Blast, caused by the fungus Pyricularia oryzae, is a major disease of wheat crop in Brazilian Cerrado and represents potential threat to world production. However, information about wheat-P. oryzae interaction still limited. In this work, activities enzymes superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), glutathione-S-transferase (GST), ascorbate (APX), glutathione reductase (GR), (GPX) concentrations (O₂(-)), hydrogen peroxide (H₂O₂), malondialdehyde (MDA) as well electrolyte...

Blast, caused by Pyricularia oryzae, has become an economically important disease in wheat Brazil, but little effort been devoted to understanding the wheat-P. oryzae interaction. This study was intended determine effects of P. infection on photosynthetic process plants using a susceptible (BR 18) and partially resistant cultivar (BRS 229). It found that net carbon assimilation rate (A), stomatal conductance (gs), transpiration were dramatically reduced both cultivars due lesser degree BRS...

This study investigated whether the increase in wheat resistance to blast, caused by P yricularia oryzae , potentiated silicon ( S i) is linked changes activity of antioxidative enzymes. Wheat plants (cv. BR 18) were grown hydroponic culture with either 0 (– or 2 m (+ i and half each group inoculated . Blast severity + was 70% lower compared − at 96 h after inoculation (hai). Superoxide dismutase SOD ), catalase CAT peroxidase POX ascorbate APX ) glutathione‐S‐transferase GST activities...

Abstract The photosynthetic performance (leaf gas exchange and chlorophyll a (Chl ) fluorescence), activities of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate (APX)] the concentrations hydrogen peroxide (H 2 O malondialdehyde (MDA) in flag leaves plants from two wheat cultivars with contrasting levels resistance to spot blotch was assessed. Spot severity significantly lower cv. BR‐18 compared Guamirim. Net carbon assimilation rate, stomatal...

Abstract Asian soybean rust ( ASR ), caused by Phakopsora pachyrhizi , is one of the most important foliar diseases affecting production worldwide. This study aimed to investigate photosynthetic performance (leaf gas exchange, chlorophyll (Chl) a fluorescence images and pigment pools) plants sprayed with Acibenzolar‐S‐Methyl ASM ) fungicide epoxiconazole + pyraclostrobin (Epo+Pyr) further inoculated P. . The symptoms progressed much faster on leaves from control treatment (water spray) in...

Two experiments were carried out to assess the changes associated with photoassimilate production and partitioning in source–sink relationship of flag leaves spikes wheat plants infected Pyricularia oryzae , causal agent blast. Flag inoculated at 10 20 days after anthesis (daa) a conidial suspension P. . Analysis chlorophyll fluorescence using maximal photosystem II quantum efficiency ( F v ⁄ m ), fraction energy absorbed that is used photochemistry YII yield non‐regulated dissipation (Y( NO...

This study investigated the effects of acibenzolar-S-methyl (ASM), ethylene (ET) and jasmonic acid (JA) on resistance two wheat cultivars (BRS-229 BR-18) to infection by Pyricularia oryzae. The treatments included spraying plants with ASM (300 mg L-1), ET (0.5 mM), JA (0.1 mM) distilled water (control) 48 h before inoculation P. Malondialdehyde concentration, an indicative oxidative damage lipids in leaf cells, was significantly higher for sprayed compared ET. Plants showed reduced values...

Blast, caused by Pyricularia oryzae, has become a devastating disease on wheat in several countries worldwide. Growers need alternative methods for blast management, and silicon (Si) stands out its potential to decrease the intensity of important diseases crops. This study investigated effect Si improving photoassimilate production flag leaves plants their partitioning spikes scenario where symptoms decreased as result potentiation defense mechanisms Si. Wheat (cultivar BRS Guamirim) were...

Mango wilt, caused by Ceratocystis fimbriata, is one of the most important diseases affecting mango yields in Brazil. Information regarding biochemical mechanisms involved resistance against C. fimbriata absent literature. Thus, present study determined and quantified alkaloids phenolics stem tissue plants from Palmer (susceptible) Ubá (resistant) cultivars. Furthermore, it was examined effect these secondary metabolites growth vitro. The high-performance liquid chromatography revealed that...

Although magnesium (Mg) is considered an essential element for wheat growth, its importance disease control has often been overlooked, and the physiological features of diseased plants mediated by Mg remain elusive. In this study, effect three concentrations (0·25, 2·5 4 m ) on resistance to leaf blast ( Pyricularia oryzae ), gas exchange, invertase activity, cellular damage foliar concentration photosynthetic pigments nutrients was investigated. Foliar increased from 1·9 3·9 g kg −1 ,...

Abstract Considering the potential of white mold, caused by fungus Sclerotinia sclerotiorum , to reduce tomato production, this study aimed determinate effect manganese (Mn) phosphite on resistance plants disease assessing photosynthetic performance (gas exchange and chlorophyll a fluorescence), activities defence enzymes those related antioxidant metabolism as well concentrations pigments, malondialdehyde (MDA), hydrogen peroxide (H 2 O ) superoxide anion (O − ). The in vitro assays showed...

Considering the importance of blast, caused by Pyricularia oryzae, to reduce wheat yield, this study investigate how silicon (Si) could blast symptoms in rachis tissues using light microscopy and scanning electron microscopy. Wheat plants (cv. BR 18) were grown hydroponic culture with either 0 (–Si) or 2 mM (+Si) Si. Blast very well developed on spikes –Si plants, which showed intense discoloration contrast +Si plants. At 72 hours after inoculation (hai), fungal hyphae extensively colonized...

Two field experiments (Exp. 1 and Exp. 2) were carried out to assess the physiological performance grain yield of wheat cultivars BR‐18 (moderately resistant) Guamirim (susceptible) inoculated with Pyricularia oryzae in plots treated or untreated Ópera (fungicide 13.3% epoxiconazole + 5% pyraclostrobin). Results from regression analyses indicated that spike leaf blast severity at 10–14 days after inoculation (dai) associated greater losses (highest negative slope) than 18–22 dai. Relative...

Anthracnose or ripe rot of blueberry (Vaccinium spp.) is caused predominantly by Colletotrichum fioriniae, which belongs to the C. acutatum complex since it has cylindrical conidia with both ends acute (2). In May 2013, an isolate typical boninense (cylindrical rounded) (1) was obtained from leaves southern highbush seedlings in a nursery located municipality Pelotas, Rio Grande do Sul, Brazil. The symptoms initially appear as circular, necrotic lesions 10 30 mm diameter. At high humidity,...