The Effect of Primary Inoculum Level ofPyrenophora tritici-repentison Tan Spot Epidemic Development in Wheat

1989 ◽  
Vol 79 (8) ◽  
pp. 873 ◽  
Author(s):  
E. A. Adee
Keyword(s):  
Tan Spot ◽  
Inoculum Level ◽  
Primary Inoculum ◽  
Epidemic Development

scholarly journals Temporal and Spatial Dynamics of Primary and Secondary Infection by Armillaria ostoyae in a Pinus pinaster Plantation

2004 ◽  
Vol 94 (2) ◽  
pp. 125-131 ◽  
Author(s):  
Brigitte Lung-Escarmant ◽  
Dominique Guyon
Keyword(s):  
Pinus Pinaster ◽  
Secondary Infection ◽  
Spatial Dynamics ◽  
Spatial Relation ◽  
Gompertz Model ◽  
Inoculum Density ◽  
Initial Inoculum ◽  
Primary Inoculum ◽  
Armillaria Ostoyae ◽  
Epidemic Development

Epidemiological investigations were performed in a 3-ha maritime pine (Pinus pinaster) plantation established on a site heavily infested by Armillaria ostoyae. Geostatistics were used to examine the density and the distribution of the initial inoculum. Disease dynamics were monitored for 17 years after planting. On the whole site, the cumulative mortality rate reached 35% over this period, plateauing at 12 years. Disease progress curves differed according to the density of the initial inoculum, although in all the cases, the Gompertz model described the epidemics well. The epidemiological contributions of both primary (initially colonized stumps) and secondary inoculum (newly dead pines) were evaluated by analyzing their spatial relation to annual mortality. Newly dead pines acted as secondary inoculum from year 3 and their role increased with time. When the initial inoculum density was low, the contribution of secondary inoculum to epidemic development increased faster and halted sooner than when the density of primary inoculum was high. Regardless of its density, the primary inoculum acted throughout the dynamic phase of the epidemic. When the inoculum density was low, the probability of mortality during the first 6 years of the epidemic depended on the tree distance from the nearest stumps colonized by Armillaria sp. When the inoculum density was high, the probability of mortality was higher and not related to the distance between trees and colonized stumps.

scholarly journals A wheat chromosome 5AL region confers seedling resistance to both tan spot and Septoria nodorum blotch in two mapping populations

2019 ◽  
Vol 7 (6) ◽  
pp. 809-818 ◽  
Author(s):  
Wenjing Hu ◽  
Xinyao He ◽  
Susanne Dreisigacker ◽  
Carolina P. Sansaloni ◽  
Philomin Juliana ◽  
...  
Keyword(s):  
Wheat Chromosome ◽  
Tan Spot ◽  
Septoria Nodorum ◽  
Seedling Resistance ◽  
Septoria Nodorum Blotch ◽  
Mapping Populations

scholarly journals Evaluation of a Novel Molecular Marker Associated with the Tan Spot Disease Response in Wheat

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 513
Author(s):  
Pao Theen See ◽  
Caroline S. Moffat
Keyword(s):  
Molecular Marker ◽  
Hexaploid Wheat ◽  
Wheat Breeding ◽  
Tan Spot ◽  
Growth Stages ◽  
Disease Score ◽  
Wheat Varieties ◽  
Disease Response ◽  
Spot Disease ◽  
Tan Spot Disease

After nearly 40 years of DNA molecular marker development in plant breeding, the wheat research community has amassed an extensive collection of molecular markers which have been widely and successfully used for selection of agronomic, physiological and disease resistance traits in wheat breeding programs. Tan spot is a major fungal disease of wheat and a significant global economic challenge and is caused by the necrotrophic fungal pathogen Pyrenophora tritici-repentis (Ptr). Here, the potential for using a PCR-based marker (Ta1AS3422) present on the short arm of wheat chromosome 1A, was evaluated for effectiveness in distinguishing tan spot disease susceptibility. The marker was initially screened against 40 commercial Australian hexaploid wheat varieties, and those that amplified the marker had an overall lower disease score (2.8 ± 0.7 for seedlings and 2.4 ± 0.4 for plants at the tillering stage), compared to those lacking the marker which exhibited a higher disease score (3.6 ± 0.8 for both growth stages). The potential of Ta1AS3422 as a marker for the tan spot disease response was further assessed against a panel of 100 commercial Australian hexaploid wheat varieties. A significant association was observed between marker absence/presence and tan spot disease rating (Pearson’s chi-squared test, χ2 (6) = 20.53, p = 0.002), with absence of Ta1AS3422 associated with susceptibility. This simple and cost-effective PCR-based marker may be useful for varietal improvement against tan spot, although further work is required to validate its effectiveness.

