This thesis deals with the relationship between the place of origin and the extend of cold hardiness of fire bug Pyrrhocoris apterus (Linnaeus, 1758). Thirteen populations from twelve European localities were used in the experiment. Linear regressions were used to relate the values of SCP (10th percentile, first quartile, mean and median) of the individual populations to minimum and average winter temperatures of given localities. The relationship between air temperatures and SCP values were significant provided that the data of all populations were used. After the removal of three southern non-diapausing populations this relationship lost its significance.

No description available.

Neonatal painted turtles (Chrysemys picta) spend their first winter inside the shallow, subterranean nest cavity where they completed embryogenesis. Consequently, hatchlings at high latitudes may be exposed to ice and cold during the winter. This study was undertaken to determine how long hatchlings withstand freezing at temperatures slightly below 0°C because tolerance for freezing has been proposed to be the key to survival by overwintering animals. A thermocouple was glued to the carapace of each hatchling. The animal was dipped in water to provide a site of nucleation of ice and was then placed into a glass jar that was partially immersed in a circulating bath at -2°C. Carapace temperature was monitored throughout the procedure. When a freezing exotherm was detected, timing of the freezing event began. Animals were maintained in a frozen state for 12-48 h prior to being warmed to room temperature. Of the 39 hatchlings, 22 did not survive, and mortality increased as the duration of freezing increased. Logistic regression indicates that no turtle would have survived in a frozen state for more than 54 h. These results indicate that hatchlings can survive only brief exposure to freezing of the body fluids. Thus, hatchlings cannot tolerate freezing during prolonged periods of cold.

The effects of temperature, defoliation, light, and certain fall cultural practices on rest and hardiness of Gleason Elberta peach buds were studied. The influence of these factors on abscisic acid concentration in peach buds and a possible role of ABA in rest and hardiness of peach buds were also investigated. Peach leaf buds enter rest in early fall, reach a rest intensity peak in early winter, then break rest as a chilling requirement is met. Complete defoliation before rest has begun will cause some leaf and flower buds to grow, while defoliation after rest has begun will not cause visible bud growth. Effective chill-unit accumulation in the fall apparently did not begin until after a certain amount of leaf abscission had occurred. A GA3 application on August 15, 1974, delayed leaf abscission, and also caused an extension of the rest period. Early fall defoliation was correlated with a reduction in rest intensity and a reduction in the rest period of leaf buds. A result of this study indicates the possibility of the existence of a rest promoting substance that was apparently translocated from a side of a tree exposed to ambient temperatures to a warm greenhouse covered side. Decreasing temperatures caused an increase in flower bud hardiness, however, other factors also had effects on hardiness. An extended day-length treatment caused flower buds to acclimate more slowly than those on untreated trees during the early fall period. The light affect was not evident as colder temperatures prevailed. Buds on trees that were kept warm, acclimated to the same level as buds on trees kept at cooler but non freezing temperatures. However, it took the warm buds approximately four months longer to acclimate. Buds on trees that were exposed to below freezing temperatures acclimated to a much lower level than those on trees not exposed to freezing temperatures. Fall pruning and heavy fertilization with ammonium nitrate did not reduce cold hardiness enough to be measured. However, buds on vigorous, large diameter twigs were more hardy during the early winter period than buds on twigs of smaller diameter. The August 15 and September 19 GA3 treated trees and the early defoliated trees had a delay in acclimation during the fall period, although they did eventually acclimate to the same level as the untreated buds. Abscisic acid concentration in peach leaf and flower buds was low before rest began, increased sharply during the rest inception period, and decreased in concentration before the end of rest. ABA may be a controlling factor in the inception of rest in peach. There was no apparent relationship between ABA concentration and cold hardiness of Gleason Elberta peach flower buds.

