Allelopathic influence of aqueous extracts from the leaves of Morus alba L. on seed germination and seedling growth of Cucumis sativus L. and Sinapsis alba L.

The aim of the present study was to elucidate impact of the aqueous extracts from leaves of Morus alba L. on germination, growth and photosynthetic activity of Cucumis sativus L. and Sinapis alba L. Plants were grown for 21 days at the temperature 25°C (day) and 18°C (night), within 12/12 hours photoperiod, light intensity 150 μmol·m-2·s-1 and relative humidity 60-70% (day/night). Our experiments proved that allelopathic compounds in aqueous extracts of the leaves M. alba at high concentrations, reduce power and energy of germination. Biometric analysis of seedlings and adult plants grown showed that allelopathic substances have stimulating or inhibiting function depending on the stage of treatment. Moreover, they cause changes in chlorophyll contents and activity of photosystem II (PS II)

Grasslands communities near the Piasek Wielki village (Staszów Region, Southern Poland)

W artykule przedstawiono wyniki badań terenowych użytków zielonych wykonane w okolicach miejscowości Piasek Wielki (Okręg Staszowski, woj. świętokrzyskie – Polska Południowa). Celem pracy było zidentyfikowanie i określenie składu fitocenoz pastwisk oraz łąk, ponieważ dotąd obszary te nie były badane pod tym kątem. W sezonie letnim, w lipcu i sierpniu 2013 r., wykonano 50 zdjęć fitosocjologicznych. W rezultacie zidentyfikowano na tym terenie cztery zbiorowiska roślinne: Cirsietum rivularis Nowiński 1927, Epilobio-Juncetum effusi Oberd. 1957 w typowej i przesuszonej formie, Arrhenatheretum elatioris Br.-Bl. Z Scherr. 1925 oraz Lolio-Cynosuretum Büker 1941. Analizując wyniki fitosocjologicznych badań terenowych, należy zaznaczyć, że obszary wokół wybranej miejscowości stwarzają korzystne warunki do rozwoju roślinności łąkowo-pastwiskowej. Jednak w płatach wyróżnionych tu fitocenoz występują oznaki zaniedbania w użytkowaniu i zabiegach pielęgnacyjnych, co przejawia się m.in. występowaniem gatunków chwastów z klasy Artemisietea

The influence of alcoholic extract from leaves of Helianthus annuus L. on germination and growth of Sinapis alba L.

The knowledge of plants interactions is used for their better protection and cultivation. The aim of this study was to determine the influence of alcoholic extracts from the leaves of the common sunflower (Helianthus annuus) on selected physiological parameters of plants of white mustard (Sinapis alba ‘Barka’). The seeds germination, the growth, the fresh and dry masses of plants grown from seeds and germinated on the sunflower extracts and plants watered by H. annuus extracts during the growth phase were studied. In the growth phase, the fresh masses of all organs were increased on 5 % extract, however significantly decreased on 10 % extract. The dry mass of S. alba was not significantly changed. In the germination phase, much less changes of these parameters were revealed. In general, extracts from H. annuus leaves inhibited germination of S. alba seeds, but stimulated growth of plants in case of application of 5 % concentrations during the germination phase and inhibited their growth in case of application of 10 % concentrations during the growth phase

Influence of extracts from peppermint (Mentha x piperita (L.) Hudson) on growth and activity of the PSII sunflower garden (Helianthus annuus L.)

Allelopathic compounds by living organisms or during the breakdown of dead organic matter are emitted. They were discovered in all plant organs, both vegetative and generative. The aim of the study was to examine influence of the aqueous extracts from leaves of peppermint (Mentha x piperita (L.) Hudson) in concentration: 1, 3, 5, 10, 15% on growth and activity of the PSII sunflower garden (Helianthus annuus L.) plants. The allelopathic compounds contained in the aqueous extracts of peppermint leaves, depending on the concentration and development stage of H. annuus, had inhibitory or stimulating effect on the growth and functioning of the photosystem PSII

Wpływ napromieniowania laserem He-Ne oraz kadmu i ołowiu na zmiany w cyklach komórkowych Zea mays L.

The aim of the study was to investigate the effect of red radiation emitted by helium-neon laser (He-Ne) with a wavelength λ = 632.8 nm and trace elements: cadmium (Cd) and lead (Pb), as cadmium nitrate and lead nitrate solutions, at 30 ppm concentrations, on the cell cycle of root-tip meristem cells in maize. Red light stimulated the mitotic activity of the meristemic cells of the maize root-tip meristem growth after irradiation of seed samples with simultaneous treatment in the presence of Cd or Pb. The mitotic index was inhibited when the seeds were treated with distilled water with the addition of Cd or Pb salts. Seeds treated with laser had significantly the highest mitotic index. Results revealed that maize seed pre-treatment with the red light protects the root-tip meristem cells against the mitodepressive effect of Cd and Pb ions. Seed biomodulation using red light emitted by He-Ne laser can positively effect the germination and plant growth

Seedlings growth of common sunflower under influence of peppermint extract

The aim of this study was to investigate the influence of aqueous extracts from the leaves of peppermint (Mentha ×piperita L.) on the seedlings and plants of common sunflower (Helianthus annuus L.). Different concentration of peppermint leaves extract: 1, 3, 5, 10, 15% was used to examine the growth (length), fresh and dry mass of common sunflower seedlings and plants watered peppermint extracts in phase of growth. We measured the length of seedlings and separated organs of plant: root, hypocotyl, epicotyl, petioles of the first row and remainder of the shoot. Additionally, we determined fresh and dry mass of these organs and cotyledons, leaves of the first order and remainder of the leaves. Depending on the concentration the aqueous extracts showed a stimulatory (low extract concentration) or inhibitory (high extract concentration) effect on growth, fresh and dry mass of common sunflower seedlings and plants