851 resultados para white rot fungi


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Take home messages: Plant only high quality seed that has been germ and vigour tested and treated with a registered seed dressing Avoid poorly drained paddocks and those with a history of lucerne, medics or chickpea Phytophthora root rot, PRR; do not grow Boundary if you even suspect a PRR risk Select best variety suited to soil type, farming system and disease risk Beware Ascochyta: follow recommendations for your variety and district Minimise risk of virus by retaining stubble, planting on time and at optimal rate, controlling weeds and ensuring adequate plant nutrition Test soil to determine risk of salinity and sodicity – do not plant chickpeas if ECe > 1.0-1.3 dS/m. Beware early desiccation of seed crops – know how to tell when 90-95% seeds are mature

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Long-fallow disorder is expressed as exacerbated deficiencies of phosphorus (P) and/or zinc (Zn) in field crops growing after long periods of weed-free fallow. The hypothesis that arbuscular-mycorrhizal fungi (AMF) improve the P and Zn nutrition, and thereby biomass production and seed yield of linseed (Linum usitatissimum) was tested in a field experiment. A factorial combination of treatments consisting of +/- fumigation, +/- AMF inoculation with Glomus spp., +/- P and +/- Zn fertilisers was used on a long-fallowed vertisol. The use of such methods allowed an absolute comparison of plants growing with and without AMF in the field for the first time in a soil disposed to long-fallow disorder. Plant biomass, height, P and Zn concentrations and contents, boll number and final seed yield were (a) least in fumigated soil with negligible AMF colonisation of the roots, (b) low initially in long-fallow soil but increased with time as AMF colonisation of the roots developed, and (c) greatest in soil inoculated with AMF cultures. The results showed for the first time in the field that inflows of both P and Zn into linseed roots were highly dependent on %AMF-colonisation (R-2 = 0.95 for P and 0.85 for Zn, P < 0.001) in a soil disposed to long-fallow disorder. Relative field mycorrhizal dependencies without and with P+Zn fertiliser were 85 % and 86 % for biomass and 68 % and 52 % for seed yield respectively. This research showed in the field that AMF greatly improved the P and Zn nutrition, biomass production and seed yield of linseed growing in a soil disposed to long-fallow disorder. The level of mycorrhizal colonisation of plants suffering from long-fallow disorder can increase during the growing season resulting in improved plant growth and residual AMF inoculum in the soil, and thus it is important for growers to recognise the cause and not terminate a poor crop prematurely in order to sow another. Other positive management options to reduce long fallows and foster AMF include adoption of conservation tillage and opportunity cropping.

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Options for the integrated management of white blister (caused by Albugo candida) of Brassica crops include the use of well timed overhead irrigation, resistant cultivars, programs of weekly fungicide sprays or strategic fungicide applications based on the disease risk prediction model, Brassica(spot)(TM). Initial systematic surveys of radish producers near Melbourne, Victoria, indicated that crops irrigated overhead in the morning (0800-1200 h) had a lower incidence of white blister than those irrigated overhead in the evening (2000-2400 h). A field trial was conducted from July to November 2008 on a broccoli crop located west of Melbourne to determine the efficacy and economics of different practices used for white blister control, modifying irrigation timing, growing a resistant cultivar and timing spray applications based on Brassica(spot)(TM). Growing the resistant cultivar, 'Tyson', instead of the susceptible cultivar, 'Ironman', reduced disease incidence on broccoli heads by 99 %. Overhead irrigation at 0400 h instead of 2000 h reduced disease incidence by 58 %. A weekly spray program or a spray regime based on either of two versions of the Brassica(spot)(TM) model provided similar disease control and reduced disease incidence by 72 to 83 %. However, use of the Brassica(spot)(TM) models greatly reduced the number of sprays required for control from 14 to one or two. An economic analysis showed that growing the more resistant cultivar increased farm profit per ha by 12 %, choosing morning irrigation by 3 % and using the disease risk predictive models compared with weekly sprays by 15 %. The disease risk predictive models were 4 % more profitable than the unsprayed control.

