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Algal and Cyanobacterial Adaptations to Low Temperature and Desiccation
Jimel, Matouš ; Elster, Josef (advisor) ; Košťál, Vladimír (referee)
Algae and cyanobacteria, due of their evolutionary antiquity, are widely distributed primary producers that can withstand extreme environmental stresses. Low temperature, freezing and melting, and desiccation and rewetting, are common stresses prevalent mainly in polar regions and in winter seasons of temperate areas. In terms of physiological effects, these types of stresses share similar effects or are closely related to one another. Low temperatures and desiccation exert a variety of stresses that need to be negated or lessened by adaptations. Specifically, adaptations to chill, freeze, and desiccation stresses will be discussed, as well as strategies that allow for stress avoidance or resistant morphological adaptations. In this thesis, characteristics, functions and mechanisms of these adaptations and stresses are reviewed, as well as potential biotechnological uses of said adaptations. Key words: algae, cyanobacteria, freezing, chill, desiccation, abiotic stress, cryoprotectants, osmoprotectants, akinetes, cryoinjury
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The effect of desiccation on streptophyte algae - mechanisms of stress resistance
Pošmourný, Martin ; Pichrtová, Martina (advisor) ; Vosolsobě, Stanislav (referee)
In this thesis I dealt streptophyta algae resistance against desiccation. Even though the area previously devoted only a few people. Considerable amount of work in recent years has been published on the subject. They were found interesting information and discovered new facts. Research continues on and on, and it would be useful to look at what was observed. I believe that understanding this phenomenon is the key to understanding some of the events in the evolution of nature and realizing how tough life can be on the very border of its possible occurrence. I tried to sort out the current knowledge about the mechanisms of stress resistance streptophyta algae and hope that I obtained an overview will help me understand better this issues. So far, it has been observed several approaches to defend against drying. Preventing drying, adaptation to water shortage and tolerance to desiccation. Among the preventive methods of defense include creating clusters of cells, multi-layered mats or secretion mucilage. As an adaptation to the lack of water algae evolved more complex answers in the form of changes in ultrastructure, or regulation of physiological processes. Klebsormidium is capable of half an hour to start the production of significant quantities callose and incorporate it into the cell wall. This...
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Vysýchání sadebního materiálu během manipulace a metody jeho hodnocení
Volf, Luděk
The target of the thesis was evaluation of adoption and growing planting material of Norway spruce ( Picea abies (L.) Karst) and European beech (Fagus sylvatica L.) after some time of having dryness caused by wrong manipulation. There were always tested different kinds of planting material - without soil and with soil on roots , fresh planting material and 1 week inserted into soil. Planting material without soil and with soil on roots was left on the soil surface next to place of planting without any protection against drying out and in specificied time intervals planted. Expose time 30mins, 60mins,120mins, 180mins, 240mins, 300min (330mins). In each tested variation was planted 20pcs of young plant. At the same time testing of new methods was realised. They secure water loss during drying out. Methods tried in practice were measuring weight loss during constant temperature conditions, measuring weight loss of plants with soil on roots and measuring humidity of soil on roots substratum. At the end of vegetational period was appointed mortality , termal growth, thickness of root shank, lenght of leaf and vitality. It was confirmed that within increasing time lenght appears reduction of growth and viability, primarily among young plants of beech. Young plants of spruce are more adaptable during mistreating and firtst of all it depends on spring time weather conditions. Tested methods of drying out should continue in further measuring.
