The Convention on Biological Diversity (CBD) aims at the conservation of all three levels of biodiversity, that is, ecosystems, species and genes. Genetic diversity represents evolutionary potential and is important for ecosystem functioning. Unfortunately, genetic diversity in natural populations is hardly considered in conservation strategies because it is difficult to measure and has been hypothesised to co-vary with species richness. This means that species richness is taken as a surrogate of genetic diversity in conservation planning, though their relationship has not been properly evaluated. We tested whether the genetic and species levels of biodiversity co-vary, using a large-scale and multi-species approach. We chose the high-mountain flora of the Alps and the Carpathians as study systems and demonstrate that species richness and genetic diversity are not correlated. Species richness thus cannot act as a surrogate for genetic diversity. Our results have important consequences for implementing the CBD when designing conservation strategies.

The effects of gamma radiation are investigated by studying plant germination, growth and development, and biochemical characteristics of maize. Maize dry seeds are exposed to a gamma source at doses ranging from 0.1 to 1 kGy. Our results show that the germination potential, expressed through the final germination percentage and the germination index, as well as the physiological parameters of maize seedlings (root and shoot lengths) decreased by increasing the irradiation dose. Moreover, plants derived from seeds exposed at higher doses (≤0.5 kGy) did not survive more than 10 days. Biochemical differences based on photosynthetic pigment (chlorophyll a, chlorophyll b, carotenoids) content revealed an inversely proportional relationship to doses of exposure. Furthermore, the concentration of chlorophyll a was higher than chlorophyll b in both irradiated and non-irradiated seedlings. Electron spin resonance spectroscopy used to evaluate the amount of free radicals induced by gamma ray treatment demonstrates that the relative concentration of radiation-induced free radicals depends linearly on the absorbed doses.

The present results suggested that seed treatment with gamma radiations (0-30 Gy) was effective in stimulating plant growth and development, as well as the content of assimilatory pigments. At a higher dose of 70 Gy, there was a drastic reduction in the length of shoots and roots and also in the total chlorophyll content. These observations confirm that ionizing radiation stimulates physiological parameters up to certain low doses, and then it inhibits these parameters at higher doses.

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In our work, we studied the possibility to use in vitro methods for the preservation of the rare species from the Red List of Romanian Flora-Dianthus nardiformis Janka. The plant material (whole plants and seeds) was collected from 3 populations from Natura 2000 sites. The in vitro cultures starting from single node stem fragments had to face with high contamination degree with fungi. Despite this fact, using different methods of disinfection, culture media and combination of growth factors, aseptic tissues cultures and micropropagation were successfully performed. The seeds were less infected and are most suitable for in vitro tissues cultures initiation. The rate of regeneration was evaluated after 2 months and the tissues cultures were used for the plant production and in the future for medium-term and long-term preservation approaches.

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Micropropagation of Lycium barbarum cv. 'Ningxia N1' was achieved. The cultures were by initiated by axenical seed germination. The highest shoot proliferation was obtained on the MS media with 1.33 or 2.22 µM benzyl adenine, gelled with wheat starch as an agar alternative. The treatments with 2.22 µM benzyl adenine ensured proliferation rates superior to the ones with 1.33 μM benzyl adenine, but the latter provided longer and more robust shoots. Use of large microcuttings as an explant onto the multiplication media ensured higher in vitro explant survival, higher number of shoots regeneration and more vigorous plantlets. The microcuttings inserted vertically into the media yielded superior growth and multiplication as compared to the microcuttings placed horizontally. The non-rooted, elongated shoots from the treatment 1.33 μM benzyl adenine were either rooted in vitro on a hormone-free MS medium with starch or used for direct ex vitro rooting and acclimatization. The optimal number of microcuttings/vessel for in vitro rooting was 40 and the rooted plantlets were efficiently acclimatized ex vitro by three methods: float hydroculture in floating cell trays, floating perlite, and in Jiffy7 pellets.