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Despite international protection of white sharks Carcharodon carcharias, important conservation parameters such as abundance, population structure and genetic diversity are largely unknown. The tissue of 97 predominately juvenile white sharks sampled from spatially distant eastern and southwestern Australian coastlines was sequenced for the mitochondrial DNA (mtDNA) control region and genotyped with 6 nuclear-encoded microsatellite loci. MtDNA population structure was found between the eastern and southwestern coasts (F-ST = 0.142, p < 0.0001), implying female reproductive philopatry. This concurs with recent satellite and acoustic tracking findings which suggest the sustained presence of discrete east coast nursery areas. Furthermore, population subdivision was found between the same regions with biparentally inherited micro satellite markers (F-ST = 0.009, p < 0.05), suggesting that males may also exhibit some degree of reproductive philopatry; 5 sharks captured along the east coast had mtDNA haplotypes that resembled western Indian Ocean sharks more closely than Australian/New Zealand sharks, suggesting that transoceanic dispersal, or migration resulting in breeding, may occur sporadically. Our most robust estimate of contemporary genetic effective population size was low and close to thresholds at which adaptive potential may be lost. For a variety of reasons, these contemporary estimates were at least 1, possibly 2, orders of magnitude below our historical effective size estimates. Population decline could expose these genetically isolated populations to detrimental genetic effects. Regional Australian white shark conservation management units should be implemented until genetic population structure, size and diversity can be investigated in more detail.

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Key message: QTLidentified for seedling and adult plant crown rot resistance in four partially resistant hexaploid wheat sources. PCR-based markers identified for use in marker-assisted selection. Abstract: Crown rot, caused by Fusarium pseudograminearum, is an important disease of wheat in many wheat-growing regions globally. Complete resistance to infection by F. pseudograminearum has not been observed in a wheat host, but germplasm with partial resistance to this pathogen has been identified. The partially resistant wheat hexaploid germplasm sources 2-49, Sunco, IRN497 and CPI133817 were investigated in both seedling and adult plant field trials to identify markers associated with the resistance which could be used in marker-assisted selection programs. Thirteen different quantitative trait loci (QTL) conditioning crown rot resistance were identified in the four different sources. Some QTL were only observed in seedling trials whereas others appeared to be adult plant specific. For example while the QTL on chromosomes 1AS, 1BS, and 4BS contributed by 2-49 and on 2BS contributed by Sunco were detected in both seedling and field trials, the QTL on 1DL present in 2-49 and the QTL on 3BL in IRN497 were only detected in seedling trials. Genetic correlations between field trials of the same population were strong, as were correlations between seedling trials of the same population. Low to moderate correlations were observed between seedling and field trials. Flanking markers, most of which are less than 10 cM apart, have now been identified for each of the regions associated with crown rot resistance.

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Results from the first of two artificially inoculated field experiments showed foliar applications of copper hydroxide (Blue Shield Copper) at 600 g a.i./100 L−1 (0% infected fruit), copper hydroxide + metalaxyl-M (Ridomil Gold Plus.) at 877.5 g a.i./100 L−1 (0.27%), metiram + pyraclostrobin (Aero) at 720 g a.i./100 L−1 (0.51%), chlorothalonil (Bravo WeatherStik) at 994 g a.i./100 L−1 (0.63%) and cuprous oxide (Nordox 750 WG) at 990 g a.i./100 L−1 (0.8%) of water significantly reduced the percentage of infected fruit compared to potassium phosphonate (Agri-Fos 600) at 1200 g a.i./100 L−1 (8.22%), dimethomorph (Acrobat) at 108 g a.i./100 L−1 (11.18%) and the untreated control (16%). Results from the second experiment showed fruit sprayed with copper hydroxide (Champ Dry Prill) at 300 (2.0% infected fruit), 375 (0.4%) and 450 g a.i./100 L−1 (0.6%) and metiram + pyraclostrobin (Aero) at 360 (2.8%), 480 (0.6%) and 600 g a.i./100 L−1 of water (1.0%) significantly reduced the percentage of infected fruit compared to the untreated control (19.4%). Foliar sprays of copper hydroxide at 375 g a.i./100 L−1 in rotation with chlorothalonil at 994 g a.i./100 L−1 every two weeks is now recommended to growers for controlling Phytophthora fruit rot of papaya.

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Interactive identification keys for Australian smut fungi (Ustilaginomycotina and Pucciniomycotina, Microbotryales) and rust fungi (Pucciniomycotina, Pucciniales) are available online at http://collections.daff.qld.gov.au. The keys were built using Lucid software, and facilitate the identification of all known Australian smut fungi (317 species in 37 genera) and 100 rust fungi (from approximately 360 species in 37 genera). The smut and rust keys are illustrated with over 1,600 and 570 images respectively. The keys are designed to assist a wide range of end-users including mycologists, plant health diagnosticians, biosecurity scientists, plant pathologists, and university students. The keys are dynamic and will be regularly updated to include taxonomic changes and incorporate new detections, taxa, distributions and images. Researchers working with Australian smut and rust fungi are encouraged to participate in the on-going development and improvement of these keys.

