Life on sand dunes from lichens point of view – effect of microclimate and seasonality on activity of terricolous lichen communities

Terricolous lichen communities are widely distributed in the Kiskunság Region, however we have limited information about the photosynthetic activity of the species living in different microhabitats. In consequence of the dominant wind direction, sand dunes of this region have mainly North-East (NE) and South-West (SW) exposure. These more humid (NE) and more arid (SW) slopes ensure diverse microhabitats for terricolous lichen species with different environmental requirements. To ascertain the effect of microclimate and seasonal weather conditions beside chlorophyll fluorescence measurements and photosynthetic pigment composition analysis, two HOBO micrometeorological stations (with Tsoil, WCsoil, Tair, RH% and PAR sensors) were placed on NE and SW facing slopes of a sand dune near Bugacpuszta. During the three year continuous data collection we got an inside view of lichen’s everyday living conditions. The most considerable differences between the two microhabitat types were in Tsoil, in irradiation and in relative humidity. In greater detail, degree and trend of variation in parameters changed during the day, and showed characteristic seasonality. We observed significant differences in all micrometeorological parameters between seasons during the years. In long-term on SW facing slope because of averagely higher air temperature (0,2 °C) and lower air humidity (0,5%) the vapour pressure deficit is higher (0,2 kPa) than that of on NE facing slopes. The higher incoming irradiation on SW side causes higher soil temperature, and lower soil water content. PAR, WCsoil and Tsoil showed significant difference between microhabitats in every season. In summer probably the short active periods on both types of microhabitats cause smaller difference in Fv/Fm, meanwhile in spring the small difference between more arid and more humid microhabitats can explain with the most beneficial environmental conditions during the year

Hazai nyárak populációgenetikai és élettani vizsgálata az erdészeti célú felhasználás fejlesztése céljából = Population genetic and physiological investigation on native poplars for development of silvicultural application

A pályázati munka során 11 tájegység 32 populációjában jelöltünk ki fehér, rezgő és szürke nyár mintafákat. A mintázott 931 egyedből 409-et vontunk be a genetikai vizsgálatokba. Az elvégzett RAPD, PCR-RFLP és SSR vizsgálatok során megállapítottuk, hogy a kiválasztott markerek alkalmasak az alapfajok egyedeinek taxonómia elkülönítésére, az SSR vizsgálat pedig a hibridizáltság mértékének megállapítására a szürke nyár esetében. Az egyes populációk genetikai diverzitását kifejező mutatóinak összevetése során megállapítottuk, hogy az alapfajok azon populációi mutatják a legmagasabb változatosságot, amelyek az ökológiai szempontból a faj optimálishoz közelebb álló termőhelyein találhatók. A molekuláris variancia forrása valamennyi vizsgálati metodika esetében a populációkon belüli változatosságra volt döntő mértékben visszavezethető. Az összehasonlító növényélettani vizsgálatok célja négy nyár faj eltérő gyökeresedési hajlamának a hátterében álló okok és azok lehetséges befolyásolásának a megállapítása volt. A klónok között a nem-strukturális szénhidráttartalomban eltérés nem mutatkozott, nem befolyásolta a gyökeresedést a dugványok eredeti helyzete és vastagsága sem. Az alkalmazott auxin kezelések a gyökeresedést nem fokozták, az auxin transzport gátlása viszont jelentősen csökkentette. Pozitív hatást az etilénszintézis fokozásával értünk el. Az eredmények alapján a nyár fajok közötti gyökeresedési különbség az eltérő etilén szintre vezethető vissza. | In the frame of the research project 32 populations in 11 regions of Hungary were mapped during the last 4 years in order to inventory the genetic diversity of white poplar, trembling aspen and grey poplar. 409 individual out of the 931 trees sampled were analysed using RAPD, PCR-RFLP and SSR markers. We were able to distinguish between the three species with all the three marker types and the proportion of parent species in grey poplar individuals were also detected. Diversity indices showed the highest values in the populations which grow on ecologically optimal habitats. The Analysis of Molecular Variance (AMOVA) signed moderate variance among regions and relatively high proportion of diversity within populations. The objectives of our comparative physiological investigation on four poplar species were to determine the reasons for their different adventitious rooting abilities and to try to improve them. There were no significant differences in non-structural carbohydrate contents among the clones, and had no effect of the original position and diameter of cuttings on rooting. Root formation could not be enhanced by the applied auxin treatments however it was remarkably reduced by the inhibition of auxin transport. Enhancement in rooting could be only achieved by the increase of ethylene synthesis, accordingly the difference in rooting ability of poplar species can be attributed to the different ethylene level of cuttings

Recovery of acetone rinsed lichen thalli of Cladonia foliacea = Cladonia foliacea zuzmótelepek regenerálódása acetonos kezelést követően

The optimal period for applying acetone (best for extraction and shortest possible for avoiding detrimental effects), was established for dry lichen thalli rinsed in acetone following the methods by Solhaug and Gauslaa applied in 2001. Secondary lichen substances (usnic and fumarprotocetraric acids) were analysed by HPTLC and HPLC, the detrimental effect of acetone was tested by chlorophyll fluorescence measurement. The optimal duration for acetone rinsing proved to be around 1– 2(–5) days in the samples collected in summer. The determined Fv/Fm values of Cladonia foliacea remained relatively high even after 1024 hours compared to any of the 12 species studied previously. A seasonal difference between summer and winter collected thalli was found. According to our results the thalli collected in winter are more sensitive to acetone rinsing. Therefore the summer period – when lichens are more frequently in dry condition and therefore photosynthetically active for a shorter period – is more advantageous for collecting samples for transplantation experiments combined with acetone rinsing. Higher concentrations of usnic acid and fumarprotocetraric acid were found in winter samples than in summer ones. The considerable variability is possibly due to a natural variability among the samples (substance content among and within thalli) and partly to the preparation methods. However, homogenised (lyophilised, then ground) samples showed no difference in usnic acid content if extracted for 15, 30, 40 or 50 minutes. The thalli re-placed in controlled field condition after acetone rinsing experiments were observed monthly. The digital images showed serious damage already after 1–2 months at most of the treated thalli. Samples were investigated after a 6 months recovery period. The results confirm the advantage of summer collecting. Though both winter and summer collected samples rinsed in acetone less than 16/32 hours showed similar, good vitality based on Fv/Fm measurements, however photosynthetically active parts of thalli were smaller in case of winter collected samples. Supported by the Hungarian Scientific Research Fund OTKA 81232, 101713, the Research Centre of Excellence – 11476-3/2016/FEKUT and the project NKFI K 124341 financed by the National Research Development and Innovation Fund