Chlorophyll Fluorescence on the Fast Timescale.

Chlorophyll fluorescence is a rapid and noninvasive tool used for probing the activity of photosynthesis that can be used in vivo and in the field. It is highly relevant to the demands of high-throughput crop phenotyping and can be automated or manually applied. In this chapter, we describe protocols and advice for making fast timescale fluorescence measurements using handheld equipment in the laboratory or in the field in the context of phenotyping.

Fungal plant pathogen "mutagenomics" reveals tagged and untagged mutations in and identifies SSK2 as key morphogenesis and stress-responsive virulence factor.

"Mutagenomics" is the combination of random mutagenesis, phenotypic screening, and whole-genome re-sequencing to uncover all tagged and untagged mutations linked with phenotypic changes in an organism. In this study, we performed a mutagenomics screen on the wheat pathogenic fungus for altered morphogenetic switching and stress sensitivity phenotypes using -mediated "random" T-DNA mutagenesis (ATMT). Biological screening identified four mutants which were strongly reduced in virulence on wheat.

Aggressiveness and mycotoxin profile of isolates causing Fusarium seedling blight and Fusarium head blight in UK malting barley.

Introduction: avenaceum causing Fusarium seedling blight (FSB) and Fusarium head blight (FHB) on barley is associated with economic losses of crop yield and quality, and the accumulation of mycotoxins including the enniatins (ENNs) A, A1, B and B1. Although is the main producer of ENNs, studies on the ability of isolates to cause severe Fusarium diseases or produce mycotoxins in barley are limited.

Methods: In this work, we investigated the aggressiveness of nine isolates of to two cultivars of malting barley, Moonshine and Quench, and defined their ENN mycotoxin profiles in and in planta experiments.

Molecular Characterization of Defense of (Oilseed Rape) to AG2-1 Confirmed by Functional Analysis in .

is a necrotrophic, soilborne fungal pathogen associated with significant establishment losses in (oilseed rape; OSR). The anastomosis group (AG) 2-1 of is the most virulent to OSR, causing damping-off, root and hypocotyl rot, and seedling death. Resistance to AG2-1 in OSR has not been identified, and the regulation of OSR defense to its adapted pathogen, AG2-1, has not been investigated.

A large bioassay identifies resistance genes that provide broad resistance against Septoria tritici blotch disease in the UK.

Introduction: Septoria tritici blotch (STB) is one of the most damaging fungal diseases of wheat in Europe, largely due to the paucity of effective resistance genes against it in breeding materials. Currently dominant protection methods against this disease, e.g.

Impact of Initial Population Density of the Dubas Bug, (Hemiptera: Tropiduchidae), on Oviposition Behaviour, Chlorophyll, Biomass and Nutritional Response of Date Palm ().

The Dubas bug () is an economically significant pest of date palms. In this study, the effect of the population density of on chlorophyll, measured by the soil plant analysis development (SPAD) chlorophyll meter, palm biomass, and the nutritional composition of date palms, were investigated. A further objective was to determine significant relationships between the population density of , the number of honeydew droplets, and oviposited eggs.

Yield Loss and Integrated Disease Control of AG2-1 Using Seed Treatment and Sowing Rate of Oilseed Rape.

anastomosis group (AG) 2-1 is an ubiquitous soilborne pathogen causing severe damping-off of oilseed rape (OSR). In the absence of varietal resistance to AG2-1, there are limited methods for integrated disease management. The objectives of these field studies were to quantify yield losses due to AG2-1 and to determine the effectiveness of integrated control using sedaxane, fludioxonil, and metalaxyl-M applied as seed treatment on two OSR genotypes at a sowing rate of 40 (low) or 80 (high) seeds m.

Yield Losses and Control by Sedaxane and Fludioxonil of Soilborne , , and Species in Winter Wheat.

Soilborne , , and species are major causal agents of seedling and stem-base diseases of wheat. Currently, seed treatments are considered the most effective solution for their control. anastomosis groups (AGs) 2-1 and 5, , , and spp.

The N-recognin E3 ligase PROTEOLYSIS1 influences the immune response.

N-degron pathways of ubiquitin-mediated proteolysis (formerly known as the N-end rule pathway) control the stability of substrate proteins dependent on the amino-terminal (Nt) residue. Unlike yeast or mammalian N-recognin E3 ligases, which each recognize several different classes of Nt residues, in , N-recognin functions of different N-degron pathways are carried out independently by PROTEOLYSIS (PRT)1, PRT6, and other unknown proteins. PRT1 recognizes type 2 aromatic Nt-destabilizing residues and PRT6 recognizes type 1 basic residues.

Infestation by Increases Susceptibility of cv. "Canard" to AG 2-1.

Activation of plant defense pathways can be influenced by the presence of different species of attacking organisms. Understanding the complicated interactions triggering plant defense mechanisms is of great interest as it may allow the development of more effective and sustainable disease control methods. and anastomosis group (AG) 2-1 are two important organisms attacking oilseed rape (OSR), causing disease and reduced yields.

Distinct branches of the N-end rule pathway modulate the plant immune response.

The N-end rule pathway is a highly conserved constituent of the ubiquitin proteasome system, yet little is known about its biological roles. Here we explored the role of the N-end rule pathway in the plant immune response. We investigated the genetic influences of components of the pathway and known protein substrates on physiological, biochemical and metabolic responses to pathogen infection.

Canopy and Ear Traits Associated With Avoidance of Fusarium Head Blight in Wheat.

