Compatibility of Talaromyces flavus with potato seedpiece fungicides     

D.R. Fravel  J.J. Marois  M.T. Dunn  G.C. Papavizas 《Soil biology & biochemistry》1985,17(2):163-166

The compatibility of conidia and ascospores of a wild-type isolate (TF1) and a benomyl-resistant biotype (TF1-1) of Talaromyces flavus with five fungicides recommended for use on potato seedpieces was investigated in the field and in vitro. The fungicides tested were captan, mancozeb, maneb, metiram and thiabendazole. In the field test, highest populations were recovered from TF1 treatments. Both the TF1 and the TF1-1 survived better in the field and were more tolerant of more fungicides when applied to the potato seedpieces as ascospores than as conidia. In the field, both fungi were most tolerant of thiabendazole and metiram and least tolerant of captan. Tolerance of fungicides in vitro was not consistent with field compatibility.  相似文献   

The impact of tillage and residual nitrogen on wheat     

P.J. Wiatrak  D.L. Wright  J.J. Marois 《Soil & Tillage Research》2006,91(1-2):150-156

Wheat (Triticum aestivum L.) yield and quality is influenced by management of the previous crop but is highly dependent on current year management. The objective of this study was to evaluate the response of winter wheat seeded in two tillage systems [conventional tillage (CT) and no-till (NT)] to four N rates applied to a previous cotton (Gossypium hirsutum L.) crop (0, 67, 134, and 202 kg ha⁻¹). The experiment with wheat was conducted on a Dothan sandy loam (fine, loamy siliceous, thermic Plinthic Kandiudults) at the University of Florida North Florida Research and Education Center near Quincy, FL from 1995 to 1997. For most plant characteristics, there was a tillage x N x year interaction. Greater plant emergence (79.4 vs. 65.3%) and grain N (23.5 vs. 21.5 g kg⁻¹), and lower grain moisture (139 vs. 142 g kg⁻¹) were obtained under NT than CT, respectively, in one out of two years. Nitrogen applied to a previous cotton crop increased wheat grain yields, plant height and seed number under NT in 1995–1996 and CT in 1996–1997, head density under NT in both years, harvest index under CT in 1996–1997, and grain N concentration in 1995–1996 and 1996–1997 due to residual plant and soil N. With every 1 kg N applied to a previous cotton crop, wheat grain yields increased by 5.38 kg ha⁻¹ under NT, whereas grain yield under CT was not influenced by N application to cotton in 1995–1996. In 1996–1997, grain yields increased by 4.96 and 4.23 kg ha⁻¹ for wheat grown in NT and CT, respectively. Generally, wheat seeded in NT following cotton did not decrease stand or yields compared to CT and wheat grain yields and grain N content increased with N fertilization of the previous crop. However, we would have to apply about 134 kg N ha⁻¹ to a previous cotton crop to maximize wheat production under NT and CT.  相似文献   

Population dynamics of the mycoparasite, sporidesmium sclerotivorum, and its host, sclerotinia minor, in soil     

P.B. Adams  J.J. Marois  W.A. Ayers 《Soil biology & biochemistry》1984,16(6):627-633

The infection and survival of sclerotia of Sclerotinia minor and the production ofmacroconidia of the mycoparasite, Sporidesmium sclerotivorum, were studied in vitro when each fungus was added to soil at various initial inoculum densities. The rate at which S. sclerotivorum invaded host sclerotia and caused their decay varied with the amount of the mycoparasite added to soil. The results suggest that approximately 5 macroconidia of the mycoparasite g^?1 of soil are needed to successfully infect sclerotia and bring about their decay, when soils are sampled and mixed every 2 weeks. The rate at which S. sclerotivorum infects sclerotia of S. minor and causes their decay is also dependent on the initial inoculum density of the host. Each infected sclerotium supports the production of about 15,000 new macroconidia in soil regardless of the initial inoculum density of the host. It is concluded that successful biological control by S. sclerotivorum is dependent on the soil population of both the host and the mycoparasite.  相似文献   

