Factors affecting the fitness of an entomopathogenic nematode (Heterorhabditis bacteriophora SUP strain) for use in biocontrol in a horticultural area of Argentina

Nematology ◽  
2021 ◽  
pp. 1-11
Author(s):  
Daiana P. Eliceche ◽  
Matias N. Rosales ◽  
María F. Achinelly
Keyword(s):  
Environmental Conditions ◽  
Storage Temperature ◽  
Entomopathogenic Nematode ◽  
Heterorhabditis Bacteriophora ◽  
Inoculum Density ◽  
Optimum Conditions ◽  
Emergence Time ◽  
Factors Affecting ◽  
Storage Density ◽  
Offspring Production

Summary The optimum conditions for storage, infectivity and multiplication of the nematode Heterorhabditis bacteriophora SUP strain, isolated from horticultural soils in Argentina, were determined for later use in biocontrol. This strain was able to kill Tenebrio molitor larvae (over 90%) at 16 and 25°C, after 7 and 4 days, respectively, with mortality being significantly higher at 25°C. No infectivity was reported at 4 and 11°C. Higher concentrations (over 150 infective juveniles (IJ) insect−1) produced higher percentages of mortality. However, increasing inoculum density reduced offspring production and increased emergence time. Storage density between 2500 and 7500 IJ ml−1 had no effect on survival of IJ. Survival of IJ maintained at 4 and 16°C was around 80% after 4 weeks storage and 30% after 32 weeks. However, at 25°C, a 60% IJ survival was observed at 4 weeks, decreasing to around 10% after 16 weeks and with no survival at 24 weeks. An overall significant decrease in virulence was observed after 90 and 120 days of storage but this was more pronounced at a storage temperature of 4°C than at 16 and 25°C. IJ stored at 4°C had reduced virulence after 90 and 120 days, but not after 60 days. This study provides useful information about some fundamental environmental conditions influencing important nematode traits of the species H. bacteriophora.

Effects of tannin-rich host plants on the infection and establishment of the entomopathogenic nematode Heterorhabditis bacteriophora

2015 ◽  
Vol 128 ◽  
pp. 31-36 ◽  
Author(s):  
Itamar Glazer ◽  
Liora Salame ◽  
Levana Dvash ◽  
Hussein Muklada ◽  
Hassan Azaizeh ◽  
...  
Keyword(s):  
Host Plants ◽  
Entomopathogenic Nematode ◽  
Heterorhabditis Bacteriophora

INHERITANCE OF RESISTANCE TO NET BLOTCH IN BARLEY. I. FACTORS AFFECTING THE PENETRANCE AND EXPRESSIVITY OF GENE(S) CONDITIONING HOST RESISTANCE

1969 ◽  
Vol 11 (3) ◽  
pp. 587-591 ◽  
Author(s):  
T. N. Khan
Keyword(s):  
Environmental Conditions ◽  
Net Blotch ◽  
Host Reaction ◽  
Susceptible Parent ◽  
Breeding Programs ◽  
Genetic Studies ◽  
Factors Affecting ◽  
Drechslera Teres ◽  
Resistant Varieties ◽  
High Level

Variability in the host-reaction of barley to infection by Drechslera teres was examined in the parents and progeny of selected crosses under different environmental conditions of testing.The Ethiopian variety C.I. 5791 exhibits a consistently high level of resistance under a range of environmental conditions, which is in contrast to the Manchurian variety C.I. 2330. The sensitivity of the genes for resistance possessed by these varieties to environmental modifications is considered to depend upon their respective genetic backgrounds. Furthermore, variability of host reaction in the progeny of these resistant varieties was shown to be influenced by the genetic background of the susceptible parent used.The implications of these findings in the conduct and interpretation of genetic studies and in backcross breeding programs is discussed.

scholarly journals Nutritional Changes and Early Warning of Moldy Rice under Different Relative Humidity and Storage Temperature

Foods ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 185
Author(s):  
Jing Du ◽  
Yingxue Lin ◽  
Yuan Gao ◽  
Yanyan Tian ◽  
Jixiang Zhang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Relative Humidity ◽  
Early Warning ◽  
Storage Temperature ◽  
Starch Content ◽  
Protein Secondary Structure ◽  
Principal Component ◽  
Storage Conditions ◽  
Factors Affecting ◽  
Total Starch

Processed unhusked rice is prone to mildew during storage. In this study, the storage conditions were simulated at temperatures of 20, 30, and 35 °C and a relative humidity of 40%, 60% and 80%, respectively. The water, fatty acid, and total starch content and the peak viscosity, mold colony number, protein secondary structure, and spatial structure of rice were monitored in order to propose the critical point of mildew during storage. In the process of rice from lively to moldy, the water content, fatty acid contents and the peak viscosity were increased. The total starch content decreased and then showed a slow increasing trend, while the microstructure of the powder particles changed from smooth and complete to loosen and hollow. With the increase in storage time, the vibration of the amide Ⅰ band of the rice samples decreased slightly, indicating that the total contents of β-fold, β-turn, α-helix, and random curl of the rice protein also changed. PCA (Principal Component Analysis) analysis showed that rice mildew index was closely related to temperature and humidity during storage. In our investigation, the best and most suitable temperature and relative humidity for rice storge is 20 °C and 40%, respectively. These results suggested that temperature and environmental humidity are vital factors affecting the physicochemical properties and nutrient changes, which provides a theoretical basis for the early warning of rice mildew during storage.

