Omnidirectional flat bands in chiral magnonic crystals.

The magnonic band structure of two-dimensional chiral magnonic crystals is theoretically investigated. The proposed metamaterial involves a three-dimensional architecture, where a thin ferromagnetic layer is in contact with a two-dimensional periodic array of heavy-metal square islands. When these two materials are in contact, an anti-symmetric exchange coupling known as the Dzyaloshinskii-Moriya interaction (DMI) arises, which generates nonreciprocal spin waves and chiral magnetic order. The Landau-Lifshitz equation and the plane-wave method are employed to study the dynamic magnetic behavior. A systematic variation of geometric parameters, the DMI constant, and the filling fraction allows the examination of spin-wave propagation features, such as the spatial profiles of the dynamic magnetization, the isofrequency contours, and group velocities. In this study, it is found that omnidirectional flat magnonic bands are induced by a sufficiently strong Dzyaloshinskii-Moriya interaction underneath the heavy-metal islands, where the spin excitations are active. The theoretical results were substantiated by micromagnetic simulations. These findings are relevant for envisioning applications associated with spin-wave-based logic devices, where the nonreciprocity and channeling of the spin waves are of fundamental and practical scientific interest.

Toggle-like current-induced Bloch point dynamics of 3D skyrmion strings in a room temperature nanowire.

Research into practical applications of magnetic skyrmions, nanoscale solitons with interesting topological and transport properties, has traditionally focused on two dimensional (2D) thin-film systems. However, the recent observation of novel three dimensional (3D) skyrmion-like structures, such as hopfions, skyrmion strings (SkS), skyrmion bundles, and skyrmion braids, motivates the investigation of new designs, aiming to exploit the third spatial dimension for more compact and higher performance spintronic devices in 3D or curvilinear geometries. A crucial requirement of such device schemes is the control of the 3D magnetic structures via charge or spin currents, which has yet to be experimentally observed. In this work, we utilise real-space imaging to investigate the dynamics of a 3D SkS within a nanowire of Co8Zn9Mn3 at room temperature. Utilising single current pulses, we demonstrate current-induced nucleation of a single SkS, and a toggle-like positional switching of an individual Bloch point at the end of a SkS. The observations highlight the possibility to locally manipulate 3D topological spin textures, opening up a range of design concepts for future 3D spintronic devices.

Real-space imaging of confined magnetic skyrmion tubes.

Magnetic skyrmions are topologically nontrivial particles with a potential application as information elements in future spintronic device architectures. While they are commonly portrayed as two dimensional objects, in reality magnetic skyrmions are thought to exist as elongated, tube-like objects extending through the thickness of the host material. The study of this skyrmion tube state (SkT) is vital for furthering the understanding of skyrmion formation and dynamics for future applications. However, direct experimental imaging of skyrmion tubes has yet to be reported. Here, we demonstrate the real-space observation of skyrmion tubes in a lamella of FeGe using resonant magnetic x-ray imaging and comparative micromagnetic simulations, confirming their extended structure. The formation of these structures at the edge of the sample highlights the importance of confinement and edge effects in the stabilisation of the SkT state, opening the door to further investigation into this unexplored dimension of the skyrmion spin texture.

Detection of White Root Rot in Avocado Trees by Remote Sensing.

White root rot, caused by the soilborne fungus Rosellinia necatrix, is an important constraint to production for a wide range of woody crop plants such as avocado trees. The current methods of detection of white root rot are based on microbial and molecular techniques, and their application at orchard scale is limited. In this study, physiological parameters provided by imaging techniques were analyzed by machine learning methods. Normalized difference vegetation index (NDVI) and normalized canopy temperature (canopy temperature - air temperature) were tested as predictors of disease by several algorithms. Among them, logistic regression analysis (LRA) trained on NDVI data showed the highest sensitivity and lowest rate of false negatives. This algorithm based on NDVI could be a quick and feasible method to detect trees potentially affected by white root rot in avocado orchards.

Flat Bands, Indirect Gaps, and Unconventional Spin-Wave Behavior Induced by a Periodic Dzyaloshinskii-Moriya Interaction.

Periodically patterned metamaterials are known for exhibiting wave properties similar to the ones observed in electronic band structures in crystal lattices. In particular, periodic ferromagnetic materials are characterized by the presence of bands and band gaps in their spin-wave spectrum at tunable GHz frequencies. Recently, the fabrication of magnets hosting Dzyaloshinskii-Moriya interactions has been pursued with high interest since properties, such as the stabilization of chiral spin textures and nonreciprocal spin-wave propagation, emerge from this antisymmetric exchange coupling. In this context, to further engineer the magnon band structure, we propose the implementation of magnonic crystals with periodic Dzyaloshinskii-Moriya interactions, which can be obtained, for instance, via patterning of periodic arrays of heavy metal wires on top of an ultrathin magnetic film. We demonstrate through theoretical calculations and micromagnetic simulations that such systems show an unusual evolution of the standing spin waves around the gaps. We also predict the emergence of indirect gaps and flat bands, effects that depend on the strength of the Dzyaloshinskii-Moriya interaction. Such phenomena, which have been previously observed in different systems, are observed here simultaneously, opening new routes towards engineered metamaterials for spin-wave-based devices.