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Pythium soft rot (PSR) of ginger caused by a number of Pythium species is of the most concern worldwide. In Australia, PSR outbreaks associated with Pythium myriotylum was recorded in 2007. Our recent pathogenicity tests in Petri dishes conducted on ginger rhizomes and pot trials on ginger plants showed that Pythiogeton (Py.) ramosum, an uncommon studied oomycete in Pythiaceae, was also pathogenic to ginger at high temperature (30–35 °C). Ginger sticks excised from the rhizomes were colonised by Py. ramosum which caused soft rot and browning lesions. Ginger plants inoculated with Py. ramosum showed initial symptoms of wilting and leave yellowing, which were indistinguishable from those of Pythium soft rot of ginger, at 10 days after inoculation. In addition, morphological and phylogenetic studies indicated that isolates of Py. ramosum were quite variable and our isolates obtained from soft rot ginger were divided into two groups based on these variations. This is also for the first time Py. ramosum is reported as a pathogen on ginger at high temperatures.

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With potential to accumulate substantial amounts of above-ground biomass, at maturity an irrigated cotton crop can have taken up more than 20 kg/ha phosphorus and often more than 200 kg/ha of potassium. Despite the size of plant accumulation of P and K, recovery of applied P and K fertilisers by the crop in our field experiment program has poor. Processing large amounts of mature cotton plant material to provide a representative sample for chemical analysis has not been without its challenges, but the questions regarding mechanism of where, how and when the plant is acquiring immobile nutrients remain. Dry matter measured early in the growing season (squaring, first white flower) have demonstrated a 50% increase in crop biomass to applied P (in particular), but it represents only 20% of the total P accumulation by the plant. By first open boll (and onwards), no response in dry matter or P concentration could be detected to P application. A glasshouse study indicated P recovery was greater (to FOB) where it was completely mixed through a profile as opposed to a banded application method suggesting cotton prefers a more diffuse distribution. The relative effects of root morphology, mycorrhizal fungi infection, seasonal growth patterns and how irrigation is applied are areas for future investigation on how, when and where cotton acquires immobile nutrients.

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Novel species of fungi described in the present study include the following from Australia: Neoseptorioides eucalypti gen. & sp. nov. from Eucalyptus radiata leaves, Phytophthora gondwanensis from soil, Diaporthe tulliensis from rotted stem ends of Theobroma cacao fruit, Diaporthe vawdreyi from fruit rot of Psidium guajava, Magnaporthiopsis agrostidis from rotted roots of Agrostis stolonifera and Semifissispora natalis from Eucalyptus leaf litter. Furthermore, Neopestalotiopsis egyptiaca is described from Mangifera indica leaves (Egypt), Roussoella mexicana from Coffea arabica leaves (Mexico), Calonectria monticola from soil (Thailand), Hygrocybe jackmanii from littoral sand dunes (Canada), Lindgomyces madisonensis from submerged decorticated wood (USA), Neofabraea brasiliensis from Malus domestica (Brazil), Geastrum diosiae from litter (Argentina), Ganoderma wiiroense on angiosperms (Ghana), Arthrinium gutiae from the gut of a grasshopper (India), Pyrenochaeta telephoni from the screen of a mobile phone (India) and Xenoleptographium phialoconidium gen. & sp. nov. on exposed xylem tissues of Gmelina arborea (Indonesia). Several novelties are introduced from Spain, namely Psathyrella complutensis on loamy soil, Chlorophyllum lusitanicum on nitrified grasslands (incl. Chlorophyllum arizonicum comb. nov.), Aspergillus citocrescens from cave sediment and Lotinia verna gen. & sp. nov. from muddy soil. Novel foliicolous taxa from South Africa include Phyllosticta carissicola from Carissa macrocarpa, Pseudopyricularia hagahagae from Cyperaceae and Zeloasperisporium searsiae from Searsia chirindensis. Furthermore, Neophaeococcomyces is introduced as a novel genus, with two new combinations, N. aloes and N. catenatus. Several foliicolous novelties are recorded from La Réunion, France, namely Ochroconis pandanicola from Pandanus utilis, Neosulcatispora agaves gen. & sp. nov. from Agave vera-cruz, Pilidium eucalyptorum from Eucalyptus robusta, Strelitziana syzygii from Syzygium jambos (incl. Strelitzianaceae fam. nov.) and Pseudobeltrania ocoteae from Ocotea obtusata (Beltraniaceae emend.). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

