Colletotrichum species causing anthracnose on avocado fruit in Mexico: Current status     

Dionicio Fuentes-Aragón  Hilda V. Silva-Rojas  Vladimiro Guarnaccia  José A. Mora-Aguilera  Sergio Aranda-Ocampo  Néstor Bautista-Martínez  Daniel Téliz-Ortíz 《Plant pathology》2020,69(8):1513-1528

Colletotrichum species cause anthracnose disease in tropical and subtropical fruit crops worldwide. Mexico is the main producer and exporter of avocado (Persea americana) globally and has yearly outbreaks of anthracnose on this crop. However, which specific Colletotrichum spp. cause these outbreaks in avocado-producing regions remain uncertain; thus, the objective of the present study was to identify the species responsible. A survey performed in six production regions of Mexico yielded 232 isolates, from which a subset of 104 strains was selected based on morphological characteristics and origin. This subset was sequenced and haplotypes were analysed in the gapdh partial gene. Finally, 31 strains were identified through multilocus phylogenetic analyses using the sequences of the internal transcribed spacer region and six loci. This study revealed the presence of two species previously reported in Mexico (C. karsti and C. godetiae), three novel records in Mexico (C. siamense, C. fioriniae, and C. cigarro), four novel records on avocado (C. chrysophilum, C. jiangxiense, C. tropicale, and C. nymphaeae), and two novel lineages (Colletotrichum sp. 1 and Colletotrichum sp. 2). C. siamense was the most prevalent, while the species reported for the first time on avocado, including the novel lineages, were the least prevalent. C. karsti was the most widespread (four regions), followed by C. siamense, C. jiangxiense, and C. chrysophilum (three regions). Pathogenicity tests showed that all species caused anthracnose on avocado fruit. These findings will be useful for improving the management of avocado anthracnose outbreaks in Mexico.  相似文献   

Characterising landscape connectivity for conservation planning using a dispersal guild approach     

Alex Mark Lechner  Daniel Sprod  Oberon Carter  Edward C. Lefroy 《Landscape Ecology》2017,32(1):99-113

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Time-delayed influence of urban landscape change on the susceptibility of koalas to chlamydiosis     

Clive McAlpine  Grant Brearley  Jonathan Rhodes  Adrian Bradley  Greg Baxter  Leonie Seabrook  Daniel Lunney  Yan Liu  Manuelle Cottin  Andrew G. Smith  Peter Timms 《Landscape Ecology》2017,32(3):663-679

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Scale-specific habitat relationships influence patch occupancy: defining neighborhoods to optimize the effectiveness of landscape-scale grassland bird conservation     

Michael R. Guttery  Christine A. Ribic  David W. Sample  Andy Paulios  Chris Trosen  John Dadisman  Daniel Schneider  Josephine A. Horton 《Landscape Ecology》2017,32(3):515-529

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Landscape metrics as a framework to measure the effect of landscape structure on the spread of invasive insect species     

Audrey Lustig  Daniel B. Stouffer  Crile Doscher  Susan P. Worner 《Landscape Ecology》2017,32(12):2311-2325

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UROCYSTOLITH DETECTION: COMPARISON OF SURVEY, CONTRAST RADIOGRAPHIC AND ULTRASONOGRAPHIC TECHNIQUES IN AN IN VITRO BLADDER PHANTOM     

Ralph C.  Weichselbaum  DVM  Daniel A.  Feeney  DVM  MS  Carl R.  Jessen  DVM  PhD  Carl A.  Osborne  DVM  PhD  V. Dreytser  MS  J. Holte  PhD 《Veterinary radiology & ultrasound》1999,40(4):386-400

Urocystoliths of 9 mineral types from 437 canine patients submitted to the University of Minnesota Urolith Bank were imaged in a urinary bladder phantom. Imaging techniques simulated were survey radiography, pneumocystography, double contrast cystography (two iodine concentrations) and real-time ultrasonography (3.5 MHz, 5.0 MHz, 7.5 MHz). Imaging techniques were compared for accuracy of urocystolith detection, accuracy of urocystolith enumeration, and tendencies for over or undercounting. Across urocystolith mineral types, the false negative rates (no urocystoliths detected in a given case) for survey radiographs range from 2 to 27%. Pneumocystographic techniques are one-half as likely to yield false negative results as are survey radiographic techniques. Underestimates of urocystolith numbers and false negatives are likely using 80 mg iodine/ml double contrast cystography because calcium-based urocystoliths are isopaque in this contrast medium dilution. The 200 mg iodine/ml double contrast cystographic techniques are unlikely to yield false negative diagnoses even for very small (< or = 1.0 mm) urocystoliths and is comparable to pneumocystography for detection and slightly better for enumeration. The likelihood of an ultrasonographic false negative for urocystoliths decreases with increasing MHz. Under optimal conditions using a 7.5 MHz mechanical sector transducer, the false negative rates were comparable to double contrast cystography, but rates increased notably with lower MHz transducers.  相似文献   

Physiological Responses of Men and Women to Barley and Oat Extracts (Nu‐trimX). II. Comparison of Glucose and Insulin Responses     

Judith Hallfrisch  Daniel J. Scholfield  Kay M. Behall 《Cereal Chemistry》2003,80(1):80-83