Perennial ryegrass (Lolium perenne L.) is a cool-season turfgrass susceptible to low temperature injury. Wilt-based (WB) irrigation is a common practice in scheduling turf irrigation as an alternative to well-watered (WW). Moisture stress has been shown to promote cold hardiness but this has not been investigated in response to WB irrigation. Measurements of 13C isotope discrimination (DELTA) are useful predictors of water use efficiency (WUE), drought resistance, evapotranspiration (ET) and salinity tolerance but the relevance to turfgrass cold hardiness has not been determined. DELTA analyses may enable more efficient screening protocols in breeding for improved cold hardiness. Objectives of this study were to examine perennial ryegrass genotypes in relation to cold hardiness, DELTA and WUE in response to WW and WB irrigation schedules, to compare genetic diversity between top-performing (TP) and bottom-performing (BP) perennial ryegrass genotypes, and to assess the predictive value of DELTA of for cold hardiness. Six genotypes were selected based on turf quality from the most northern NTEP location (Orono, ME) and included three TP (‘All Star 2’, ‘Mach I’ and ‘Sunkissed’) and three BP (‘APR-1234’, ‘Buccaneer’ and ‘WVPB-R-82’) genotypes. ET, yield, WUE, shoot water content, rooting potential, wilting tendency, DELTA and median lethal temperatures (LT50) using whole-plant survival were measured from greenhouse samples grown in weighing lysimeters in 2007 and 2008. Plant measurements in both years were based on sampling conducted at the last cycle after 68-d of irrigation with 100% of ET applied at leaf-roll (WB) versus ET replacement every 4-d (WW). Lower LT50 values were generally associated with low yield, low WUE and low shoot water content, whether the result of irrigation treatment or genotypic variation. TP genotypes demonstrated significantly lower LT50 temperatures (greater cold hardiness) in comparison to BP genotypes in both years. Modest cold hardiness enhancement with WB irrigation was highest for TP genotypes. Wilting tendency and DELTA were not reliable predictors of cold hardiness, although individual TP genotypes exhibited responses distinctly different than some BP genotypes. Further research is needed to investigate the physiological mechanisms of enhanced turfgrass cold hardiness in response to moisture stress.

Western redcedar (Thuja plicata Donn ex D. Don; redcedar), an indeterminate conifer in the Cupressaceae family, is vulnerable to maladaptation in the face of climate change. Assisted gene flow is one mitigation strategy and involves human-mediated migration of populations, where the projected climate of the area of deployment matches the source climate of the population. Despite the overall projections of warmer temperatures globally, in British Columbia (B.C.), the risk of seasonal frost events will remain and therefore the potential for cold damage and mortality of redcedar exists if the newly migrated populations cannot withstand these freezing events. Knowledge of redcedar's ability to withstand freezing temperatures (cold hardiness) is therefore crucial. Redcedar, like many Cupressaceae species, produces and accumulates the purple-coloured carotenoid rhodoxanthin during the winter. This was hypothesized to be correlated with cold hardiness. Assessment of variation in overall, fall and spring cold hardiness and associated rhodoxanthin concentrations were done through repeated, seasonal freeze testing of clonal grafts originating from across the range of redcedar, and seedling progeny from a subset of these clones. Cold damage was quantified using electrolyte leakage and rhodoxanthin concentrations were quantified using high performance liquid chromatography. Cold hardiness and rhodoxanthin were individually modelled using univariate and bivariate mixed effect models with clone/family as a random effect. Model outputs were compared to climatic variables associated with clonal origin to test for climatic relationships. This study found genetic variation in cold hardiness of redcedar with weak climatic clines. This indicates that assisted gene flow of redcedar should be done on a case-by-case basis, with no need for a climatic threshold. Overall heritability of cold hardiness was 0.17 ± 0.03. Novel findings included the positive genetic correlation between fall and spring cold hardiness (0.55 ± 0.33); lack of reciprocal or parental effect for overall cold hardiness; and weak climatic relationships between cold hardiness and predominantly temperature, with the strongest correlation between number of frost-free days in January (0.38, p < 0.01) in the location of origin and cold hardiness. All findings related to rhodoxanthin were novel. Rhodoxanthin varied with family/provenance and season with heritabilities of 0.30 ± 0.09 in fall, 0.42 ± 0.09 in winter and 0.28 ± 0.09 in spring. Winter and spring rhodoxanthin concentrations were phenotypically correlated (0.50, p < 0.01) and genetically correlated (0.76 ± 0.14). Surprisingly, rhodoxanthin was not detected in clonal grafts of redcedar in any season. Results also indicate that rhodoxanthin cannot be used to estimate cold hardiness. The absence of rhodoxanthin in the clonal grafts compared to the seedlings suggests that plant age impacts rhodoxanthin accumulation. / Graduate / 2021-12-14

