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Dozrávání rajčat z pozdních sběrů
Němec, Michal
In this diploma thesis "Ripening tomatoes from the late harvest" were investigated supporting options of the post harvest of the completely green fruit, which remained unharvested in the later stages of harvest. Fruits were transferred from the field conditions to the temperature of 20 °C and afterwards were successively treated with ethylene as the supportive maturing factor, which helped them to get to the suitable conditions for subsequent maturation. Two varieties of tomatoes were used for the speed of ripening. At the end of the cultivation period, both varieties of tomatoes 'Expres' and 'Premio' were treated by the three concentrations of exogenous ethylene, 2 100 ppm, 7 360 ppm and 2 200 ppm. Technologically important parameters such as the size and weight of fruit, fruit color, fruit firmness, soluble solids and titration acid were evaluated during the post-harvest storage (21 days). Influence of ethylene in concentrations up to 7 360 ppm has proven effective post-harvest treatment that supports ripening of originally unripe fruit at the end of the growing season. Also differences in the investigated varieties were proved, the 'Premio' variety was after the ethylene treatment sensitive in parameters, which were monitored.
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Factors influencing seed development and maturation
Leová, Phuong Yen ; Pazderů, Kateřina (advisor) ; Hnilička, František (referee)
Cereals are the most common group of grown crops in the world. Winter wheat (Triticum aestivum L.) is the most grown cereal in the Czech republic, represented almost in all growing areas and covers more than a quarter of arable land and over half of grain surfaces. This bachelors's thesis ,,Factors affecting seeds development and maturation" is a compilation based on scientific literature concerning environmental influcences on the development, maturation and germination of seeds. The thesis also describes the basic physiological processes such as germination and dormancy and knowledges about seed vitality and effects of phytohormones.
The main point of this thesis was to determine whether the arrangement of grains per spikelet affect their germination and other seed parametres. The thesis practically deals mainly with the seed germination in 30 ml and 20 ml of water. The experiment was created with the variety of winter wheat named Bohemia and new genotype of winter wheat called MRS or multi row spike.
Seeds were gained by manual scaling out of the spikes and categorized into fractions, according to the position of seed in a spikelet (i. e. first, seconad, third, fourth or fifth).
Seed tests were performed on the folded filter paper Hahnemühle in 30 ml and 20 ml of water. Germination took place at constatnt temperature of 20 °C in air - conditionted box. Measured values were germination percent, mean time of germination and germinating energy. Gained results were statistically evaluated.
Seeds were also analyse with the OmegAnalyzer G, where the point was to determine wheter the position of the grain spikelet affects the content of the seed (nitrogen, gluten, strach). Seed parametres were different not only depending on the position of the seed on the grain spikelet, but also on the variety and amount of water. Comparing the different categories of grains among themselves differences were found. Both in optimal and stress moisture conditions were registred the best results in the Bohemia breed. MRS wheat genotype fared significantly worse in both conditions. The highest average seed germination in 30 ml of water showed third grains of Bohemia breed, which also was the only one able to achieve 100% germination. First grains had the lowest average germination (94 %). MRS in 30 ml of water reached lower values than Bohemia breed. The highest average germination reached the first grains (94%), but neither one grain fraction MRS did not reach 100% germination. The worst levels of seed germination reached second and fifth grains (93%). In 20 ml of water had Bohemia breed lower average germination than average germination in 30 ml of water, even so it still achieved relatively high values. The highest average germination achieved first grains with 98% and the second grains showed the worst germination value (95%). The fastest average germinating had third and fourth grains, second grains had the slowest germination. In 20 ml of water fifth grains germinated the fastest, and also reached the highest germination (95%). Grains of the first fraction were the worst and ended with very low germination (88 %).
Fifth grains had the highest germination energy (90 %) fifth day in 20 ml of water. The lowest values, only 1 % were reached by the first and second grains third day. The fourth and fifth grains showed higher values of germination energy under stressful conditions than in optimal. The first and second grains conversly germinated faster in optimal conditions.
In experimental part of this bachelors's thesis was found that the position of the grains, its weight and size togehter with the different amout of water affects germination. Next the influence of the position of the grains on the grains content wasn't shown.
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Úloha regulačních proteinů pro pohyblivost rybích spermií
DZYUBA, Viktoriya
The investigation of the energetic aspects of spermatozoon motility implementation (Chapter 2) was carried out using demembranated spermatozoa of taxonomically distant fish species (common carp and sterlet). Special attention was given to the functioning of ATP regeneration systems: adenylate kinase (AK), and creatine kinase (CK). It was shown for the first time that the phosphocreatine/CK system is present in sterlet spermatozoa and plays an essential role in ATP regeneration. Spermatozoa of carp and sterlet were shown to have similar systems for ATP regeneration, while the efficacy of the studied systems differs in these species. The low baseline activity of CK in carp and AK in sterlet suggest these to be the source of the most pronounced effects of their inhibition on energy supply for flagella movement in the respective species. The presence of a maturational process during the post-testicular transit of sperm in sturgeon was recently ascertained in our laboratory (Chapter 3). This discovery prompted investigation of the factors that regulate this process including the involvement of proteolysis regulators and prooxidant-antioxidant system. As a result of this study (Chapter 3.3), we found that there was no significant difference between proteolytic profiles of seminal fluids (SF) of testicular sperm (TS) and Wolffian duct sperm (WS). It suggests that the majority of proteases present in SF of mature sperm originate in the testis. Measure of amidase and anti-proteolytic activities in the SF of sterlet sperm showed significant decrease in activities as the sperm passed through the kidneys and Wolffian ducts. Considering our observation that trypsin inhibition during in vitro TS maturation blocked the maturation process (Chapter 3.1), and based on zymography, amidase and anti-proteolytic activity determination, we think that the decrease in anti-proteolytic activity of spermatozoa surroundings during their post-testicular transit could be needed to prepare them for maturation. The present study showed that maturation of sturgeon spermatozoa and different times of storage in Wolffian ducts (in vivo storage), are accompanied by significant alterations in motility parameters as well as in SF redox balance (Chapter 4.1). A high level of TBA-reactive substances (TBARS) and a high activity of antioxidant enzymes were found in immature TS compared to those in WS. The high activity of the enzymatic antioxidant system (AOS) allows TS to cope with the deleterious effects of excessive reactive oxygen species production and to retain the ability to become motile after post-testicular transit, or after in vitro maturation. The increase in TBARS content during in vivo storage was not accompanied by a corresponding increase in activity of AOS. We suggest that extended time in the Wolffian ducts resulted in sperm oxidative damage resulting from inadequate AOS efficacy and, finally, in decreases in motility parameters. Short-term hypothermic in vitro storage of sterlet sperm resulted in a significant decrease in motility and velocity without changes of AOS activity (Chapter 4.2). It means that AOS of sterlet sperm is effective enough to prevent the development of oxidative stress during short-term storage. Short period of tench sperm exposure to hypotonic conditions was shown to induce oxidative stress and, as a result, sperm quality decline (Chapter 4.3). The combined results of the study concerning the regulation of sperm prooxidant-antioxidant status (Chapter 4) during spermatozoa maturation, motility activation and sperm in vivo and in vitro storage may confirm a dual role of reactive oxygen species (regulatory or damaging depending from the levels of their formation and elimination) in fish sperm physiology.
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