A preliminary study of the sources of potato gangrene infection     

A. A. Khan  C. Logan 《Potato Research》1968,11(2):77-87

Summary Using a tuber-baiting technique,Phoma foveata and occasionallyP. solanicola were recovered from N. Ireland soils where potatoes had been grown in the previous year and from some where a potato crop had not been grown for over 5 years.P. foveata was consistently isolated from a proportion of stems produced by gangrene-affected tubers, grown in sterilized soil, from 3 weeks after planting to maturity; no symptoms of infection were visible until stems began to show signs of senescence when pycnidia formed on their surfaces. The incidence of infection was high in both stems and tubers from plants grown in soil heavily contaminated by inoculation withP. foveata or produced by gangrene-affected parent tubers, the lowest incidence being in stems and tubers from ‘healthy’ seed grown in soil neither sterilized nor inoculated. The close relationship between the incidence of stem infection on plants grown in variously treated soils, contained in sunken polythene bags in the field, and tuber infection in storage provides a possible method of predicting potential storage losses.

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Zusammenfassung Es wird eine Methode beschrieben (Isolierung des Erregers von der Knolle), die zur Untersuchung von B?den aus verschiedenen Regionen Nordirlands auf das Vorkommen vonPhoma spp. angewendet wurde. Die Ergebnisse (Tabelle 1) zeigen, dassP. foveata stets undP. solanicola gelegentlich in B?den, auf denen im vorhergehenden Jahr Kartoffeln angebaut wurden, nachgewiesen werden konnten, ebenso in einigen B?den, auf denen seit mehr als 5 Jahren keine Kartoffeln gepflanzt wurden. In der Zeit von 3 Wochen nach dem Auspflanzen in sterilen Boden bis zur Reife konntenP. foveata immer undP. solanicola gelegentlich vom unteren Teil einiger ausPhoma-befallenen Knollen entstandener Stengel isoliert werden. Diese Stengel zeigten keine sichtbaren Befallssymptome bis zum Zeitpunkt, wo sie zu altern begannen und sich ihre Oberfl?che mit Pyknidien bedeckte, was darauf hinweist, dassP. foveata undP. solanicola w?hrend der Vegetationszeit eine latente Stengelinfektion verursachen k?nnen. Stengelz?hlungen (Tabelle 2) ergaben, dassPhoma-befallene Knollen mehr Stengel bildeten als ‘gesunde’ Knollen. Das Vorkommen sowohl der Stengelinfektion (Tabelle 3) als auch der Knolleninfektion am Lager (Tabelle 4) war extrem hoch, wenn entweder ‘gesundes’ oder krankes Saatgut in künstlich mitP. foveata stark verseuchte B?den ausgepflanzt wurde. Stengel- und besonders Knolleninfektionen waren auch bei allen Bodenbehandlungen zahlreich, wenn die Mutterknolle vonPhoma-Pilzen befallen war. Am wenigsten Stengel- und Knolleninfektionen traten auf, wenn gesundes Saatgut in nicht sterilisierten und nicht inokulierten Boden gepflanzt wurde. Die enge lineare Beziehung (R² = 0,72, P>0,01) zwischen Stengelinfektion und nachfolgendem Vorkommen der Knolleninfektion am Lager erlaubt m?glicherweise, die Menge der Knollen, die am LagerPhoma-f?ule aufweisen wird, vorherzusagen.

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Résumé Les auteurs décrivent une technique par infection des tubercules pour tester les sols de différentes régions de l'Irlande du Nord pour la présence dePhoma spp. Les résultats (Tableau 1) révèlent queP. foveata est régulièrement présent, etP. solanicola occasionnellement, dans les sols qui ont porté une récolte de pommes de terre l'année précédente et dans quelques sols où la pomme de terre n'a pas été cultivée depuis plus de 5 ans. P. foveata est régulièrement isolé, etP. solanicola occasionnellement, à la base quelques-unes des tiges provenant de tubercules atteints de gangrène, plantés en sol stérilisé, depuis 3 semaines après la plantation jusqu'à la maturité. Aucun sympt?me visible n'apparait sur ces tiges jusqu' au début de la sénescence; à ce moment leur surface se couvre de pycnides, ce qui révèle queP. foveata etP. solanicola peuvent causer un type latent d'infection des tiges pendant la saison de croissance. Le dénombrement des tiges (Tableau 2) montre que les tubercules atteints de gangrène produisent plus de tiges que les tubercules sains. L'incidence de l'infection à la fois des tiges (Tableau 3) et des tubercules pendant le stockage (Tableau 4) est très élevée quand des plants sains ou malades sont mis à pousser dans des sols gravement contaminés par inoculation avecP. foveata. L'incidence de l'infection des tiges et particulièrement des tubercules, est également élevée avec tous traitements de sol quand le tubercule-mère est atteint de gangrène. L'incidence de l'infection à la fois des tiges et des tubercules est plus basse à partir de plants sains récoltés dans des sols qui ne sont ni stérilisés ni inoculés. L'étroite relation linéaire (R ² = 0,72,P>0,01) entre l'infection des tiges et l'incidence subséquente de l'infection des tubercules pendant la conservation laisse espérer une méthode possible de prévoir les chances de développement de la gangrène sur les tubercules pendant le stockage.