scholarly journals Resistance of winter wheat varieties to tan spot in the North Caucasus region of Russia

2020 ◽  
Author(s):  
Oksana Yu. Kremneva ◽  
Nina V. Mironenko ◽  
Galina V. Volkova ◽  
Olga A. Baranova ◽  
Yuri S. Kim ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Tan Spot ◽  
North Caucasus ◽  
Wheat Varieties ◽  
Caucasus Region ◽  
The North ◽  
Winter Wheat Varieties

Nitrogen accumulation in grains, remobilization and post-anthesis uptake under tan spot and leaf rust infections on wheat

2019 ◽  
Vol 235 ◽  
pp. 27-37 ◽  
Author(s):  
Matías Schierenbeck ◽  
María Constanza Fleitas ◽  
Facundo Cortese ◽  
Silvina Inés Golik ◽  
María Rosa Simón
Keyword(s):  
Leaf Rust ◽  
Tan Spot ◽  
Nitrogen Accumulation

Evaluation of Modification of the 3M™ Molecular Detection Assay (MDA) Salmonella Method (2013.09) for the Detection of Salmonella in Selected Foods: Collaborative Study

2014 ◽  
Vol 97 (5) ◽  
pp. 1329-1342 ◽  
Author(s):  
Patrick Bird ◽  
Kiel Fisher ◽  
Megan Boyle ◽  
Travis Huffman ◽  
M Joseph Benzinger ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Molecular Detection ◽  
Collaborative Study ◽  
Ground Beef ◽  
Inoculum Level ◽  
Test Portion ◽  
Low Level ◽  
Dog Food ◽  
Detection Assay ◽  
The U.S

Abstract The 3M™ Molecular Detection Assay (MDA) Salmonella utilizes isothermal amplification of nucleic acid sequences with high specificity, efficiency, rapidity and bioluminescence to detect amplification of Salmonella spp. in food, food-related, and environmental samples after enrichment. A method modification and matrix extension study of the previously approved AOAC Official MethodSM 2013.09 was conducted, and approval of the modification was received on March 20, 2014. Using an unpaired study design in a multilaboratory collaborative study, the 3M MDA Salmonella method was compared to the U.S. Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS) Microbiology Laboratory Guidebook (MLG) 4.05 (2011), Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg, and Catfish Products for raw ground beef and the U.S. Food and Drug Administration (FDA)/Bacteriological Analytical Manual (BAM) Chapter 5, Salmonella reference method for wet dog food following the current AOAC guidelines. A total of 20 laboratories participated. For the 3M MDA Salmonella method, raw ground beef was analyzed using 25 g test portions, and wet dog food was analyzed using 375 g test portions. For the reference methods, 25 g test portions of each matrix were analyzed. Each matrix was artificially contaminated with Salmonella at three inoculation levels: an uninoculated control level (0 CFU/test portion), a low inoculum level (0.2–2 CFU/test portion), and a high inoculum level (2–5 CFU/test portion). In this study, 1512 unpaired replicate samples were analyzed. Statistical analysis was conducted according to the probability of detection (POD). For the low-level raw ground beef test portions, the following dLPOD (difference between the LPODs of the reference and candidate method) values with 95% confidence intervals were obtained: –0.01 (–0.14, +0.12). For the low-level wet dog food test portions, the following dLPOD with 95% confidence intervals were obtained: –0.04 (–0.16, +0.09). No significant differences were observed in the number of positive samples detected by the 3M MDA Salmonella method versus either the USDA/FSIS-MLG or FDA/BAM methods.

