Yazar "Vardar, Filiz" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • Küçük Resim Yok
    Yayın
    THE EFFECTS OF COLCHICINE ON GROWTH AND DEVELOPMENT OF SUNFLOWER (HELIANTHUS ANNUUS L.) SEEDLINGS
    (PARLAR SCIENTIFIC PUBLICATIONS (P S P), 2017) Vardar, Filiz; Aydin, Yildiz; Ayturk, Ozlem; Unal, Meral
    In the present study we aimed to observe the effects of different doses of colchicine during optimizing the appropriate time and dose on poly-ploid sunflower production. When the sunflower seeds germinated and cotiledonary leaves opened, cotton balls soaked in aqueous solutions of 0.2%, 0.4% and 0.6% colchicine were applied to apical shoots for 12 h in three sets for each concentration. The process was repeated three consecutive days. Morphological, anatomical and photosynthetic pig-ment analyses were performed. According to the results shoot length, stoma number, stoma size, total chlorophyll, chlorophyll a, b and carotenoid contents were decreased. In higher concentrations of 0.4% and 0.6% the reduction was more sensitive. Additionally, SEM results revealed some defects in pollen morphology. Although no pollen was produced in 0.6% colchicine treatment, the pollen grains were tied to each other forming a mass by exine wall bridges in 0.4% colchicine treatment. However these defects were rare in 0.2% colchicine. Our results demonstrated that 0.4% and 0.6% colchicine application for a duration of 12 h induced toxic effects on growth and development of sunflower seedlings.
  • Küçük Resim Yok
    Yayın
    Programmed cell death evidence in wheat (Triticum aestivum L.) roots induced by aluminum oxide (Al2O3) nanoparticles
    (TAYLOR & FRANCIS LTD, 2017) Yanik, Fatma; Ayturk, Ozlem; Vardar, Filiz
    Nanoparticles have been recognized as an abiotic stress factor in the last decade. Although they are extensively used in nanotechnology, the possible effects of nanoparticles on plants are still unclear. Therefore the aim of the present study was to determine the dose dependent effects of 13 nm-sized aluminum oxide nanoparticles (Al2O3 NPs) on wheat roots correlating with programmed cell death related characteristics. Exposure to different concentrations of Al2O3 NPs (5, 25 and 50 mg ml(-1)) decreased the mitotic indices dose dependently and caused chromosomal abnormalities such as c-mitosis, monopolar metaphase and stickiness after 96h. Loss of plasma membrane integrity and irregular microtubule aggregations were determined. Nuclear deformations and TUNEL positive reactions indicating programmed cell death were also observed. Al2O3 NP-induced caspase 3, 8 and 9-like activities which control programmed cell death were observed in all concentrations. According to our results Al2O3 NPs induced programmed cell death in wheat roots after 96h.
  • Küçük Resim Yok
    Yayın
    Salicylic acid-induced germination, biochemical and developmental alterations in rye (Secale cereale L.)
    (UNIV ZAGREB, FAC SCIENCE, DIV BIOLOGY, 2018) Yanik, Fatma; Ayturk, Ozlem; Cetinbas-Genc, Aslihan; Vardar, Filiz
    Salicylic acid (SA) is one of the endogenous plant growth regulators that modulate various metabolic and physiological events. To evaluate the exogenous SA-induced germination, biochemical and developmental alterations, different concentrations (10, 100, 500 and 1000 mu M) of SA were applied to rye (Secale cereale L.) seeds in hydroponic culture conditions for 15 days. The observations revealed that seed germination and root elongation were stimulated in 10 mu M SA treatment, however they were inhibited in higher concentrations (100 and 500 mu M) of SA. Furthermore, there was no germination in 1000 mu M SA. The analysis of antioxidant enzymes revealed that although superoxide dismutase activity increased, catalase activity decreased in comparison to control. Besides, lipid peroxidation and peroxidase activity increased in 10 mu M SA, whereas they decreased in higher concentrations. Similarly total chlorophyll content increased in 10 mu M SA, but it decreased in 100 and 500 mu M SA treatments. Moreover anthocyanins and carotenoids increased after SA treatment. In conclusion, exogenous SA application causes developmental and biochemical alterations in rye.