Doubled haploid and elite wheat genotypes were ground inoculated in three field experiments and head spray inoculated in two glasshouse experiments, using mixed and species, to identify crop canopy and ear traits associated with Fusarium head blight (FHB) disease. In all experiments, flag leaf length and tiller number were consistently identified as the most significant canopy traits contributing to progression of FHB caused by , and . The influence of ear traits was greater for that may possess more diverse routes for transmission and spread.

Chlorophyll Fluorescence on the Fast Timescale.

Chlorophyll fluorescence is a rapid and non-invasive tool used for probing the activity of photosynthesis that can be used in vivo and in the field. It is highly relevant to the demands of high-throughput crop phenotyping and can be automated or manually applied. Here we describe protocols and advice for making fast timescale fluorescence measurements using handheld equipment in the laboratory or in the field.

Development of high-throughput methods to screen disease caused by AG 2-1 in oilseed rape.

Background: (Kühn) is a soil-borne, necrotrophic fungus causing damping off, root rot and stem canker in many cultivated plants worldwide. Oilseed rape (OSR, ) is the primary host for anastomosis group (AG) 2-1 of causing pre- and post-emergence damping-off resulting in death of seedlings and impaired crop establishment. Presently, there are no known resistant OSR genotypes and the main methods for disease control are fungicide seed treatments and cultural practices.

Altered gene expression by sedaxane increases PSII efficiency, photosynthesis and growth and improves tolerance to drought in wheat seedlings.

Succinate dehydrogenase inhibitor (SDHI) fungicides have been shown to increase PSII efficiency and photosynthesis under drought stress in the absence of disease to enhance the biomass and yield of winter wheat. However, the molecular mechanism of improved photosynthetic efficiency observed in SDHI-treated wheat has not been previously elucidated. Here we used a combination of chlorophyll fluorescence, gas exchange and gene expression analysis, to aid our understanding of the basis of the physiological responses of wheat seedlings under drought conditions to sedaxane, a novel SDHI seed treatment.

Contrasting Roles of Deoxynivalenol and Nivalenol in Host-Mediated Interactions between Fusarium graminearum and Sitobion avenae.

is the predominant causal species of Fusarium head blight in Europe and North America. Different chemotypes of the species exist, each producing a plethora of mycotoxins. Isolates of differing chemotypes produce nivalenol (NIV) and deoxynivalenol (DON), which differ in toxicity to mammals and plants.

Aphid Infestation Increases Fusarium langsethiae and T-2 and HT-2 Mycotoxins in Wheat.

Unlabelled: Fusarium langsethiae is a fungal pathogen of cereal crops that is an increasing problem in northern Europe, but much of its epidemiology is poorly understood. The species produces the mycotoxins T-2 and HT-2, which are highly toxic. It was hypothesized that grain aphids, Sitobion avenae, may transmit F.

Chlorophyll fluorescence parameters allow the rapid detection and differentiation of plant responses in three different wheat pathosystems.

The present study was undertaken to identify chlorophyll fluorescence (CF) parameters that can quantify changes in PSII associated with plant responses in three different wheat pathosystems of foliar, stem-base and ear diseases. The pathosystems included powdery mildew caused by Blumeria graminis, eyespot caused by Oculimacula yallundae or Oculimacula acuformis and Fusarium head blight (FHB) caused by Fusarium culmorum, F. avenaceum or F.

Effects of damping-off caused by Rhizoctonia solani anastomosis group 2-1 on roots of wheat and oil seed rape quantified using X-ray Computed Tomography and real-time PCR.

Rhizoctonia solani is a plant pathogenic fungus that causes significant establishment and yield losses to several important food crops globally. This is the first application of high resolution X-ray micro Computed Tomography (X-ray μCT) and real-time PCR to study host-pathogen interactions in situ and elucidate the mechanism of Rhizoctonia damping-off disease over a 6-day period caused by R. solani, anastomosis group (AG) 2-1 in wheat (Triticum aestivum cv.

Sharing a Host Plant (Wheat [Triticum aestivum]) Increases the Fitness of Fusarium graminearum and the Severity of Fusarium Head Blight but Reduces the Fitness of Grain Aphids (Sitobion avenae).

We hypothesized that interactions between fusarium head blight-causing pathogens and herbivores are likely to occur because they share wheat as a host plant. Our aim was to investigate the interactions between the grain aphid, Sitobion avenae, and Fusarium graminearum on wheat ears and the role that host volatile chemicals play in mediating interactions. Wheat ears were treated with aphids and F.

Foliar application of isopyrazam and epoxiconazole improves photosystem II efficiency, biomass and yield in winter wheat.

A range of fungicides including epoxiconazole, azoxystrobin and isopyrazam, were applied to winter wheat at GS 31/32 to determine their effect on photosystem II (PSII) efficiency, biomass and yield. Frequent, repeated measurements of chlorophyll fluorescence were carried on plants grown under different water regimes in controlled environment and in the field to establish the transiency of fluorescence changes in relation to fungicide application. Application of the succinate dehydrogenase inhibitor isopyrazam in a mixture with the triazole epoxiconazole increased PSII efficiency associated with a 28% increase in biomass in the controlled environment and 4% increase in grain yield in the field in the absence of disease pressure.

Effect of eyespot caused by Oculimacula yallundae and O. acuformis, assessed visually and by competitive PCR, on stem strength associated with lodging resistance and yield of winter wheat.

Winter wheat, (cv. Consort) was inoculated with three isolates of either Oculimacula yallundae or O. acuformis to determine the effect of eyespot caused by each species on yield and lodging resistance of winter wheat.