SUBMERGED CITRIC ACID FERMENTATION OF SUGAR BEET MOLASSES: INCREASE IN SCALE

1955 ◽  
Vol 1 (5) ◽  
pp. 299-311 ◽  
Author(s):  
R. Steel ◽  
C. P. Lentz ◽  
S. M. Martin
Keyword(s):  
Citric Acid ◽  
Scale Up ◽  
Aeration Rate ◽  
Small Scale ◽  
Acid Fermentation ◽  
Inoculum Level ◽  
Cross Sectional ◽  
Factors Affecting ◽  
Beet Molasses ◽  
Initial Ph

Factors affecting the production of citric acid in the submerged fermentation of ferrocyanide-treated beet molasses by Aspergillus niger were studied in 2.5 and 36 liter fermenters. The small fermenters were used to determine the effects of changes in sterilization technique, phosphate supplement, ferrocyanide treatment, inoculum level, initial pH, fermentation temperature, and aeration rate. The relation between ferrocyanide concentration and inoculum level was also studied. Four different samples of molasses were fermented successfully. An average yield of 8.2% citric acid (64% conversion) was obtained from 51 small-scale fermentations. Comparable yields were obtained in the large fermenters under comparable conditions. Most of the information obtained with the small fermenters was applicable to the larger-scale fermenters, but in the latter the fermentation was significantly more stable. Aeration was the main problem in the scale-up and aeration rates approximately double those calculated on a fermenter cross-sectional area basis were required for comparable results in the large fermenters.

scholarly journals Influence of Different Filling, Cooling, and Storage Conditions on the Growth of Alicyclobacillus acidoterrestris CRA7152 in Orange Juice

2009 ◽  
Vol 75 (23) ◽  
pp. 7409-7416 ◽  
Author(s):  
Ana Cláudia N. F. Spinelli ◽  
Anderson S. Sant'Ana ◽  
Salatir Rodrigues-Junior ◽  
Pilar R. Massaguer
Keyword(s):  
Orange Juice ◽  
Storage Temperature ◽  
Growth Parameters ◽  
Storage Conditions ◽  
Inoculum Level ◽  
Alicyclobacillus Acidoterrestris ◽  
Time Required ◽  
Cold Point ◽  
And Storage ◽  
A Current

ABSTRACT The prevention of spoilage by Alicyclobacillus acidoterrestris is a current challenge for fruit juice and beverage industries worldwide due to the bacterium's acidothermophilic growth capability, heat resistance, and spoilage potential. This study examined the effect of storage temperature on A. acidoterrestris growth in hot-filled orange juice. The evolution of the A. acidoterrestris population was monitored under six different storage conditions after pasteurization (at 92°C for 10 s), maintenance at 85°C for 150 s, and cooling with water spray to 35°C in about 30 min and using two inoculum levels: <101 and 101 spores/ml. Final cooling and storage conditions were as follows: treatment 1, 30°C for the bottle cold point and storage at 35°C; treatment 2, 30°C for 48 h and storage at 35°C; treatment 3, 25°C for the bottle cold point and storage at 35°C; treatment 4, 25°C for 48 h and storage at 35°C; treatment 5, storage at 20°C (control); and treatment 6, filling and storage at 25°C. It was found that only in treatment 5 did the population remain inhibited during the 6 months of orange juice shelf life. By examining treatments 1 to 4, it was observed that A. acidoterrestris predicted growth parameters were significantly influenced (P < 0.05) either by inoculum level or cooling and storage conditions. The time required to reach a 104 CFU/ml population of A. acidoterrestris was considered to be an adequate parameter to indicate orange juice spoilage by A. acidoterrestris. Therefore, hot-filled orange juice should be stored at or below 20°C to avoid spoilage by this microorganism. This procedure can be considered a safe and inexpensive alternative to other treatments proposed earlier.

Botryosphaeriaceae species associated with blueberry dieback and sources of primary inoculum in propagation nurseries in New Zealand

2017 ◽  
Vol 150 (2) ◽  
pp. 363-374 ◽  
Author(s):  
K. M. S. Tennakoon ◽  
Hayley J. Ridgway ◽  
Marlene V. Jaspers ◽  
E. Eirian Jones
Keyword(s):  
New Zealand ◽  
Primary Inoculum ◽  
Botryosphaeriaceae Species
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