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Germination of long-term storaged seeds of selected grass and legumes
VONDRÁŠEK, Vít
Quality reproductive material is created in the fields but its subsequent quality and the general ability to germinate may be affected by many other factors. The fundamental and necessary capability of the seeds is their germinability. In my thesis I selected seeds approximately 6 - 8 years old of certain types of grass or clover plants (Trifolium repens, Trifolium pratense, Medicago sativa - Zuzana, Medicago sativa - Pálava, Medicago lupulina, Trifolium hybridum - Oderský, Anthyllis vulneraria and Onobrychis viciifolia) and I monitored their germinability, its dynamics and capacity. Subsequently, I also used fresh seeds to compare the results and to demonstrate how seeds of different ages may differ. The experiment was performed under home conditions. All seeds to be germinated were placed on Petri dishes on which I maintained stable humidity. I monitored germinability of the seeds in previously set intervals after 2, 3, 5, 7, 10 and 15 days. Originally, the plan was to measure germinability also after 21 days but the germinating material did not last that long and losses were detected as early as after 15 days. I saw big differences between the individual species. Some of them germinated very well and their dynamics was high (Trifolium repens, Medicago sativa - Zuzana, Medicago sativa - Pálava), while others did not germinate at all or very little (Onobrychis viciifolia, Anthyllis vulneraria). In some species I even observed differences in germination dynamics.
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Ecological study of epixylic species \kur{Lophozia ascendens} and \kur{Anastrophyllum hellerianum (Lophoziaceae)}
HOLÁ, Eva
Seasonal pattern and extent of asexual reproduction in liverwort species Lophozia ascendens, L. ventricosa and L. longiflora were studied in the Boubínský prales and Milešický prales old-growth forest reserves in the Šumava Mts., South Bohemia. Asexual reproduction was quantified as the number of 1{--}2 -celled gemmae produced per individual shoot. Numbers of gemmae per shoot among sampling months differed significantly as did the numbers of gemmae in samples among Lophozia ascendens, L. ventricosa and L. longiflora among sampling months. Germinability of gemmae was low in early spring, highest in August and September and slightly decreased in October. Spreading potential of gemmae was investigated in the epixylic hepatic Anastrophyllum hellerianum. Gemmae were trapped at different distances (0 {--} 10 m) and directions from the source colonies in two experiments: one was realized in the natural habitat within a forest and the other in an artificial set-up in the open habitat. Dispersal of gemmae showed slight distance dependence both in the natural and open habitats. Habitat requirements (e. g. decay degree, texture, bark cover, log diameter) of the L. ascendens and A. hellerianum were investigated in both reserves, 126 logs were found. Mostly tiny liverworts grew with L. ascendens and A. hellerianum. Both studied species occurred on logs with degree of decay 2 {--} 7 and degree of texture 2 {--} 6.
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