Dictyterina cholodkowskii (Skrjabin, 1914) is recorded from iMnius collurio L. in Bulgaria (new geographical record). The species is redescribed and figured. A full list of synonyms is presented; it includes, among the other synonyms, Deltokeras delachauxi Hsii, 1935 (new synonym), Biulerina passerina of Oshmarin (1963) and Paruterina parallelipipeda of Paspalev and Paspaleva (1972). A survey of published records characterizes D. cholodkowskii as limited to the Palaearctic in six species of the genus Lanius (Aves, Passeriformes, Laniidae).
Autor příspěvku poukazuje na významný teoretický přínos D. Kastovského, jedné z nej výraznějších současných světových osobností v oblasti synchronní a diachronní slovotvorby. Jeho dílo je neobyčejné rozsáhlé, takže se příspěvek zaměřuje jen na základní myšlenky, které charakterizují dílo tohoto velikána a které byly podrobně rozpracované v desítkách jeho studií.
The effects of continuous soil hypoxia on stomatal conductance (g^ and net photosynthetic rate (P^) ů* seedlings of Taxodium disíichum, Quercus lyrata, and Q. falcata var. pagodaefolia were studied under controlled environment. Soil oxygen deficiency induced significant stomatal closure and reduction of in oak species within 1-3 d. This response pattem continued resulting in average daily values of g^ reduced 85 and 40 % within 14 d in g. falcata and Q. lyrata as compared to control plants, respectively. Ehiring the same period Pn reduced 96 and 71 % in 0. falcata and Q. lyrata as compared to control plants, respectively. In T. distichum, however, gg and Pff were reduced 18 and 33 % by day 8. Significant recoveiy of gg and was noted in T. distichum. By day 14, gg had recovered to 91 % and to 92 % of control plants. In oak species, however, remained significantly lower than in control plants without any apparent recovery. The regain of photosynthetic activity and stomatal functioning in flood-tolerant species appears to be an important flood- tolerance characteristic allowing these species to fimction under flooded soil.
Chlorophyll fluorescence analysis was conducted to evaluate why the frost-hardened winter rye is more resistant to photoinhibition of photosynthesis at 5 ®C than the non-hardened winter rye. Under a similar irradiance, the leaves of frost-hardened rye were able to keep a larger fraction of photosystem 2 reaction centres open than lhose of non-hardened rye. This ability of the frost-hardened rye fully accounts for its higher resistance to photoinhibition.
The reduction in chlorophyll (Chl) and protein contents and the increase in amino acid content in leaf discs in response to aqueous SO2 exposure under continuous irradiance were more expressed in Amaranthus paniculatus (C4 plant) than in Cajanus cajan (C3 plant). The content of SH-compounds increased more in pigeonpea than in amaranth leaf discs in response to SO2. Aqueous SO2 exposure also reduced the CO2 fixation and ribulose-l,5-bisphosphate carboxylase (RuBPC) and phosphoenolpyruvate carboxylase (PEPC) activities in leaf discs of both plant species. The differences in sensitivity of these plants to SO2 were related to their conversion efficiency of SO2 to less toxic substances and sulphydryl compounds.
Similar-aged leaflets of kidney beán plants grown either in soii or sand culture but otherwise under identical laboratory conditions, were exposed to acute O3 concentrations of 0.5 to 0.7 pmol mol"l for 1-1.5 h with a 15 to 20 min respite interval in the middle of the ozonation period. The CO2 exchange versus leaf intemal CO2 concentration relationships were determined just before ozonation, during respite period and immediately after the treatment. Under comparable absorbed O3 fluxes the calculated mesophyll conductance (gn,) and measured C02-saturated photosynthesis (Pj) in leaflets of sand-grown plants declined more rapidly than in leaflets of soil-grown plants. A rise in the CO2 compensation concentration in the sand-grown plants was also more pronounced. About 20 % greater thickness of leaves of the sand-grown plants was probably not the cause for their higher susceptíbility to absorbed O3. From the proportíonal decline in ^nd Pg, it is concluded that possible differences in patchiness of stomatal closure under O3 were also not the cause. A weaker O3 defence systém in the mesophyll cells of the sand- grown plants may be the cause of their greater sensitivity to absorbed O3.