A rapid method for detecting cold injury in conifer seedling root systems

1990 ◽  
Vol 20 (1) ◽  
pp. 26-30 ◽  
Author(s):  
Gary A. Ritchie
Keyword(s):  
Weight Loss ◽  
Root Systems ◽  
Douglas Fir ◽  
Cold Injury ◽  
Percent Weight Loss ◽  
Seedling Root ◽  
Seedling Roots ◽  
Temperature Exposure ◽  
Low Temperature Exposure ◽  
Conifer Seedling

A method is described for rapidly determining the extent of cold injury to Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedling root systems. It is based upon pressure:volume theory but short-cuts the tedious pressure:volume method. Injured root systems were brought to full hydration, then weighed and placed into a pressure chamber. A pressure of 1.5 MPa was applied for a 5-min period, then the root system was removed from the chamber and reweighed. The percent weight loss was then calculated. Percent weight loss was closely related to degree of low temperature exposure in Douglas-fir seedling roots. Percent weight loss values were near 5 in uninjured controls, whereas freeze-injured seedlings had percent weight loss values of 7 or greater. Percent weight loss values measured on seedlings just before planting were closely correlated with seedling vigor and mortality 3 months following planting in both a field test and a greenhouse pot trial.

scholarly journals Duration of Low Temperature Exposure Affects Egg Hatching of the Colorado Potato Beetle and Emergence of Overwintering Adults

Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 609
Author(s):  
Jianghua Liao ◽  
Juan Liu ◽  
Zhijian Guan ◽  
Chao Li
Keyword(s):  
Low Temperature ◽  
Colorado Potato Beetle ◽  
Treatment Time ◽  
Early Summer ◽  
Short Term ◽  
Egg Survival ◽  
Egg Hatching ◽  
Potato Beetle ◽  
Temperature Exposure ◽  
Low Temperature Exposure

The Colorado potato beetle is a serious pest of Solanaceae in China. In early summer, cold spells in later spring may occur for brief periods in the field environmental conditions, and temperatures often deviate far below the normal temperature for short periods, such as sudden short-term low temperature, may affect the development of Colorado potato beetle eggs. This paper studies the effects of low temperature stress at 8 °C for 0 d, 1 d, 3 d, 5 d, 7 d, and 10 d on the development of Colorado potato beetle eggs. Our results show that egg survival is significantly affected by short-term low temperature exposure. The percentage of eggs hatched is significantly affected by different treatment times (p = 0.000)—the percentage of eggs hatched decreases with increased treatment time, and Colorado potato beetles will extend the wintering time of their soil to resist the effects of lower temperatures. Thus, exposure of Colorado potato beetles to a short-term low temperature affects their emergence and population growth; this study could provide information for the occurrence, monitoring, and early warning of Colorado potato beetle during short-term temperature.

Root systems of older immature hemlock, cedar, and Douglas-fir

1988 ◽  
Vol 18 (5) ◽  
pp. 657-657
Author(s):  
S. Eis
Keyword(s):  
Root Systems ◽  
Douglas Fir

not available

scholarly journals Study of low-temperature exposure on biotissue using an elongated cryoapplicator

2021 ◽  
Vol 2103 (1) ◽  
pp. 012049
Author(s):  
A V Pushkarev ◽  
N A Andreev
Keyword(s):  
Atrial Fibrillation ◽  
Data Analysis ◽  
Low Temperature ◽  
Nitrogen Dioxide ◽  
Liquid Nitrogen ◽  
Biological Tissue ◽  
The Novel ◽  
Treatment Data ◽  
Temperature Exposure ◽  
Low Temperature Exposure

Abstract The article presents the results of a study of low-temperature exposure on animal biological tissue using the novel prototype of a liquid nitrogen cryoapplicator. The data obtained are compared with the cryoapplicator characteristics cooled by nitrogen dioxide that are currently used for the atrial fibrillation treatment. Data analysis confirmed the liquid nitrogen cryoapplicators effectiveness and made it possible to highlight their advantages.

Twenty-year survival of Phellinus (Poria) weirii in Douglas-fir stumps

1976 ◽  
Vol 6 (2) ◽  
pp. 123-128 ◽  
Author(s):  
Everett M. Hansen
Keyword(s):  
Root Systems ◽  
Root Diameter ◽  
Douglas Fir ◽  
Hand Tools ◽  
Outer Limit ◽  
Dying Back

Fungus survival was examined in root systems of stumps of trees that were harvested 20 years previously. Roots were excavated with dynamite and hand tools to the outer limit of living P. weirii or until the roots went deeper than 45 cm. Sixty-nine stumps infected before harvest were excavated; P. weirii was still viable in 94%. The fungus was dying back in 68% of the stumps. Some roots as small as 1.3 cm had viable P. weirii, but the margin between living and dead P. weirii occurred at an average root diameter of 12.5 cm.The margin between living and dead P. weirii was often marked by a black zone line. The fungus survived only within roots with intact bark. Ectotrophic mycelium occurred in discontinuous patches on roots of 33% of the stumps.

