Syria was virulent against widely deployed resistance genes (Yr2, Yr6, Yr7, Yr9, Yr25, and Yr27); virulence against Yr3, Yr8, Yr17, and YrSP occurred at various frequencies, but Yr1, Yr4, Yr5, Yr10, Yr15, and Yr32 were effective against all isolates. No host effect was detected. The presence of diverse host populations consisting of landraces and elite varieties, and diverse climatic conditions may account for the unexpectedly high diversity of this clonal population. 相似文献