Toxicosis with grapes or raisins causing acute kidney injury and neurological signs in dogs     

Ariane Schweighauser  Diana Henke  Anna Oevermann  Corinne Gurtner  Thierry Francey 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(5):1957-1966

  相似文献   

Effects of relative humidity and high temperature on spore germination and development of tomato powdery mildew (Leveillula taurica)     

Remigio A. Guzman-Plazola  R. Michael Davis  James J. Marois 《Crop Protection》2003,22(10):1157-1168

The effects of relative humidity (RH) and temperature on tomato powdery mildew (Leveillula taurica) were studied in controlled environments to define conditions that affect disease development in fresh market tomatoes in California. Gradients of RH (20–90%) at constant temperatures (20–30°C) were generated in single growth chambers to determine their effect on mildew development on mature tomato plants. Temperatures of 30°C and above were deleterious for spore germination, germ tube elongation, and disease development. Lesion growth and rate of disease progress were significantly higher at 20°C than at 25°C. Low RH levels (20–40%) reduced spore germination and lesion growth, accelerated host tissue death and reduced disease progress. Intermediate RH levels (50–70%) increased spore germination and optimized disease development, provided temperatures were maintained within favorable limits. High RH levels (80–90%) were favorable for spore germination but continued exposure to these conditions led to a limited lesion growth and disease progress. Short daily periods (two or three daily exposures of at least 2 h) of high temperatures (35°C) suppressed disease development by 70–92%.  相似文献   

Prevalence of specific IgG-antibodies against Toxoplasma gondii in domestic turkeys determined by kinetic ELISA based on recombinant GRA7 and GRA8     

Koethe M  Pott S  Ludewig M  Bangoura B  Zöller B  Daugschies A  Tenter AM  Spekker K  Bittame A  Mercier C  Fehlhaber K  Straubinger RK 《Veterinary parasitology》2011,180(3-4):179-190

The protozoan parasite Toxoplasma (T.) gondii is one of the most common zoonotic infectious agents worldwide. Besides its sexual reproduction in cats, T. gondii can also infect a wide spectrum of other warm-blooded animals. These include animals used for human consumption such as pigs or chickens. Nevertheless, the role of turkeys for the epidemiology of T. gondii infections has not been studied thoroughly. We have established a kinetic ELISA (KELA) for the detection of T. gondii-specific IgG antibodies in turkey serum samples. The test is based on the recombinant dense granule antigens GRA7 and GRA8. These proteins were used as an antigen mixture at a concentration of 0.13 μg per well. The overall sensitivity of the assay was between 92.6% and 100% and the specificity ranged from 78.1% to 100%, depending on the method used to calculate these parameters. Using this KELA we examined 1913 turkey serum samples from 14 turkey farms from different areas of Germany. From these sera, 387 produced a signal in the KELA, corresponding to a true seroprevalence of up to 20.2%. The seropositivity rate in individual fattening cycles at individual farms ranged from 0.0% to 77.1%, whereas the rates were highly variable within the individual farms and individual fattening cycles. Consequently, conditions of animal husbandry could not be associated with particular seroprevalence rates. Although seropositivity cannot be linked directly to infectious tissue cysts in the muscle tissue of commercially produced turkey meat, we state that there is a potential risk of being infected by consuming turkey meat products that were not heat treated.  相似文献   

Gender, livestock assets, resource management, and food security: Lessons from the SR-CRSP     

