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    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.
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    Reorganization of microtubules in pistil cells undergoing programmed cell death in Ficus carica L.
    (TAYLOR & FRANCIS LTD, 2018) Ayturk, Ozlem; Unal, Meral
    In the present study, the changes in the arrangement of microtubules (MTs) were identified in the pistil cells of female, gall and male flowers exposed to programmed cell death (PCD) in Ficus carica, by using fluorescence and confocal microscopy. The microtubule organization was analyzed by labeling the pistil cells with FITC (fluorescein-isothiocyanate) and we noticed that they essentially show similarity in three morphs of the flowers prior to and during PCD. The MTs in small vacuolated cells homogenously oriented in the cytoplasm but intensively around the nucleus and within the cell cortex. MTs lie continuously parallel to the cortex and they circumferentially lie around the nucleus. MTs in large vacuolated cells radiate from the nucleus to the cortex and they appear as lightly thick bundles between cortex and vacuoles. The few small microtubule aggregations are present among the thick bundles. The organization of the MTs changes with the start of the PCD in the pistil cells. Vacuolization is one of the factors affecting MT organization in the cells showing PCD. Consequently, our data suggest that PCD affects the organization of MTs in the pistil cells and they gradually lose regular and parallel arrangement, coordinately with the degree of PCD.