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Androgenesis
Kočová, Helena ; Honys, David (advisor) ; Kocábek, Tomáš (referee)
(anglicky) Androgenesis in the plant kingdom is an interesting phenomenon, in which a new individual is regenerated from male gametophyte. Having gametophytic, i.e. haploid number of chromosomes, these plants are potentially useful in research as well as for the generation of new genotypes. Duplication of their genetic information then results in fully homozygous plants, that can be used for breeding. At the same time, microspores represent a unique system for studying totipotency, cell proliferation, differentiation and embryogenesis. However, in many important crops as well as in some model species, such technology has not yet been efficiently managed. The aim of this thesis is to summarize the knowledge about androgenesis, from the historical context to the latest discoveries, including methods, development, complications and at the end also the possible use of obtained doubled haploid plants. Keywords: androgenesis, male gametophyte, microspore embryogenesis, pollen, totipotency, cell differentiation, stress, organogenesis, haploid
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Androgenesis and its using for interspecific hybridisation of potato
Suková, Eva ; Sedlák, Petr (advisor) ; Matiska, Pavel (referee)
The production of homozygous lines has been an important part of breeding programs. The most effective and widely used method suitable for the production of homozygous plants is induced androgenesis via anther, pollen and isolated microspore cultures. The principle of androgenic induction consists in reprogramming microspores from gametophytic to sporophytic development. Physical or chemical factors can be used on the whole inflorescence, flower-buds or isolated anthers for reprograming. The genotype of donor plant and poolen developmental stage plays a fundamental role in determination of androgenesis in vitro. Pre-treatments such as chilling, high temperature, high humidity, centrifugation, water stress, oxidative stress, osmotic pressure change in the level of endogenous growth substances, transfer anthers from anaerobic to aerobic environment, starvation, colchicine application and, heavy metals treatment are other important factors that affect the response of anthers to in vitro culture.
The aim of this work was to design and confirm the methodology used for induced androgenesis of potatoes. The achieved results of our experiment showing only trends and hypotheses. The size of the most suitable flower-buds for anther culture is 2-3 mm. It is highly likely that the sucrose concentration in MS medium had no impact on the callus induction. The genotype of tested hybrids probably plays a major role in the induced androgenesis process. The influence of the media on the formation of callus was statistically proven. Calluses were transferred to regeneration medium, but organogenesis has not yet come through.
The results show that the proposed methodology is appropriate to derive calluses at least.
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Využití transgenních linií ječmene SCLW-GP-PHYA ve šlechtění
Hanáková, Marie
The F1 generation, which was obtained by hybridization transgenic lines of malting barley SCLW-GP-PHYA with feed barley of varieties Azit, Heris and Tocada, was formed for the purpose of transmission of the phyA transgene, which controls the production of the enzyme phytase. 107 hybrids of F1 generation, where it feed variety Azit was used as male plants, has been verified hybrid origin using SSR EBmac0603. In 27 individuals have been confirmed hybrid origin and by 23 individuals has been showed by the method PCR of the phyA transgene. Based on the measurement of phytase activity in the caryopsis F1 generation, which was lower compared with the female transgenic lines, but higher than in male feed variety Azit. F2 generation was observed phenotypic cleavage in size plant, length spike and grain size. Positive plants of the phyA transgene have been used to stabilize transgene and obtained homozygous plants by method androgenesis. From 4834 anthers have been obtained 54 green plants and 148 albinotic plants The phyA transgene were by the method PCR in 33 green plants (61.6 %) and 2 albinotic plants (1.4 %). Flow cytometry has been used to determine to level of ploidy in 54 green plants and have been 42 doubled haploid (77.7 %), 6 haploid (11.1 %), 4 tetrahaploid (7.4 %) and 2 trihaploid (3.7 %). Reciprocal hybridization has been performed, when feed varieties were used as female plants and transgenic barley lines SCLW-GP-PHYA as a male plants. By 10 plants od F1 generation were by the method PCR the transgene phyA in 8 plants.
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