Correlation of the Glomerular Filtration Rate Measured With the Use of DTPA-Tc99m in Live Kidney Donors With Equations Based on Creatinine and Cystatin C.

BACKGROUND: Renal donation leads to a risk of developing chronic kidney disease, with an incidence of 0.47%. To evaluate for its presence, formulas based on serum creatinine are used, but up to 80% of these formulas underestimate the glomerular filtration rate (GFR) in donors. The aim of this work was to confirm the highest correlation of the GFR as measured with the use of DTPA-Tc99m with the GFR as estimated by means of the formula based on serum cystatin C (CKD-EPI creatinine-cystatin C) in healthy kidney donors. METHODS: In this observational, analytic, cross-sectional study, the GFR of kidney donors was determined ≥1 year after donation by means of DTPA gammagram and estimation with the use of conventional formulations and with cystatin C. RESULTS: Of 112 donors, 38 (34%) were included, 20 (60%) were female, with an overall average age of 40 years, 36.5 months after donation, and body mass index of 25.5 kg/m2. Correlation with the GFR as measured by means of DTPA gammagram was better with the use of CKD-EPI cystatin C (0.402; P = .020) and CKD-EPI creatinine-cystatin (0.549; P < .001) than the conventional formulas. Linear correlation with serum cystatin C was 0.825 (P < .001; 95% confidence interval, -105.3 to -63.2) for the CKD-EPI cystatin C formula, 0.77 (P < .001; -89.9 to -48.1) for the CKD-EPI creatinine-cystatin formula, and 0.525 (P = .002; -91.1 to -23.2) for DTPA-Tc99m scintigraphy. CONCLUSIONS: There is a strong correlation between estimate the GFR by equations based on cystatin C and the measurement of the GFR by DTPA-Tc99m gammagram.

Correlation of the Renal Cortex Volume With the Glomerular Filtration Rate in Live Donors for Renal Transplantation.

INTRODUCTION: As a pretransplantation evaluation, renal function is determined by the glomerular filtration rate (GFR) with the use of renal scintigraphy (RS) and the estimated glomerular filtration rate (eGFR). To date, there are few studies that correlate renal cortex volume with eGFR determined with renal gammagram (GR) and eGFR by equations (Cockroft-Gault, Modification of Diet in Renal Disease, and Chronic Kidney Disease Epidemiology Collaboration equation) in Latin American living donors. AIM: This study sought to determine whether there is correlation of the volume of the renal cortex by Herts equation with the GFR determined with renal gammagram (GFR-GR). PATIENTS AND METHODS: This was an analytical, observational, and cross-sectional study. A review of the donor charts from January 1, 2014, to December 1, 2014, with a complete clinical file, kidney measurements, predonation tomography volume, and eGFR by different formulas and by renal scintigraphy. RESULTS: Thirty-three donors were included, 51.5% male and 48.5% female. The mean age was 38.58 ± 10 years, with an average volume of 127.83 ± 28.30 mL, with diethylenetriamine-pentaacetate (DTPA) of 54.80 ± 7.13 mL/min/1.73 m2 in the donated kidney. Spearman correlation showed the best association with the Herts equation (r = 0.346) reaching significance (P = .049) when comparing the different equations against the GFR with DTPA. Using the Bland-Altman method, the lowest variability and best significance was verified with the same equation compared to the other formulas (P = .0002). CONCLUSIONS: There is no consensus regarding which is the best formula for calculating the GFR of both kidneys. Of the different formulas, the one that best correlated with the GFR was the Herts method, which uses the volume of the kidney.

Cardiac Remodeling in Structure and Function Six Months After Kidney Transplantation.

BACKGROUND: Cardiovascular disease accounts for 35% to 50% of the causes of mortality in chronic kidney disease. The majority of patients in substitution therapy in Mexico are subdialyzed owing to limited economic resources. This produces more cardiac deterioration than described in the statistics and has a direct impact on the prognosis of kidney transplantation. The aim of this work was to demonstrate and to quantify the improvement in the echocardiographic parameters 6 months after renal transplantation in patients with stable renal function. METHODS: This was an observational, analytic, prospective study of 23 patients with chronic kidney disease who received transplants in 2016 and had a glomerular filtration rate ≥80 mL/min (Chronic Kidney Disease-Epidemiology Collaboration) 6 months after transplantation. RESULTS: Echocardiographic results showed an increase in the left ventricular ejection fraction from 57.17 ± 10.46% to 64.09 ± 9.8%, an increase in the right ventricular ejection fraction from 0.56 ± 0.09% to 0.60 ± 0.08% and a reduction of the pulmonary arterial systolic pressure from 44.57 ± 13.88 mm Hg to 39.74 ± 11.04 mm Hg. There were also decreases in mitral regurgitation from 1.0 to 0.43, tricuspid insufficiency from 1.35 to 0.43, pulmonary insufficiency from 0.48 to 0.04, and aortic insufficiency from 0.35 to 0.04, all of these significant with P < .05. CONCLUSIONS: There was a significant improvement in cardiovascular function in our population 6 months after transplantation, despite the fact that renal transplantation is performed with greater cardiac deterioration than described in patients in other countries.