This study was designed to compare the glucose, insulin, and glucagon responses to consumption of high‐soluble β‐glucan compounds from oats and barley. After an initial medical evaluation that included blood and urine testing, 11 men and 11 women, nondiabetics, 35–57 years, were selected. Subjects consumed a controlled diet for three days. On the third day of five successive periods, subjects consumed 1 g/kg of body weight of carbohydrate as glucose or 0.66 g/kg of body weight pudding (predominantly sucrose) and 0.33 g/kg of body weight as oat bran, barley flour, oat or barley extract (Nu‐trimX) in a Latin square design. Order of treatment was randomly assigned. Glycemic responses were calculated using the trapezoid method. Data were analyzed using mixed procedure analysis of variance program. Glucose responses to oats, barley, and both extracts, and areas under the curve were significantly lower than responses to the glucose solution (P < 0.0001). Insulin responses for the barley extract were lowest and were significantly lower than for glucose solution. Oat and barley extracts retain the beneficial effects of the grains from which they are extracted. High‐soluble fiber barley is more effective than standard oats. Oat and barley carbohydrate‐based fat substitutes can provide a useful addition to menus to control plasma glucose responses.  相似文献   

Haematological and oxidative stress responses in Piaractus mesopotamicus under temperature variations in water     

Daniel Pinto  Lucas Pellegrin  Lilian Fiori Nitz  Sílvio Teixeira da Costa  Jos Maria Monserrat  Luciano Garcia 《Aquaculture Research》2019,50(10):3017-3027

In this study, the influence of temperature variation on the blood and oxidative stress parameters of pacu Piaractus mesopotamicus juveniles was evaluated. Fish were subjected to gradual changes of temperature, over 5 days, by 24°C until reaching to experimental temperatures 18, 21, 24 (control), 27 and 30°C. There were significant differences (p < .05) in glucose and lactate of blood in both the haematological relationships and oxidative stress parameters. Glucose levels increased at 30°C and decreased at 21°C. Lactate levels were highest at 18°C. While the haematocrit was higher at all altered temperatures, haemoglobin levels decreased at 21°C and increased at 30°C, causing alterations in haematimetric indices. In the liver, glutathione‐S‐transferase (GST) activity was reduced at 18°C while antioxidant capacity against peroxyl radicals (ACAP) was highest at 30°C. Thiobarbituric acid reactive substances (TBARS) increased at 18, 21 and 27°C. In the muscle, ACAP decreased at 27 and 30°C and TBARS increased at 30°C. The results indicate that the species shows sensitivity to temperature variations. Accordingly, we conclude that with short‐term temperature variations >3°C, it is possible to induce higher alterations in the observed parameters in pacu juveniles.  相似文献   

Emigration of hatchery‐reared Pallid Sturgeon,Scaphirhynchus albus (Forbes and Richardson), through a Missouri River dam     

Landon L. Pierce  Dane A. Shuman  Daniel A. James  Kirk D. Steffensen  Ryan Wilson  Kyle Winders  Adam McDaniel 《Fisheries Management and Ecology》2019,26(3):295-305

The middle Missouri River (MMR; Fort Randall Dam, SD to Gavins Point Dam, NE‐SD) is stocked with hatchery‐reared pallid sturgeon, Scaphirhynchus albus (Forbes and Richardson), from upper Missouri River broodstock to aid recovery of this federally endangered species. Emigration of these fish through Gavins Point Dam restores genetic connectivity that likely existed pre‐impoundment but could lead to outbreeding depression in the future. Recapture data of hatchery‐reared pallid sturgeon stocked in the MMR were evaluated to improve understanding of pallid sturgeon emigration. From 2004 to 2015, 219 emigrants were caught: 4 stocked at age ≥2 years and 215 stocked at age ≤1 year. Emigration of the 2001‐2007 year classes stocked at age 1 was a consistent phenomenon and appeared higher than emigration of year classes stocked at ages 2–3. Little evidence suggested emigration was associated with an unusually high‐water event in 2011. The annual emigration probability of individuals stocked at age 1 estimated from multi‐state mark–recapture models was 0.05 [95% confidence interval = 0.04–0.06] for fish ages ≥1 year. This study suggests that alterations to stocking practices (e.g. stocking age) may affect emigration rates and, therefore, connectivity among pallid sturgeon populations.  相似文献   

Nutrient uptakes and biochemical composition of Lemna minor in brackish water     

Daniel Nesan  Kethis Selvabala  Derek Chan Juinn Chieh 《Aquaculture Research》2020,51(9):3563-3570

The freshwater plant species Lemna minor suffers significantly in nutrient uptake and biomass accumulation performance when grown in saline effluents, such as those produced in brackish aquaculture operations. To determine the exact impact of salinity to these plant traits, this study measured the nutrient uptakes and biochemical composition of L. minor grown in synthetic aquaculture medium of increasing salinity levels. The overall trend for biomass growth showed that higher salinity levels resulted in lower growth with a mass gain of about 13% in 12.5 ppt medium compared with 96% in the control. However, the NO₃^– uptake appeared to be unaffected by differences in salinity. NH₄⁺ uptake was significantly affected only at salinity concentrations of 10 ppt and 12.5 ppt. The relationship between PO₄^3– uptake and salinity was less clear, as PO₄^3– levels appeared to decrease linearly for all test groups and were shown to be statistically insignificant. At the end of the experiment period, the control medium showed the lowest measured COD levels, 17 mg/L while the 12.5 ppt solution has the highest COD level, 61 mg/L. Protein content showed a decline with increasing salinity of growth medium, while carbohydrate content was shown to be increasing. These preliminary data identify the general relationship between salinity and the measured criteria of L. minor and will subsequently serve as the basis for further remediation studies and the development of salinity mitigation methods.  相似文献