scholarly journals Comparing Weight Loss–Maintenance Outcomes of a Worksite-Based Lifestyle Program Delivered via DVD and Face-to-Face: A Randomized Trial

2018 ◽  
Vol 45 (4) ◽  
pp. 569-580 ◽  
Author(s):  
Claire Townsend Ing ◽  
Robin E. S. Miyamoto ◽  
Rui Fang ◽  
Mapuana Antonio ◽  
Diane Paloma ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Weight Loss ◽  
Systolic Blood Pressure ◽  
Physical Functioning ◽  
Maintenance Phase ◽  
Weight Loss Maintenance ◽  
Overweight And Obesity ◽  
Percent Weight Loss ◽  
Face To Face ◽  
Baseline Systolic Blood Pressure

Background. Native Hawaiians and other Pacific Islanders have high rates of overweight and obesity compared with other ethnic groups in Hawai‘i. Effective weight loss and weight loss–maintenance programs are needed to address obesity and obesity-related health inequities for this group. Aims. Compare the effectiveness of a 9-month, worksite-based, weight loss–maintenance intervention delivered via DVD versus face-to-face in continued weight reduction and weight loss maintenance beyond the initial weight loss phase. Method. We tested DVD versus face-to-face delivery of the PILI@Work Program’s 9-month, weight loss–maintenance phase in Native Hawaiian–serving organizations. After completing the 3-month weight loss phase, participants ( n = 217) were randomized to receive the weight loss–maintenance phase delivered via trained peer facilitators or DVDs. Participant assessments at randomization and postintervention included weight, height, blood pressure, physical functioning, exercise frequency, and fat intake. Results. Eighty-three face-to-face participants were retained at 12 months (74.1%) compared with 73 DVD participants (69.5%). There was no significant difference between groups in weight loss or weight loss maintenance. The number of lessons attended in Phase 1 of the intervention (β = 0.358, p = .022) and baseline systolic blood pressure (β = −0.038, p = .048) predicted percent weight loss at 12 months. Discussion and Conclusion. Weight loss maintenance was similar across groups. This suggests that low-cost delivery methods for worksite-based interventions targeting at-risk populations can help address obesity and obesity-related disparities. Additionally, attendance during the weight loss phase and lower baseline systolic blood pressure predicted greater percent weight loss during the weight loss–maintenance phase, suggesting that early engagement and initial physical functioning improve long-term weight loss outcomes.

Importance of anther dehiscence for low-temperature tolerance in rice at the young microspore and flowering stages

2019 ◽  
Vol 70 (2) ◽  
pp. 113 ◽  
Author(s):  
Zuziana Susanti ◽  
Peter Snell ◽  
Shu Fukai ◽  
Jaquie H. Mitchell
Keyword(s):  
Low Temperature ◽  
Field Experiments ◽  
Recombinant Inbred Lines ◽  
Temperature Tolerance ◽  
Screening Methods ◽  
Genotypic Differences ◽  
Anther Dehiscence ◽  
Low Temperature Tolerance ◽  
Temperature Exposure ◽  
Low Temperature Exposure

Low temperature, particularly during the reproductive stage in rice (Oryza sativa L.), leads to reduced fertility and yield and is a major constraint faced in temperate rice ecology. The floral trait anther dehiscence length has not been quantified in relation to low-temperature tolerance in rice. Two controlled-temperature glasshouse experiments evaluated 120 genotypes from BC1F6 recombinant inbred lines when exposed to low air temperature at the booting (young microspore) and flowering stages. Genotypic differences existed for spikelet sterility (SS) after low-temperature exposure at booting and flowering stages, and a significant positive correlation (R2=0.22**) was found between SS of individual genotypes at booting and flowering stages. Number of dehisced anthers had the highest correlation with SS, and accounted for 58% and 44% of variation in SS with exposure to low temperature at booting and flowering, respectively. Anther dehiscence length and number of dehisced anthers were highly correlated (r=0.90**). After low-temperature exposure at booting, pollen number in the anther as well as the pollen’s capacity to germinate effectively further differentiated low-temperature-tolerant and -susceptible genotypes. Positive relationships (r=0.56** and 0.46*) between SS in the glasshouse and in field experiments in 2015 and 2016 seasons, respectively, provided validation of the phenotypic glasshouse screening methods utilised for low-temperature tolerance in relation to target production environments. This repeatable phenotyping system in combination with improved understanding of underlying floral traits will lead to increased efficiency in breeding for low-temperature tolerance in rice.

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