Lack of Association Between Elevated Urinary Levels of Interleukin-10 and Interferon Gamma With the Presence of Inflammation in Kidney Transplant Recipients.

INTRODUCTION: A lot of evidence has demonstrated the importance of different cytokines in acute renal rejection. Previous studies have examined the presence or absence of interleukin (IL)-10 in related immunopathologic rejection grafts as well as other interleukins. Studies in human transplantation show elevated levels of IL-10 and gamma interferon (INF-γ) in inflammation and rejection. OBJECTIVE: The objective of this study was to demonstrate the lack of association of elevated urinary levels of IL-10 and IFN in the presence of active inflammation. METHODS: An observational, descriptive, cross-sectional study conducted in transplant recipients at 12 months of follow-up after renal transplantation. In those who were held biopsy after renal transplantation at one year follow-up, or allograft dysfunction, we also measured IL-10 and INF-γ in the urine. The following were considered as variables: age, body mass index (BMI), gender, transplant type, creatinine, chronic kidney disease epidemiology collaboration equation, (CKD-EPI), modification of diet in renal disease study equation (MDRD), Banff classification, and levels of IL-10 and INF-γ. Statistical analysis was performed calculating a sample size of 25 patients, with an alpha bias of 0.05%, yielding measures of central tendency and determining no association between levels of IL-10 and INF-γ with the presence of rejection using SPSS 21.0 program. RESULTS: A total of 50 patients, 34 (68%) males, 16 (32%) females, with an average 31.7 ± 9.9 years, weight of 64.91 ± 13.84 kg, size 1.60 ± 0.10 m and 24.97 ± 4.07 BMI were included,39 (78%) living donor and 11 (22%) cadaveric. Twenty-six (52%) showed inflammation in the biopsy and 24 (48%) showed none. Mean creatinine was 1.81 ± 1.5, and the estimated glomerular filtration rate (eGFR) was 55.27 ± 22.46, 65.76 ± 26.7. (MDRD and CKD-EPI, respectively). No statistical difference was found in the levels of IL-10 and IFN-γ using analysis of variance. (ANOVA; P = .467 and P = .063, respectively) Based on Banff, the inflammation on biopsy score was 2.78 ± 2.84. There was statistical significance (P < .05) with respect to the Cr and eGFR by different equations. There were no significant interactions between cytokine levels and more than 1 factor. (as indicated by P < .2). DISCUSSION AND CONCLUSIONS: No significant differences were observed in the level of interleukins in patients with and without inflammation, denoting an adequate immunosuppression in most of these patients. Determination of inflammatory cytokines in urine could be used as a determinant of a good immunosuppression status, rather than as an early marker of rejection.

First Report of Fludioxonil Resistance in Botrytis cinerea, the Causal Agent of Gray Mold, from Strawberry Fields in Maryland and South Carolina.

Botrytis cinerea Pers. is the causal agent of gray mold and one of the most economically important plant-pathogenic fungi affecting strawberry (Fragaria × ananassa). Control of gray mold mainly depends on the use of site-specific fungicides, including the phenylpyrrole fludioxonil. This fungicide is currently registered in combination with cyprodinil in form of Switch 62.5WG (Syngenta Crop Protection, Greensboro, NC) for gray mold control of small fruits in the United States. In June 2013, strawberries affected with symptoms resembling gray mold were observed despite the application of Switch in one field located in Federalsburg, MD, and one located near Chesnee, SC. Ten single-spore isolates, each from a different fruit, were obtained from each location and confirmed to be B. cinerea using cultural and molecular tools as described previously (3). In vitro sensitivity to fludioxonil (Scholar SC, 20.4% [v/v] active ingredient, Syngenta Crop Protection, Greensboro, NC) was determined using a conidial germination assay as previously described (4). Eight of the 20 isolates (six from Maryland and two from South Carolina) were moderately resistant to fludioxonil, i.e., they grew on medium amended with 0.1 µg/ml fludixonil and showed residual growth at 10 µg/ml (4). The in vitro assay was repeated obtaining the same results. To assess in vivo sensitivity on fungicide-treated fruit, commercially grown strawberries were rinsed with water, dried, and sprayed 4 h prior to inoculation with either water or 2.5 ml/liter of Scholar SC to runoff using a hand mister. Fruit was stab-wounded with a sterile syringe and inoculated with a 30-µl droplet of conidia suspension (106 spores/ml) of either two sensitive or four resistant isolates (two isolates from Maryland and two isolates from South Carolina). Each isolate/treatment combination consisted of 24 mature but still firm strawberry fruit with three 8-fruit replicates. The fruit were kept at 22°C and lesion diameters were measured after 4 days of inoculation. The sensitive isolates developed gray mold symptoms on nontreated (2.5 cm lesion diameter) but not on Scholar SC-treated fruit. The resistant isolates developed gray mold on both, the water-treated control (2.3 cm lesion diameter), and the fungicide-treated fruit (1.8 cm lesion diameter). The experiment was performed twice. To our knowledge this is the first report of fludioxonil resistance in B. cinerea from strawberry fields in Maryland and South Carolina. Resistance to fludioxonil is still rare in the United States and has only been reported in B. cinerea isolates from a Virginia strawberry field (1). The increase in occurrence of resistance to fludioxonil may be a result of increased use of Switch following reports of resistance to other chemical classes in this pathogen in southern strawberry fields (2). References: (1) D. Fernández-Ortuño et al. Plant Dis. 97:848, 2013. (2) D. Fernández-Ortuño et al. Plant Dis. 96:1198, 2012. (3) D. Fernández-Ortuño et al. Plant Dis. 95:1482, 2011. (4) R. W. S. Weber and M. Hahn. J. Plant Dis. Prot. 118:17, 2011.