<p>Kukuruzni plamenca (<em>Ostrinia nubilalis</em>, Hbn.) je vrsta umerenog klimatskog područja&nbsp;<br />koja niske zimske&nbsp; temperature preživljava ulaskom u dijapauzu u stadijumu gusenice.&nbsp;Dijapauza i otpornost na hladnoću (cold hardiness,&nbsp; eng.), kod mnogih insekatskih vrsta često&nbsp;predstavljaju esencijalne, tesno povezane komponente strategije preživljavanja delovanja&nbsp;niske temperature, kao &scaron;to je to slučaj i kod kukuruznog plamenca&nbsp; <em>Ostrinia&nbsp; nubilalis</em>, Hbn. U&nbsp;okviru grupe insekata otpornih na hladnoću, svrstava se u insekte otporne na zamrzavanje&nbsp;(freeze tolerant,&nbsp; eng.) jer su&nbsp; sposobne da prežive ekstracelularno zamrzavanje telesnih&nbsp;tečnosti.</p><p>Iako se o osnovnim strukturnim i metaboličkim de&scaron;avanjima u dijapauzi insekata već dosta&nbsp;zna, jo&scaron; uvek postoje brojne dileme o ovom vidu preživljavanja insekata u nepovoljnim&nbsp;uslovima sredine, posebno sa aspekta izloženosti niskim zimskim temperaturama i&nbsp;mehanizmima krioprotekcije. Zbog toga je&nbsp; cilj ove doktorske disertacije&nbsp; bio&nbsp; da se sa aspekta&nbsp;biofizičkih osobina lipida i sastava masnih kiselina: &nbsp;odrede biofizičke osobine (temperature&nbsp;faznog prelaza) ukupnih lipida nedijapauzirajućih i dijapauzirajućih gusenica tokom dijapauze&nbsp;(početak, sredina i kraj),&nbsp; kao i u kontrolisanim uslovima hlađenja dijapauzirajućih gusenica;&nbsp;zatim da se&nbsp; odredi zastupljenost pojedinih klasa lipida u hemolimfi i masnom telu&nbsp;nedijapauzirajućih i dijapauzirajućih gusenica;&nbsp; da se&nbsp; utvrde promene sastava masnih kiselina&nbsp;strukturne (polarne) i rezervne (nepolarne)&nbsp; frakcije&nbsp; lipida celih gusenica&nbsp; tokom dijapauze i&nbsp;pod uticajem različitih temperatura u eksperimentalnim uslovima; kao i da se&nbsp; odredi tkivna&nbsp;specifičnost, hemolimfe i masnog tela, masnih kiselina ukupnih lipida&nbsp; i&nbsp; biofizičke&nbsp; osobine&nbsp;ukupnih lipida masnog tela nedijapauzirajućih i dijapauzirajućih gusenica tokom dijapauze,&nbsp;kao i u kontrolisanim uslovima hlađenja dijapauzirajućih gusenica.&nbsp;&nbsp;</p><p>U analizi lipida kukuruznog plamenca <em>Ostrinia nubilalis</em>, Hbn. kori&scaron;ćene su sledeće tehnike:&nbsp;tankoslojna hromatografija (TLC) sa skenirajućom denzitometrijom, za razdvajanje i analizu&nbsp;klasa lipida;&nbsp; zatim&nbsp; gasno-masena hromatografija (GC-MS), za analizu masnih kiselina kao i&nbsp;diferencijalna skenirajuća kalorimetrija (DSC&nbsp; &ndash;&nbsp; differential scanning calorimetry,&nbsp; eng.), za&nbsp;termalnu analizu ekstrahovanih lipida.</p><p>Kod&nbsp; gusenica <em>Ostrinia&nbsp; nubilalis</em>&nbsp;sastav&nbsp; masnih kiselina ukupnih lipida analiziranih tkiva i&nbsp;lipidnih frakcija značajno se razlikuje između&nbsp; ova dva fiziolo&scaron;ka stanja, stanja dijapauze i&nbsp;nedijapauze.&nbsp; Dijapauza indukuje značajno povećanje sadržaja mononezasićenih masnih&nbsp;kiselina, pre svega palmitoleinske (16:1n-7) i oleinske masne kiseline (18:1n-9) uz&nbsp;istovremeno smanjenje sadržaja zasićenih i&nbsp; polinezasićenih masnih kiselina, pre svega&nbsp;palmitinske (16:0) i linolne masne kiseline (18:2n-6).&nbsp; Temperature faznog prelaza ukupnih&nbsp;lipida celih gusenica i masnog tela&nbsp; značajno su niže kod dijapauzirajućih gusenica&nbsp; <em>O.&nbsp;nubilalis</em>,&nbsp; usled &nbsp;značajnog povećanja&nbsp; stepena nezasićenosti masnih kiselina u njihovom&nbsp;sastavu. Značajno niže temperature&nbsp; faznog prelaza lipida dijapauzirajućih gusenica&nbsp; <em>O.<br />nubilalis</em>&nbsp; rezultat su povećanja stepena nezasićenosti njihovih masnih kiselina. Možemo&nbsp;zaključiti da su&nbsp; promene u sastavu&nbsp; masnih kiselina lipida indukovane dijapauzom važna&nbsp;komponenta preživljavanja niskih temperatura kod&nbsp; <em>O. nubilalis</em>&nbsp; Hbn. jer se&nbsp; veliki deo lipida&nbsp;održava u tečnom stanju čak i na temperaturama daleko ispod 0&deg;C, &scaron;to je neophodno za&nbsp;održavanje njihove fluidnosti odnosno funkcionalnosti.