Výber najvhodnejších klonov odrody 'Velkopavlovická' a ich genetická variabilita.

The aim of this work was to evaluate choosen group of 26 clones of apricot variety 'Velkopavlovická' and to select the best clone and subclone for growers in south Moravia. Beside of classical pomological and biological evaluation characteristics the objective was to verify some older as well as newer, less known methods for evaluation of relevant characteristics of clones. Descriptors for choosen biological and pomological characters were used for the evaluation of clones. The clones were analysed with molecular genetic methods to establish the genetic relationship and to search for the possibilities of distinguishing them. The floral morphology and its influence on bearing of the clones was evaluated in this work. Formation of bearing shoots according to their lenght, their morphological conformation, bearing potential and their longevity were evaluated using modern methods. The physiological performance was evaluated using calorimetry. After all, the health of the clones was studied by molecular identification of present patogens and biochemical aspects of plant defense response against patogens related to precocious dieback of apricots. For the data processing ANOVA, X2, Mantel tests were used. For the evaluation of clones, following 11 biological and pomological characteristics were assessed: 1. precocious dieback occurence, 2. stem necrotic injuries, 3. patogen occurence of Gnomonia erythrostoma, 4. flower set, 5. fruit set, 6. bearing, 7. yield efficiency , 8. flowering date, 9. fruit weight, 10. fruit width, 11. relative rate of the stone to whole fruit weight. Evaluation of genetic relationship using molecular genetic methods S-SAP offereds the possibility of parcial distinction of 'Velkopavlovická' clones to 5 groups based on the transposonal polymorphic loci. Molecular genetic methods AFLP, S-SAP and iPBS provided similar profiles of the evaluated clones and genotypes. Differences in floral morphology shows low ranking stability in the number of each floral organs of those clones and their considerably lower occurence in contrast to the current experience. Based on this results, this method seems to be not perspective for clonal selection. The evaluation of morphological structure of bearing shoots, their bearing and longevity gives many informations about the morphological structure of the clones and it seems to be a perspective method for clonal selection. Differences between the clones were found in the high number of generative organs on short shoots, medium shoots and their distribution along the central axis of scaffold branches. The physiological characteristics of adult idividuals of evaluated clones using net asimilation rate seems to be hard to interpret and its use in clonal selection need fruther research. Research of patogen presence using PCR method shows significant presence of ESFY and Cytospora cincta in the tissues of evaluated clones. Those patogens were most likely related to the precocious dieback of apricots. Salycilic acid and the number of transcript copies of the beta-1,3-glucanase and gene expresion of Pru ar1 markers are most likely associated with plant defense of apricots. Based on results of biochemical analysis of the substances assosiated with plant defense the possibility to evaluate plant health of apricots considering precocious dieback with help of used markers in field conditions can be suggested. There use for clonal selection need fruther researche. The best clones LE-108, LE-111, LE-120 and M.72A of variety 'Velkopavlovická' seems to be the most promising from the evaluated group of clones. As the best subclones following individuals were choosen: clone LE-120 - tree 36 (1. row), clon M.72A - trees 26, 37 a 49 (8. row), clon LE-108 trees 28 a 29 (3. row) and clon LE-111 tree 27 (6. row)