First Report of Fludioxonil Resistance in Botrytis cinerea from a Blackberry Field in Georgia.

Botrytis cinerea Pers. is an important plant-pathogenic fungi responsible for gray mold on more than 230 plant species worldwide, including blackberry (Rubus). One of the main strategies to control the disease involves the application of different classes of fungicides. The phenylpyrrole fludioxonil is currently marketed in combination with the anilinopyrimidine cyprodinil as Switch 62.5WG (Syngenta Crop Protection Inc., Greensboro, NC) for gray mold control. In August 2013, blackberries affected with symptoms resembling gray mold were collected from a field located in Berrien County (Georgia), where Switch 62.5WG had been used extensively over the last 5 years. Three single-spore isolates, each from a different fruit, were obtained and identified as B. cinerea on the basis of morphology and confirmed by a 238-bp PCR amplification product obtained with primer set G3PDH-F1 (5'-GGACCCGAGCTAATTTATGTCACGT-3'), G3PDH-F2 (5'-GGGTGTCAACAACGAGACCTACACT-3'), and G3PDH-R (5'-ACCGGTGCTCGATGGGATGAT-3'). In vitro sensitivity to fludioxonil (Scholar SC, Syngenta) was determined on 1% malt extract agar (MEA) using a conidial germination assay as previously described (4). One isolate was moderately resistant due to growth on medium amended with the discriminatory dose of 0.1 µg/ml fludioxonil and residual growth at 10 µg/ml (4). To assess performance of fludioxonil in detached fruit assays, commercially grown strawberries (24 in total for each isolate and treatment) were rinsed with water, dried, and sprayed 4 h prior to inoculation with either water (control fruit) or 2.5 ml/liter of Scholar SC to runoff using a hand mister. Scholar SC was used because fludioxonil was the sole active ingredient in this product and strawberries were used because latent infections in fresh blackberry fruit interfered with inoculation experiments. This dose reflects the rate recommended for postharvest gray mold control according to the Scholar label. Fruit was stab-wounded with a sterile syringe and inoculated with a 30-µl droplet of conidia suspension (106 spores/ml) of the two sensitive or the resistant isolate. After inoculation, the fruit were kept at 22°C for 4 days. The sensitive isolates developed gray mold on non-treated (2.7 cm lesion diameter) but not on Scholar SC-treated fruit (0.0 cm lesion diameter). The resistant isolate developed gray mold disease on the water-treated control fruit (2.5 cm lesion diameter) and the fungicide-treated fruit (1.8 cm lesion diameter). EC50 values were determined in microtiter assays as described previously (3) using the concentrations of 0.01, 0.04, 0.12, 0.37, 1.1, 3.3, and 10 µg/ml fludioxonil. Values were 0.02 and 0.05 µg/ml for the two sensitive isolates and 3.15 µg/ml for the resistant isolate. All experiments were performed twice. This is the first report of fludioxonil resistance in B. cinerea from blackberry in Georgia. Prior to this study, resistance to fludioxonil in B. cinerea was reported in France, Germany, and only a few states in the United States including Maryland, South Carolina, Virginia, and Washington (1,2). The emergence of resistance to fludioxonil emphasizes the importance of resistance management strategies. References: (1) D. Fernández-Ortuño et al. Plant Dis. 97:848, 2013. (2) D. Fernández-Ortuño et al. Plant Dis. 98:692, 2013. (3) M. Kretschmer et al. PLOS Pathog. 5:e1000696, 2009. (4) R. W. S. Weber and M. Hahn. J. Plant Dis. Prot. 118:17, 2011.

First Report of Pilidium concavum Causing Tan-brown Rot on Strawberry Nursery Stock in South Carolina.