Corinne Valdivia 《Agriculture and Human Values》2001,18(1):27-39

North Sumatra and West Java in Indonesia, the Andes of Bolivia and Peru, Western Province, the Coast and Machakos in Kenya, were Small Ruminant Collaborative Research Support Program (SR-CRSP) sites in which the role of small ruminants was studied and where technological interventions were designed. In all cases the target groups were poor rural households that could maintain sheep, goats, or South American camelids. The objective was to increase the welfare of families through the use of small ruminant technologies. Access to and control of resources, and intrahousehold dynamics were analyzed to understand if, how, and when, technological interventions help achieve this objective. The way in which the studied villages integrate into the market, the specific role that livestock and other productive enterprises play in the household economy, the risks faced by families in rural areas condition the role of livestock and other resource management technologies. As an asset, small and large stock are gendered, but this is qualified by the alternatives that household members have. Small ruminants under the domain of women, either through production or marketing, are shown to contribute to in-kind consumption or, as liquid assets, to household welfare purchases, in the case of Andean agropastoral households and households in Kenya. Women are also managers of the grazing areas, which are often fallow fields. The research experiences show the relationship between gender, resource management, and the ability to build livestock assets and security, in different houehold production systems. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

A role for CD40 expression on CD8+ T cells in the generation of CD8+ T cell memory     

Bourgeois C  Rocha B  Tanchot C 《Science (New York, N.Y.)》2002,297(5589):2060-2063

The delivery of CD4 help to CD8+ T cell responses requires interactions between CD40 and CD40 ligand and is thought to occur through antigen-presenting cell (APC) activation. Here we show that generation of memory CD8+ T cells displaying an enhanced capacity for cell division and cytokine secretion required CD4 help but not CD40 expression by the APCs. Activated CD4+ and CD8+ T cells expressed CD40; and in the absence of this protein, CD8+ T cells were unable to differentiate into memory cells or receive CD4 help. These results suggest that, like B cells, CD8+ T cells receive CD4 help directly through CD40 and that this interaction is fundamental for CD8+ T cell memory generation.  相似文献   

Can germplasm resources be used to increase the ascorbic acid content of stored potatoes?     

Corinne S. Davies  Michael J. Ottman  Stanley J. Peloquin 《American Journal of Potato Research》2002,79(4):295-299

Freshly harvested potato tubers contain up to 50 mg/100g ascorbic acid (AA), but levels decline rapidly during cold storage. Genetic alterations to boost the AA content of stored tubers would contribute to human nutrition and might improve tuber resistance to oxidative damage during chilling. While studying the breeding potential ofSolanum phureja germplasm, we identified a 24-chromosome Phureja-haploid Tuberosum hybrid (clone I, USW5295.7) that retained a twofold higher content of tuber AA than neighboring clones after storage at 5 C. Clone I produces 2n-pollen through a mechanism genetically equivalent to first-division restitution (FDR), which transmits much of the nonadditive genetic variance for tuber yield. We now report a survey of clone I progeny showing significant family and ploidy effects on tuber AA levels during cold storage, consistent with the transmission of information for higher AA by FDR 2n-pollen. These results encourage further study of 2n-gametes and wild species germplasm to breed for increased tuber AA.  相似文献   

Epidemiology,molecular virology and diagnostics of Schmallenberg virus,an emerging orthobunyavirus in Europe     

Virginie Doceul  Estelle Lara  Corinne Sailleau  Guillaume Belbis  Jennifer Richardson  Emmanuel Bréard  Cyril Viarouge  Morgane Dominguez  Pascal Hendrikx  Didier Calavas  Alexandra Desprat  Jér?me Languille  Lo?c Comtet  Philippe Pourquier  Jean-Fran?ois Eléou?t  Bernard Delmas  Philippe Marianneau  Damien Vitour  Stéphan Zientara 《Veterinary research》2013,44(1):31

After the unexpected emergence of Bluetongue virus serotype 8 (BTV-8) in northern Europe in 2006, another arbovirus, Schmallenberg virus (SBV), emerged in Europe in 2011 causing a new economically important disease in ruminants. The virus, belonging to the Orthobunyavirus genus in the Bunyaviridae family, was first detected in Germany, in The Netherlands and in Belgium in 2011 and soon after in the United Kingdom, France, Italy, Luxembourg, Spain, Denmark and Switzerland. This review describes the current knowledge on the emergence, epidemiology, clinical signs, molecular virology and diagnosis of SBV infection.  相似文献