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Brassica napus is one of the most important oil crops in the world, and stem rot caused by the fungus Sclerotinia sclerotiorum results in major losses in yield and quality. To elucidate resistance genes and pathogenesis-related genes, genome-wide association analysis of 347 accessions was performed using the Illumina 60K Brassica SNP (single nucleotide polymorphism) array. In addition, the detached stem inoculation assay was used to select five highly resistant (R) and susceptible (S) B. napus lines, 48 h postinoculation with S. sclerotiorum for transcriptome sequencing. We identified 17 significant associations for stem resistance on chromosomes A8 and C6, five of which were on A8 and 12 on C6. The SNPs identified on A8 were located in a 409-kb haplotype block, and those on C6 were consistent with previous QTL mapping efforts. Transcriptome analysis suggested that S. sclerotiorum infection activates the immune system, sulphur metabolism, especially glutathione (GSH) and glucosinolates in both R and S genotypes. Genes found to be specific to the R genotype related to the jasmonic acid pathway, lignin biosynthesis, defence response, signal transduction and encoding transcription factors. Twenty-four genes were identified in both the SNP-trait association and transcriptome sequencing analyses, including a tau class glutathione S-transferase (GSTU) gene cluster. This study provides useful insight into the molecular mechanisms underlying the plant's response to S. sclerotiorum.

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Total lipid content in the thermophilic fungi—Thermoascus aurantiacus, Humicola lanuginosa, Malbranchea pulchella var.sulfurea, andAbsidia ramosa—varied from 5.3 to 19.1% of mycelial dry weight. The neutral and polar lipid fractions accounted for 56.4 to 80.2% and 19.8 to 43.6%, respectively. All the fungi contained monoglycerides, diglycerides, triglycerides, free fatty acids, and sterols in variable amounts. Sterol ester was detected only inA. ramosa. Phosphatide composition was: phosphatidyl choline (15.9–47%), phosphatidyl ethanolamine (23.4–67%), phosphatidyl serine (9.3–17.6%), and phosphatidyl inositol (1.9–11.9%). Diphosphatidyl glycerol occurred in considerable quantity only inH. lanuginosa andM. pulchella var.sulfurea. Phosphatidic acid, detected as a minor component only inM. pulchella var.sulfurea andA. ramosa, does not appear to be a characteristic phosphatide of thermophilic fungi as suggested earlier. The 16∶0, 16∶1, 18∶0, 18∶1, and 18∶2 acids were the main fatty acid components. In addition,A. ramosa contained 18∶3 acid. Total lipids contained an average of 0.93 double bonds per mole of fatty acids, and neutral lipids tend to be more unsaturated than phospholipids.

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The White Possessive explores the links between race, sovereignty, and possession through themes of property: owning property, being property, and becoming propertyless. Focusing on the Australian Aboriginal context, Aileen Moreton-Robinson questions current race theory in the first world and its preoccupation with foregrounding slavery and migration. The nation, she argues, is socially and culturally constructed as a white possession. Moreton-Robinson reveals how the core values of Australian national identity continue to have roots in Britishness and colonization, built on the disavowal of Indigenous sovereignty. Whiteness studies are central to Moreton-Robinson’s reasoning, and she shows how blackness works as a white epistemological tool that bolsters the social production of whiteness—displacing Indigenous sovereignties and rendering them invisible in a civil rights discourse, sidestepping issues of settler colonialism. Throughout this critical examination Moreton-Robinson proposes a bold new agenda for critical Indigenous studies, one that involves deeper analysis of the prerogatives of white possession within the role of disciplines.