Pilidium concavum (Desm.) Höhn. [synanamorph: Hainesia lythri (Desm.) Höhn.] is an opportunistic pathogen that causes leaf spots and stem necrosis in a wide range of hosts, including strawberry (Fragaria ananassa) (1,2). In October 2013, 24 strawberry plug plants (cv. Chandler) with brown to dark brown necrotic lesions on stolons were obtained from a nursery in Easley, SC. The lesions were oval shaped and varied in length from 2 to 8 mm. The tips of stolons with larger spots had died. To isolate the causal agent, 3 to 5 cm of necrotic stolon tissue was surface disinfected for 1 min with 10% bleach, rinsed with sterile distilled water, air dried, and placed on potato dextrose agar (PDA). After 7 days of incubation at 22°C, pink-orange masses of spores emerged. Single spore colonies on PDA produced a gray to brown colony with whitish aerial mycelium. Numerous discoid to hemisphaerical conidiomata (0.3 to 2.2 mm in diameter) developed with a dark base and exuded a pink, slimy mass that contained many conidia. Conidiophores (10.2 to 47.8 × 0.8 to 2.0 µm) were hyaline, unicellular, cylindrical, and filiform. Conidia (3.0 to 8.5 × 1.0 to 2.9 µm) were aseptate, fusiform, hyaline, and canoe-shaped to allantoid. On the basis of morphology, the pathogen was identified as P. concavum (3). The internal transcribed spacer region ITS1-5.8S-ITS2 was amplified by PCR and sequenced with primers ITS1 and ITS4 (4). The sequence was submitted to GenBank (Accession No. KF911079) and showed 100% homology with sequences of P. concavum. Pathogenicity was examined on strawberry fruit and leaves. Our previous efforts to achieve infection without wounding failed, which is consistent with experiences of other scientists (not cited). Thus, 24 strawberry fruit were wounded (1 cm deep) with a needle once, and submerged for 3 min in a conidial suspension (2 × 106 conidia ml-1). Controls were wounded and submerged in sterile water. After 4 days of incubation at 22°C, characteristic symptoms were observed at the wound site only on inoculated fruit. Detached leaves (about 6 cm in diameter) from 3- to 4-week-old strawberry plants cv. Chandler were surface sterilized and placed right side up in petri dishes (one leaf per dish) containing water agar. Leaves were inoculated at one site with a 50 µl conidial suspension (2 × 106 conidia ml-1) after inflicting a scraping-type injury with a needle to the surface at the point of inoculation. Control leaves received just water. After 7 days of incubation at 22°C, only the inoculated leaves showed symptoms similar to those observed on strawberry stolons. The fungus was re-isolated from symptomatic fruit and leaf lesions and identity was confirmed based on morphological features. The experiments were repeated. To our knowledge, this is the first report of P. concavum causing tan-brown rot on strawberry tissue in South Carolina. Prior to this study, the pathogen has been described from different hosts and countries including Belgium, Brazil, China, France, Iran, Poland, and the United States. Contamination of strawberry nursery stock by P. concavum could become a plant health management issue in the United States, especially if the pathogen is transferred to strawberry production areas. Further information on in-field occurrence of P. concacum is needed. References: (1) J. Debode et al. Plant Dis. 95:1029, 2011. (2) W. L. Gen et al. Plant Dis. 96:1377, 2012. (3) A. Y. Rossman et al. Mycol. Prog. 3:275, 2004. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.

Influence of the Dzyaloshinskii-Moriya interaction on the spin-wave spectra of thin films.

We have developed a theory that describes the spin-wave spectra of ferromagnetic films with Dzyaloshinskii-Moriya interactions. In agreement with recent experiments (Zakeri et al 2010 Phys. Rev. Lett. 104 137203), we demonstrate that the spin-wave dispersion relation is asymmetric with respect to wave vector inversion for a variety of ferromagnetic films with Dzyaloshinskii-Moriya interactions and different crystallographic classes. It is also predicted that, for non-zero wave vectors, the resonance frequency and resonance field can increase or decrease depending on the spin-wave vector orientation. We provide explicit formulas for the spin-wave dispersion relation and its asymmetry, as well as for the dynamic susceptibility for a film under microwave excitation, that can be used to understand ferromagnetic resonance as well as Brillouin light scattering experiments in these classes of magnetic thin films.

First Report of Fludioxonil Resistance in Botrytis cinerea from a Strawberry Field in Virginia.

Gray mold caused by Botrytis cinerea Pers.:Fr. is one of the most economically important diseases of cultivated strawberry (Fragaria × ananassa) worldwide. Control of gray mold mainly depends on fungicides, including the phenylpyrrole fludioxonil, which is currently marketed in combination with cyprodinil as Switch 62.5WG (Syngenta Crop Protection, Research Triangle Park, Raleigh, NC). In 2012, 790 strains of B. cinerea were collected from 76 strawberry fields in eight states, including Arkansas, Florida, Georgia, Kansas, Maryland, North Carolina, South Carolina, and Virginia. Strains were collected from sporulating flowers and fruit and sensitivity to fludioxonil was determined using a conidial germination assay as previously described (2). Only one isolate from a farm located in Westmoreland County, Virginia, grew on medium amended with the discriminatory dose of 0.1 µg/ml fludioxonil and was therefore considered low resistant. The isolate did not grow on 10 µg/ml. All other 789 isolates did not grow at either of the two doses. This assay was repeated twice with a single-spore culture of the same strain. In both cases, residual growth was observed on the fludioxonil-amended medium of 0.1 µg/ml. The single spore isolate was confirmed to be B. cinerea Pers. using cultural and molecular tools as described previously (1). To assess resistance in vivo, commercially grown ripe strawberry fruit were rinsed with sterile water, dried, placed into plastic boxes (eight strawberries per box for each of the three replicates per treatment), and sprayed 4 h prior to inoculation with either water or 2.5 ml/liter of fludioxonil (Scholar SC, Syngenta) to runoff using a hand mister. This dose reflects the rate recommended for gray mold control according to the Scholar label. Each fruit was stabbed at three equidistant points, each about 1 cm apart and 1 cm deep using a syringe tip. Wounds were injected with a 30-µl droplet of conidia suspension (106 spores/ml) of either 5 sensitive or the resistant isolate. Control fruit were inoculated with water. After inoculation, the fruit were kept at 22°C for 4 days. In two independent experiments, sensitive and low resistant isolates were indistinguishable in pathogenicity on detached, unsprayed fruit. The low resistant isolate developed gray mold disease on all treated and untreated fruit (100% disease incidence) as determined by the absence or presence of gray mold symptoms. The sensitive isolates only developed disease on untreated fruit. The EC50 values, determined in microtiter assays with concentrations of 0.01, 0.03, 0.1, 0.3, 1, 3, and 10 µg/ml fludioxonil, were 0.01 µg/ml for the sensitive isolates and 0.26 µg/ml for the resistant isolate. To our knowledge, this is the first report of fludioxonil resistance in B. cinerea from strawberry in North America. Our monitoring results indicate that resistance is emerging 10 years after the introduction of fludioxonil and stress the importance of chemical rotation for gray mold control. References: (1) X. P. Li et al. Plant Dis. 96:1634, 2012. (2) R. W. S. Weber and M. Hahn. J. Plant Dis. Prot. 118:17, 2011.

