Diapause induction and termination in Indian strains of Trichogramma chilonis (Hymenoptera: Trichogrammatidae)

2017 ◽  
Vol 149 (5) ◽  
pp. 607-615 ◽  
Author(s):  
Enakshi Ghosh ◽  
Chandish R. Ballal

AbstractThe role of temperature in diapause induction was studied as a mode of long-term storage of Trichogramma chilonis (Ishii) (Hymenoptera: Trichogrammatidae). Three different strains of this widely used biocontrol agent (T. chilonis Nilgiris strain, T. chilonis Kodaikanal strain, and T. chilonis 15 °C strain) reared on the factitious host Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) were used for this experiment. Except T. chilonis laboratory strain, all the other strains could successfully undergo diapause at their pre-pupal stage. Maximum percentage of healthy pre-pupae were recorded in the three strains by providing a pre-storage temperature of 10 °C for 35 days with eight hours of photophase wherein 75–87% could enter into diapause. Further, at a maintenance temperature of 5 °C with 24 hours of scotophase, diapause could be maintained. Diapause could be terminated after six months of storage with 23–36% of adult emergence. However, there was significant reduction in longevity and parasitism rate of the emerged adults. Considering superior biological parameters, 95 days of storage (including pre-storage duration) could provide around 60% adult emergence. Successful long-term storage of T. chilonis strains through diapause induction can facilitate commercial insectaries in stockpiling this biocontrol agent for large-scale field releases. This is the first study on successful induction and termination of diapause in T. chilonis strains and evaluating their performance attributes.

2016 ◽  
pp. 760-764 ◽  
Author(s):  
Maciej Wojtczak ◽  
Aneta Antczak-Chrobot ◽  
Paulina Miko ◽  
Magdalena Molska ◽  
Ilona Baszczyk ◽  
...  

Due to the prolongation of the period of the sugar campaign, it is necessary to optimize the storage conditions, so that changes in the quality of the raw material could be minimized. The aim of this study was to determine the effect of storage duration and temperature on changes in the composition of sugar beet. The study presents the changes in the content of glucose, fructose, raffinose, lactic and acetic acids, nitrates and nitrites as well as in the content of the total number of mesophilic bacteria, denitrifying bacteria and spores of denitrifying bacteria during storage under various conditions.


2022 ◽  
Vol 31 ◽  
pp. 100770
Author(s):  
Lucas Mallmann Wendt ◽  
Vagner Ludwig ◽  
Fabiane Portella Rossato ◽  
Magno Roberto Pasquetti Berghetti ◽  
Erani Eliseu Schultz ◽  
...  

2016 ◽  
Vol 141 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Yan Wang

Alternatives to ethoxyquin (Etq) are needed for controlling superficial scald of ‘Anjou’ european pears (Pyrus communis) during long-term storage. The current commercial standard storage conditions [Etq + −1 °C + controlled atmosphere (CA) with 1.5 kPa O2] reduced scald occurrence compared with control fruit (−1 °C + CA) during 6–8 months storage. At 1 °C in air, 1-methylcyclopropene (1-MCP) fumigation at 0.15 µL·L−1 at harvest was more efficient on reducing scald than Etq but did not prevent scald during 6–8 months storage. The 1-MCP-treated fruit at 1 °C in air developed their ripening capacity at 20 °C following 6–8 months storage but had deceased shipping ability (softening and yellowing of fruit). Although Etq inhibition of scald was associated with the inhibition of α-farnesene oxidation to conjugated trienols (CTols); 1-MCP reduced α-farnesene synthesis and thereby the availability of substrate to oxidize to CTols. CA storage at 1.5 kPa O2 totally prevented scald and retarded the loss of shipping ability without affecting the ripening capacity of 1-MCP-treated fruit at 1 °C through further decreases in the syntheses of ethylene, α-farnesene and CTols during 6–8 months storage. In addition, 1-MCP prevented a CA-induced disorder, pithy brown core (PBC), in ‘Anjou’ pears possibly through enhancing an oxidative/reductive metabolic balance during extended storage. In conclusion, the combinations of 1 °C + 1-MCP + CA is a potential commercial alternative to Etq for scald control while allowing the 1-MCP-treated ‘Anjou’ pears to recover ripening capacity during the shelf life period after 6–8 months storage.