Preparation of Nanoscale CuO Powders

2010 ◽  
Vol 113-116 ◽  
pp. 1770-1773 ◽  
Author(s):  
Xi Hua Zhao ◽  
Min Xu
Keyword(s):  
Raw Materials ◽  
Precipitation Method ◽  
Optimum Conditions ◽  
Muffle Furnace ◽  
Factors Affecting ◽  
Direct Precipitation ◽  
Average Grain Size ◽  
Scherrer Formula ◽  
Average Size ◽  
Direct Precipitation Method

Cu(OH)2 precursor was synthesized by direct precipitation method and CuSO4 and NaOH were used as raw materials. Then, Cu(OH)2 precursor was calcined in muffle furnace at 400°C for 2h in order that CuO particle was obtained. Through the analysis of the factors affecting the CuO, the paper determined the optimum conditions for the synthesis of nano-CuO with the direct-precipitation method. Then the paper analyzed phase composition and crystal structure of samples using XRD and calculated the average grain size of samples by Scherrer formula, and observed and analyzed by TEM to characterize the morphology and particle size of samples. The optimum precipitation conditions are as follows: when the precipitation agent is 3.2:1, reaction time 40min and precipitant concentration 0.6mol.L-1. The average size of CuO particle prepared under the conditions is 18nm and the yield is 96%.

Modeling the Effect of Water Activity, pH, and Temperature on the Probability of Enterotoxin A Production by Staphylococcus aureus

2016 ◽  
Vol 79 (1) ◽  
pp. 148-152 ◽  
Author(s):  
TIAN DING ◽  
YAN-YAN YU ◽  
CHENG-AN HWANG ◽  
QING-LI DONG ◽  
SHI-GUO CHEN ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Water Activity ◽  
Storage Temperature ◽  
Probability Model ◽  
Toxin Production ◽  
Factors Affecting ◽  
Model Predictions ◽  
And Storage ◽  
Storage Temperatures ◽  
Good Agreement

ABSTRACT The objectives of this study were to develop a probability model of Staphylococcus aureus enterotoxin A (SEA) production as affected by water activity (aw), pH, and temperature in broth and assess its applicability for milk. The probability of SEA production was assessed in tryptic soy broth using 24 combinations of aw (0.86 to 0.99), pH (5.0 to 7.0), and storage temperature (10 to 30°C). The observed probabilities were fitted with a logistic regression to develop a probability model. The model had a concordant value of 97.5% and concordant index of 0.98, indicating that the model satisfactorily describes the probability of SEA production. The model showed that aw, pH, and temperature were significant factors affecting the probability of toxin production. The model predictions were in good agreement with the observed values obtained from milk. The model may help manufacturers in selecting product pH and aw and storage temperatures to prevent SEA production.

Optimization of Grease Dispensing Unit Using Fuzzy Logic Algorithm

2016 ◽  
Vol 852 ◽  
pp. 859-866
Author(s):  
Milind Havanur ◽  
A. Arockia Selvakumar
Keyword(s):  
Artificial Intelligence ◽  
Fuzzy Logic ◽  
Process Parameters ◽  
Environmental Conditions ◽  
Fuzzy Logic System ◽  
Automated System ◽  
Factors Affecting ◽  
Fuzzy Logic Algorithm ◽  
Optimal Quantity ◽  
Logic System

Grease dispensing unit is a well invented tool for greasing application which preserves health of operator working and ensures optimal quantity. There are fluctuations in the process of grease dispensing which is dependent on process parameters which make the grease dispensing. The properties of grease vary which depend on environmental conditions. In this paper the modeling of grease dispensing process using artificial intelligence method, fuzzy logic to optimize the flow of grease by considering the factors affecting the flow of grease and usage of automated system for grease dispensing process. The work involves usage of LabVIEW for modeling of fuzzy logic network Based on the results obtained a detailed discussions were made on how to implement the fuzzy logic system for optimization of flow of grease for the existing process. Further, the work also details the future scope of work that can be carried out.

scholarly journals Factors Affecting Egg Deposition of the European Mantis

2020 ◽  
Vol 68 (2) ◽  
pp. 45-49
Author(s):  
Joanna Kajzer-Bonk
Keyword(s):  
Habitat Selection ◽  
Environmental Conditions ◽  
Plant Cover ◽  
Egg Laying ◽  
Natural Conditions ◽  
Factors Affecting ◽  
Egg Deposition ◽  
Predatory Insect ◽  
Egg Case ◽  
Potential Tool

In this paper, we studied the egg-case (oothecae) deposition of the European mantis, Mantis religiosa (Linnaeus 1758), a predatory insect. We hypothesized that the height of ootheca deposition on a plant reflects the insolation requirements of the species, and would increase when plant cover is denser. We found that the taller the plants nearby, the greater the height of egg deposition. Oothecae were also oviposited higher in denser vegetation. The observed behavior may ensure the proper insolation of developing offspring. To our knowledge, this is the first description of an egg laying strategy of this species under natural conditions. This finding allows for a better understanding of habitat selection and the overall ecology of the European mantis. It may be also useful in identifying the mechanisms of the range extension of this species and is a potential tool to effectively conserve xerothermic ootheca-laying animals. Further studies are required to assess the flexibility of this behavior under different environmental conditions.

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