First Report of Fusarium Wilt of Strawberry Caused by Fusarium oxysporum in South Carolina.

During October 2011, wilted and dead strawberry (Fragaria × ananassa cv. Albion) plants from two commercial fields in South Carolina were sent to the Clemson University Plant Problem Clinic in Pendleton, SC. Symptoms consisted of wilting and chlorosis of foliage, scorch and dieback of older leaves, and stunting of plants. Internal vascular and cortical tissues of plant crowns showed a distinct reddish brown discoloration. To isolate the causal agent, necrotic crown tissue selected from two symptomatic plants from one location and four symptomatic plants from the other were placed on acidified potato dextrose agar (APDA) and on quarter strength acidified PDA (QPDA). Colonies with light purple mycelia and beige or orange reverse colony colors developed on APDA after 5 days of incubation at 25°C. Colonies on QPDA were light purple. Morphology, growth, and development of macroconidia and microconida were consistent with descriptions of Fusarium oxysporum Schlechtend emend. Snyder & Hansen (3). Genomic DNA from 3 isolates (11-1246A, 11-1247A, and 11-1247B) was extracted and purified according to Chi et al. (1). The internal transcribed spacer region comprising ITS1, ITS2, and 5.8S rRNA was amplified by primers ITS1 and ITS4 (4). The sequence comparison revealed a 100% match with F. oxysporum sequences in GenBank. To confirm the pathogenicity of the fungus, roots of 15 strawberry plants (cv. Albion) were cut and then five plants were soaked for 10 min in either 500 ml of conidial suspension (104 conidia/ml) of one of the two isolates or in sterile distilled water. All were then potted in 15-cm pots with artificial peat-based soil mix and maintained at 25°C in the greenhouse. After 6 weeks, all plants inoculated with isolates 1247A and B were stunted and developed wilt symptoms similar to those observed in the field, while the control plants remained healthy. Support roots on all affected plants were soft and flaccid and new feeder roots had brown lesions. Crowns of three plants inoculated with isolate 1247A and four plants inoculated with 1247B showed vascular discoloration. To reisolate, crowns were plated as above and roots were surface sterilized in 10% bleach for 1 min and rinsed in sterile distilled water prior to plating on QPDA. F. oxysporum was isolated at frequencies of 70 and 100% from crowns and 100% from roots of all inoculated plants. To our knowledge, this is the first report of the occurrence of Fusarium wilt caused by F. oxysporum on strawberry plants in South Carolina. The presence of Fusarium wilt in South Carolina should alert growers, county agents, and specialists to properly identify Fusarium wilt symptoms, which may be confused with Anthracnose or Phytophthora crown rot of strawberry. The disease has been reported previously in other countries including the United States (2). References: (1) M. H. Chi et al. Plant Pathol. J. 25:108, 2009. (2) S. T. Koike et al. Plant Dis. 93:1077, 2009. (3) W. C. Snyder and H. N. Hansen. Am. J. Bot. 27:64, 1940. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Application. Academic Press, NY, 1993.

First Report of Gray Mold of Strawberry Caused by Botrytis caroliniana in North Carolina.