</p> / <p>European corn borer (<em>Ostrinia nubilalis</em>,&nbsp; Hbn.)&nbsp; inhabiting temperate regions&nbsp; that&nbsp;survive low winter temperatures as a diapausing fifth instar larva.&nbsp; Diapausing larvae are cold&nbsp;hardy and freeze tolerant as they are able to survive the extracellular formation of ice crystals.&nbsp;Winter survival for many insect species living in seasonally cold environments includes a&nbsp;radical remodeling of metabolism. This implies entry into a developmentally arrested,&nbsp;hypometabolic state of winter diapause, which in <em>O. nubilalis</em>&nbsp; and&nbsp; many&nbsp; other&nbsp; insect species&nbsp;of these habitats is closely related to their cold hardiness.</p><p>Although the basic structural and metabolic events consider insect diapause is already known,&nbsp;there are still many doubts about the survival of insects in an unfavorable environment,&nbsp;particularly in terms of&nbsp; exposure to low winter temperatures &nbsp;and mechanisms of&nbsp;cryoprotection. Therefore, the aim of this thesis in terms of biophysical properties of lipids&nbsp;and fatty acid compositions,&nbsp; was to: i) to determine &nbsp;the biophysical properties (phase&nbsp;transition temperatures) of the total lipids of non-diapausing&nbsp; larvae&nbsp; and diapausing larvae&nbsp;during diapause (early diapause, mid diapause and termination of diapause), as well as under&nbsp;controlled cooling conditions during different phases of diapause; ii) to determine the fatty&nbsp;acid compositions of structural (polar) and storage (non-polar)&nbsp; total&nbsp; lipid fractions of non-diapausing&nbsp; larvae&nbsp; and diapausing larvae, as well as under the influence of different&nbsp;<br />temperatures during diapause in the controled experimental conditions; iii)&nbsp; to determine the&nbsp;lipid classes&nbsp; composition of total lipids extracted from the haemolymph and fat body of non-diapausing and diapausing larvae;&nbsp; iiii) to determine&nbsp; the haemolymph and fat body total lipid&nbsp;fatty acid compositions&nbsp; as well as the biophysical properties of the fat body total lipids of&nbsp;non-diapausing larvae&nbsp; and diapausing larvae during diapause as well as in terms of controlled&nbsp;cooling conditions. Thus, our research was focused on the non-diapausing (ND) as well as the&nbsp;diapausing larvae&nbsp; (D) that&nbsp; were exposed to low temperatures during different phases&nbsp; of&nbsp;diapause.</p><p>During analysis of European corn borer&nbsp; <em>O. nubilalis</em>&nbsp; lipids, the following techniques was&nbsp;used: thin&nbsp; layer&nbsp; chromatography (TLC) with scanning densitometry, for the separation and&nbsp;quantification&nbsp; of lipid classes; gas-mass chromatography (GC-MS ) for the&nbsp; analysis of the&nbsp;fatty acid composition&nbsp; of lipids and&nbsp; the differential scanning calorimetry (DSC), for the&nbsp;thermal analysis of the extracted lipids.</p><p>The fatty acid compositions&nbsp; and biophysical properties of lipids differed markedly between&nbsp;non-diapausing and diapausing larvae&nbsp; of&nbsp; <em>O. nubilalis</em>. Diapause was associated with a&nbsp;dramatic increase&nbsp; mainly the proportions of palmitoleic acid (16:1n-7) and oleic acid (18:1n-9), with concurrent reductions in palmitic acid (16:0) and linoleic acid (18:2n-6). The increase&nbsp;in&nbsp; the level of unsaturation of&nbsp; lipids,&nbsp; which caused a marked shift in their phase transitions to&nbsp;lower temperatures,&nbsp; was triggered&nbsp; by diapause rather than low temperatures.&nbsp; Adjustments of&nbsp;fatty acid compositions are likely to be an important component of winter diapause &nbsp;mechaisms, possibly maintaining the fluidity of cell membranes, and the functionality &nbsp;of the&nbsp;organism during lower winter temperatures.&nbsp; We conclude that&nbsp; <em>O. nubilalis &nbsp;</em>undergoes&nbsp;remodeling of fatty acid profiles of lipids as an element of its overwintering physiology which&nbsp;may improve the ability to harden during diapause.</p>

