Student Number : 9903228W - MSc dissertation - School of Molecular and Cell Biology - Faculty of Science / Plant populations show an ability to survive and adapt under varying environmental conditions. Adaptation to heavy metal contaminated soils usually results in a decrease in genetic variation. Slimes dams consist of the pulverized rock slurry left after the extraction of gold or uranium. High toxicity levels mean that these wastes often remain uncolonised and are therefore easily eroded through wind or water. Plant populations that will be viable for long-term vegetation of slimes dams will prevent erosion, and stabilise and improve the quality of the soil. Indigenous, locally adapted species are the most likely to be successful candidates for vegetation. Indigenous, slimes-tolerant species Indigofera adenoides and Indigofera zeyheri were therefore studied. The aim was to determine if plant populations show local adaptation to the adverse substrate conditions emanating from slimes dams, by investigating genetic and morphological variation between adjacent populations growing at different distances in relation to slimes dams. The AFLP technique was used to analyse genetic variation as it produces rapid results, is inexpensive, reproducible, and capable of screening the entire genome. Lower genetic diversity was observed in those areas of the dams with higher levels of slimes-associated contamination. This difference was observed in both species, and for all measures of genetic diversity (Shannon’s information index, Nei’s gene diversity, percentage of loci polymorphic). This may be due to a founder effect following colonisation, natural selection, flowering time differences, or a combination of these factors. Reduced morphological variation was observed in those areas of the dams with higher levels of slimes-associated contamination. Significant morphological differences were observed between groups of plants from different areas, some of which appear to have the capability to assist the plants in a slimes-contaminated environment. Some degree of adaptation to slimes-contaminated soil therefore seems to have occurred, with this being more pronounced in Indigofera adenoides, although it cannot be determined whether this is purely phenotypic, or a combination of phenotypic and genetic. These species therefore seem suitable as candidates for vegetation of slimes dams, although further work must be done to fully understand the effect of slimes-associated toxicity.

As achieving higher frost resistance is one of the apricot breeding goals in the Czech Republic, it is important to obtain a deeper understanding of the genetic background of the exit from endogenous dormancy for apricot flower buds. The reason is that frost resistance of flower buds is significantly reduced after exit from endogenous dormancy. The aim of this work was to contribute to the understanding of the process of exit of various plant tissues from dormancy, as the problem is very complex and containing a number of physiological processes that are controlled by the function and regulation of many various substances and corresponding genes. The time of exit of flower buds from endogenous dormancy was established by counting of flowering buds on sampled twigs after their transport to laboratory conditions. Furthermore, the production of ethylene, ethane, and CO2 was monitored for sampled twigs with flower and leaf buds. Other physiological parameters monitored during the course of this study were the level of abscisic acid in flower buds and their weigh during the sampling close to the period of exit from endogenous dormancy. An analysis of transcriptome using the cDNA-AFLP method was carried out on four apricot variants ('Sundrop', SEO, 'Vestra' a 'Betinka') to achieve a deeper understanding of the genetic background of exit of flower buds from endogenous dormancy. The transcription profiles obtained from this experiment were evaluated for changes in the expression profiles and fragments of genes with modified expression during the monitored period were sequenced identified. Obtained sequences were compared with sequences in electronic databases (NCBI and TIGR). The results of this comparison led to the identification of a number of the sequenced genes. The results of this study confirmed the suitability of use of the cDNA-AFLP method for the identification of gene candidates and getting a preliminary picture of the main molecular mechanisms taking place during the time of exit of flower buds from endogenous dormancy. The suitability of the used procedure was confirmed by the match between the genes identified from the sequencing and genes already described in the literature as being linked to the exit of plants from endogenous dormancy (e.g. gene coding for acquaporin, GTP-binding proteins, elongation factor 1 alpha, ubiquitin, and xyloglucan endotransglycosylase hydrolase). Measurements of concentration of selected substances during exit from endogenous dormancy do not allow definite conclusions about their influence on this process. On the other hand were identified several genes that might be candidates for markers identifying the output timing of endogenous dormancy of buds and provide a good starting point for further scientific research in this field.