Gray mold caused by Botrytis spp. is one of the most economically important diseases of cultivated strawberry (Fragaria × ananassa) worldwide. In June 2011, strawberry fruit that was symptomatic of gray mold disease was collected from High Point county in North Carolina. Fruit had brown lesions that enlarged quickly and were covered with green-gray masses of spores followed by a soft rot. To isolate the causal agent, conidia were scraped off the fruit, suspended in 1% Tween 20, spread on water agar amended with 0.1% lactic acid, and emerging colonies were then transferred onto potato dextrose agar (PDA) medium. All but one single-spore colony (designated HP33) were at first colorless and later became gray to brown when the conidiphores and conidia developed on PDA. Isolate HP33 was white to pale gray with short, tufted aerial mycelium, black sclerotia in concentric rings, and did not produce conidia on PDA. Conidia were subhyaline to light brown, smooth, ellipsoid, ovoid or obovoid, and were on average 11.7 × 8.6 µm. The conidiophores were erect, septate, and brown to subhyaline from the base to apex, with swollen basal cell and multiple inflated conidiogenous cells. These morphological features were consistent with Botrytis caroliniana X. P. Li & G. Schnabel sp. nov., a new species isolated recently from blackberry fruit in South Carolina (2). All other single-spore isolates were confirmed to be B. cinerea as described previously (1). To confirm the identity of isolate HP33 to the species level, the necrosis and ethylene-inducing protein 1 (NEP1) was PCR amplified and sequenced by primer pairs NEP1for/NEP1rev as described previously (3). The nucleotide sequence matched the ones published for B. caroliniana (GenBank Accession Nos. JF811593, JF811594, and JF811595). Pathogenicity tests were conducted by inoculating 10 surface-sterilized strawberry fruit with single agar plugs (6 mm in diameter) containing actively growing mycelium; 10 control fruit received agar plugs without mycelium. The inoculated fruit were incubated for 3 days at room temperature in airtight plastic bags and after that developed typical gray mold symptoms. Koch's postulates were fulfilled by the reisolation of B. caroliniana from symptomatic fruit. Control fruit remained healthy. To our knowledge, this is the first report of B. caroliniana on strawberry. It is uncertain whether the new species requires management strategies different from those that control gray mold caused by B. cinerea. References: (1) D. Fernández-Ortuño et al. Plant Dis. 95:1482, 2011. (2) X. P. Li et al. Mycologia 2012, doi:10.3852/11-218. (3) M. Staats et al. Fungal Genet. Biol. 44:52, 2007.

First Report of Thiophanate-Methyl Resistance in Botrytis cinerea on Strawberry from South Carolina.

Botrytis cinerea Pers.:Fr. is the causal agent of gray mold disease and one of the most important plant-pathogenic fungi affecting strawberry (Fragaria× ananassa). Control of gray mold mainly depends on fungicides, including the methyl benzimidazole carbamate (MBC) thiophanate-methyl. In 2011, strawberries with gray mold symptoms were collected from commercial fields near Chesnee, Florence, Lexington, McBee, Monetta, and North Augusta, all in South Carolina. MBC fungicides were used in most of these fields for gray mold control during the last 3 years. A total of 124 single spore B. cinerea isolates were obtained, each from a different fruit. Resistance to thiophanate-methyl (Topsin M 70WP, Cerexagri-Nisso LLC, King of Prussia, PA) was determined using a conidial germination assay as described previously (1). The majority of isolates (81.4%) were resistant; the rest were sensitive. Resistant isolates were found in all locations with some populations (Chesnee, McBee, and Lexington) revealing no sensitive isolates. Genomic DNA from 35 resistant isolates (representing all locations) and 10 sensitive isolates (from Chesnee, Monetta, and North Augusta, SC) was extracted, and the molecular basis of MBC fungicide resistance was determined as described previously (2). All MBC-resistant isolates possessed the E198A mutation known to confer high levels of MBC fungicide resistance in many fungi, including B. cinerea (2,3). Disease was assessed using a detached strawberry fruit assay. Commercially grown strawberry fruit (24 in total for each isolate and fungicide treatment) were rinsed with water, dried, and sprayed 4 h prior to inoculation with either water or 2.4 g/liter of Topsin M to runoff using a hand mister. Fruit was stab-wounded with a sterile syringe and inoculated with a 30-µl droplet of a conidial suspension (106 spores/ml) of either a sensitive or resistant isolate. After inoculation, the fruit were kept at 22°C for 4 days. The sensitive isolate developed gray mold disease in untreated but not Topsin M-treated fruit. The resistant isolate developed gray mold disease of equal severity in both, the control and fungicide-treated fruit. This experiment was repeated once. The results of the study show that resistance to MBC fungicides is common and widespread in B. cinerea from strawberry in South Carolina. Prior to this study, resistance to MBCs has only been reported in B. cinerea from ornamental crops grown in greenhouses in South Carolina (4). References: (1) J. E. Luck and M. R. Gillings. Mycol. Res. 99:1483, 1995. (2) R. W. S. Weber and M. Hahn. J. Plant Dis. Prot. 118:17, 2011. (3) O. Yarden and T. Katan. Phytopathology 83:1478, 1993. (4) L. F. Yourman and S. Jeffers. Plant Dis. 83:569, 1999.

First Report of Gray Mold of Strawberry Caused by Botrytis cinerea in South Carolina.