1988 ◽  
Vol 6 (2) ◽  
pp. 39-41 ◽  
Author(s):  
James A. Robbins ◽  
Mark J. Campidonica ◽  
David W. Burger

Concentrated [4.9 mM (1,000 ppm) and 24.6 mM (5,000 ppm)] IBA solutions in 50% isopropyl alcohol were stored in amber and clear glass bottles at 3 temperatures [22–25°, 6°, O°C (72–77°, 43°, 32°F)]. No significant change in biological activity of the solutions or breakdown of IBA was observed for solutions stored for 4 and 6 months. Solution color changed during storage. Color development was dependant on storage temperature, but not on exposure to light. Chemical names used: IAA = indole-3-acetic acid; IBA = indole-3-butyric acid; NAA = 1-naphthaleneacetic acid


1996 ◽  
Vol 121 (5) ◽  
pp. 804-809 ◽  
Author(s):  
I. David van der Walt ◽  
Gail M. Littlejohn

The influence of storage temperature and humidity on pollen viability was studied in four Protea species. Pollen was stored at a range of temperatures and relative humidities for up to 1 year and tested for ability to germinate in vitro. Pollen of P. repens (L.) L. `Sneyd', P. eximia (Salisb. ex Knight) Fourcade `Fiery Duchess' and P. magnifica Link. clone T 84 07 05 stored at -196 °C and -14 to -18 °C retained a germination percentage as high as that of fresh pollen regardless of humidity. Humidity control became increasingly important at storage temperatures above 0 °C. The study showed that long-term storage of Protea pollen is not feasible at temperatures above 0 °C. The relationship between germinability and fluorochromasia (FCR) was studied during storage of `Sneyd' pollen. The correlations between FCR and germinability were found to be low and nonsignificant. Fifteen-month-old cryopreserved `Sneyd' pollen functioned in fertilization and seed set as effectively as fresh pollen.


2021 ◽  
pp. 1-12
Author(s):  
Hiaki Sato ◽  
Yoshiaki Norimatsu ◽  
Satoshi Irino ◽  
Takeshi Nishikawa

<b><i>Introduction/Objective:</i></b> Liquid-based cytology (LBC) is advantageous as multiple stained specimens can be prepared and used for additional assays such as immunocytochemical and molecular-pathological investigations. Two types of preservative-fixative solutions (fixatives) are used for nongynecologic specimens used in the BD SurePath-LBC (SP-LBC) method, and their components vary. However, few studies have evaluated the differences in antigen-retaining ability between these fixatives. Therefore, we investigated and compared the antigen-retaining ability of the fixatives in immunocytochemical staining (ICC) under long-term storage conditions. <b><i>Materials and Methods:</i></b> Sediments of cultured RAJI cells (derived from Burkitt’s lymphoma) were added to each fixative (red and blue) and stored at room temperature for a specified period (1 h; 1 week; and 1, 3, and 6 months). The specimens were then prepared using the SP-LBC method and subjected to ICC. Positivity rate was calculated using the specimens fixed at room temperature for 1 h as a control. Antibodies against Ki67 expressed in the nucleus and against CD20 and leukocyte common antigen (LCA) expressed on the cell membrane were used. <b><i>Results:</i></b> For CD20 and LCA, the positivity rate increased with time in the red fixative compared with that in the control. In the blue fixative, the positivity rate was highest at 1 h and was maintained at a high level throughout the storage period. In contrast, the Ki67 positivity rate was highest at 1 h in both red and blue fixatives and markedly decreased with time. Therefore, although refrigerated (8°C) storage was used, no improvement was noted. <b><i>Conclusions:</i></b> Long-term storage is possible for cell membrane antigens at room temperature; however, it is unsuitable for intranuclear antigens. Therefore, we conclude that suitable fixative type and storage temperature differ based on antigen location. Further investigation is warranted.


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