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Spiritualiteetti viittaa syvälliseen, inhimilliseen ulottuvuuteen ja ominaisuuteen, jonka tarkka määritteleminen on haasteellista, ellei mahdotonta. Sitä vastaa yhtäältä uskonnollisuuden kautta toteutuva, elämän tarkoitukseen ja syvemmän olemuksen etsintään liittyvä hengellisyys, mutta toisaalta myös kaikkea muuta hengen viljelyä ja mielekkään olemisen tavoittelua tarkoittava henkisyys. John Swintonin mukaan hengen ulottuvuus on se inhimilliseen olemukseen kuuluva, dynaaminen elinvoima, joka virkistää ja elävöittää ihmistä ja motivoi häntä etsimään Jumalaa, arvoja, merkitystä, tarkoitusta ja toivoa. Tämä tutkimus nostaa tarkastelun kohteeksi kokonaisvaltaisen hengellisyyden, jolloin huomio kiinnitetään niihin sidoksiin, joiden kautta hengen ulottuvuus liittyy muihin inhimillisen elämän olennaisiin toimintoihin ja näkökulmiin. Tällaisia ovat 1) ajattelu 2) teot ja käytännön toiminta 3) suhteet ja vuorovaikutusverkostot 4) tunteet ja kanssakäymistä ohjaavat asenteet 5) olemassaolon ja olemisen ulottuvuudet. Kokemusten merkitys, arvo ja mielekkyys hahmottuvat juuri hengen alueella, toisin sanoen sisäisesti, hengellisenä ja henkisenä asiana. Tutkimusmateriaalina tässä tutkimuksessa on amerikkalaisen vuosina 1827 1915 eläneen Ellen Whiten kuusi myöhäiskauden teosta vuosilta 1892 1905 ja tutkimusmenetelmänä on käytetty systemaattista analyysiä. Olennaista Whiten tavassa käsitellä uskonnon harjoitukseen liittyviä aiheita on hänen käytännöllinen ja elämän arkeen kiinteästi niveltyvä otteensa. Tutkimus paljastaa, että Martti Lutherin käsitykset ovat merkittävästi vaikuttaneet Whiten ajatteluun. Lähteistä paljastuu samankaltaisuutta hänen näkemystensä ja uusimman suomalaisen Luther-tutkimuksen Martti Lutherin tuotannosta esiin nostaman ajattelutavan välillä. Vaikka teologisen oppineisuuden kannalta White ja Luther ovat eri tasoilla, kummankin käsitys ihmisen ja Jumalan välisen suhteen perusolemuksesta on samankaltainen: Lähtökohtana sille on Jumalan rakkaus ja hänen armostaan lähtenyt toiminta. Toiseksi, ihmisen ja Kristuksen välinen, olemuksellinen yhteys, unio , on perustana sille, että Jumala hyväksyy ihmisen ja huolehtii hänestä nyt ja ikuisesti. Kolmanneksi, tämä ihmisen ja Kristuksen liittoutuminen ja yhdistyminen ilmenee yhteistoimintana ja kumppanuutena yhteisten tavoitteiden saavuttamiseksi maailmassa. White korostaa ihmisen ja Kristuksen välisen hengellisen suhteen vuorovaikutteista ja toiminnallista luonnetta, joka tulee ilmi epäitsekkyytenä, toisten ihmisten ja heidän tarpeittensa huomioimisena sekä myötätuntona ja kykynä asettua toisen asemaan. Terveellistä elämäntapaa ja kasvatusta koskevat ajatuksensa White liittää siihen laaja-alaiseen näkemykseen hengellisyydestä, jonka tavoitteena on ihmisen kokonaisvaltainen hyvinvointi. Hän ei näe spiritualiteettia elämän arjesta irrallisena tai erillisenä saarekkeena, vaan ihmistä kaikessa ohjaavana, voimaannuttavana ja mielekkyyttä tuottavana, ensisijaisena ulottuvuutena. Tutkimuksen kuluessa myös Whiten usein käyttämät Jumalalle antautumisen ja luonteen käsitteet nousevat tarkastelun kohteiksi. Hänen mukaansa ihminen ei tahdonponnistuksillaan yksin pysty tavoittamaan Jumalaa vaan hänen on lakattava Jumalan rakastavan kutsun edessä itse tahtomasta ja suostuttava liittymään Jumalan tahtoon ja tarkoitukseen. Tämä liittyy siihen sisäiseen muutokseen, jota White kuvaa luonteen käsitteen avulla. Jumalan armon vaikuttama tahdon uudelleen suuntaaminen muuttaa ihmisen olemusta, arvoja, asennoitumisen tapaa ja myötätuntoisen vuorovaikutuksen kykyä niin ettei ihminen ole enää aivan sama kuin ennen. Kysymys on toisaalta yhtäkkisestä ja kertakaikkisesta olemuksellisesta muuttumisesta, mutta samalla myös hiljaisesta, elämänmittaisesta kasvusta ja kypsymisestä. Juuri luonteen käsitteen avulla White kuvaa hengellisyyttä ja siihen kuuluvaa sisästä matkaa. Tässä tutkimuksessa spiritualiteettia lähestytään yleisinhimillisenä piirteenä ja ominaisuutena, jolloin huomio ei ole ensisijaisesti yksittäisissä opillisissa käsityksissä tai uskonnollisuuden harjoittamisen muodoissa. Tarkoituksena on luoda kokoava rakenne, jonka puitteissa holistinen spiritualiteetti voidaan selkeämmin hahmottaa ja yksilöidymmin ymmärtää.