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Vysychání krytokořenného sadebního materiálu při manipulaci a jeho vliv na ujímavost a odrůstání rostlin po výsadbě
Volf, Luděk
The aim of this Master thesis was to assess the survival and growing out of container planting stock for the Norway spruce (Picea abies (L.) Karst) and the European beech (Fagus sylvatica L.) after the set period of stressing by dessication due to incorrect manipulation. The plants exposed to desiccation for 2, 3, 4 and 5 days were planted in a research area. During the first day of testing, the variant for checking of unstressed planting stock was planted. The research also included the testing of new methods for assessing root ball water loss during plant desiccation. The method for measuring the decrease in weight of a root ball during manipulation was used and two devices for measure moisture levels in root balls were tested (HH2 and WHT 860). The first assessment was carried out five weeks after planting out, during which vitality and sprouting progress were assessed. The second assessment took place at the end of the vegetation period, and vitality, duration of apical increment, thickness of the rootcollar and the length of needles and leaves were assessed. It was confirmed that with an increased duration of root ball desiccation comes the loss of moisture which after a certain period of time negatively impacted the survival and growing out of the tested plants. The limit for the root ball was a 3-day-long exposure of the planting stock to desiccation. The spruce planting stock is significantly more resistant to the negative effects of radiation and desiccation than the beech planting stock. The minimal threshold for moisture levels was set, determining when the planting stock can grow out without any major problems. The tested methods appear to be promising and can be used to assess the planting stock quality before the planting.
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Algal and Cyanobacterial Adaptations to Low Temperature and Desiccation
Jimel, Matouš ; Elster, Josef (advisor) ; Košťál, Vladimír (referee)
Algae and cyanobacteria, due of their evolutionary antiquity, are widely distributed primary producers that can withstand extreme environmental stresses. Low temperature, freezing and melting, and desiccation and rewetting, are common stresses prevalent mainly in polar regions and in winter seasons of temperate areas. In terms of physiological effects, these types of stresses share similar effects or are closely related to one another. Low temperatures and desiccation exert a variety of stresses that need to be negated or lessened by adaptations. Specifically, adaptations to chill, freeze, and desiccation stresses will be discussed, as well as strategies that allow for stress avoidance or resistant morphological adaptations. In this thesis, characteristics, functions and mechanisms of these adaptations and stresses are reviewed, as well as potential biotechnological uses of said adaptations. Key words: algae, cyanobacteria, freezing, chill, desiccation, abiotic stress, cryoprotectants, osmoprotectants, akinetes, cryoinjury
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Desiccation as a structuring factor in desmid communities
Jirková, Kateřina ; Neustupa, Jiří (advisor) ; Kopalová, Kateřina (referee)
Desmids are an important part of the phytobenthos in the wetland ecosystems. These ecosystems are often ephemeral and changes in the hydrological regime is a typical characterisic of this habitat type. Dessication is a significant stress factor that affects water organisms. Different species differ in their extent of tolerance to dessication stress and it can affect their community structure and also their phylogenetic diversity. Two sites, the nature reserve Borkovická Blata and the nature locality Na Plachtě, were selected for this work. Ephemeral (seasonally dessicating) and permanent pools differed in the structure of desmid communities but the difference was signifacant only for Borkovická blata. At both localities, the samples from the dessicating pools showed in average lower species richness and Shannon's diversity index than samples from non-dessicating pools, but the differences between these groups of samples were not statistically significant. Phylogenetic analysis showed that the desmids community were phylogenetically overdispersed; closely related species tended to not appear together on the same sites at both localities. The difference in the phylogenetic structure between ephemeral and permanent was detected only in the Borkovická blata site, where the ephemeral pools exhibited weaker...
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The effect of desiccation on streptophyte algae - mechanisms of stress resistance
Pošmourný, Martin ; Pichrtová, Martina (advisor) ; Vosolsobě, Stanislav (referee)
In this thesis I dealt streptophyta algae resistance against desiccation. Even though the area previously devoted only a few people. Considerable amount of work in recent years has been published on the subject. They were found interesting information and discovered new facts. Research continues on and on, and it would be useful to look at what was observed. I believe that understanding this phenomenon is the key to understanding some of the events in the evolution of nature and realizing how tough life can be on the very border of its possible occurrence. I tried to sort out the current knowledge about the mechanisms of stress resistance streptophyta algae and hope that I obtained an overview will help me understand better this issues. So far, it has been observed several approaches to defend against drying. Preventing drying, adaptation to water shortage and tolerance to desiccation. Among the preventive methods of defense include creating clusters of cells, multi-layered mats or secretion mucilage. As an adaptation to the lack of water algae evolved more complex answers in the form of changes in ultrastructure, or regulation of physiological processes. Klebsormidium is capable of half an hour to start the production of significant quantities callose and incorporate it into the cell wall. This...
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