No description available.

This diploma thesis is focused on invertebrates' survival and activity during winter; and on methods of their capture. The first part of the theoretical section describes principles of cold hardiness, strategies of winter survival and activity in snow environment. Furthermore, different methods of invertebrates capturing are presented. The practical part of the thesis is focused on the verification of selected invertebrates capturing methods during winter. The results summarize the differences in the diversity and quantity of animals caught; and provide an overview and characteristics of selected captured taxa. Suggestions for a snow fauna excursion and a practical exercise focused on capturing invertebrates during winter are proposed based on the results of the study. KEYWORDS cold hardiness, winter survival, winter activity, snow fauna, invertebrate animals, catching methods, pitfall traps

Red alder (Alnus rubra Bong.) is the only tree in British Columbia and the Northwest US to engage in actinorhizal symbiosis to fix atmospheric nitrogen. This study was conducted to explore the plasticity in growth and physiology among 58 17-year-old red alder families in response to variation in climate in two common garden plots, one at Bowser, BC and one at Terrace, BC. Physiological assessments included height and diameter growth, bud flush, water use efficiency as measured by δ13C, cold hardiness as measured by controlled freezing and electrolyte leakage, autumn leaf senescence, and instantaneous and seasonally integrated rates of nitrogen fixation as measured by acetylene reduction and natural abundance δ15N isotope analysis, respectively. Significant differences were identified among families for growth (height and diameter), bud burst stage, leaf senescence, cold hardiness, and bud nitrogen content. No significant differences among families were identified for water use efficiency as measured by δ13C, or for rates of nitrogen fixation as measured by either acetylene reduction or natural abundance δ15N. This study identified possible adaptive differences among red alder genotypes, especially in traits such as bud flush timing, cold hardiness, or nitrogen fixation and their respective contributions to growth. These differences often reflected a tradeoff between growth and the ability to tolerate an extreme environment. Cold hardiness results indicate that red alder families are well adapted to their climate of origin, and may not be able to acclimate sufficiently to a northward assisted migration of genotypes. Nitrogen fixation results demonstrated gaps in our current knowledge of Frankia distribution and impact on the actinorhizal symbiosis in British Columbia. / Graduate