Gray mold caused by Botrytis spp. is one of the most economically important diseases of cultivated strawberry (Fragaria × ananassa) worldwide. From April to June 2011, strawberries with symptoms resembling gray mold disease were collected from different locations (Chesnee, Florence, Lexington, McBee, Monetta, and North Augusta) in South Carolina. Fruit infections began as small, firm, light brown lesions that enlarged quickly, becoming covered with a gray, fuzzy mass of spores followed by a soft rot. To isolate the causal agent, spores from symptomatic fruit were suspended in 1% Tween 20, streaked onto the surface of potato dextrose agar plates, and incubated at 22°C. Fungal colonies from single spores were at first colorless and later became gray to brown when the conidiphores and conidia developed. Conidia were identified by their morphological characteristics: an average size of 14 × 9 µm, ellipsoid to rounded without internal structure, and with a scar on the point of union to the conidiophore (1). Sclerotia produced in culture were hard, dark, irregular shaped, and formed after 2 weeks. The pathogen was identified as Botrytis cinerea Pers.: on the basis of morphology and confirmed by a restriction digest with ApoI of the 413-kb PCR amplification product obtained with BA2f/BA1r primers (2). Koch's postulates were conducted by inoculating 10 surface-sterilized strawberries with a conidial suspension (105 spores/ml) of a randomly chosen B. cinerea isolate previously characterized; 10 control fruit received sterile water without conidia. The inoculated fruit were incubated for 3 days at room temperature in air-tight plastic bags. Inoculated fruit developed typical gray mold symptoms with gray sporulating lesions. The developing spores on inoculated fruit were confirmed to be B. cinerea. All control fruit remained healthy. For many Botrytis spp., the internal transcribed spacer region does not reveal nucleotide variations and thus is useless for species identification. We used additional, more appropriate genetic markers for molecular-based species identification and verified that strawberries in South Carolina are affected by gray mold disease caused by B. cinerea. To our knowledge, this is the first scientific report of B. cinerea causing gray mold of strawberry in South Carolina. References: (1) W. R. Jarvis. Botryotinia and Botrytis Species: Taxonomy, Physiology and Pathogenicity. A Guide to the Literature. Monograph no. 15. Canada Department of Agriculture, Research Branch, Ottawa, 1977. (2) K. Nielsen et al. Plant Dis. 86:682, 2002.

Organ donors with exceptional medical conditions also count!

All organ donors, even those who have died under exceptional conditions, can provide at least one valid organ for transplantation. It is thus necessary to evaluate the outcomes of donors with unusual diseases. We reviewed 909 organ donors at six hospitals over the last 15 years. Of these, 29 (3.19%) were considered to be exceptional either because of prior disease, the circumstance of death, or complications arising during admission. Among the 53 organs transplanted from all these donors (except two), the mean number of valid organs per donor was 1.88 rather than 2.36 for standard donors. One patient who received a liver transplant died due to the same infection as that diagnosed in the donor. The remaining recipients experienced no primary graft failure or transmission of problems present in the donor.

First Report of Powdery Mildew Elicited by Podosphaera fusca (Synonym Podosphaera xanthii) on Euryops pectinatus in Spain.

Euryops pectinatus Cass. is an evergreen shrub that is planted extensively in Spain for landscape use. In 2007, powdery mildew outbreaks were observed on E. pectinatus in several nurseries located in the Axarquia area (Malaga, southern Spain). Fungal growth appeared as typical, white, powdery mildew colonies that were restricted to upper leaf surfaces. Initially, individual colonies were small and nearly circular, but later enlarged and coalesced to cover the whole leaf surface. With progress of the disease, all green parts (leaves, stems, and petioles) were covered with a white mycelium. Newly developed leaves especially became rapidly infected. Diseased leaves ultimately dried up and senesced, making nursery plants aesthetically unattractive and unsaleable. Conidiophores were erect, had crenate edge lines, cylindrical foot cells that measured 37.5 to 45.0 × 10.0 to 12.5 µm, and were followed by one to three shorter cells. Conidia were hyaline, ellipsoid to ovoid, borne in chains, and measured 27.5 to 35.0 × 12.5 to 17.5 µm. Conidial length-to-width ratios ranged from 1.6 to 2.4. Conidia possessed conspicuous fibrosin bodies and from their sides produced short germ tubes. No chasmothecia were found. The nuclear rDNA internal transcribed spacer (ITS) regions were amplified by PCR and sequenced (GenBank Accession No. EU424056). On the basis of morphological characteristics of the imperfect state and ITS sequence data, this powdery mildew was identified as Podosphaera fusca (Fr.) U. Braun & N. Shishkoff (1), this isolate belonging to ITS haplotype 15 (group III) (3); this group is considered a separate species, P. xanthii (Castagne) U. Braun & N. Shishkoff by some authors (2). Pathogenicity was confirmed by gently pressing diseased leaves onto leaves of healthy E. pectinatus plants. Plants were incubated in a growth chamber at 25°C, and after 14 days, powdery mildew colonies developed. A similar disease of E. pectinatus was observed in 1999 in California (4). P. fusca parasitizes a large number of asteraceous species including field marigold (Calendula arvensis) and fleabane (Erigeron sp.) weeds, as previously reported in the same area, and ornamentals such as Calendula officinalis, Chrysanthemum spp., and Gerbera spp., which are also grown in the same nurseries and frequently attacked by powdery mildew. References: (1) U. Braun and S. Takamatsu. Schlechtendalia 4:1, 2000. (2) U. Braun et al. Schlechtendalia 7:45, 2001. (3) T. Hirata et al. Can. J. Bot. 78:1521, 2000. (4) G. S. Saenz et al. Plant Dis. 84:1048, 2000.