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Spatially explicit correlates of plant functional traits inform landscape patterns of resource quality     

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Medicine. Mouse study suggests cancer drugs could help prematurely aging kids     

Travis J 《Science (New York, N.Y.)》2006,311(5763):934-935

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Exploring ethyl methanesulfonate (EMS) treated cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis> L.) to improve drought tolerance     

Travis W. Witt  Mauricio Ulloa  Mathew G. Pelletier  Venugopal Mendu  Glen L. Ritchie 《Euphytica》2018,214(7):123

The Texas High Plains often has extended periods between rainfall events, which can lead to a reduction in the yield and fiber quality of cotton (Gossypium hirsutum L.). It is known that cultivated cotton suffers from low levels of genetic diversity due to the over-use in breeding of similar gene pools, which may hinder breeding for drought tolerance. In this study, for the first time the novel variability or genetic diversity of morphological and agronomic traits possibly created by the chemical mutagen ethyl methanesulfonate (EMS) was evaluated to improve drought tolerance in cotton by traits’ response to different irrigation regimes. EMS is a chemical mutagen that has been shown to cause point mutations in the DNA of many model plants and crop species. Three EMS treated lines were advanced from the M₁ to M₄ generation as bulk-harvested populations. A diverse selection scheme was applied to capture most of the genetic trait-variability or diversity and superior lines in these populations. In 2014–2016 the diversity of these populations was evaluated based on four agronomic and thirteen morphological traits to determine differences in response to multiple irrigation rates. Analyses of these traits showed statistically significant (p?≤?0.05) differences between and within populations when compared to the original non-treated EMS source, with most of the variability being observed in the high irrigation rate. However, none of the EMS treated populations had significantly (p?≤?0.05) better lint yield than the commercial cultivar (control) in 2016. EMS yield performance was possibly constrained by the applied diverse selection scheme of this study. Traits such as total number of bolls, bolls retained at node 7 and below, and those retained between nodes 8 and 12, and bolls retained at node of first fruiting branch may be predictors to improve cotton production (yield) in water limiting environments.  相似文献   

Cloning and large-scale expansion of epitope-specific equine cytotoxic T lymphocytes using an anti-equine CD3 monoclonal antibody and human recombinant IL-2     

Mealey RH  Littke MH  Leib SR  Davis WC  McGuire TC 《Veterinary immunology and immunopathology》2007,118(1-2):121-128

Cytotoxic T lymphocytes are involved in controlling intracellular pathogens in many species, including horses. Particularly, CTL are critical for the control of equine infectious anemia virus (EIAV), a lentivirus that infects horses world-wide. In humans and animal models, CTL clones are valuable for evaluating the fine specificity of epitope recognition, and for adoptive immunotherapy against infectious and neoplastic diseases. Cloned CTL would be equally useful for similar studies in the horse. Here we present the first analysis of a method to generate equine CTL clones. Peripheral blood mononuclear cells were obtained from an EIAV-infected horse and stimulated with the EIAV Rev-QW11 peptide. Sorted CD8+ T cells were cloned by limiting dilution, and expanded without further antigen addition using irradiated PBMC, anti-equine CD3, and human recombinant IL-2. Clones could be frozen and thawed without detrimental effects, and could be subsequently expanded to numbers exceeding 2 x 10(9)cells. Flow cytometry of expanded clones confirmed the CD3+/CD8+ phenotype, and chromium release assays confirmed CTL activity. Finally, sequencing TCR beta chain genes confirmed clonality. Our results provide a reliable means to generate large numbers of epitope-specific equine CTL clones that are suitable for use in downstream applications, including functional assays and adoptive transfer studies.  相似文献   

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Several new bermudagrass cultivars are available and commonly used on golf course fairways. However, little is known about their cultural requirements or how these cultivars perform under lower inputs regimes. A 2-year study was conducted at University of Florida, Fort Lauderdale Research and Education Center, to assess performance of four hybrid bermudagrass [Cynodon dactylon L. Pers. X Cynodon transvaalensis (Burtt-Davy)] cultivars (‘Latitude 36’, ‘Tifway 419’, ‘TifGrand’ and ‘TifTuf’), and 2 common bermudagrass (Cynodon dactylon L. Pers.) cultivars (‘Bimini’ and ‘Celebration’) irrigated at either 50% or 80% reference evapotranspiration (ET_o) and fertilised at either 0, 146, 244, or 342 kg N ha⁻¹ year⁻¹. Plots were evaluated monthly for turfgrass quality, dark green colour index (DGCI), normalised difference vegetation index (NDVI), and Chlorophyll Index, and seasonally for N tissue content. Plots watered at 80% ET_o enhanced bermudagrass quality compared to 50% ET_o, DGCI and NDVI only in two months out of 24. Latitude 36 and Celebration were the top-rated cultivars, and their quality was not affected by no N fertilisation. Conversely, TifGrand, TifTuf and Tifway that received no N fertilisation resulted in insufficient quality during the second year of the study. Insufficient quality may be linked to reduced N metabolization compared to the highest rated cultivars. Results show that new cultivars such as Latitude 36 and Bimini could be maintained at sufficient quality levels with reduced water and N inputs in South Florida.  相似文献